Article

The Italian National Survey for Prader-Willi syndrome: An Epidemiologic Study

May 2008
American Journal of Medical Genetics Part A 146(7):861-72

May 2008
146(7):861-72

DOI:10.1002/ajmg.a.32133

Source
PubMed

Authors:

Graziano Grugni

I.R.C.C.S. Istituto Auxologico Italiano

Antonino Crinò

Ospedale Pediatrico Bambino Gesù

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Twenty-five medical centers and the Prader-Willi Syndrome (PWS) Association collaborated on a study which attempted to identify all people with genetically confirmed diagnosis of PWS living in Italy. Investigators of the participating centers contacted PWS subjects and/or their family, filled in a specially developed form with the required data and forwarded this information by email. The study identified 425 subjects (209 males and 216 females, between the ages of 0.4-46.7). Two hundred thirty-eight patients had del15, 104 had UPD15, 4 demonstrated a translocation affecting chromosome 15 and 79 showed a positive methylation test. There were fewer subjects found over the age of 35, probably due to the low rate of identification of older PWS patients as well as the high mortality rate. There were a greater number of male children and adolescents with PWS whilst, amongst adults, there were more females. As expected, the majority of subjects with PWS were obese, especially in adult life. Nevertheless, it is noteworthy that 26% of patients aged between 6 and 17 were normal weight. A total of 212 subjects had received GH treatment, of which 141 were still receiving therapy, while the remaining 71 had stopped. In children and adolescents (233 cases), 89 subjects had never undergone GH therapy. Eighteen PWS patients had died in the past 20 years. Obesity-related cardiovascular and respiratory diseases were the cause of death, both during childhood and after 18 years of age. Three children died suddenly whilst undergoing GH therapy. Respiratory infection and cardiac illness were the causes of death in two cases. There was no definitive cause of death found in the third case. Overall, there was no increase in number of deaths during GH treatment, suggesting that GH administration in patients with PWS, as a group, does not increase the risk of death.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

Article

Full-text available

Jan 2024
J INTELL DISABIL RES

Background: Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication. Methods: Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication. Results: The cohort included 177 participants (aged 6-48 years), 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterized by more frequent age ≥30, high level of hyperactivity and a psychiatric diagnosis. Conclusion: Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

Causes of death in Prader-Willi syndrome: Lessons from 11 years' experience of a national reference center

Article

Full-text available

Dec 2019
ORPHANET J RARE DIS

Background: In the last 20 years, substantial improvements have been made in the diagnosis, treatment and management of patients with Prader-Willi syndrome (PWS). Few data on causes of death are available since those improvements were made. Our study assessed the causes of death among French patients with PWS over the first 11 years of experience of the nationwide French Reference Center for PWS (FRC-PWS). Methods: Our study relied on two sources of mortality information at national level between 2004 and 2014: The French Epidemiological Centre for the Medical Causes of Death (CépiDc) Registry and the FRC-PWS database. Causes of death were classified into seven categories: respiratory, cardiovascular, gastrointestinal, severe infection, sudden death, other causes, and unknown. Descriptive statistics were calculated separately for children (< 18 years-old) and adults (≥18 years-old). Results: One hundred and four deaths were identified in France from 2004 to 2014. The median age at death was 30 years, ranging from less than 1 month to 58 years. Seventeen deaths occurred in patients under 18 years, with 70% of them in children under 2 years. Respiratory causes accounted for more than 50% of the deaths in patients with PWS in both children and adults. Both cause and age of death did not significantly differ according to gender or genetic subtype. Conclusions: Patients with PWS die prematurely due to a respiratory cause in most cases at all ages. In those adult patients with data on obesity, 98% were reported to be obese.

Obesity management in Prader–Willi syndrome: current perspectives

Article

Full-text available

Oct 2018

Prader–Willi syndrome (PWS) is a complex multisystem disorder due to the absent expression of the paternally active genes in the PWS critical region on chromosome 15 (15q11.2-q13). The syndrome is considered the most common genetic cause of obesity, occurring in 1:10,000–1:30,000 live births. Its main characteristics include neonatal hypotonia, poor feeding, and lack of appetite in infancy, followed by weight gain, lack of satiety, and uncontrolled appetite, frequently after the age of 2–3 years. The clinical picture includes short stature, multiple endocrine abnormalities (hypogonadism, growth hormone/insulin-like growth factor-I axis dysfunction, hypothyroidism, central adrenal insufficiency), dysmorphic features, scoliosis, osteoporosis, mental retardation, and behavioral and psychiatric problems. Subjects with PWS will become severely obese unless their food intake is strictly controlled. Constant and obsessive food seeking behavior can make life very difficult for both the family and caretakers. Prevention of obesity is mandatory in these patients from the first years of life, because once obesity develops it is difficult to maintain the control of food intake. In fact, PWS subjects die prematurely from complications conventionally related to obesity, including diabetes mellitus, metabolic syndrome, sleep apnea, respiratory insufficiency, and cardiovascular disease. The mechanisms underlying hyperphagia in PWS are not completely known, and to date no drugs have proven their efficacy in controlling appetite. Consequently, dietary restriction, physical activity, and behavior management are fundamental in the prevention and management of obesity in PWS. In spite of all available therapeutic tools, however, successful weight loss and maintenance are hardly accomplished. In this context, clinical trials with new drugs have been initiated in order to find new possibilities of a therapy for obesity in these patients. The preliminary results of these studies seem to be encouraging. On the other hand, until well-proven medical treatments are available, bariatric surgery can be taken into consideration, especially in PWS patients with life-threatening comorbidities.

Scoliosis and rare diseases: our experience with the Prader–Willi syndrome

Article

Full-text available

Apr 2024
EUR SPINE J

Introduction Prader–Willi syndrome (PWS) represents a difficult challenge for spine surgeons, due to the association of a structural scoliosis, with a prevalence between 15 and 86%. Conservative therapy is a viable option, but surgery is increasingly becoming the treatment of choice. Methods The authors reviewed a series of 15 patients affected by PWS treated at their institution between 2008 and 2023. The mean age at index treatment was 9 years and 3 months (range 1–15 years) with a prevalence of female subjects. Primary scoliotic curve ranged from 14 to 102°, and mean thoracic kyphosis was 56° (range 20–75°). Eleven patients underwent conservative treatment, while four were treated surgically. Results Mean follow-up was 5 years and 3 months (range 2–12 years). Among the 11 patients treated conservatively, only two showed improvements of the coronal curve, while the remaining nine displayed a worsening of the deformity during follow-up. Complication rate after surgery was 75%. One patient developed paraplegia after pedicle screw positioning. One patient displayed rod breakage and PJK that required revision surgery proximally. Hardware deep infection was seen in one case where it was necessary to proceed with instrumentation removal after 10 years. Discussion and conclusions Spine surgery represents a convincing option in patients affected by PWS, but the risks of complications are high. Correct patient selection must be the main objective, and multilevel pedicle screw fixation should be the procedure of choice. Traditional growing rod should be prudently evaluated in every single case.

Sleep Disorders in Prader-Willi syndrome, evidence from animal models and humans

Article

Jan 2021
SLEEP MED REV

Prader-Willi Syndrome (PWS) is a complex genetic disorder with multiple cognitive, behavioral and endocrine dysfunctions. Sleep alterations and sleep disorders such as Sleep-disordered breathing and Central disorders of hypersomnolence are frequently recognized (either isolated or in comorbidity). The aim of the review is to highlight the pathophysiology and the clinical features of sleep disorders in PWS, providing the basis for early diagnosis and management. We reviewed the genetic features of the syndrome and the possible relationship with sleep alterations in animal models, and we described sleep phenotypes, diagnostic tools and therapeutic approaches in humans. Moreover, we performed a meta-analysis of cerebrospinal fluid orexin levels in patients with PWS; significantly lower levels of orexin were detected in PWS with respect to control subjects (although significantly higher than the ones of narcoleptic patients). Sleep disorders in humans with PWS are multifaceted and are often the result of different mechanisms. Since hypothalamic dysfunction seems to partially influence metabolic, respiratory and sleep/wake characteristics of this syndrome, additional studies are required in this framework.

Prevalence of prader-willi syndrome in Western India

Article

Full-text available

Jul 2014

Pankaj Gadhia

The prevalence of Prader-Willi Syndrome (PWS) was studied using both classic cytogenetic and FISH techniques in referred cases of microdeletion 15q11-13 to our laboratory from Western India. A total of 53 cases were registered, of which 08(15%) were found positive for Prader-Willi Syndrome i.e. 15q11-13 microdeletion syndrome. FISH technique found to be suitable and sensitive to confirm clinically diagnosed PWS.

The prevalence of metabolic risk factors of atherosclerotic cardiovascular disease in Williams syndrome, Prader–Willi syndrome, and Down syndrome

Article

Mar 2016

Background Risk for atherosclerotic cardiovascular disease (CVD) and association with abdominal obesity have not been extensively studied in genetic syndromes associated with intellectual disability.Methods A cross-sectional study was conducted in individuals aged 20–43 years with Williams syndrome (WS; n = 21), Prader–Willi syndrome (PWS; n = 20), and Down syndrome (DS; n = 31). Established metabolic risk factors of CVD were assessed.Results High prevalence of hypertension and type 2 diabetes was seen in the group with PWS, whereas low prevalence rates were found in the group with DS. In the group with WS, we found a high prevalence of hypertension and a trend towards increased risk of type 2 diabetes, combined with better blood lipid profile. Abdominal obesity was prevalent in all 3 subgroups and was associated with an increased risk of hypertension and metabolic syndrome.Conclusion PWS and WS had increased risk of CVD. In order to prevent CVD in these groups, regular assessments of the known risk factors are recommended.

Endocrine features of Prader-Willi syndrome: a narrative review focusing on genotype-phenotype correlation

Article

Full-text available

Apr 2024

Prader-Willi syndrome (PWS) is a complex genetic disorder caused by three different types of molecular genetic abnormalities. The most common defect is a deletion on the paternal 15q11-q13 chromosome, which is seen in about 60% of individuals. The next most common abnormality is maternal disomy 15, found in around 35% of cases, and a defect in the imprinting center that controls the activity of certain genes on chromosome 15, seen in 1-3% of cases. Individuals with PWS typically experience issues with the hypothalamic-pituitary axis, leading to excessive hunger (hyperphagia), severe obesity, various endocrine disorders, and intellectual disability. Differences in physical and behavioral characteristics between patients with PWS due to deletion versus those with maternal disomy are discussed in literature. Patients with maternal disomy tend to have more frequent neurodevelopmental problems, such as autistic traits and behavioral issues, and generally have higher IQ levels compared to those with deletion of the critical PWS region. This has led us to review the pertinent literature to investigate the possibility of establishing connections between the genetic abnormalities and the endocrine disorders experienced by PWS patients, in order to develop more targeted diagnostic and treatment protocols. In this review, we will review the current state of clinical studies focusing on endocrine disorders in individuals with PWS patients, with a specific focus on the various genetic causes. We will look at topics such as neonatal anthropometry, thyroid issues, adrenal problems, hypogonadism, bone metabolism abnormalities, metabolic syndrome resulting from severe obesity caused by hyperphagia, deficiencies in the GH/IGF-1 axis, and the corresponding responses to treatment.

Markedly Low Prevalence of Fatty Liver despite Obesity in Prader-Willi Syndrome: A Search for Protective Genetic Markers

Preprint

Full-text available

Jul 2023

Background & Aims Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in all ages that may cause significant morbidity and mortality. The pathogenesis of the disease is not fully elucidated but genetic factors have a major role in the development of NAFLD. Prader-Willi syndrome (PWS) is a neurogenetic, multisystemic disorder in which the main symptom is lack of satiety with uncontrolled eating and severe obesity. Despite obesity, NAFLD is relatively rare in PWS. The aim of this study was to assess whether known NAFLD-associated small nucleotide variants (SNVs) play a role in the protection from NAFLD in PWS. Approach & Results Using targeted amplicon next generation sequencing, we studied DNA from patients with PWS and genotyped 13 SNVs that were previously associated with high risk for NAFLD. The study population included 142 (69 females) individuals with genetically confirmed PWS. Median age was 17.5 years, BMI z-score was 2.13 ± 1.9 and mean ALT and AST were 22 ± 20 units/L and 29 ± 17 units/L, respectively. Five of the 13 SNVs showed significantly lower frequency of the risk allele in our cohort compared to healthy population frequencies. Cumulative risk score for all 13 SNVs was also significantly lower in our cohort of PWS patients compared to the healthy population (adjusted p-value, 1.85E-5). Furthermore, it was found that Ashkenazi Jews have lower frequency of the risk alleles of NAFLD. Conclusions Our results show that genetic factors may protect patients with PWS from developing NAFLD. Larger scale studies should be performed to confirm our findings.

Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

Article

Full-text available

Jul 2023

Background Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria. Methods We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS. Results We included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR ( p =0.027, p =0.019, p <0.001, p <0.001, p =0.011 and respectively). Conclusion Upon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.

Hyperphagia in Prader-Willi syndrome with obesity: From development to pharmacological treatment

Article

Full-text available

Feb 2023

Prader-Willi syndrome (PWS) is a rare genetic disorder due to lack of genes expression inherited from the paternal chromosome 15q11-q13 region usually from paternal deletions, maternal uniparental disomy 15 or imprinting defect. There are two different nutritional stages reported in an individual with PWS; first stage during infancy marked by feeding and growth difficulties and second stage where hyperphagia starts and leads to development of obesity. However, the exact mechanism of hyperphagia development, from having difficulties in feeding during early years to insatiable appetite after they grow is still unknown and is the focused in this review. The keywords used for literature search such as "Prader-Willi syndrome", "hyperphagia", "obesity", and "treatment" were used to create the search strings by using synonyms in order to retrieve the relevant records from PubMed, Scopus and Science Direct. The possible mechanism of hyperphagia can be classed into hormonal abnormalities such as increase in ghrelin and leptin from infancy to adulthood. Low level of hormones was observed in the thyroid, insulin and peptide YY at certain ages. Neuronal abnormalities contributed by Orexin A and brain structure alteration was documented at 4-30 years old. Treatment in the form of drugs such as livoletide, topiramate, and diazoxide could potentially alleviate these abnormalities and make hyperphagia less prominent in PWS. The approaches are important to regulate the hormonal changes and neuronal involvement as potentially controlling hyperphagia and obesity.

