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Congenital Generalized Lipodystrophy
Abstract and Figures
Congenital Generalized Lipodystrophy (CGL) is a rare and severe autosomal recessive disease. Patients are defective in the storage of body fat and, consequently, they deposit fat in ectopic tissues, mainly liver, and can develop cirrhosis. Insulin resistance is a typical finding, causing diabetes that require high daily doses of insulin. In the state of Rio Grande do Norte, Brazil, we have one of the largest cohorts of patients with CGL. In this article, we review pathophysiology, clinical picture and treatment of this disease.
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... CGL4, first described in 2009 (20), is due to mutations in the polymerase I and transcript release factor (PTRF) gene located on chromosome 17q21.2 (21). PTRF gene encodes a cytoplasmatic protein called caveolae-associated protein 1 (Cavin-1), which, together with caveolin 1, is responsible for the biogenesis of caveolae and co-localizes in the adipocytes (22,23), being a master regulator of cell differentiation and adipose tissue expandability (24). ...
... Common findings in CGL4 subjects are the following: a progressive loss of adipose tissue during infancy, emaciated face due to the absence of Bichat fat pads, acromegalic features (mainly face, hands, and feet), prominent superficial subcutaneous veins (pseudoflebomegaly), accelerated growth, umbilical hernia, hirsutism, clitoromegaly and amenorrhea, osteopenia and distal metaphyseal deformation with joint stiffness, pyloric stenosis, atlantoaxial instability, and percussion-induced muscle mounding (2,8,25). Patients display lack of the subcutaneous adipose tissue, while the mechanical adipose tissue (primary in the retro-orbital region and in small amounts in the buccal, masticator, para-pharyngeal, infrapatellar, and popliteal regions) and bone marrow fat are preserved (21,26,27). Regarding their metabolic profile, subjects may present with hypertriglyceridemia, hepatomegaly and hepatic steatosis, hyperinsulinemia, and insulin resistance, although clear evidence of type 2 diabetes has not been described (1,11,19,28). ...
... Apart from the bone, CGL4 importantly affects skeletal, cardiac, and gastrointestinal muscles (21,23). Bioptic, electron microscopy, and US studies have shown chronic dystrophic changes, including marked variation in muscle fiber size, internal nucleation, a few necrotic and regenerating fibers, increased interstitial fibrosis with reduced caveolae formation, and accumulation of lipid droplets (20,29,(39)(40)(41). ...
Lipodystrophy syndromes are characterized by a progressive metabolic impairment secondary to adipose tissue dysfunction and may have a genetic background. Congenital generalized lipodystrophy type 4 (CGL4) is an extremely rare subtype, caused by mutations in the polymerase I and transcript release factor ( PTRF ) gene. It encodes for a cytoplasmatic protein called caveolae-associated protein 1 (Cavin-1), which, together with caveolin 1, is responsible for the biogenesis of caveolae, being a master regulator of adipose tissue expandability. Cavin-1 is expressed in several tissues, including muscles, thus resulting, when dysfunctional, in a clinical phenotype characterized by the absence of adipose tissue and muscular dystrophy. We herein describe the clinical phenotypes of two siblings in their early childhood, with a phenotype characterized by a generalized reduction of subcutaneous fat, muscular hypertrophy, distinct facial features, myopathy, and atlantoaxial instability. One of the siblings developed paroxysmal supraventricular tachycardia leading to cardiac arrest at 3 months of age. Height and BMI were normal. Blood tests showed elevated CK, a mild increase in liver enzymes and triglycerides levels, and undetectable leptin and adiponectin concentrations. Fasting glucose and HbA1c were normal, while Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was mildly elevated. Both patients were hyperphagic and had cravings for foods rich in fats and sugars. Genetic testing revealed a novel pathogenic mutation of the CAVIN1 / PTRF gene (NM_012232 exon1:c T21A:p.Y7X) at the homozygous state. The diagnosis of lipodystrophy can be challenging, often requiring a multidisciplinary approach, given the pleiotropic effect, involving several tissues. The coexistence of generalized lack of fat, myopathy with elevated CK levels, arrhythmias, gastrointestinal dysmotility, and skeletal abnormalities should prompt the suspicion for the diagnosis of CGL4, although phenotypic variability may occur.
