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a Dismorphic features of the patient at 7.5 years of age. Microcephaly, triangular face, high forehead, protruding low set ears, micrognathia, esotropia, epicanthus, right palpebral ptosis are shown. b Height curve of the subject. The arrow indicates the start of GH substitutive therapy
Source publication
Background
Rearrangements involving the short arm of chromosome 18 have been extensively described. Here we report a microduplication of 320.5–431.5 Kb at 18p11.31-p11.23 in a 10 year-old boy. Case presentationIn a 10 year-old boy with moderate psychomotor delay, hypoplasia of the cerebellar vermis, chorioretinal coloboma, deafness and growth hormo...
Citations
... The review of previous cases suggests that different genetic alterations (chromosome deletions as well as various gene variants) can be associated with Dubowitz phenotype. These findings support the hypothesis that DS could be a mix of disorders with a similar phenotypic expression but a different genotype, instead of being a single syndromic entity (Giordano et al., 2016;Urquhart et al., 2015). ...
... Growth hormone treatment was also reported in patients suspected to have DS, in particular two siblings (Dentici et al., 2011) and a boy with a 18p11.23-p11.31 microduplication (Giordano et al., 2016) who showed a satisfactory increase in height without mention of side effects. Unfortunately, height gain and height velocity were not reported. ...
Background
Dubowitz syndrome (DS) is a complex and rare condition characterized by postnatal growth retardation, microcephaly, short stature, mild developmental delay, facial dysmorphism, skin eruption and bone marrow failure. Though approximately 200 cases have been described so far, no specific genetic analysis, laboratory tests or radiological exams are available to confirm the diagnosis which is still based on clinical and facial features. Although short stature is a major feature of the syndrome, no endocrine alterations have been reported so far and scant data are available about the efficacy and safety of GH treatment in these patients.
Methods
A 13‐year‐old male patient was referred to our attention for short stature. Endocrinological evaluation including GH axis, adrenal and gonadal functions were assessed. aCGH was performed.
Results
14q terminal microdeletion associated with Dubowitz phenotype was found. Endocrinological investigations revealed the presence of hypopituitarism which showed a satisfactory response to short‐term growth hormone therapy. The subject also started glucocorticoid replacement therapy. Disorders in pubertal progression and gonadal function were noted.
Conclusions
Dubowitz syndrome (DS) includes different clinical findings variably occurring.
Subjects with a Dubowitz phenotype should be carefully monitored for endocrinological anomalies. The prompt recognition of potential life‐threatening endocrinological condition for example adrenal insufficiency is mandatory in order to start an adequate and early treatment.
... In the literature there are some reports of interstitial microduplication that partially overlap each other with some genes in common. Giordano et al. [18] describe a microduplication of 320-431 Kb at 18p11.31-p11.23 identified through array CGH encompassing three genes (ARHGAP28, LINC00668 and LAMA1) in 10 years old boy with moderate psychomotor delay and other physical anomalies: cerebellar vermis hypoplasia, coloboma, deafness and GH deficiency. ...
... DECIPHER patient ID 25404 carry a duplication of 1,11 Mb at 18p11.31-p11.23 showing clinical features similar to those described by Giordano et al. [18]: aplasia/hypoplasia of cerebellar vermis, intellectual disability moderate sensorineural hearing impairment. The duplicated region compasses only five genes including LAMA1, a gene mutated in Poretti-Boltshauser syndrome, a neurodevelopmental disorder presenting congenital cerebellar anomalies and characterized by delayed motor development with cognitive function ranging from normal to intellectually disabled [19]. ...
Background
Small supernumerary marker chromosomes (sSMC) are a heterogeneous group of structurally abnormal chromosomes, with an incidence of 0,044% in newborns that increases up to almost 7 times in developmentally retarded patients. sSMC from all 24 chromosome have been described, most of them originate from the group of the acrocentric, with around half deriving from the chromosome 15. Non-acrocentric sSMC are less common and, in the 30 percent of the cases, are associated with phenotypic effect. Complex sSMC consist of chromosomal material derived from more than one chromosome. Genotype–phenotype correlations in patients with sSMC are difficult to assess. Clinical features depend on factors such as its size, genetic content, the involvement of imprinted genes which may be influenced by uniparental disomy and the level of mosaicism. Trisomy of the short arm of chromosome 18 (18p) is an infrequent finding and does not appear to be associated with a specific syndrome. However, mild intellectual disability with or without other anomalies is reported in almost one-third of the patients.
Case presentation
Here we present clinical and molecular characterization of a new case of de novo complex sSMC consisting of the entire short arm of chromosome 18p associated with a centromere of either chromosome 13 or 21, evidenced in a 5-year-old boy during diagnostic workup for moderate intellectual disability and dysmorphisms. To date, only seven cases of isolated trisomy 18p due to a sSMC have been reported, three of which have been characterized by array CGH. In two of them the breakpoints and the size of the duplication have been described. In the manuscript we also reviewed cases reported in the DECIPHER database carrying similar duplication and also considered smaller duplications within the region of interest, in order to evaluate the presence of critical regions implicated in the pathological phenotype.