Effects of early recombinant human growth hormone treatment in young Chinese children with Prader–Willi syndrome

Article

Full-text available

Feb 2023
ORPHANET J RARE DIS

Background Prader–Willi syndrome (PWS) is a rare and multisystemic genetic disorder that is characterized by severe hypotonia, hyperphagia, short stature, and global developmental delay. Although early recombinant human growth hormone (rhGH) treatment has been proven to rescue some symptoms and bring additional benefits to PWS patients, studies in patients under 2 years old are scarce. Thus, this study aims to investigate the effectiveness and safety of rhGH treatment for young children. Methods A total of 96 genetically confirmed Chinese PWS infants or toddlers (47 males) followed between 2013 and 2022 were retrospectively analyzed. Sixty-five infants (early treatment group) started rhGH treatment during their first year, and 31 toddlers (later treatment group) started at the age of 1–2 years. Auxological parameters, carbohydrate metabolism parameters, thyroid function, liver function, insulin-like growth factor-1 (IGF-1), and radiographs were acquired before the initiation of the treatment and every 3–6 months thereafter. Height/length, weight, and weight for height were expressed as standard deviation scores (SDSs) according to WHO child growth standards. Results The mean SDS of length/height in the early treatment group was significantly higher than that in the later treatment group throughout the observation period (all P < 0.001). The change in the length SDS between the two groups at 1 year old and 4 years old was 1.50 (95% CI, 0.88–2.13) and 0.63 (95% CI, 0.16–1.10), respectively. Compared to the later treatment group, the weight SDS in the early treatment group increased by 0.94 (95% CI, 0.37–1.52) at 1 year old and 0.84 (95% CI, 0.28–1.39) at 2 years old. No statistical significance was found after 2.5 years of age. No significant differences were observed in IGF-1, incidence of liver dysfunction, hypothyroidism or spinal deformity between the two groups. Conclusions rhGH treatment improved growth and body composition in infants and toddlers. Furthermore, an early start of rhGH treatment is expected to have more efficacy than the later treatment group without an increase in adverse effects.

Health Problems in Individuals With PWS Are Associated With Lower Quality of Life for Their Parents: A Snapshot in the Brazilian Population

Article

Full-text available

Feb 2022

Prader-Willi syndrome (PWS) is a complex genetic disorder requiring interdisciplinary team monitoring and intensive care by parents. So far there is little information on people with PWS in Brazil. Our aim was to describe health problems and treatments used by people with PWS in Brazil and their relationship to their parents' quality of life. Parents answered questionnaires about their child's medical and exercise history, behavior problems, sociodemographic characteristics, and their own quality of life. Results: The responses of the participants showed similar health problems as in other countries. Anxiety and tantrums were the behavioral problems most commonly cited by parents. Parents of people with PWS had lower scores in respect of quality of life than the Brazilian population. Behavioral problems in individuals with PWS were negatively associated with their parents' quality of life. Behavioral and medical conditions in the children were associated with reduced quality of life in the parents. We conclude that heath care should not only be directed toward those with PWS, but also their parents.

Subtle Cardiovascular Abnormalities in Prader-Willi Syndrome Might Begin in Young Adulthood

Article

Full-text available

Nov 2021

Objective Patients with Prader-Willi syndrome (PWS) are known to have a high mortality rate. However, little is known about the exact reason for this, particularly in adults, because so few reports have been published. The present study examined cardiovascular abnormalities to determine the cause of death in adults with PWS. Methods From September 2017 to April 2019, a total of 18 adults with PWS, and, no history of cardiovascular diseases, were enrolled. We investigated the levels of the cardiovascular biomarkers: high-sensitivity C-reactive protein (hs-CRP) and troponin T (TnT). To estimate the cardiac function, we measured the left ventricular ejection fraction (LVEF), global longitudinal systolic strain (GLS) of the left ventricle, ratio of peak early mitral filling velocity (E) to early diastolic mitral annular velocity (E/e' ratio), mitral annular plane systolic excursion (MAPSE) and tricuspid annular plane systolic excursion (TAPSE) using standard and tissue Doppler echocardiography. Results The mean patient age was 28±9 years old. There were 11 men, and the mean body mass index was 45.1 kg/m². Dyslipidemia (82%), diabetes mellitus (82%) and hypertension (83%) were commonly found as comorbidities. Most patients had elevated levels of hs-CRP (mean 1.007±0.538 mg/dL). The LVEF (mean 61%±5%) showed normal values, while the GLS (mean 15.0%±3.0%) was decreased. The TAPSE was mildly reduced (mean 16±3 mm). Conclusion These results suggest that subtle cardiovascular abnormalities have already begun in young adults with PWS. We need to manage obesity and the resultant obesity-related disorders in order to prevent heart failure and coronary atherosclerosis in PWS patients.

Double paternal uniparental isodisomy 7 and 15 presenting with Beckwith-Wiedemann spectrum features

Article

Full-text available

Oct 2021

Here we describe for the first time double paternal uniparental isodisomy (iUPD) 7 and 15 in a baby boy with features in the Beckwith-Wiedemann syndrome spectrum (BWSp) (placentomegaly, hyperinsulinism, enlarged viscera, hemangiomas, and earlobe creases) in addition to conjugated hyperbilirubinemia. His phenotype was also reminiscent of genome-wide paternal uniparental isodisomy. We discuss the most likely origin of the UPDs; a maternal double monosomy 7 and 15 rescued by duplication of the paternal chromosomes after fertilization. So far, paternal UPD7 is not associated with an abnormal phenotype, while paternal UPD15 causes Angelman syndrome. Methylation analysis for other clinically relevant imprinting disorders, including BWSp, was normal. Therefore, we hypothesized that the double UPD affected other imprinted genes. To look for such effects, patient fibroblast RNA was isolated and analyzed for differential expression compared to six controls. We did not find apparent transcription differences in imprinted genes outside chromosomes 7 and 15 in patient fibroblast. PEG10 (7q21.3) was the only paternally imprinted gene on these chromosomes upregulated beyond double-dose expectation (6-fold). We speculate that a high PEG10 level could have a growth-promoting effect as his phenotype was not related to aberrations in BWS-locus on 11p15.5 after DNA, RNA, and methylation testing. However, many genes in gene sets associated with growth were upregulated. This case broadens the phenotypic spectrum of UPDs but did not show evidence of involvement of an imprinted gene network.

Obesity in Prader-Willi syndrome: physiopathological mechanisms, nutritional and pharmacological approaches

Article

Full-text available

Apr 2021
J ENDOCRINOL INVEST

Prader-Willi syndrome (PWS) is a genetic disorder caused by the lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. The three main genetic subtypes are represented by paternal 15q11-q13 deletion, maternal uniparental disomy 15, and imprinting defect. Clinical picture of PWS changes across life stages. The main clinical characteristics are represented by short stature, developmental delay, cognitive disability and behavioral diseases. Hypotonia and poor suck resulting in failure to thrive are typical of infancy. As the subjects with PWS age, clinical manifestations such as hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency due to hypothalamic dysfunction occur. Obesity and its complications are the most common causes of morbidity and mortality in PWS. Several mechanisms for the aetiology of obesity in PWS have been hypothesized, which include aberration in hypothalamic pathways of satiety control resulting in hyperphagia, disruption in hormones regulating appetite and satiety and reduced energy expenditure. However, despite the advancement in the research field of the genetic basis of obesity in PWS, there are contradictory data on the management. Although it is mandatory to adopt obesity strategy prevention from infancy, there is promising evidence regarding the management of obesity in adulthood with current obesity drugs along with lifestyle interventions, although the data are limited. Therefore, the current manuscript provides a review of the current evidence on obesity and PWS, covering physiopathological aspects, obesity-related complications and conservative management.

Changes of Body Weight and Body Composition in Obese Patients with Prader–Willi Syndrome at 3 and 6 Years of Follow-Up: A Retrospective Cohort Study

Article

Full-text available

Nov 2020

Few short-term studies of weight loss have been performed in adult patients with Prader–Willi syndrome (PWS) undergoing metabolic rehabilitation. We performed a retrospective cohort study of 45 adult obese PWS patients undergoing a long-term multidisciplinary metabolic rehabilitation program based on diet and physical activity. Body composition was evaluated by dual-energy X-ray absorptiometry in 36 (80%) patients. The mean (95% CI) weight change was −3.6 (−7.6 to 0.4, p = 0.08) kg at 3 years and −4.6 (−8.5 to −0.8, p = 0.02) kg at 6 years, and that of BMI was −1.7 (−3.4 to 0.1, p = 0.06) kg/m2 at 3 years and −2.1 (−3.8 to −0.4, p = 0.02) kg/m2 at 6 years. A decrease of about 2% in fat mass per unit of body mass was observed, which is in line with the expectations for moderate weight loss. A possibly clinically relevant decrease in total and low-density lipoprotein cholesterol was also observed. These long-term results are important for patients with PWS, which is characterized by severe hyperphagia, behavioral disturbances, and cognitive impairment and is generally considered “resistant” to classical weight loss interventions.

Early start of growth hormone is associated with positive effects on auxology and metabolism in Prader-Willi-syndrome

Article

Full-text available

Dec 2020
ORPHANET J RARE DIS

Background Prader-Willi-Syndrome (PWS) is characterized by hypothalamic-pituitary dysfunction. Recent research suggests starting growth hormone-treatment (GHT) as soon as possible. The aim of this study is to analyze possible differences in auxological parameters, carbohydrate and lipid metabolism between two groups of children with PWS that started GHT either during or after their first year of life. Study design Retrospective longitudinal study of 62 children (31 males) with genetically confirmed PWS. Upon diagnosis all children were offered GHT, some started immediately, others commenced later. Cohort A ( n = 21; 11 males) started GHT at 0.3–0.99 yrs. (mean 0.72 yrs) and Cohort B ( n = 41; 20 males) commenced GHT at 1.02–2.54 yrs. (mean 1.42 yrs) of age. Fasting morning blood samples and auxological parameters were obtained before the start of therapy and semi-annually thereafter. Differences between the two cohorts were estimated with a linear mixed-effect model. Results Mean length/height-SDS PWS differed significantly between the groups [1 yr: A: 0.37 (±0.83) vs B: 0.05 (±0.56); 5 yrs.: A: 0.81 (±0.67) vs B: 0.54 (±0.64); p = 0.012]. No significant differences were found in BMI, lean body mass or body fat. Low-density cholesterol was significantly lower in A than in B [LDL: 1 yr: A: 79 (±20) mg/dl vs B: 90 (±19) mg/dl; 5 yrs.: A: 91(±18) mg/dl vs 104 (±26) mg/dl; p = 0.024]. We found significant differences in the glucose homeostasis between the groups [fasting insulin: p = 0.012; HOMA-IR: p = 0.006; HbA1c: p < 0.001; blood glucose: p = 0.022]. Conclusions An early start of GHT during the first year of life seems to have a favorable effect on height-SDS and metabolic parameters.

Clinical Observations and Treatment Approaches for Scoliosis in Prader–Willi Syndrome

Article

Full-text available

Feb 2020

Prader–Willi syndrome (PWS) is recognized as the first example of genomic imprinting, generally due to a de novo paternal 15q11-q13 deletion. PWS is considered the most common genetic cause of marked obesity in humans. Scoliosis, kyphosis, and kyphoscoliosis are commonly seen in children and adolescents with PWS with a prevalence of spinal deformities cited between 15% to 86%. Childhood risk is 70% or higher, until skeletal maturity, with a bimodal age distribution with one peak before 4 years of age and the other nearing adolescence. As few reports are available on treating scoliosis in PWS, we described clinical observations, risk factors, therapeutic approaches and opinions regarding orthopedic care based on 20 years of clinical experience. Treatments include diligent radiographic screening, starting once a child can sit independently, ongoing physical therapy, and options for spine casting, bracing and surgery, depending on the size of the curve, and the child’s age. Similarly, there are different surgical choices including a spinal fusion at or near skeletal maturity, versus a construct that allows continued growth while controlling the curve for younger patients. A clear understanding of the risks involved in surgically treating children with PWS is important and will be discussed.

Update on Diabetes Mellitus and Glucose Metabolism Alterations in Prader-Willi Syndrome

Article

Full-text available

Feb 2020
Curr Diabetes Rep

Purpose of Review This review summarizes our current knowledge on type 2 diabetes mellitus (T2DM) and glucose metabolism alterations in Prader-Willi syndrome (PWS), the most common syndromic cause of obesity, and serves as a guide for future research and current best practice. Recent Findings Diabetes occurs in 10–25% of PWS patients, usually in adulthood. Severe obesity is a significant risk factor for developing of T2DM in PWS. Paradoxically, despite severe obesity, a relative hypoinsulinemia, without the expected insulin resistance, is frequently observed in PWS. The majority of PWS subjects with T2DM are asymptomatic and diabetes-related complications are infrequent. Long-term growth hormone therapy does not adversely influence glucose homeostasis in all ages, if weight gain does not occur. Summary Early intervention to prevent obesity and the regular monitoring of glucose levels are recommended in PWS subjects. However, further studies are required to better understand the physiopathological mechanisms of T2DM in these patients.

Relationship between phenotype and genotype of 102 Chinese newborns with Prader–Willi syndrome

Article

Full-text available

Oct 2019
MOL BIOL REP

High rates of misdiagnosis and delayed intervention in neonatal PWS are leading to poor prognoses. To determine the clinical and image characteristics of newborns with Prader–Willi syndrome (PWS). A total of 102 cases of newborns definitively diagnosed with PWS at the Children’s Hospital of Fudan University from 02/2014 to 12/2017 were retrospectively analyzed. We analyzed the modulated voxel-based morphology (VBM) of gray matter in PWS by T2 weighted imaging. Of 102 cases, 75 (73.5%) have paternal deletion of 15q11.2-q13, whereas 27 (26.5%) have maternal uniparental disomy (UPD). Of the 75 deletion cases, 75 (100%) week crying, 71 (94.7%) hypotonia, 70 (93.3%) poor feeding, 46 (61.3%) hypopigmentation, 43 (57.3%) male cryptorchidism, 10 (13.3%) female labia minora, 48 (64%) characteristic facial features. Of 27 UPD cases, 27 (100%) week crying and hypotonia, 25 (92.6%) hypophagia, 20 (74.1%) male cryptorchidism, 1 (3.7%) female labia minora, 19 (70.4%) characteristic facial features, 12 (44.4%) hypopigmentation. The modulated VBM analysis shows that the middle frontal gyrus, orbitofrontal cortex (middle), and inferior frontal gyrus are the most variable brain regions that determine the endo-phenotype difference between the two genotypes. Hypotonia, hypophagia, and maldevelopment of sexual organs are general characteristics of newborns with PWS in Chinese population. In UPD cases, the proportions of premature newborns, elderly parturient women and congenital malformations were higher than for paternal deletion cases. The differences in the gray matter volume of these three regions between the two genotypes may explain the differences in maladaptive behaviors and emotions.