... CGL is characterized by the almost total absence of subcutaneous adipose tissue observed since birth or early childhood due to the inability of storing lipid in adipocytes. The extremely low adipose tissue is caused by mutations of genes responsible for adipocyte development [7]. Currently, the syndrome is described in four subtypes according to the corresponding mutations in four genes: AGPAT2, BSCL2, CAV1, and CAVIN 1 [7]. ...
... The extremely low adipose tissue is caused by mutations of genes responsible for adipocyte development [7]. Currently, the syndrome is described in four subtypes according to the corresponding mutations in four genes: AGPAT2, BSCL2, CAV1, and CAVIN 1 [7]. The first two types, associated with mutations in AGPAT2 and BSCL2, correspond to almost 95% of patients [5]. ...
... CGL patients, especially BSCL2 gene mutants, have a greatly reduced life expectancy. They evolve with severe metabolic disorders, non-alcoholic fatty liver disease, early cardiac abnormalities, and infectious complications, which can lead to death before the fourth decade of life [7,11]. ...
Congenital Generalized Lipodystrophy (CGL) is a rare syndrome characterized by the almost total absence of subcutaneous adipose tissue due to the inability of storing lipid in adipocytes. Patients present generalized lack of subcutaneous fat and normal to low weight. They evolve with severe metabolic disorders, non-alcoholic fatty liver disease, early cardiac abnormalities, and infectious complications. Although low body weight is a known risk factor for osteoporosis, it has been reported that type 1 and 2 CGL have a tendency of high bone mineral density (BMD). In this review, we discuss the role of bone marrow tissue, adipokines, and insulin resistance in the setting of the normal to high BMD of CGL patients. Data bases from Pubmed and LILACS were searched, and 113 articles published until 10 April 2021 were obtained. Of these, 76 were excluded for not covering the review topic. A manual search for additional literature was performed using the bibliographies of the studies located. The elucidation of the mechanisms responsible for the increase in BMD in this unique model of insulin resistance may contribute to the understanding of the interrelationships between bone, muscle, and adipose tissue in a pathophysiological and therapeutic perspective.
... Patients present intense insulin resistance, poorly controlled diabetes mellitus (around 45% diagnosed in pubertal years), and hypertriglyceridemia (21). Besides metabolic disorders, CGL patients develop liver disease, early cardiac abnormalities, and infectious complications, which result in greatly reduced life expectancy (24,25). ...
... CGL is categorized in four subtypes according to the affected gene (24). CGL subtype 1 (CGL1) and 2 (CGL2), associated with mutations in AGPAT2 and BSCL2, correspond to almost 95% of cases (21). ...
... The late CGL diagnosis is probably because of the rarity of this disease and because of the fact that, in males, classic lipodystrophic features, such as muscular hypertrophy, phlebomegaly, and acromegaloid facies, are less suspicious than in women. Therefore, health professionals should be aware about this condition to make an early diagnosis (24). The patient also had preserved mechanical adipose tissue in the hands and soles, suggestive of CGL 1, in which bone radiological findings (radiologically similar to "pagetic" lytic lesions) are more commonly found (21). ...
Paget’s disease of bone (PDB) is a common skeleton disorder in which the diagnosis is suggested by radiological analyses. Congenital generalized lipodystrophy (CGL) is a rare, but a radiologic differential diagnosis of Paget’s disease. Patients present total or almost total lack of subcutaneous adipose tissue, leptin deficiency, and precocious ectopic lipid accumulation, which lead to intense insulin resistance, poorly controlled diabetes mellitus, and hypertriglyceridemia. CGL subtypes 1 and 2 present sclerosis and osteolytic lesions that can resemble “pagetic” lesions. The clinical correlation is, therefore, essential. We report a CGL patient with bone lesions in which the radiographic findings led to a misdiagnosis of PDB. This case report brings awareness to CGL, a life-threating condition. Its early recognition is essential to avoid clinical complications and premature death. Therefore, it is important to consider CGL as PDB’s differential diagnosis, especially in countries with high prevalence of this rare disease, such as Brazil.