Conclusions
Our case provides additional information about phenotypic effects of pure trisomy 18p, confirms chromosomal microarray analysis as gold standard to characterize complex sSMC, and supplies additional elements for genetic counselling.
... Some of these triplicated genes could also be associated with mental disorders. A genotype-phenotype correlation was discussed with particular attention to the LAMA1 , ARH-GAP28 , LINC00668 , and TXNDC2 genes [Guillaume et al., 2015;Giordano et al., 2016]. However, further studies are necessary to determine whether the presence of cooccurring variants could explain the incomplete penetrance. ...
Trisomy 18p is a rarely observed chromosomal aberration. Only 31 cases have previously been described in the literature. Trisomy 18p is associated with mild to moderate phenotypic anomalies and intellectual disability. Here, we report on a pregnant woman in whom noninvasive prenatal testing indicated a high risk of fetal trisomy 18. Prenatal diagnosis and karyotyping of the parents were performed and demonstrated that both the mother and the fetus had a derivative chromosome 15 with a segment of unknown origin. Chromosomal microarray analysis and FISH revealed a 14.9-Mb duplication of 18p and detected 3 centromeres of chromosome 18. To our knowledge, this is the first study reporting trisomy 18p due to an unbalanced translocation of 18p onto chromosome 15q showing 2-generation transmission. The results suggest that trisomy 18p can be considered a euchromatic variant.
... Moreover, some pivot lncRNAs have been reported to be directly or indirectly related to ASD. The lncRNA LINC00668 is located downstream of gene LAMA1 involved in cerebellum and retinal development [21] suggesting that it may implicated autism etiology. LINC01749 is validated associated with Major Depressive Disorder (MDD) [22], and so on. ...
Autism spectrum disorder (ASD) is a complex neurodevelopmental disease in early childhood, and growing up to be a major cause of disability in children. However, the underlying molecular mechanism of ASD remains elusive. Hence, we represented integrated multifactor analysis exploring dysfunctional modules based on RNA-Seq data from corpus callosum in 6 patients with ASD and 6 normal individuals. According to protein-protein interactions (PPIs) and WGCNA, we performed co-expression modules analysis for ASD-associated genes, and identified 25 modules with differentially expressed genes (DEGs), observing that genes in these modules were significantly involved in various biological processes in nervous system, sensory system, phylogenetic system and variety of signaling pathways. Then, based on transcriptional and post-transcriptional regulations, integrating transcription factor (TF)-target and RNA-associated interactions, significant regulators of co-expression modules were identified as pivot regulators, including 67 pivot TFs, 13 pivot miRNAs and 6 pivot lncRNAs. GO and KEGG pathway enrichment analysis demonstrated that the pivot miRNAs significantly enriched in neural or mental-associated biological progresses. The pivot TFs were mainly involved in various regulation of transcription, immune system and organs development. Finally, our work deciphered a multifactor dysfunctional co-expression subnetwork involved in ASD, helps uncover core dysfunctional modules for this disease and improves our understanding of its underlying molecular mechanism.
... Neuroimaging of these patients showed cerebellar dysplasia with cysts, an enlarged 4th ventricle, and hypoplasia of the cerebellar vermis [Aldinger et al., 2014;Micalizzi et al., 2016]. Some of the clinical features in our patient, such as hypoplasia of cerebellar vermis, Dandy-Walker malformations, cognitive impairment, language and motor delay, may be caused by LAMA1 deletions [Hasi-Zogaj et al., 2015;Abdel Razek and Castillo, 2016;Giordano et al., 2016]. TWSG1 encodes a bone morphogenetic protein antagonist and plays a role in craniofacial development [Kauvar et al., 2011;Billington et al., 2015;Huntley et al., 2015]. ...
18p deletion syndrome is a rare chromosomal disease caused by deletion of the short arm of chromosome 18. By using cytogenetic and SNP array analysis, we identified a girl with 18p deletion syndrome exhibiting craniofacial anomalies, intellectual disability, and short stature. G-banding analysis of metaphase cells revealed an abnormal karyotype 46,XX,del(18)(p10). Further, SNP array detected a 15.3-Mb deletion at 18p11.21p11.32 (chr18:12842-15375878) including 61 OMIM genes. Genotype-phenotype correlation analysis showed that clinical manifestations of the patient were correlated with LAMA1, TWSG1, and GNAL deletions. Her neuropsychological assessment test demonstrated delay in most cognitive functions including impaired mathematics, linguistic skills, visual motor perception, respond speed, and executive function. Meanwhile, her integrated visual and auditory continuous performance test (IVA-CPT) indicated a severe comprehensive attention deficit. At age 7 and 1/12 years, her height was 110.8 cm (-2.5 SD height for age). Growth hormone (GH) treatment was initiated. After 27 months treatment, her height was increased to 129.6 cm (-1.0 SD height for age) at 9 and 4/12 years, indicating an effective response to GH treatment.