Requirements for improving health and well‐being of children with Prader‐Willi syndrome and their families

Article

Full-text available

Jul 2019

Prader‐Willi syndrome (PWS) is a rare genetic condition with multi‐system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored. Challenging behaviours contribute to poorer well‐being and quality of life for both the child and caregiver. Recent evidence indicates healthy outcomes of weight and height can be achieved with growth hormone therapy and dietary restriction and should be the current target for all individuals with PWS. Gaps in the literature included therapies to manage challenging behaviours, as well as understanding the effects of growth hormone on respiratory and sleep function. New knowledge regarding the transition of children and families from schooling and paediatric health services to employment, accommodation and adult health services is also needed. Developing a national population‐based registry could address these knowledge gaps and inform advocacy for support services that improve the well‐being of individuals with PWS and their families.

Treatment with growth hormone in the Prader-Willi syndrome

Article

Full-text available

Apr 2018

Introduction The Prader-Willi syndrome (PWS) is a rare genetic disorder caused by absence of expression of the paternal alleles in region 15q11.2-q13. Obesity and hormonal deficiencies, especially of growth hormone (GH), are the most important signs from the therapeutic viewpoint. Recombinant GH (rGH) is effective in children and represents the mainstay in treatment; by contrast, little evidence in available in adult patients. Objective To review the reported evidence on the beneficial and adverse effects of treatment with rGH in children and adults. Design A review was made of 62 original articles published between 2000 and 2017 using the PubMed database. Results In pediatric and adult PWS, rGH improves body morphology and composition, physical performance, cognition, psychomotor development, respiratory function, and quality of life with few adverse effects. Conclusions Treatment with rGH is effective and safe and improves quality of life in both children and adults with PWS.

Tratamiento con hormona de crecimiento en el síndrome de Prader-Willi

Article

Full-text available

Mar 2018

Introduction: The Prader-Willi syndrome (PWS) is a rare genetic disorder caused by absence of expression of the paternal alleles in región 15q11.2-q13. Obesity and hormonal deficiencies, especially of growth hormone (GH), are the most important signs from the therapeutic viewpoint. Recombinant GH (rGH) is effective in children and represents the mainstay in treatment; by contrast, little evidence in available in adult patients. Objective: To review the reported evidence on the beneficial and adverse effects of treatment with rGH in children and adults. Design: A review was made of 62 original articles published between 2000 and 2017 using the PubMed database. Results: In pediatric and adult PWS, rGH improves body morphology and composition, physical performance, cognition, psychomotor development, respiratory function, and quality of life with few adverse effects. Conclusions: Treatment with rGH is effective and safe and improves quality of life in both children and adults with PWS.

Article

Apr 2017

Rossella Snenghi

Diagnosis and treatment of GH deficiency in Prader-Willi syndrome

Article

Nov 2016

Prader–Willi syndrome (PWS) results from under-expression of the paternally-derived chromosomal region 15q11-13. Growth failure is a recognized feature of PWS, and both quantitative and qualitative defects of the GH/IGF-I axis revealing GH deficiency (GHD) have been demonstrated in most children with PWS. In PWS adults, criteria for GHD are biochemically fulfilled in 8-38% of the studied cohorts. Published data support benefits of early institution of GH therapy (GHT) in PWS children, with positive effects on statural growth, body composition, metabolic homeostasis, and neurocognitive function. Like in pediatric PWS, GHT also yields beneficial effects on lean and body fat, exercise capacity, and quality of life of PWS adults. Although GHT has been generally administered safely in PWS children and adults, careful surveillance of risks is mandatory during prolonged GH replacement for all PWS individuals.

Disorders of Sleep and Ventilatory Control in Prader-Willi Syndrome

Article

Full-text available

Jul 2016

Prader-Willi syndrome (PWS) is an imprinted genetic disorder conferred by loss of paternal gene expression from chromosome 15q11.2-q13. Individuals with PWS have impairments in ventilatory control and are predisposed toward sleep disordered breathing due to a combination of characteristic craniofacial features, obesity, hypotonia, and hypothalamic dysfunction. Children with PWS progress from failure to thrive during infancy to hyperphagia and morbid obesity during later childhood and onward. Similarly, the phenotype of sleep disordered breathing in PWS patients also evolves over time from predominantly central sleep apnea in infants to obstructive sleep apnea (OSA) in older children. Behavioral difficulties are common and may make establishing effective therapy with continuous positive airway pressure (CPAP) more challenging when OSA persists after adenotonsillectomy. Excessive daytime sleepiness (EDS) is also common in patients with PWS and may continue after OSA is effectively treated. We describe here the characteristic ventilatory control deficits, sleep disordered breathing, and excessive daytime sleepiness seen in individuals with PWS. We review respiratory issues that may contribute to sudden death events in PWS patients during sleep and wakefulness. We also discuss therapeutic options for treating sleep disordered breathing including adenotonsillectomy, weight loss, and CPAP. Lastly, we discuss the benefits and safety considerations related to growth hormone therapy.

Growth hormone therapy for Prader–willi syndrome: challenges and solutions

Article

Full-text available

Jun 2016

Prader–Willi syndrome (PWS) is characterized by a dysregulation of growth hormone (GH)/insulin-like growth factor I axis, as the consequence of a complex hypothalamic involvement. PWS’ clinical picture seems to resemble the classic non-PWS GH deficiency (GHD), including short stature, excessive body fat, decreased muscle mass, and impaired quality of life. GH therapy is able to ameliorate the phenotypic appearance of the syndrome, as well as to improve body composition, physical strength, and cognitive level. In this regard, however, some pathophysiologic and clinical questions still remain, representing a challenge to give the most appropriate care to PWS patients. Data about the prevalence of GHD in PWS children are not unequivocal, ranging from 40% to 100%. In this context, to establish whether the presence (or not) of GHD may have a different effect on clinical course during GH therapy may be helpful. In addition, the comparison of GH effects in PWS children diagnosed as small for gestational age with those obtained in subjects born appropriate for gestational age is of potential interest for future trials. Emerging information seems to demonstrate the maintenance of beneficial effects of GH therapy in PWS subjects after adolescent years. Thus, GH retesting after achievement of final height should be taken into consideration for all PWS patients. However, it is noteworthy that GH administration exerts positive effects both in PWS adults with and without GHD. Another critical issue is to clarify whether the genotype–phenotype correlations may be relevant to specific outcome measures related to GH therapy. Moreover, progress of our understanding of the role of GH replacement and concomitant therapies on bone characteristics of PWS is required. Finally, a long-term surveillance of benefits and risks of GH therapy is strongly recommended for PWS population, since most of the current studies are uncontrolled and of short duration.

Prader-Willi Syndrome: guidance for children and transition into adulthood

Article

Full-text available

Jun 2024

Prader Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability, and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.

Effect of semaglutide on weight loss and glycaemic control in patients with Prader–Willi Syndrome and type 2 diabetes

Article

Feb 2024

Effect of semaglutide on weight loss and glycaemic control in patients with Prader–Willi Syndrome and type 2 diabetes

Article

Feb 2024

Food cue reward salience does not explain Hyperphagia in adolescents with Prader-Willi syndrome

Article

Nov 2023
DEV NEUROPSYCHOL

Prader-Willi Syndrome (PWS) is characterized by hyperphagia, an extreme and persistent hunger that emerges in early childhood. We used event-related potentials (ERPs) to objectively investigate brain responses to low- and high-calorie foods, animals, and household objects in 20 satiated adolescents with PWS. Late Positive Potential (LPP) responses to food images did not differ from non-food images. Rather, we observed larger ERPs to high-calorie foods relative to animal images (p=.001) in an earlier time window. These responses correlated with greater severity of hyperphagia (p = .01). Thus, hyperphagia associated with PWS may be due to altered satiety regulation rather than increased motivational salience.

Vagal Asystoles in a Boy With Prader-Willi Syndrome

Article

Aug 2023
Pediatrics

Prader-Willi syndrome (PWS) is a genetic hormonal disorder of the hypothalamic-pituitary-axis resulting in mental retardation, muscle hypotonia, hypogonadism, and hyperphagia leading to significant obesity. Cardiovascular morbidity and mortality in adult patients with PWS is higher than in healthy controls and mainly secondary to massive obesity. In childhood, mortality may result from respiratory or gastrointestinal illnesses. We present a case of a 10-year-old boy with PWS who experienced recurrent and asymptomatic episodes of sinus pauses caused by the ingestion of large gulps of apple juice, which could be provoked and reproduced. The asystoles could not be provoked by any other vagal maneuvers and an initial diagnostic workup revealed no indication for structural heart disease. Because of the asymptomatic character of the asystoles, no treatment was initially provided. When he re-presented 3 months later after a clinically relevant syncope at school, pacemaker therapy was initiated, and he has demonstrated no subsequent sinus pauses or syncopes. Regarding the rising awareness of subtle cardiac alterations including autonomic dysfunction and electrocardiogram changes in young patients with PWS and especially the occurrence of unexplained sudden deaths in childhood that may be precipitated by arrhythmia, we suggest that the utility of periodic screening for arrhythmia risk should be evaluated in children with PWS.

The effects of glucagon‐like peptide (GLP)‐1 receptor agonists on weight and glycaemic control in Prader–Willi syndrome: A systematic review

Article

Aug 2021

Objective The mainstay management of hyperphagia and obesity in Prader–Willi syndrome (PWS) relies on dietary restrictions, strict supervision and behavioural modifications, which can be stressful for the patient and caregiver. There is no established pharmacological strategy to manage this aspect of PWS. Theoretically, glucagon-like peptide-1 (GLP-1) receptor agonists (GLP1-RA) used in patients with obesity and type 2 diabetes mellitus (T2DM) may be efficacious in weight and glycaemic control of PWS patients. We conducted a systematic review of the literature to summarize the evidence on the use of GLP1-RA in PWS patients. Design Primary studies were searched in major databases using key concepts ‘Prader–Willi syndrome’ and ‘GLP1 receptor agonist’ and outcomes, ‘weight control OR glycaemic control OR appetite regulation’. Results Ten studies included, summarizing GLP1-RA use in 23 PWS patients (age, 13–37 years), who had used either exenatide (n = 14) or liraglutide (n = 9) over a duration of 14 weeks to 4 years. Sixteen (70%) of these patients had T2DM. Ten patients experienced improvement in body mass index, ranging from 1.5 to 16.0 kg/m², while improvement in HbA1c was seen in 19 of 23 cases, ranging between 0.3% and 7.5%. All five studies reporting appetite or satiety showed improvement in satiety levels. There were no reported serious side effects. Conclusions GLP1-RA appears safe in PWS patients and may have potential benefits for weight, glycaemic and appetite control. Nonetheless, we also highlight a significant gap in the literature on the lack of well-designed studies in this area, which limits the recommendation of GLP1-RA use in PWS patients at present.

The Cost of Raising Individuals with Fragile X or Chromosome 15 Imprinting Disorders in Australia

Article

Full-text available

Jul 2021
J AUTISM DEV DISORD

The study characterised differences in costs associated with raising a child between four rare disorders and examined the associations between these costs with clinical severity. Caregivers of 108 individuals with Prader-Willi, Angelman (AS), Chromosome 15q Duplication and fragile X (FXS) syndromes completed a modified Client Services Receipt Inventory and participants completed intellectual/developmental functioning and autism assessments. AS incurred the highest yearly costs per individual ($AUD96,994), while FXS had the lowest costs ($AUD33,221). Intellectual functioning negatively predicted total costs, after controlling for diagnosis. The effect of intellectual functioning on total costs for those with AS was significantly different to the other syndromes. The study highlights the significant costs associated with these syndromes, particularly AS, linked with severity of intellectual functioning.

Angiopoietin-like 8 (ANGPTL8) as a potential predictor of NAFLD in paediatric patients with Prader-Willi Syndrome

Article

Full-text available

Oct 2020
J ENDOCRINOL INVEST

Purpose: Angiopoietin-like 8 (ANGPTL8) is a liver-and adipose tissue-produced protein that predicts non-alcoholic fatty liver disease (NAFLD) and altered metabolic homeostasis in the general population as well as in persons with common and genetic obesity, including the Prader-Willi syndrome (PWS). However, its metabolic correlate in paediatric patients with respect to PWS is unknown. Methods: This cross-sectional study investigated circulating ANGPTL8 and adipocytokines levels in 28 PWS and 28 age-, sex-and BMI-matched children and adolescents (age, 7.0-17.8y) in relation to NAFLD and metabolic homeostasis assessed by OGTT, paediatric metabolic index (PMI) and fatty liver index (FLI), liver ultrasonography (US), as well as dual-energy X-ray absorptiometry (DEXA) for analysis of fat (FM) and fat-free mass (FFM). Results: At the set level of significance, PWS children showed lower values of FFM (p < 0.01) but healthier insulin profiles (p < 0.01) and PMI values (p < 0.05) than matched controls. By US, the prevalence of NAFLD was similar between groups but less severe in PWS than controls. Analysis of ANGPTL8 levels showed no difference between groups, yet only in PWS ANGPTL8 levels were associated with ALT levels, FLI values and NAFLD. In stepwise multivariable regression analysis on merged data, ANGPTL8 levels were independently predicted by BMI SDS, leptin levels and NAFLD. Conclusion: ANGPTL8 levels are similar in PWS and controls and, overall, they are directly associated with the presence and severity of NAFLD in patients with PWS.