Congenital Generalized Lipodystrophy (CGL) is a rare autosomal recessive disease characterized by near complete absence of functional adipose tissue from birth. CGL diagnosis can be based on clinical data including acromegaloid features, acanthosis nigricans, reduction of total body fat, muscular hypertrophy, and protrusion of the umbilical scar. The identification and knowledge of CGL by the health care professionals is crucial once it is associated with severe and precocious cardiometabolic complications and poor outcome. Image processing by deep learning algorithms have been implemented in medicine and the application into routine clinical practice is feasible. Therefore, the aim of this study was to identify congenital generalized lipodystrophy phenotype using deep learning. A deep learning approach model using convolutional neural network was presented as a detailed experiment with evaluation steps undertaken to test the effectiveness. These experiments were based on CGL patient’s photography database. The dataset consists of two main categories (training and testing) and three subcategories containing photos of patients with CGL, individuals with malnutrition and eutrophic individuals with athletic build. A total of 337 images of individuals of different ages, children and adults were carefully chosen from internet open access database and photographic records of stored images of medical records of a reference center for inherited lipodystrophies. For validation, the dataset was partitioned into four parts, keeping the same proportion of the three subcategories in each part. The fourfold cross-validation technique was applied, using 75% (3 parts) of the data as training and 25% (1 part) as a test. Following the technique, four tests were performed, changing the parts that were used as training and testing until each part was used exactly once as validation data. As a result, a mean accuracy, sensitivity, and specificity were obtained with values of [90.85 ± 2.20%], [90.63 ± 3.53%] and [91.41 ± 1.10%], respectively. In conclusion, this study presented for the first time a deep learning model able to identify congenital generalized lipodystrophy phenotype with excellent accuracy, sensitivity and specificity, possibly being a strategic tool for detecting this disease.
Mutations in 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2) cause congenital generalized lipodystrophy. To understand the molecular mechanisms underlying the metabolic complications associated with AGPAT2 deficiency, Agpat2 null mice were generated. Agpat2(-/-) mice develop severe lipodystrophy affecting both white and brown adipose tissue, extreme insulin resistance, diabetes, and hepatic steatosis. The expression of lipogenic genes and rates of de novo fatty acid biosynthesis were increased approximately 4-fold in Agpat2(-/-) mouse livers. The mRNA and protein levels of monoacylglycerol acyltransferase isoform 1 were markedly increased in the livers of Agpat2(-/-) mice, suggesting that the alternative monoacylglycerol pathway for triglyceride biosynthesis is activated in the absence of AGPAT2. Feeding a fat-free diet reduced liver triglycerides by approximately 50% in Agpat2(-/-) mice. These observations suggest that both dietary fat and hepatic triglyceride biosynthesis via a monoacylglycerol pathway may contribute to hepatic steatosis in Agpat2(-/-) mice.
Background
Berardinelli-Seip Congenital Lipodystrophy (BSCL) is a rare disease characterized by the almost complete absence of adipose tissue. Although a large number of BSCL cases was previously identified in Rio Grande do Norte (RN), a state in Northeast Brazil, its prevalence in RN regions and municipalities remains unknown. The purpose of this study was to better characterize the prevalence of BSCL in RN.
Methods
A descriptive study was conducted using secondary data obtained from the Association of Parents and People with BSCL of RN to determine its prevalence. The patients’ socio-demographic characteristics and geolocalization were analyzed.
Results
We estimated a total of 103 BSCL cases in RN, resulting in a prevalence of 3.23 per 100,000 people. The Central Potiguar mesoregion, Seridó territory, Carnaúba dos Dantas and Timbaúba dos Batistas municipalities had a much higher prevalence of BSCL, with 20.56, 20.66, 498.05 and 217.85 per 100,000 people, respectively.
Conclusions
Together, our results showed that BSCL is highly prevalent in RN and confirmed that our state has one of the highest prevalences of this lipodystrophy worldwide. More studies are still needed to better estimate the prevalence and incidence of BSCL in RN as well as in other states in Brazil.
Trial registration Study Number 31809314.0.0000.5568
Background
Lipodystrophy (LD; non-human immunodeficiency virus [HIV]-associated) syndromes are a rare body of disorders for which true prevalence is unknown. Prevalence estimates of rare diseases are important to increase awareness and financial resources. Current qualitative and quantitative estimates of LD prevalence range from ~0.1 to 90 cases/million. We demonstrate an approach to quantitatively estimate LD prevalence (all, generalized, and partial) through a search of 5 electronic medical record (EMR) databases and 4 literature searches.
Methods
EMR and literature searches were conducted from 2012 to 2014. For the EMR database searches (Quintiles, IMS LifeLink, General Electric Healthcare, and Humedica EMR), LD cases were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 272.6 (United Kingdom General Practice Research Database used other diagnostic codes to identify LD) plus additional LD-associated clinical characteristics (patients with HIV or documented HIV treatment were excluded). Expert adjudication of cases was used for the Quintiles database only. Literature searches (PubMed and EMBASE) were conducted for each of the 4 major LD subtypes. Prevalence estimates were determined by extrapolating the total number of cases identified for each search to the database population (EMR search) and European population (literature search).
Results
The prevalence range of all LD across all EMR databases was 1.3–4.7 cases/million. For the adjudicated Quintiles search, the estimated prevalence of diagnosed LD was 3.07 cases/million (95% confidence interval [CI], 2.30–4.02), 0.23 cases/million (95% CI, 0.06–0.59) and 2.84 cases/million (95% CI, 2.10–3.75) for generalized lipodystrophy (GL) and partial lipodystrophy (PL), respectively. For all literature searches, the prevalence of all LD in Europe was 2.63 cases/million (0.96 and 1.67 cases/million for GL and PL, respectively).
Conclusion
LD prevalence estimates are at the lower range of previously established numbers, confirming that LD is an ultra-rare disease. The establishment of diagnostic criteria and coding specific to the 4 major LD subtypes and future studies/patient registries are needed to further refine our estimates.
Significance
The relationship between body fat and male reproduction is clearly seen when excess fat compromises fertility; however, potential consequences of adipose tissue paucity on fertility are unclear. We report that lack of seipin, a transmembrane protein localizing to the endoplasmic reticulum, causes both paucity of adipose tissue and male sterility. Human patients and mouse models lacking seipin in germ cells produce severely abnormal sperm because of impaired lipid distribution during sperm maturation. These defects are testis-intrinsic; scarcity of adipose tissue per se does not affect male fertility. Our work shows that two distinct organs—adipose tissue and the male germ line—depend on seipin function and that appropriate lipid distribution is essential for production of mature, functional sperm.
Objective:
Lipodystrophy syndromes are extremely rare disorders of deficient body fat associated with potentially serious metabolic complications, including diabetes, hypertriglyceridemia, and steatohepatitis. Due to their rarity, most clinicians are not familiar with their diagnosis and management. This practice guideline summarizes diagnosis and management of lipodystrophy syndromes not associated with HIV or injectable drugs.
Participants:
Seventeen participants were nominated by worldwide endocrine societies or selected by the committee as content experts. Funding was via unrestricted educational grant (Astra Zeneca) to the Pediatric Endocrine Society. Meetings were not open to the general public.
Evidence:
Literature review was conducted by the committee. Recommendations of the committee were graded using the system of the American Heart Association. Expert opinion was used when published data were not available or scarce.
Consensus process:
The guideline was drafted by committee members, and reviewed, revised, and approved by the entire committee during group meetings. Contributing societies reviewed the document and provided approval.
Conclusions:
Lipodystrophy syndromes are heterogeneous, and are diagnosed by clinical phenotype, supplemented by genetic testing in certain forms. Patients with most lipodystrophy syndromes should be screened for diabetes, dyslipidemia, and liver, kidney, and heart disease annually. Diet is essential for management of metabolic complications of lipodystrophy. Metreleptin therapy is effective for metabolic complications in hypoleptinemic patients with generalized lipodystrophy, and selected patients with partial lipodystrophy. Other treatments not specific for lipodystrophy may be helpful as well (e.g. metformin for diabetes, statins or fibrates for hyperlipidemia). Oral estrogens are contraindicated.
Thrombocytopenia is the most common hematological abnormality encountered in patients with chronic liver disease (CLD). In addition to being an indicator of advanced disease and poor prognosis, it frequently prevents crucial interventions. Historically, thrombocytopenia has been attributed to hypersplenism, which is the increased pooling of platelets in a spleen enlarged by congestive splenomegaly secondary to portal hypertension. Over the past decade, however, there have been significant advances in the understanding of thrombopoiesis, which, in turn, has led to an improved understanding of thrombocytopenia in cirrhosis. Multiple factors contribute to the development of thrombocytopenia and these can broadly be divided into those that cause decreased production, splenic sequestration, and increased destruction. Depressed thrombopoietin levels in CLD, together with direct bone marrow suppression, result in a reduced rate of platelet production. Thrombopoietin regulates both platelet production and maturation and is impaired in CLD. Bone marrow suppression can be caused by viruses, alcohol, iron overload, and medications. Splenic sequestration results from hypersplenism. The increased rate of platelet destruction in cirrhosis also occurs through a number of pathways: increased shear stress, increased fibrinolysis, bacterial translocation, and infection result in an increased rate of platelet aggregation, while autoimmune disease and raised titers of antiplatelet immunoglobulin result in the immunologic destruction of platelets. An in-depth understanding of the complex pathophysiology of the thrombocytopenia of CLD is crucial when considering treatment strategies. This review outlines the recent advances in our understanding of thrombocytopenia in cirrhosis and CLD.