Cardiac autonomic control during non-REM and REM sleep stages in paediatric patients with Prader-Willi syndrome

Article

Aug 2020

Cardiac death is the second most prevalent cause in Prader-Willi syndrome (PWS). Paediatric patients with PWS often present cardiac autonomic dysfunction during wakefulness, obesity and sleep-disordered breathing. However, the extent of cardiac autonomic modulation during sleep in PWS has not been documented. The objective of this study was to assess alterations in cardiac autonomic modulation of paediatric patients with PWS during different sleep stages. Thirty-nine participants in three groups: 14 PWS, 13 sex and age-matched lean controls (LG) and 12 obese-matched controls (OB). All participants underwent overnight polysomnography, including continuous electrocardiogram recordings. Heart rate variability (HRV) was analysed during representative periods of each sleep stage through time and frequency domains calculated across 5-min periods. Between-within ANOVAs were employed (p < .05). The results show that total HRV was lower in PWS than OB and LG during slow-wave sleep (SWS) (standard deviation of all NN intervals [SDNN] ms, p = .006). Parasympathetic modulation assessed by time-domain analysis was lower during SWS in PWS compared to both OB and LG (square root of the mean of the sum of the squares of differences between adjacent NN intervals [RMSSD] ms, p = .004; SDSD, standard deviation of differences between adjacent NN intervals [SDSD] ms, p = .02; number of adjacent NN intervals differing by >50 ms [NN50] ms, p = .03; proportion of adjacent NN intervals differing by >50 ms [pNN50] ms, p = .01). Sympathovagal balance assessed by frequency-domain analysis was lower during both N2 and SWS than during the rapid eye movement (REM) sleep stage, but not different among groups. In conclusion, this group of paediatric patients with PWS had impaired cardiac autonomic balance due to reduced parasympathetic modulation during SWS. This result could imply an underlying increased cardiovascular risk in PWS even during early age and independent of obesity.

Cardiac autonomic control during non-REM and REM sleep stages in paediatric patients with Prader-Willi syndrome

Article

Aug 2020
J SLEEP RES

Sleep-Disordered Breathing in Children with Prader-Willi Syndrome in Relation to Growth Hormone Therapy Onset

Article

Jun 2020

Objective: The aim of this study was to consider sleep apnea in Prader-Willi syndrome (PWS) children depending on age at growth hormone (GH) therapy onset. Study design: We analyzed longitudinally cardiorespiratory polygraphy of 62 PWS children (aged 0-2.5 years at baseline). Twenty-one children (Group A) started GH-therapy during and 41 children (Group B) after their first year of life. Data were acquired before, at 3 and 6 months, then 1.2, 2.2, and 3.2 years after GH onset. Outcomes were determined with the obstructive apnea hypopnea index (OAHI), central apnea index (CAI), oxygen desaturation index (ODI), and by measuring obstructive sleep apnea (OSA) and peripheral blood oxygen saturation (SpO2). Results: We observed no significant differences in OAHI, CAI, ODI, and SpO2 depending on treatment onset. At baseline, 5/21 patients (23.8%) in Group A versus 15/41 patients (36.6%) in Group B showed pathological sleep apnea (OAHI ≥1.5). Pathological OSA increased significantly in Group A during the first 3 months of therapy but dropped below baseline after 1 year in both groups. ODI changed during GH therapy in both groups (from 4.0 to 2.6 in Group A, and 3.6 to 1.6 in Group B; baseline to 3.2 years; p < 0.05). Conclusions: OSA in PWS children appears to develop independently of treatment onset. Treatment may therefore safely be initiated early but should be accompanied by regular sleep analysis.

Comparison of Hip and Knee Arthroplasty Rates of Individuals With and Without Prader-Willi Syndrome

Article

Dec 2019

Background: Prader-Willi syndrome (PWS) is a complex genetic condition, affecting between 1:10,000 and 1:30,000. The prevalence of hip dysplasia in children with PWS is reportedly between 8% and 30%, but the long-term consequences of residual hip dysplasia remain largely unknown in this population. The purpose of this study was to comparatively estimate the number of total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures performed on adults with and without PWS, using a national hospital discharge database, in an effort to elucidate long-term outcomes and guide clinicians treating orthopaedic concerns in younger individuals with PWS. Methods: The National Inpatient Sample of the Healthcare Cost and Utilization Project is the largest all-payer inpatient care database, containing annual data from >7 million hospital stays; sampling weights and stratification variables are provided for producing estimates of >35 million hospitalizations nationwide. THA and TKA procedures were identified, then stratified by whether or not the patient had a diagnosis of PWS. The ages of the 2 groups and sex mix were compared, as was the length of stay for the procedure, and discharge status. Results: From 2004 to 2014, 9.4 million patients nationwide, by weighted estimate, underwent THA (3.1 million) or TKA (6.3 million). Sixty-five patients were identified as having the diagnosis of PWS (39 with THA, 26 with TKA); 7 patients per million having hip or knee arthroplasties had PWS. Sixty-eight percent of those with PWS were younger than 50 years, compared with only 7% of those without PWS (P<0.001). The female:male prevalence was 47:53 for patients with PWS and 60:40 for the total group. The mean length of stay was similar, but patients with PWS were more likely to be transferred to another facility after surgery (77% vs. 36%; P=0.008). Conclusions: Hip dysplasia prevalence is higher in persons with PWS, but the rate of late treatment with THA is much lower than in the general population. We recommend only active observation for stable and improving hips in young children with PWS, as the consequences of overtreatment can be serious, including further delaying their neuromuscular development, and exposure to possibly unnecessary perioperative risks. Level of evidence: Nation-wide database analysis, Level IV.

Bone, Growth Plate and Mineral Metabolism

Article

Sep 2019

Growth hormone prescribing patterns in the UK, 2013–2016

Article

Full-text available

Dec 2018

Introduction Prescribing of recombinant human growth hormone (rhGH) for growth failure in UK children is based on guidance from the National Institute for Health and Care Excellence. In 2013, the British Society for Paediatric Endocrinology and Diabetes initiated a national audit of newly prescribed rhGH treatment for children and adolescents. In this review, we have examined prescribing practices between 2013 and 2016. Methods All patients ≤16.0 years of age starting rhGH for licensed and unlicensed conditions in the UK were included. Anonymised data on indication and patient demographics were analysed. Results During the 4 years, 3757 patients from 76 of 85 (89%) centres started rhGH. For each licensed indication, proportions remained stable over this period: 56% growth hormone deficiency (GHD), 17% small for gestational age (SGA), 10% Turner syndrome, 6% Prader-Willi syndrome (PWS), 3% chronic renal insufficiency (CRI) and 2% short stature homeobox deficiency (SHOXd). However, the unlicensed category decreased from 10% (n=94) in 2013 to 5% (n=50) in 2016. The median age of patients starting rhGH was 7.6 years (range 0.1–16.0). Patients with PWS were significantly younger (median 2.2 years, range 0.2–15.1) compared with other indications (p<0.0001) and were followed by the SGA group (median 6.2 years, range 1.3–15.6, p<0.0001). Boys predominated in all groups except for PWS and SHOXd. Conclusion We demonstrate significant engagement of prescribing centres in this audit and a decline in unlicensed prescribing by half in this 4-year period. Patients in the PWS group were younger at initiation of rhGH compared with other indications and had no male predominance unlike GHD, SGA and CRI.

Trends in growth hormone prescription in the UK: Results from the 3 year National Growth Hormone Audit

Article

Full-text available

Nov 2016

Subclinical dysphagia in persons with Prader-Willi syndrome

Article

Oct 2016
AM J MED GENET A

Prader–Willi Syndrome (PWS) is caused by a genetic imprinting abnormality resulting from the lack of expression of the paternal genes at 15q11–q13. Intellectual disability, low muscle tone, and life-threatening hyperphagia are hallmarks of the phenotype. The need for the Heimlich maneuver, death from choking, and pulmonary infection occur in a disproportionally high number of persons with PWS. The widely held belief is that eating behaviors are responsible for choking and aspiration; yet, no investigation had sought to determine if swallowing impairments were present in persons with PWS. To address this research and clinical gap, simultaneous videofluoroscopy and nasal respiratory signals were used to record swallowing function and breathing/swallowing coordination in 30 participants with PWS. Subjects consumed thin liquid and barium cookies under two randomized conditions as follows: (i) controlled (cues to swallow and standardized bolus sizes); (ii) spontaneous (no cues or bolus size control). Under videofluoroscopy, the cohort showed disordered pharyngeal and esophageal swallowing in both conditions with disturbances in timing, clearance, and coordination of swallowing with the respiratory cycle. No participant showed a sensory response such as attempting to clear residue or coughing; thereby supporting the lack of overt symptoms. We conclude that the high death rate from choking and pulmonary infection in children and adults with PWS may be related, in part, to underlying, asymptomatic dysphagia. The combination of rapid eating and dysphagia would increase the risk of aspiration-related morbidity and mortality.

Endocrine management of children with Prader–Willi syndrome

Article

Full-text available

Oct 2013

Clarice Borschiver Medeiros,1 Ana Paula Bordallo,1 Flavio Moutinho Souza,2 Paulo Ferrez Collett-Solberg1,31Endocrinology Unit, Departamento de Medicina Interna, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, Brazil; 2Pediatric Endocrinology Unit, Departamento de Pediatria, Hospital Federal Cardoso Fontes – Ministério da Saúde do Brasil, Brasília, Brazil; 3Laboratório de Pesquisas Clínicas e Experimentais em Biologia Vascular (BioVasc), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, BrazilAbstract: Prader–Willi syndrome is a rare genetic condition afflicting nearly 1/15,000 live births. Clinical features include neonatal hypotonia, poor weight gain in early infancy followed by binge eating from childhood to adulthood, severe obesity, developmental delay, short stature, and hypogonadism of both central and peripheral etiology. Central hypothyroidism and adrenal insufficiency may occur. Sleep disordered breathing, by obstruction of upper airways associated with central hypoventilation, is a common feature. Most of these characteristics are assumed to be the result of a hypothalamic dysfunction. The most important complication and the most difficult to manage is the obesity. This review aims at discussing the most recent strategies to manage the endocrine complications of Prader–Willi syndrome patients, with a special approach on the treatment of obesity, hypogonadism, and short stature. We summarize the indication and effects of recombinant human growth hormone therapy on growth, cognitive development, and body composition, and discuss the effects of recombinant human growth hormone therapy on the resulting sleep disorders.Keywords: Prader–Willi syndrome, obesity, hypogonadism, growth hormone, sleep disorder

Disorders of glucose metabolism in Prader-Willi syndrome: Results of a multicenter Italian cohort study

Article

Jun 2016

Background and aims: Prader-Willi syndrome (PWS) is characterized by a high incidence of altered glucose metabolism (AGM). However, epidemiological data on impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) are still discordant. Methods and results: We performed a multicenter study based on 274 PWS patients [144 females, aged 20.3 ± 10.4 yrs (range: 8.1-50.1 years)] evaluating the prevalence for AGM in the entire group, and according to age (children <10 yrs; adolescents 10-18 yrs, and adults >18 yrs), Body Mass Index (BMI = kg/m(2)), gender, genotypes (deletion or uniparental disomy for chromosome 15), and GH therapy (GHT) (untreated, previously or currently treated). Altogether, AGM was detected in 67 (24.4%) of patients (0.7% IFG, 10.2% IGT, 13.5% T2DM). The prevalence of AGM was correlated to age (p = 0.001), BMI (p = 0.001) and HOMA-IR (p = 0.001). However, gender, genotype, and GHT did not influence AGM development in univariate analysis. These data were confirmed as positive predictors when inserted in a multivariate analysis model. Conclusion: This study is the first report on the prevalence of AGM in a large population of PWS. Overall, PWS subjects show a high prevalence of AGM that appears more common in obese and adult subjects. Our data confirm the main role of obesity on the individual metabolic risk clustering in PWS, and thus reinforce the concept that improvement in weight control remains the most important goal of any PWS treatment program.

Feeding and Satiety Signals in Prader-Willi Syndrome: Relation to Obesity, Diet, and Behavior

Chapter

Jan 2011

Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder that arises from lack of expression of paternally inherited imprinted genes on chromosome 15q11-q13. PWS has been classically described as having two nutritional phases, but detailed descriptions recently led to the characterization of four main nutritional phases, with a particular emphasis on the fact that excessive weight gain occurs prior to hyperphagia. Patients with PWS show reduced satiety and early return of hunger. They are prone to eating nonfood items (pica) or contaminated foods, and to combine foods inappropriately. The abnormal feeding behavior in PWS includes a morbid obsession with food, food stealing, hoarding, and foraging. Evaluation of eating behavior has not yet been standardized in PWS, but questionnaires are being validated and this will enable caregivers to better characterize certain features of the syndrome, such as satiety and hyperphagic behavior, drive, and severity. PWS has been described as a genetic hypothalamic syndrome, because it includes hyperphagia as well as temperature dysregulation, sleep-wake cycles abnormalities, and metabolic and endocrine disorders. Recent data also suggest more complex dysfunctions involving the corticolimbic areas. In any case, the most striking and specific defects in PWS feeding and satiety signals is the high circulating level of the orexigenic stomach-derived hormone ghrelin and the decreased level of pancreatic polypeptide. Hypergrhelinemia could explain the obesity and the GH deficiency. Interestingly, these two main abnormal signals may explain the major feeding disturbances described in individuals with PWS. Part of their action requires an intact vagal nerve reflex and they both regulate gastric emptying. These findings suggest that the eating behavior of people with PWS may be due to decreased satiety rather than to increased hunger. Recent functional MRI findings suggest that hyperphagia may be linked to at least two mechanisms involving limbic and paralimbic regions that drive eating behavior (e.g., the amygdala) and regions that regulate food intake (e.g., the medial PFC). Management of PWS involves strict and permanent environmental control with early institution of a low-calorie, well-balanced diet, with regular exercise, rigorous supervision, restriction of access to food and money, with consideration of legal and ethical obligations, and appropriate psychological and behavioral counseling for the patient and family. The effects of GH treatment on hyperphagia remain to be demonstrated, but GH prevents the increase in BMI and the decrease in lean-body mass observed in patients without treatment.