Background:
Berardinelli-Seip congenital lipodystrophy (BSCL) was initially described by Berardinelli in Brazil in 1954 and 5 years later by Seip in Norway. It is an autosomal recessive disease that leads to a generalized deficit of body fat, evolving with diabetes and hypertriglyceridemia. The aim of this study was to describe the clinical and laboratory characteristics of a large series of patients with BSCL.
Methods:
This is a cross-sectional study of patients with BSCL. A total of 54 cases of BSCL were diagnosed, treated and followed for the past 17 years. We report clinical and laboratorial data of 44 of those patients.
Results:
There was a predominance of female patients (27 patients), and the mean age was 21.3 ± 13.7 years old. The majority of patients (30/44; 68.2 %) were diabetic, and almost half of them (14/30 patients, 46.7 %) were on insulin. The mean body mass index was 19.6 ± 3.3 and the mean body fat measured by dual-energy X-ray absorptiometry (DEXA) was 5.4 ± 0.8 %. Acanthosis nigricans, acromegaloid facies, atrophic cheeks, prognathism, phlebomegaly, and muscle hypertrophy were the most common clinical features. Only two patients had triglyceridemia lower than 150 mg/dl without the use of lipid-lowering drugs. Hyperinsulinemia was present in the majority of patients, and leptin values were very low in all patients.
Conclusions:
We report one of the largest series of patients with BSCL treated at a single medical center. Earlier identification of the mutations and a better understanding of the pathophysiology can aid to better treatment and decrease complications, potentially improving life quality and expectancy.
lipodystrophy (BSCL). The aim of this article is to identify whether BSCL patients
have umbilical herniation or protrusion.
Cases and methods: We clinically evaluated twelve BSCL patients (eight females)
through abdominal palpation sensitized by Valsalva maneuver. None of them had
a history of surgical treatment for umbilical hernia repair neither complained of
symptoms such as pain, abdominal discomfort, nausea, nor vomiting. We did not
find any case of umbilical hernia, but all of them had protrusion of the umbilicus.
Conclusion: At least in our patients, umbilical hernia is not part of BSCL and
patients truly have protrusion of the umbilicus due to the almost complete
absence of subcutaneous fat tissue.
Berardinelli-Seip congenital lipodystrophy (BSCL) is a rare autosomal recessive syndrome characterized by a difficulty storing lipid in adipocytes, low body fat, hypoleptinemia, and hyperinsulinemia. We report here laboratory, bone mineral density (BMD), and bone mineral content findings of 21 patients (24.1 ± 8.4 yr old, 14 females, 18 diabetics, 5.3% total body fat) with BSCL. The mean leptin was very low (0.91 ± 0.42 ng/mL), and the mean values of the Z-scores for all studied sites were positive, except for the 33% radius (Z-score −0.5 standard deviation [SD]). Twelve patients (57.1%) had a BMD Z-score higher than +2.5 SD in at least 1 site. There was no significant difference in the Z-scores between males and females. None of type 1 (AGPAT2) patients had Z-scores higher than +2.5 SD, and these patients had a smaller Z-score of BMD total body (0.26 SD vs 1.90 SD, p = 0.022) and of bone mineral content (1.59 SD vs 3.3 SD, p = 0.032) than type 2 (seipin) patients. Insulin, as well as HOMAIR (homeostasis model assessment), correlated positively with the BMD of all sites, except for the 33% radius. Z-Scores on this site (33% radius) were the smallest of all. More than half of our patients with BSCL have BMD Z-scores higher than +2.5 SD on at least 1 site, and this increase is more pronounced in the trabecular sites and in type 2 patients.