Prader-Willi Syndrome: A Spectrum of Anatomical and Clinical Features

Article

Jan 2016
CLIN ANAT

Prader-Willi Syndrome (PWS) is estimated to affect 400,000 people worldwide. First described clinically in 1956, PWS is now known to be a result of a genetic mutation, involving Chromosome 15. The phenotypical appearance of individuals with the syndrome follows a similar developmental course. During infancy, universal hypotonia accompanied by feeding problems, hypogonadism and dolichocephaly are evident. Characteristic facial features such as narrow bifrontal diameter, almond-shaped eyes and small mouth (with downturned corners and thin upper lip) may also be evident at this stage. In early childhood, the craniofacial features become more obvious and a global developmental delay is observed. Simultaneously, individuals develop hyperphagia that leads to excessive or rapid weight gain, which, if untreated, exists throughout their lifespan and may predispose them to numerous, serious health issues. The standard tool for differential diagnosis of PWS is genetic screening, however, clinicians also need to be aware of the characteristic features of this disorder, including differences between the genetic sub-types. As the clinical manifestations of the syndrome vary between individuals and become evident at different developmental time points, early assessment is hindered. This review focuses on the clinical and anatomical manifestations of the syndrome and highlights areas of discrepancy and limitations within the existing literature. This article is protected by copyright. All rights reserved.

Prader-Willi Syndrome

Article

May 2010

The major features of this multisystem disorder include prenatal and neonatal central hypotonia causing poor suck and infantile failure to thrive, characteristic facial appearance, developmental delay/generally mild mental retardation, childhood-onset obesity, short stature for the family, hypogonadism causing genital hypoplasia and pubertal insufficiency, and a characteristic behavior disorder. Obesity-related complications are the major cause of morbidity and mortality. The cause of Prader-Willi syndrome is absence of paternal contribution at chromosome 15q11-13, a region involving genomic imprinting, through deletion, maternal uniparental disomy, or an imprinting defect. The specific genes involved are not yet definitively delineated. Clinical diagnostic criteria for Prader-Willi syndrome have been published, but confirmation requires diagnostic testing, which is clinically available. Management is mostly supportive since no definitive treatment is known. Special feeding techniques are usually required to avoid or treat failure to thrive in infancy. Early infant stimulation followed by special educational resources can optimize developmental outcome. Obesity can be avoided or treated through appropriate nutrition, exercise, and environmental controls. Growth deficiency and abnormal body composition (high fat:lean body mass) respond well to growth hormone replacement. Sex hormones can be given to replace the deficient ones. Behavioral problems are treated through parenting skill enhancement, behavior modification, or psychotropic medication. Treatment of abnormal saliva secretion and sleep disturbance are also possible.

Trends in off-label prescription of GH: results from the National GH Audit

Article

Full-text available

Oct 2014

2000 CDC Growth Charts for the United States: methods and development

Article

Full-text available

Jan 2000

CDC Growth Charts for the United States: Methods and development. Vital Health Stat

Article

Full-text available

Jan 2000

Analysis of survival data

Article

Full-text available

Jan 2002

Svetlana Borovkova

Body-mass Index reference curves for the UK, 1990

Article

Full-text available

Aug 1995
Arch Dis Child

Reference curves for stature and weight in British children have been available for the past 30 years, and have recently been updated. However weight by itself is a poor indicator of fatness or obesity, and there has never been a corresponding set of reference curves to assess weight for height. Body mass index (BMI) or weight/height has been popular for assessing obesity in adults for many years, but its use in children has developed only recently. Here centile curves for BMI in British children are presented, from birth to 23 years, based on the same large representative sample as used to update the stature and weight references. The charts were derived using Cole's LMS method, which adjusts the BMI distribution for skewness and allows BMI in individual subjects to be expressed as an exact centile or SD score. Use of the charts in clinical practice is aided by the provision of nine centiles, where the two extremes identify the fattest and thinnest four per 1000 of the population.

Prader-Willi Syndrome: Consensus Diagnostic Criteria

Article

Full-text available

Mar 1993

The diagnosis of Prader-Willi syndrome (PWS) is based on clinical findings that change with age. Hypotonia is prominent in infancy. Obesity, mild mental retardation or learning disability, and behavior problems, especially in association with food and eating, result in a debilitating physical and developmental disability in adolescence and adulthood. No consistent biological marker is yet available for PWS in spite of recent research activity in cytogenetics and molecular genetics. Diagnostic criteria for PWS were developed by consensus of seven clinicians experienced with the syndrome in consultation with national and international experts. Two scoring systems are provided: one for children aged 0 to 36 months and another one for children aged 3 years to adults. These criteria will aid in recognition of the syndrome in hypotonic infants and in obese, mildly retarded, behaviorally disturbed adolescents and adults. They will also ensure uniform diagnosis for future clinical and laboratory research in PWS.

Peculiar Body composition in patients with Prader-Labhart-Willi sindrome

Article

Full-text available

May 1997

Prader-Labhart-Willi syndrome (PWS)-characterized by severe obesity, short stature, hypogonadism, and muscle hypotonia-appears to be an interesting model for body-composition abnormalities. Twenty-seven PWS patients (15 males and 12 females) aged 6-22 y underwent total-body analysis by dual-energy X-ray photon absorptiometry (DXA). For each PWS patient two age- and sex-matched control subjects were studied: one obese subject with a relative body weight (RBW > 120%) and body mass index (BMI) similar to that of the patient and one normal-weight subject (RBW < 120%). Percentage body fat was significantly greater in PWS patients than in obese subjects (47.4 +/- 7.2% compared with 41.9 +/- 9.9%, P < 0.0001) and the same difference was evident for arms and legs but not for the trunk. Lean mass was significantly lower in PWS patients (26.4 +/- 8.2 kg) than in normal-weight subjects (32.9 +/- 10.2 kg) and even more so than in obese subjects (40.3 +/- 13.2 kg) (P < 0.0001). The most affected regions were limbs; thus, the ratio of lean mass in the trunk to that in the limbs was significantly higher in PWS patients (1.19 +/- 0.15) than in obese (1.07 +/- 0.13) and normal-weight (1.07 +/- 0.09) subjects (P < 0.002). The ratio of fat mass to lean mass was significantly higher in PWS patients than in obese subjects (0.90 +/- 0.32 and 0.74 +/- 0.27, P < 0.05). Bone mineral content (BMC) was significantly lower in PWS patients (1503 +/- 46 g) than in normal-weight (1876 +/- 677 g) and obese (2322 +/- 773 g) subjects (P < 0.0001); this difference was most pronounced in the limb region. Bone mineral density (BMD) in PWS patients (0.993 +/- 0.116 g/cm2) did not differ significantly from that of normal-weight subjects (1.033 +/- 0.147 g/cm2) but was significantly lower than that of obese subjects (1.154 +/- 0.139 g/cm2). The influence of age on body composition was assessed by comparing two age subgroups (< 12 y, n = 10; and > or = 12 y, n = 17). The older PWS patients had higher adiposity, lower BMC, and dramatically lower BMD. Also, the lean mass deficit increased with age so that the ratio of fat mass to lean mass was close to 1. In conclusion, PWS patients showed a peculiar body composition, to some extent similar to that found in subjects deficient in growth hormone or even to sedentary and elderly people. These results suggest the importance of an accurate analysis of body composition in PWS patients.

A rapid, PCR based test for differential molecular diagnosis of Prader-Willi and Angelman syndromes

Article

Full-text available

Jul 1998

Approximately 98% of Prader-Willi syndrome (PWS) and 80% of Angelman syndrome (AS) cases have deletions at a common region in chromosome 15q11-13, uniparental disomy for chromosomes 15 (UPD15), or mutations affecting gene expression in this region. The resulting clinical phenotype (PWS or AS) in each class of mutation depends upon the parent of origin. Both disorders are characterised at the molecular level by abnormal methylation of imprinted genes at 15q11-q13 including the small nuclear ribonucleoprotein N gene (SNRPN). Current diagnostic strategies include high resolution cytogenetics, fluorescence in situ hybridisation (FISH), Southern blot hybridisation, or microsatellite typing. We have developed a novel and rapid diagnostic test for PWS and AS based on differential digestion of expressed (paternally imprinted) SNRPN sequences by the methylation sensitive endonuclease NotI or repressed (maternally imprinted) SNRPN sequences by the methylation requiring nuclease McrBC, followed by PCR amplification of the SNRPN promoter. We have evaluated this test by blinded analysis of 60 characterised DNA samples (20 PWS, 20 AS, and 20 unaffected controls). SNRPN sequences could not be amplified from PWS patient DNA which had been digested with McrBC, nor from AS patient DNA which had been digested with NotI. We were able to make a correct diagnosis of PWS, AS, or unaffected in all 60 samples tested. This novel test is rapid and has a high specificity and sensitivity for deletion and UPD15 cases. These features make this new test suitable as the initial step in a molecular diagnostic strategy for PWS/AS.

Establishing standard definition for child overweight and obesity worldwide: International survey

Article

Full-text available

Jun 2000

To develop an internationally acceptable definition of child overweight and obesity, specifying the measurement, the reference population, and the age and sex specific cut off points. International survey of six large nationally representative cross sectional growth studies. Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States. 97 876 males and 94 851 females from birth to 25 years of age. Body mass index (weight/height(2)). For each of the surveys, centile curves were drawn that at age 18 years passed through the widely used cut off points of 25 and 30 kg/m(2) for adult overweight and obesity. The resulting curves were averaged to provide age and sex specific cut off points from 2-18 years. The proposed cut off points, which are less arbitrary and more internationally based than current alternatives, should help to provide internationally comparable prevalence rates of overweight and obesity in children.

Population prevalence and estimated birth incidence and mortality rate for people with Prader-Willi syndrome in one UK Health Region [7]

Article

Full-text available

Dec 2001
J MED GENET

Editor—Prader-Willi syndrome (PWS) is a genetically determined disorder in which the absence of expression of one or more maternally imprinted gene(s) in the chromosomal region 15q11-13 results in a characteristic facial appearance, learning disabilities (mental retardation), and severe overeating behaviour owing to an abnormal satiety response to food intake, together with a range of other behaviours. Initially, as reported by Prader et al ,1 PWS was conceived as a syndrome of obesity, short growth, cryptorchidism, and mental retardation following hypotonia in the neonatal period. As more and more people with PWS were reported and research into the syndrome began, behavioural characteristics and other clinical features were added, culminating in the consensus diagnostic criteria.2Concurrently, the genetics of the disorder were receiving attention. First was the discovery that for many there was a visible chromosomal deletion in the proximal part of the long arm of chromosome 15 (15q11-13). Reports of an apparently similar deletion being associated with a phenotypically very different syndrome (Angelman syndrome, AS),3 and the observation that PWS was the result of a deletion on the chromosome 15 of paternal origin, and AS the chromosome 15 of maternal origin, led to the recognition that gender specific imprinting of genes at that locus accounted for two diverse syndromes being associated with apparently similar chromosomal deletions.4 Maternal chromosome 15 disomies, mutations of an imprinting centre, and chromosomal translocations accounted for non-deletion cases of PWS.5 In published reports on Prader-Willi syndrome (PWS), prevalence has been variously quoted as “about 1 in 25 000 live births”,6 “between one in 25 000 and one in 10 000 live born children”,7 “[estimates] vary 6-fold from 1 in 5000 to 10 000; 1 in 10 000; 1 in 15 000; 1 in 25 000; to 1 in 10 000 to 30 000”.8 Only two estimates …

Endocrine Dysfunction in Prader-Willi Syndrome: A Review with Special Reference to GH

Article

Full-text available

Jan 2002

Prader-Willi syndrome is a genetic disorder occurring in 1 in 10,000-16,000 live-born infants. In the general population, approximately 60 people in every 1,000,000 are affected. The condition is characterized by short stature, low lean body mass, muscular hypotonia, mental retardation, behavioral abnormalities, dysmorphic features, and excessive appetite with progressive obesity. Furthermore, morbidity and mortality are high, probably as a result of gross obesity. Most patients have reduced GH secretory capacity and hypogonadotropic hypogonadism, suggesting hypothalamic-pituitary dysfunction. Replacement of GH and/or sex hormones may therefore be beneficial in Prader-Willi syndrome, and several clinical trials have now evaluated GH replacement therapy in affected children. Results of GH treatment have been encouraging: improved growth, increased lean body mass, and reduced fat mass. There was also some evidence of improvements in respiratory function and physical activity. The long-term benefits of GH treatment are, however, still to be established. Similarly, the role of sex hormone replacement therapy needs to be clarified as few data exist on its efficacy and potential benefits. In summary, Prader-Willi syndrome is a disabling condition associated with GH deficiency and hypogonadism. More active treatment of these endocrine disorders is likely to benefit affected individuals.

Resting metabolic rate, plasma leptin concentrations, leptin receptor expression, and adipose tissue measured by whole-body magnetic resonance imaging in women with Prader-Willi syndrome

Article

Full-text available

Apr 2002

Obesity in Prader-Willi syndrome (PWS) may be related to abnormalities in the adipocyte-leptin-hypothalamic pathway and may be exacerbated by reductions in the resting metabolic rate (RMR). We compared body composition, body-composition- adjusted RMR, and adiposity-adjusted plasma leptin between women with PWS and control women. We also examined leptin receptor expression in the PWS group. We studied body composition using whole-body magnetic resonance imaging and measured plasma leptin by radioimmunoassay in 45 control women aged 18-56 y and in 13 women with PWS aged 20-38 y. RMR was measured by indirect calorimetry in 41 control women and in 8 women with PWS. Age, body composition, and regional adipose tissue (AT) depots were corrected for by multiple regression analysis. Messenger RNA expression of the leptin receptor was examined by reverse transcriptase-polymerase chain reaction in lymphocytes. In the PWS group, fat mass was greater after correction for fat-free mass, and RMR was normal after correction for both fat-free mass and fat mass. Leptin was influenced primarily by subcutaneous AT volume in both subject groups. Leptin concentrations were not significantly different between the 2 groups after adjustment for age and AT content or distribution. Full-length leptin receptor messenger RNA was expressed in the lymphocytes of the PWS group. Differences in RMR in women with PWS are explained by abnormal body composition, suggesting that energy expenditure is normal at the tissue level in PWS. There is no evidence that defective leptin production causes obesity in PWS, and leptin receptor deficiency is not a primary consequence of the gene defects leading to leptin resistance.

2000 CDC Growth Charts for the United States: Methods and development

Article

Full-text available

Jun 2002

This report provides detailed information on how the 2000 Centers for Disease Control and Prevention (CDC) growth charts for the United States were developed, expanding upon the report that accompanied the initial release of the charts in 2000. The growth charts were developed with data from five national health examination surveys and limited supplemental data. Smoothed percentile curves were developed in two stages. In the first stage, selected empirical percentiles were smoothed with a variety of parametric and nonparametric procedures. In the second stage, parameters were created to obtain the final curves, additional percentiles and z-scores. The revised charts were evaluated using statistical and graphical measures. The 1977 National Center for Health Statistics (NCHS) growth charts were revised for infants (birth to 36 months) and older children (2 to 20 years). New body mass index-for-age (BMI-for-age) charts were created. Use of national data improved the transition from the infant charts to those for older children. The evaluation of the charts found no large or systematic differences between the smoothed percentiles and the empirical data. The 2000 CDC growth charts were developed with improved data and statistical procedures. Health care providers now have an instrument for growth screening that better represents the racial-ethnic diversity and combination of breast- and formula-feeding in the United States. It is recommended that these charts replace the 1977 NCHS charts when assessing the size and growth patterns of infants, children, and adolescents.

Growth hormone therapy in the Prader-Willi syndrome

Article

Full-text available

May 2003
Arch Dis Child

Who should receive it and when? In November 2000 the Department of Health in England granted a licence to Pharmacia Limited for the use of their recombinant growth hormone, Genotropin (somatropin rbe), in the Prader-Willi syndrome. The indications for use were given as “improvement of body composition and growth”. In this leading article we shall attempt to examine the role of growth hormone in the Prader-Willi syndrome by considering linear growth and body composition in untreated and treated individuals, the pathophysiology of the abnormal linear growth, and the scope for future research. While the growth and body composition aspects of the Prader-Willi syndrome are important, they must be seen in the context of a disabling disorder with major implications for the individual and family.1 Therefore a brief account of the condition is in order. The Prader-Willi syndrome results from loss of an imprinted gene or genes on the long arm of chromosome 15 within the q11–13 region, usually as a result of a deletion on the paternal chromosome or less commonly to inheritance of both chromosomes from the mother—maternal disomy.2 The gene(s) presumably encode(s) a protein or proteins important for brain development, loss of which leads to a generalised brain disorder which affects the hypothalamus in particular.3 Indeed, many of the characteristic traits of the syndrome, such as hyperphagia, somnolence, skin picking, and hypogonadism, are attributable to hypothalamic dysfunction. Severe hypotonia and weakness cause reduced fetal movements, poor feeding from birth, usually requiring tube feeding, weak or absent cry, and inertia during infancy, with developmental delay and failure to thrive. Tone and movement improve towards the end of the first year and developmental milestones are achieved, albeit delayed. By 2 or 3 years of age the hyperphagic phase of the condition begins, and unless diet is strictly …

Death in adults with Prader-Willi syndrome may be correlated with maternal uniparental disomy

Article

Full-text available

Jun 2003
J MED GENET

Prader-Willi syndrome (PWS) is a disorder comprising severe neonatal hypotonia, hypogonadism, gross obesity, short stature, small hands and feet, mental handicap, a characteristic facial appearance (almond shaped eyes, thin downturned upper lip, and a narrow bitemporal diameter), nasal, inarticulate speech, and a particular personality profile.1,2 Prader-Willi syndrome has a biphasic course. Initially there is severe neonatal hypotonia, difficulty in feeding, and failure to thrive, usually persisting for 12 months. This is followed by weight gain, and if unchecked obesity is well developed by 6 years of age.1,2 The gain in weight is primarily attributable to a hypothalamic defect resulting in an insatiable appetite and hyperphagia,3,4 but a lowered metabolic rate and lack of exercise owing to continuing hypotonia contribute.5 The patients have a food obsession with a rather specific food related behavioural phenotype, which includes foraging for food, stealing food, and eating inedibles.1,3 The clinical diagnosis of PWS can now be confirmed by accurate genetic testing. Methylation testing makes a definitive diagnosis in about 99% of patients, but will not define the genetic mechanism. Further simple DNA studies of the chromosome 15 (q11-q13) region will do this. These include fluorescence in situ hybridisation (FISH) to check for deletion and DNA polymorphisms for maternal uniparental disomy (UPD).6 A patient with a positive methylation result who is non-deleted and non-disomic has an imprinting defect (ID).7 The commonest genetic mechanism is paternal deletion of the imprinted region (about 75% of patients), followed by UPD in 24% and about 1% have an ID for this region.6,7 ### Key points

Minimum prevalence, birth incidence and cause of death for Prader-Willi Syndrome in Flanders

Article

Full-text available

Apr 2004

The identification of all people with a diagnosis of Prader-Willi syndrome (PWS) confirmed by DNA methylation analysis living in Flanders was attempted through contact with the four genetic centres and the PWS Association. The birth incidence for the period 1993-2001 was 1:26 676, the minimum prevalence at 31 December 2001 was 1:76 574. A decreasing number of cases with age was found, which can be explained by a number of missing cases in the older population, a higher neonatal mortality in the past and an increasing mortality with age. Childhood death is usually sudden and associated with respiratory infection and high temperature, while the cause of death in adults is considered to be circulatory or respiratory in origin.

Prader-Willi syndrome: Advances in genetics, pathophysiology and treatment

Article

Jan 2004

Anthony P Goldstone

Management of Prader-Willi syndrome

Article

Jan 2006

Growth Hormone and Prader-Willi Syndrome

Chapter

Jan 2006

In the previous edition of this textbook, various lines of evidence for the occurrence of a defi ciency in the growth hormone (GH) axis were reviewed as one of several sections in a chapter entitled "Endocrine and Metabolic Aspects of Prader-Willi Syndrome."76 At that time, it was suggested that GH therapy may have benefi cial effects on growth and body composition in individuals with PWS. Over the succeeding decade, a number of scientifi c investigations have provided defi nitive evidence in support of these suggestions.16,37,72,73 In 2000, biosynthetic GH became the fi rst and, to date, only medication to receive regulatory approval for treatment of children with PWS. In addition, it appears that GH may also have potential utility in adults with PWS.61,86 This chapter presents a comprehensive review of relevant physiology and pathophysiology of the GH system and GH treatment effi cacy and safety in PWS.

Molecular Genetic Findings in Prader-Willi Syndrome

Chapter

Jan 2006

Prader-Willi syndrome (PWS), the most common genetic cause of marked obesity in humans,17 is due to loss of expression of paternal genes from the 15q11-q13 region under the control of an imprinting center. PWS and Angelman syndrome, an entirely different clinical condition due to lack of maternally expressed genes, were the first examples in humans of genomic imprinting. There are three recognized genetic subtypes in PWS, including paternally derived interstitial deletions of the 15q11-q13 region, maternal uniparental disomy 15 (both 15 s from the mother), and imprinting defects.

Clinical Findings and Natural History of Prader-Willi Syndrome

Chapter

Jan 2006

Management of Prader-Willi Syndrome

Chapter

Jan 2006

Endocrine Dysfunction in Prader-Willi Syndrome: A Review with Special Reference to GH

Article

Dec 2001

Pia Burman

Analysis of Survival Data

Article

Jun 1986

Introduction. Survival distributions. Single sample nonparametric methods. Dependence on explanatory variables. Model formulation. The multiplicative log-linear hazards model. Partial likelihood. Several types of failure. Further problems. Exercises. Bibliography. Index.

Analysis Of Survival Data

Article

Jun 1985

Prader-Willi syndrome

Article

Nov 1997
J MED GENET

S.B. Cassidy

Prader-Willi syndrome is a complex disorder affecting multiple systems with many manifestations relating to hypothalamic insufficiency. Major findings include infantile hypotonia, developmental delay and mental retardation, behaviour disorder, characteristic facial appearance, obesity, hypogonadism, and short stature. Obesity and the behavioural problems are the major causes of morbidity and mortality. Prader-Willi syndrome is caused by abnormalities of the imprinted region of proximal 15q and results from absence of the normally active paternal genes in this region. Such absence results from paternal interstitial deletion, maternal uniparental disomy, or a mutation or other abnormality in the imprinting process. Diagnostic identification of all causes has become available in recent years, permitting early detection and institution of appropriate management. This testing has permitted recent identification of some phenotypic differences among affected subjects of different race and between those with deletions and uniparental disomy as a cause.

Growth hormone therapy improves body composition in adults with Prader-Willi syndrome: A preliminary report

Article

Apr 2000
GROWTH HORM IGF RES

Non Parametric Estimation From Incomplete Observation

Article

Nov 1957
J AM STAT ASSOC

Growth hormone and body composition in children younger than 2 years with Prader-Willi syndrome*1

Article

Jun 2004
J Pediatr

OBJECTIVES: To assess body composition of infants with Prader-Willi syndrome (PWS) by using deuterium dilution and investigating the efficacy of early institution of growth hormone (GH) therapy in increasing lean mass (LM) and preventing massive obesity. STUDY DESIGN: One group of 11 children with PWS <2 years before and during 30-month GH therapy (GH group) was compared with 6 infants administered only coenzyme Q(10) for 1 year (Q10 group). LM adjusted for height (LM(Ht)) and relative fat mass (%FM(Age)) standard deviation scores (SDS) were calculated from data of 95 healthy children. RESULTS: Initially, LM(Ht) of all patients was below the normal average. LM(Ht) decreased by -0.46 +/- 0.3 SD (P=.03) per year in the Q10 group but rose by 0.25 +/- 0.3 SD (P=.02) per year during GH therapy, normalizing after 30 months (-0.70 +/- 1.0 SD). Despite low to normal weight for height (WfH), %FM(Age) was above the normal average (GH group, 31.0% +/- 4.5%, Q10 group, 32.4% +/- 9.5%). In the Q10 infants, %FM(Age) increased by 0.71 +/- 0.7 SD per year, whereas in the GH group, %FM(Age) remained more stable up to 30 months. CONCLUSIONS: Diminished LM(Ht) found in infants with PWS further declines during the early years. Early institution of GH therapy lifts LM(Ht) into the normal range and delays fat tissue accumulation.

Establishing a standard definition for child overweight and obesity worldwide: International survey

Article

May 2000

Tim J Cole

Objective To develop an internationally acceptable definition of child overweight and obesity, specifying the measurement, the reference population, and the age and sex specific cut off points. Design International survey of six large nationally representative cross sectional growth studies. Setting Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States Subjects 97 876 males and 94 851 females from birth to 25 years of age Main outcome measure Body mass index (weight/height2). Results For each of the surveys, centile curves were drawn that at age 18 years passed through the widely used cut off points of 25 and 30 kg/m2 for adult overweight and obesity. The resulting curves were averaged to provide age and sex specific cut off points from 2-18 years. Conclusions The proposed cut off points, which are less arbitrary and more internationally based than current alternatives, should help to provide internationally comparable prevalence rates of overweight and obesity in children.

Nonparametric Estimation From Incomplete Observations

Article

Jun 1958

In lifetesting, medical follow-up, and other fields the observation of the time of occurrence of the event of interest (called a death) may be prevented for some of the items of the sample by the previous occurrence of some other event (called a loss). Losses may be either accidental or controlled, the latter resulting from a decision to terminate certain observations. In either case it is usually assumed in this paper that the lifetime (age at death) is independent of the potential loss time; in practice this assumption deserves careful scrutiny. Despite the resulting incompleteness of the data, it is desired to estimate the proportion P(t) of items in the population whose lifetimes would exceed t (in the absence of such losses), without making any assumption about the form of the function P(t). The observation for each item of a suitable initial event, marking the beginning of its lifetime, is presupposed. For random samples of size N the product-limit (PL) estimate can be defined as follows: List and label the N observed lifetimes (whether to death or loss) in order of increasing magnitude, so that one has $0 \leqslant t_1^\prime \leqslant t_2^\prime \leqslant \cdots \leqslant t_N^\prime .$ Then $\hat P\left( t \right) = \Pi r\left[ {\left( {N - r} \right)/\left( {N - r + 1} \right)} \right]$, where r assumes those values for which $t_r^\prime \leqslant t$ and for which $t_r^\prime$ measures the time to death. This estimate is the distribution, unrestricted as to form, which maximizes the likelihood of the observations. Other estimates that are discussed are the actuarial estimates (which are also products, but with the number of factors usually reduced by grouping); and reduced-sample (RS) estimates, which require that losses not be accidental, so that the limits of observation (potential loss times) are known even for those items whose deaths are observed. When no losses occur at ages less than t the estimate of P(t) in all cases reduces to the usual binomial estimate, namely, the observed proportion of survivors.

Prader-Willi syndrome in a Swedish rural county: Epidemiological aspects

Article

Sep 1991

The total population under 25 years of age in one rural county in Sweden was screened in an attempt to find all cases of Prader‐Willi syndrome and to establish prevalence rates for the disorder. 11 clear and five suspect cases were found. For the seven‐ to 25‐year‐old age‐group the prevalence was 13 per 100,000 for clear cases only, but 20 per 100,000 if borderline cases were included. There was a slight over‐representation of males, but it was possible that this was a result of under‐representation of females in the very young age‐groups, in whom hypogonadism may be difficult to diagnose. RÉSUMÉ Syndrome de Prader‐ Willi dans un comté rural suédois: aspects épidémiologiques La population totale de moins de 25 ans dans un comté rural a étéétudié dans le but de détecter tous les cas de syndrome de Prader‐Willi et d'établir les taux de prévalence du trouble. 11 cas indiscutables et cinq cas douteux ont été trouvés. Pour le groupe d'âge de sept à 25 ans la prévalence a été de 13 cas indiscutables pour 100 000, et de 20 pour 100 000 si les cas suspects étaient inclus. II y avait une légère sur‐représentation masculine, et ceci pourrait être liéà une sousreprésentation des filles dans le groupe d'âge des plus jeunes, chez qui l'hypogonadisme peut être difficile à diagnostiquer. ZUSAMMENFASSUNG Prader‐ Willi Syndrom in einem schwedischen Landbezirk: epidemiologische Aspekte In einem Landbezirk wurde die Gesamtbevölkerung unter 25 Jahren mit dem Ziel untersucht, alle Fälle mit Prader‐Willi Syndrom herauszufinden und die Häufigkeit dieser Erkrankung festzustellen. 11 eindeutige unf fünf verdächtige Fälle wurden gefunden. Für die Gruppe der sieben‐ bis 25‐jährigen betrug die Häufigkeit nur 13/100,000 für eindeutige Fälle, aber 20/100,000 wenn Grenzfälle mit berücksichtigt wurden. Die Zahl der männlichen Patienten war etwas höher, was möglicherweise mit einer zu geringen Zahl weiblicher Patienten in den sehr jungen Altersgrupen zusammenhängt, bei denen ein Hypogonadismus schwer zu diagnostizieren sein kann. RESUMEN Síndrome de Prader‐Willi en un condado rural de Suecia:aspectos epidemiológicos La población total por debajo de 25 años en un condado rural fue estudiada con la intención de hallar todos los casos de síndrome de Prader‐Willi y establecer las relaciones de prevalencia para esta alteración. Se hallaron 11 casos claros y otros cinco sospechosos. Para el grupo de edad entre los siete y 25 años la prevalencia fue de 13 por 100,000 sólo para los casos claros si se incluian los casos borderline. Había una ligera prevalencia de varones, y se especuló si esto era el resultado de una baja representación de hembras en los grupos muy jóvenes, en los que es difícil diagnosticar un hipogonadismo.

Prevalence study of Prader-Willi syndrome in North Dakota

Article

Sep 1990

A prevalence study of Prader-Willi syndrome (PWS) has been conducted in North Dakota. All pediatricians, neurologists, child psychiatrists, psychologists, and clinical geneticists were surveyed. The state's comprehensive evaluation center, the state hospital, the state institution for the mentally retarded, and group homes for the developmentally disabled, including one for persons with PWS, were also contacted. Seventeen patients were identified, 8 males, 8 females, and one patient whose sex was not specified. This suggests a prevalence rate of 1 per 16,062 in North Dakota.

Nonreciprocal and jumping translocations of 15q1→qter in Prader-Willi syndrome

Article

Nov 1990

We analyzed 33 cases of Prader-Willi syndrome (PWS) (including 2 personal observations) with translocations of 15q1----qter onto the terminals of different, apparently whole chromosomes. In all but one of the 23 informative cases the translocations was de novo. Thirty of the patients were unbalanced and 27 had a 45-chromosome constitution compatible with a 3:1 segregation. One balanced and 2 unbalanced translocations were jumping ones. The possible existence of actual non-reciprocal translocations in man is indicated by the following considerations about these and other PWS-associated rearrangements: 1) The observed excess of de novo translocations; 2) the relatively frequent familial occurrence of reciprocal 15q translocations; 3) the concurrence in 3 terminal translocation cases of an idic (15); 4) the visualization of jumping terminal translocations as simple transpositions rather than as successive reciprocal exchanges; 5) the predominance of true isodicentrics in PWS patients with extra inv dup(15) chromosomes; and 6) the rarity of extra derivatives resulting in 15q proximal tertiary trisomy. Additional findings in the present series were normal parental age in the de novo 45-chromosome cases, an apparently random distribution of telomeric breakpoints, and the occurrence of different breakpoints within the 15q1 region.

Frequency of the Prader-Willi syndrome in the San-in district, Japan

Article

Sep 1995
BRAIN DEV-JPN

Nineteen cases of the Prader-Willi syndrome were collected in the San-in district, in the western part of Japan, and an epidemiological study was carried out. The male to female ratio was 1:1.11. Deletion of chromosome 15q11-13 was found in seven of 16 patients examined by means of high-resolution chromosome banding. The incidence among live-births was estimated to be 6.64 x 10(-5) (1 in 15,060 live-births) in 1980-1989, and the mutation rate was 3.32 x 10(-5) per gene per generation, as determined by a direct method. The prevalence was estimated to be 5.72 x 10(-5) (1 in 17,483) in patients under 15 years old, which was higher than that in other autosomal dominant diseases (tuberous sclerosis and congenital myotonic dystrophy) also studied in the San-in district. A birth-order effect was revealed and a slightly significant difference was found as to the fathers' age between the patients and their normal siblings. The results of these two tests are in accord with the recent discovery that this syndrome is caused by paternal chromosomal aberrations.

Prader-Willi Syndrome

Article

Dec 1997

Brenda Cassidy

Reference values for height and weight in Prader-Willi syndrome based on 315 patients

Article

Sep 1998

The spontaneous growth of 315 patients (109 girls and 208 boys) with Prader-Willi syndrome (PWS) was analysed in a mixed longitudinal and cross-sectional manner. 33 patients were seen in the department between 1970 and 1994; height and weight of 76 patients from Germany were evaluated by means of a questionnaire with detailed measuring instructions, and 206 definite cases were added from the literature. Mean (±SD) length of newborn babies with PWS was 50.2 ± 2.8 cm (145 boys) and 48.9 ± 3.3 cm (79 girls). Mean weight at birth was 2945 ± 570 g in boys and 2782 ± 594 g in girls. During the 1st year, the children's growth was nearly normal, thereafter short stature was present in approximately 50% of PWS patients. Between 3 and 13 years of age, the 50th percentile for height in PWS is roughly identical with the 3rd percentile in healthy controls. Body weight was normal for all boys and girls during the first 2 years. Thereafter, a rapid weight gain occurred; after an age of 10 years weight-for-height index in nearly all patients exceeded the normal range. The extent of pubertal growth was reduced for the group. Mean adult height was 161.6 ± 8.1 cm (23 males) and 150.2 ± 5.5 cm (21 females). Head circumference for age was normal for boys and girls. Conclusion Reference data on spontaneous development of growth and weight gain of children with Prader-Willi syndrome are described allowing a better counselling of patients and parents.

Growth hormone improves body composition, fat utilization, physical strength and agility, and growth in Prader-Willi syndrome: A controlled study

Article

Mar 1999
J Pediatr

Obesity and hypotonia in children with Prader-Willi syndrome (PWS) are accompanied by abnormal body composition and diminished energy expenditure resembling a growth hormone deficient state. Hypothalamic dysfunction in PWS often includes decreased growth hormone (GH) secretion, suggesting a possible therapeutic role for exogenous GH treatment. After 6 months of observation to determine baseline growth rate, and with the use of a 12-month randomized controlled study design, the effects of GH treatment (1 mg/m2/d) on growth, body composition, strength and agility, pulmonary function, resting energy expenditure (REE), and fat utilization were assessed in 54 children with PWS (n = 35 treatment and n = 19 control). Percent body fat and bone mineral density were measured by dual x-ray absorptiometry. Indirect calorimetry was used to determine REE and to calculate respiratory quotients. Stimulated levels of GH in response to clonidine testing were low in all patients (peak, 2.0 ng/mL). After 12 months, GH-treated subjects showed significantly increased height velocity Z scores (mean, 1.0 1.7 to 4.6 2.9; P <.001), decreased percent body fat (mean, 46.3% 8.4% to 38.3% 10.7%; P <.001), and improved respiratory muscle function, physical strength, and agility (sit-ups, weight-lifts, running speed, and coordination). A significant decline in respiratory quotients occurred during GH therapy (0.81 to 0.77, P <.001), but total REE did not change. GH treatment of children with PWS accelerated growth, decreased percent body fat, and increased fat oxidation but did not significantly increase total REE. Improvements in respiratory muscle strength, physical strength, and agility also occurred, suggesting that GH treatment may have value in reducing some physical disabilities experienced by children with PWS.

Sustained Benefit After 2 Years Of Growth Hormone On Body Composition, Fat Utilization, Physical Strength And Agility, And Growth In Prader-Willi Syndrome

Article

Aug 2000
J Pediatr

Obesity and hypotonia in children with Prader-Willi syndrome (PWS) are accompanied by abnormal body composition resembling a growth hormone (GH)-deficient state. Hypothalamic dysfunction in PWS includes decreased GH secretion, suggesting a possible therapeutic role for GH treatment. Although recent studies have demonstrated short-term benefits of treatment with GH, a critical question is whether beneficial changes persist or wane with prolonged therapy. Effects of 24 months of GH treatment (1 mg/m(2)/d) on growth, body composition, strength and agility, pulmonary function, resting energy expenditure, and fat utilization were assessed in 35 children with PWS. Percent body fat, lean muscle mass, and bone mineral density were measured by dual-energy x-ray absorptiometry. Indirect calorimetry was used to determine resting energy expenditure and to calculate the respiratory quotient. Compared with baseline evaluations, increased height velocity (SD score -1.1 +/- 2.5 to 2.2 +/- 2.3; P <. 001), reduced percent body fat (46.4% +/- 8.4% to 40.3% +/- 10.0%, P <.001), and improved respiratory muscle function and physical strength and agility (sit-ups, weight-lifts, running speed, and broad jump; P <.01) were observed after 24 months of GH treatment. A decline in respiratory quotient (0.81 +/- 0.07 to 0.75 +/- 0.06; P <. 01) and a trend toward increased resting energy expenditure were also observed. Changes in response to GH occurred predominantly during the initial 12 months of GH therapy. Children with PWS had sustained increases in lean body mass, decreases in percent body fat, improvements in physical strength and agility, and increased fat oxidation after 24 months of GH therapy. However, between 12 and 24 months, the growth rate slowed. Consequently, encouraging initial results require even more prolonged study to draw conclusions regarding the long-term value of GH therapy in changing body composition in children with PWS.

Adult patients with Prader-Willi syndrome: Clinical characteristics, life circumstances and growth hormone secretion

Article

May 2000
GROWTH HORM IGF RES

Prader-Willi syndrome is characterized by a typical clinical phenotype and by a complex genetic basis that includes large deletions, uniparental disomy and imprinting mutations of chromosome region 15q11-q13. This report delineates the clinical characteristics, morbidity and growth hormone secretory status of 19 adults with Prader-Willi syndrome. The patients were 18-34 years of age. Morbidity included marked obesity with body mass index in excess of 30 kg/m2 (grade 1-3 according to WHO), metabolic diseases, sleep apnoea and lipolymphoedema. Severe growth hormone deficiency (GHD) was seen in 38% of the patients, and levels of insulin-like growth factor I were decreased in 87%. Thus, GHD is seen, not only in children with Prader-Willi syndrome, but also in adults with the syndrome.

The Changing Purpose of Prader-Willi Syndrome Clinical Diagnostic Criteria and Proposed Revised Criteria

Article

Nov 2001
Pediatrics

Background: Prader-Willi syndrome (PWS) is a complex, multisystem disorder. Its major clinical features include neonatal hypotonia, developmental delay, short stature, behavioral abnormalities, childhood-onset obesity, hypothalamic hypogonadism, and characteristic appearance. The genetic basis of PWS is also complex. It is caused by absence of expression of the paternally active genes in the PWS critical region on 15q11-q13. In approximately 70% of cases this is the result of deletion of this region from the paternal chromosome 15. In approximately 28%, it is attributable to maternal uniparental disomy (UPD; inheritance of 2 copies of a chromosome from the mother and no copies from the father, as opposed to the normal 1 copy from each parent) of chromosome 15, and in <2%, it is the result of a mutation, deletion, or other defect in the imprinting center. Clinical diagnostic criteria were established by consensus in 1993. Subsequently, definitive molecular genetic testing became available for laboratory diagnosis of PWS. However, identification of appropriate patients for testing remains a challenge for most practitioners because many features of the disorder are nonspecific and others can be subtle or evolve over time. For example, hypotonic infants who are still in the failure to thrive phase of the disorder often do not have sufficient features for recognition of PWS and often are not tested. Initial screening with these diagnostic criteria can increase the yield of molecular testing for older children and adults with nonspecific obesity and mental retardation. Therefore, the purpose of clinical diagnostic criteria has shifted from assisting in making the definitive diagnosis to raising diagnostic suspicion, thereby prompting testing. We conducted a retrospective review of patients with PWS confirmed with genetic testing to assess the validity and sensitivity of clinical diagnostic criteria published before the widespread availability of testing for all affected patients and recommend revised clinical criteria. Methods: Charts of all 90 patients with laboratory-confirmed PWS were reviewed. For each patient, the presence or absence of the major, minor, and supportive features listed in the published diagnostic criteria was recorded. The sensitivity of each criterion, mean of the total number of major and minor criteria, and mean total score for each patient were calculated. Results: There were 68 patients with a deletion (del 15q11-q13), 21 with maternal UPD of chromosome 15, and 1 with a presumed imprinting defect. Age range at the time of the most recent evaluation was 5 months to 60 years (median: 14.5 years; del median: 14 years; range: 5 months-60 years; UPD median: 18 years; range: 5-42 years). The sensitivities of the major criteria ranged from 49% (characteristic facial features) to 98% (developmental delay). Global developmental delay and neonatal hypotonia were the 2 most consistently positive major criteria and were positive in >97% of the patients. Feeding problems in infancy, excessive weight gain after 1 year, hypogonadism, and hyperphagia were all present in 93% or more of patients. Sensitivities of the minor criteria ranged form 37% (sleep disturbance and apneas) to 93% (speech and articulation defects). Interestingly, the sensitivities of 8 of the minor criteria were higher than the sensitivity of characteristic facial features, which is a major criterion. Fifteen out of 90 patients with molecular diagnosis did not meet the clinical diagnostic criteria retrospectively. Conclusion: When definitive diagnostic testing is not available, as was the case for PWS when the 1993 criteria were developed, diagnostic criteria are important to avoid overdiagnosis and to ensure that diagnostic test development is performed on appropriate samples. When diagnostic testing is available, as is now the case for PWS, diagnostic criteria should serve to raise diagnostic suspicion, ensure that all appropriate people are tested, and avoid the expense of testing unnecessarily. Our results indicate that the sensitivities of most of the published criteria are acceptable. However, 16.7% of patients with molecular diagnosis did not meet the 1993 clinical diagnostic criteria retrospectively, suggesting that the published criteria may be too exclusive. A less strict scoring system may ensure that all appropriate people are tested. Accordingly, we suggest revised clinical criteria to help identify the appropriate patients for DNA testing for PWS. The suggested age groupings are based on characteristic phases of the natural history of PWS. Some of the features (eg, neonatal hypotonia, feeding problems in infancy) serve to diagnose the syndrome in the first few years of life, whereas others (eg, excessive eating) are useful during early childhood. Similarly, hypogonadism is most useful during and after adolescence. Some of the features like neonatal hypotonia and infantile feeding problems are less likely to be missed, whereas others such as characteristic facial features and hypogonadism (especially in prepubertal females) may require more careful and/or expert examination. The issue of who should have diagnostic testing is distinct from the determination of features among confirmed patients. Based on the sensitivities of the published criteria and our experience, we suggest testing all newborns/infants with otherwise unexplained hypotonia with poor suck. For children between 2 and 6 years of age, we consider hypotonia with history of poor suck associated with global developmental delay sufficient criteria to prompt testing. Between 6 and 12 years of age, we suggest testing those with hypotonia (or history of hypotonia with poor suck), global developmental delay, and excessive eating with central obesity (if uncontrolled). At the ages of 13 years and above, we recommend testing patients with cognitive impairment, excessive eating with central obesity (if uncontrolled), and hypogonadotropic hypogonadism and/or typical behavior problems (including temper tantrums and obsessive-compulsive features). Thus, we propose a lower threshold to prompt diagnostic DNA testing, leading to a higher likelihood of diagnosis of this disorder in which anticipatory guidance and intervention can significantly influence outcome.

Angelman syndrome: a review of the clinical and genetic aspects

Article

Mar 2003
J MED GENET

Angelman syndrome (AS) is a neurodevelopmental disorder characterised by severe learning difficulties, ataxia, a seizure disorder with a characteristic EEG, subtle dysmorphic facial features, and a happy, sociable disposition. Most children present with delay in developmental milestones and slowing of head growth during the first year of life. In the majority of cases speech does not develop. Patients with AS have a characteristic behavioural phenotype with jerky movements, frequent and sometimes inappropriate laughter, a love of water, and sleep disorder. The facial features are subtle and include a wide, smiling mouth, prominent chin, and deep set eyes. It is caused by a variety of genetic abnormalities involving the chromosome 15q11-13 region, which is subject to genomic imprinting. These include maternal deletion, paternal uniparental disomy, imprinting defects, and point mutations or small deletions within the UBE3A gene, which lies within this region. UBE3A shows tissue specific imprinting, being expressed exclusively from the maternal allele in brain. The genetic mechanisms identified so far in AS are found in 85-90% of those with the clinical phenotype and all interfere with UBE3A expression.

Growth hormone treatment improves body composition in adults with Prader-Willi syndrome

Article

Jun 2003

Low growth hormone (GH) secretion and hypogonadism are common in patients with Prader-Willi syndrome (PWS). In this study we present the effects of GH treatment on body composition and metabolism in adults with PWS. Nineteen patients with clinical PWS were recruited, 13 had PWS genotype. They were randomised to treatment with placebo or GH (Genotropin, Pharmacia Corporation, Sweden) 0.8 IU (0.2 mg) daily for 1 month and then 1.6 IU (0.5 mg) daily for 5 months. Thereafter patients received open label treatment so that all had 12 months of active GH treatment. Doses were individually titrated to keep serum IGF-I within the normal range for age. Body composition using dual energy X-ray absorptiometry (DXA), metabolic and endocrinological parameters, including oral glucose tolerance test (OGTT), were studied every 6 months. Seventeen patients, nine men and eight women, 17-32 years of age, with a mean body mass index (BMI) of 35 +/- 3.2 kg/m2 completed the study. Compared to placebo, GH treatment increased IGF-I (P < 0.01) levels and decreased body fat (P = 0.04). When all patients recieved GH treatment a mean reduction in body fat of 2.5% (P < 0.01) concomitant with a mean increase in lean body mass of 2.2 kg (P < 0.05) was seen. Significant changes in body composition were only seen in the patients with the PWS genotype. Lipid profiles were normal in most patients before treatment and did not change. OGTT was impaired in five patients at 12 months, but two of these patients increased in fat mass. Insulin levels were unchanged. According to homeostasis model assessment (HOMA), insulin resistance did not change. Side-effects attributed to water retention occurred in three patients, one of whom had to be given increased diuretic therapy. This study shows beneficial effects of GH treatment on body composition in adult PWS patients without significant side-effects. Consequently, further studies are encouraged.

Goldstone, A. P. Prader-Willi syndrome: advances in genetics, pathophysiology and treatment. Trends Endocrinol. Metab. 15, 12-20

Article

Feb 2004
TRENDS ENDOCRIN MET

Anthony P Goldstone

Prader-Willi syndrome (PWS) is a complex human genetic disease that arises from lack of expression of paternally inherited imprinted genes on chromosome 15q11-q13. Identification of the imprinting control centre, novel imprinted genes and distinct phenotypes in PWS patients and mouse models has increased interest in this human obesity syndrome. In this review I focus on: (i) the chromosomal region and candidate genes associated with PWS, and the possible links with individual PWS phenotypes identified using mouse models; (ii) the metabolic and hormonal phenotypes in PWS; (iii) postmortem studies of human PWS hypothalami; and (iv) current and potential advances in the management of PWS and its complications. This could have benefits for a wide spectrum of endocrine, paediatric and neuropsychiatric diseases.

Unexpected Death and Critical Illness in Prader-Willi Syndrome: Report of Ten Individuals

Article

Jan 2004

Individuals with Prader-Willi syndrome (PWS) generally survive into adulthood. Common causes of death are obesity related cor pulmonale and respiratory failure. We report on a case series of eight children and two adults with unexpected death or critical illness. Our data show age-specific characteristics of PWS patients with fatal or life-threatening illnesses. Under the age of 2 years, childhood illnesses in general were associated with high fever and rapid demise or near-demise. Hypothalamic dysfunction likely plays a role in exaggerated fever response, but also perhaps in central regulation of adrenal function. Below average sized adrenal glands were found in three children, which raises the possibility of unrecognized adrenal insufficiency in a subset of individuals with PWS and emphasizes the vital role of autopsy. The tub drowning death of an adult patient could be related to central hypersomnia, which has been reported in PWS. We suggest that increased risk for critical illness be considered in the discussion of anticipatory guidance for the care of infants with PWS. Since a number of children died while hospitalized, particularly close observation of PWS children who are ill enough to warrant hospital admission is recommended.

Endocrine and metabolic aspects of adult Prader-Willi syndrome with special emhapsis on the effect of growth hormone treatment

Article

Mar 2004
GROWTH HORM IGF RES

Charlotte Höybye

Prader-Willi syndrome (PWS) is a genetic disorder characterized by mild mental retardation, short stature, abnormal body composition, muscular hypotonia and distinctive behavioural features. Excessive eating causes progressive obesity with increased cardiovascular morbidity and mortality. In the PWS genotype loss of one or more normally active paternal genes in region q11-13 on chromosome 15 is seen. It is supposed that the genetic alteration leads to dysfunction of several hypothalamic centres and growth hormone (GH) deficiency (GHD) is common. PWS is well described in children, in whom GH treatment improves body composition, linear growth, physical strength and agility. Few studies have focused on adults. We examined a cohort of 19 young adults with clinical PWS (13 with positive genotype) and mean BMI of 35 kg/m2. At baseline the activity of the GH-insulin-like growth factor-I (IGF-I) system was impaired with low GH values, low total IGF-I and in relation to the obesity low levels of free IGF-I and non-suppressed IGF-binding-protein-1 (IGFBP-1). 2/3 were hypogonadal. Bone mineral density (BMD) was low. Four patients had impaired glucose tolerance and nine patients high homeostasis model assessment (HOMA) index, indicating insulin resistance. Seven patients had a moderate dyslipidemia. The 13 patients with the PWS genotype were shorter and had significantly lower IGF-I. Seventeen (9 men and 8 women), subsequently completed a 12 months GH treatment trial, and GH had beneficial effects on body composition without significant adverse effects. The effects were more pronounced in the patients with the PWS genotype. Analysis of peptides involved in appetite regulation showed that leptin levels were high reflecting obesity and as a consequence NPY levels were low. In relation to the patients obesity circulating oxytocin levels were abnormally low and ghrelin levels abnormally high. Thus, oxytocin and ghrelin might be involved in the hyperphagia. NPY, leptin and ghrelin did not change during GH treatment. In conclusion this pilot study showed that adults with PWS have a partial GH deficiency, and GH treatment has beneficial effects on body composition in adult PWS without significant side-effects. Larger and longer term studies on the effect of GH replacement in adult PWS are encouraged.

Prader-Willi Syndrome: Causes of Death in an International Series of 27 Cases

Article

Feb 2004

Prader-Willi syndrome (PWS) is a complex condition with many medical and psychological features. In individuals with this syndrome, causes of death were studied. Data of 27 case reports were collected. Ages at death ranged from neonatal to 68 years. None of the individuals were treated with growth hormone (GH). Most cases were not completely documented and autopsy was performed in a minority of cases only. In five cases, death was considered not to be causally related to PWS. Hypotonia with hypoventilation was noted in the babies, and acute respiratory illness with unexpected sudden death was experienced in young children with PWS. Two young children died after a short period of fever and gastroenteritis. Obesity and its complications leading to death were pronounced in the adult group. One (possibly two) adult(s) died from gastric dilatation and shock. Based on these data, some cautious conclusions can be drawn. In babies with PWS hypoventilation is a risk factor; upper airway infection may be more serious than anticipated and any other clinical features pointing to an infection should be taken very seriously. Therefore, young infants with PWS hospitalized with an upper airway infection and/or hypoventilation or gastroenteritis symptoms, should be closely monitored. Early diagnosis and prevention of overweight is a major factor in preventing early causes of death in individuals with PWS. In the adult group, weight reduction is important but difficult to manage. Sleep apnea should be recognized and treated. Pain in the upper stomach and/or vomiting should be taken as a possible sign of acute intestinal dilatation; intravenous support may be life saving.

Growth hormone and body composition in children younger than 2 years with Prader-Willi syndrome

Article

Jun 2004
J Pediatr

To assess body composition of infants with Prader-Willi syndrome (PWS) by using deuterium dilution and investigating the efficacy of early institution of growth hormone (GH) therapy in increasing lean mass (LM) and preventing massive obesity. One group of 11 children with PWS <2 years before and during 30-month GH therapy (GH group) was compared with 6 infants administered only coenzyme Q(10) for 1 year (Q10 group). LM adjusted for height (LM(Ht)) and relative fat mass (%FM(Age)) standard deviation scores (SDS) were calculated from data of 95 healthy children. Initially, LM(Ht) of all patients was below the normal average. LM(Ht) decreased by -0.46 +/- 0.3 SD (P=.03) per year in the Q10 group but rose by 0.25 +/- 0.3 SD (P=.02) per year during GH therapy, normalizing after 30 months (-0.70 +/- 1.0 SD). Despite low to normal weight for height (WfH), %FM(Age) was above the normal average (GH group, 31.0% +/- 4.5%, Q10 group, 32.4% +/- 9.5%). In the Q10 infants, %FM(Age) increased by 0.71 +/- 0.7 SD per year, whereas in the GH group, %FM(Age) remained more stable up to 30 months. Diminished LM(Ht) found in infants with PWS further declines during the early years. Early institution of GH therapy lifts LM(Ht) into the normal range and delays fat tissue accumulation.

Prader-Willi Syndrome: The Care And Treatment of Infants, Children, and Adults

Article

Feb 2004
Adv Pediatr

William B Zipf

With appropriate intervention, the clinical course of children with PWS can be changed for the better. Individuals who have had the benefit of early diagnosis and treatment will have more normal (although generally still excessive) weight, less severe short stature, less persistent hypotonia, and significantly improved mobility and activity than would otherwise be possible. With proper care, the behavior problems, while significant, are manageable. The expected lifespan of individuals with PWS who have received anticipatory care and appropriate attention to medical problems has yet to be determined but can be beyond 30 to 40 years and can be associated with an absence of the related major comorbidities and a markedly improved quality of life.

Growth hormone therapy for Prader-Willi syndrome: A critical appraisal

Article

Oct 2004

Prader-Willi syndrome (PWS) is characterized by hypothalamic dysfunction resulting in obesity, hypotonia, hypogonadism, and behavioral abnormalities. Clinical features of PWS resemble those of GH deficiency (decreased total lean body mass, IGF-I levels, and poor linear growth). Marked reductions in muscle mass are associated with diminished strength, physical function, and energy expenditure. Lifelong morbidities of PWS include osteoporosis, type 2 diabetes mellitus, respiratory disorders, and cardiorespiratory failure related to obesity and hypotonia. Recent studies show that GH therapy improves linear growth, final height, physical strength, and agility in patients with PWS. Some effects of GH therapy wane with time, however, and strategies for treating adults with PWS remain uncertain. In addition, deaths in markedly obese, GH-treated children with PWS have been reported, and a possible contribution of GH to these events has not yet been definitively excluded. Consequently, critical evaluation should continue of the long-term benefits, risks, and costs of GH therapy for patients with PWS.

A Comprehensive Team Approach to the Management of Patients with Prader-Willi Syndrome

Article

Oct 2004

Prader-Willi syndrome (PWS) is a genetic disorder characterized by extreme obesity accompanied by other, multisystem clinical manifestations encompassing both physical and behavioral/cognitive abnormalities. The multi-dimensional problems of patients with PWS cannot be treated with a single intervention and benefit from a team approach to management to optimize outcomes. Childhood stature below target height and reduced final height are some defining characteristics of PWS, and compelling evidence from growth hormone (GH) treatment trials suggests that hypothalamic GH deficiency exists. Treatment with GH has been shown to increase height velocity in children with PWS, decrease weight-for-height index values and body fat mass, and have a positive effect on lean body mass during at least the first year of therapy. In addition to medical concerns, the behavioral manifestations, including an uncorrectable deficit in appetite control, and cognitive limitations associated with PWS, require long-term multidisciplinary management.

The Italian National Survey for Prader-Willi syndrome: An Epidemiologic Study

Abstract

No full-text available

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