Abnormal hypothalamic/posterior pituitary development seems to be a major determinant of pituitary stalk interruption syndrome (PSIS). The observation of familial cases and associated congenital abnormalities suggest a genetic basis. Single‐gene mutations explain less than 5% of the cases, and whole exome sequencing has shown heterogeneous results. To assess copy number variation (CNV) using array‐based comparative genomic hybridization (aCGH) in patients with non‐syndromic PSIS and comprehensively review data from the literature on CNV analysis in congenital hypopituitarism (CH) patients. Twenty‐one patients with sporadic CH from our outpatient clinics presented with ectopic posterior pituitary (EPP) and no central nervous system abnormalities on magnetic resonance image (MRI) or any other malformations on physical examination at presentation were enrolled in the study. aCGH using a whole‐genome customized 400K oligonucleotide platform was performed in our patients. For the literature review, we searched for case reports of patients with CH and copy number variants (CNVs) detected by either karyotype or aCGH reported in PubMed up to November 2021. Thirty‐five distinct rare CNVs were observed in 18 patients (86%), and 2 of them (6%) were classified as pathogenic: one deletion of 1.8 Mb in chromosome 17 (17q12) and one deletion of 15 Mb in chromosome 18 (18p11.32p11.21), each one in a distinct patient. In the literature review, 67 pathogenic CNVs were published in 83 patients with CH, including the present study. Most of these patients had EPP (78% out of the 45 evaluated by sellar MRI) and were syndromic (70%). The most frequently affected chromosomes were X, 18, 20, and 1. Our study has found that CNV can be a mechanism of genetic abnormality in non‐syndromic patients with CH and EPP. In future studies, one or more genes in those CNVs, both pathogenic and VUS, may be considered good candidate genes.
Objective
The aim was to evaluate the main indications for prenatal diagnosis, the prevalence of abnormal copy number variations (CNVs), correlate them with clinical findings, analyze the prevalence of VUS, report the rare variants found and additionally highlight the clinical importance of microarray-based comparative genomic hybridization (aCGH) in prenatal diagnosis.
Study design
We retrospectively analyzed a cohort of 772 fetuses with indication for genetic study in two tertiary hospitals, in a 9-years-period, using aCGH.
Results
Our results demonstrated 8.3 % (6.4–10.5 %, 95 % CI) detection rate of pathogenic CNVs. Within this group, the main indication was structural malformations (57 %) mainly involving central nervous system, skeletal and cardiac systems. Pathogenic results in cases with multiple malformations were higher than in cases with isolated anatomical system malformations showing statistical significant differences (p < 0.001). The second indication where we found more pathogenic CNVs was increased nuchal translucency (5–6.4 mm). In fact, the rate of pathogenic CNVs did not show significant differences between structural and non-structural malformations (p > 0.001), highlighting the relevance of genetic study by aCGH also in cases with no structural malformations.
A total of 217 fetuses with CNVs classified as VUS were identified, mainly involving chromosomes X, 1 and 16.
Conclusion
Our findings demonstrate 4.9 % (4.2–5.6 %, 95 % CI) increased in the diagnostic yield using aCGH compared to the use of conventional karyotype alone, confirming that the aCGH can improve the accuracy of prenatal diagnosis. Our survey provides a full genotype-phenotype analysis that can be clinically useful for the classification of variants in the context of prenatal setting, helping to provide a better reproductive genetic counselling.
Chromosomal duplications are associated with a large group of human diseases that arise mainly from dosage imbalance of genes within the rearrangements. Phenotypes range widely but are often associated with global development delay, intellectual disability, autism spectrum disorders, and multiple congenital abnormalities. How different contiguous genes from a duplicated genomic region interact and dynamically affect the expression of each other remains unclear in most cases. Here, we report a genomic comparative delineation of genes located in duplicated chromosomal regions 8q24.13q24.3, 18p11.32p11.21, and Xq22.3q27.2 in three patients followed up at our genetics service who has the intellectual disability (ID) as a common phenotype. We integrated several genomic data levels by identification of gene content within the duplications, protein-protein interactions, and functional analysis on specific tissues. We found functional relationships among genes from three different duplicated chromosomal regions, reflecting interactions of protein-coding genes and their involvement in common cellular subnetworks. Furthermore, the sharing of common significant biological processes associated with ID has been demonstrated between proteins from the different chromosomal regions. Finally, we elaborated a shared model of pathways directly or indirectly related to the central nervous system (CNS), which could perturb cognitive function and lead to ID in the three duplication conditions.
Recent advances in Bionano optical mapping (BOM) provide a great insight into the determination of structural variants (SVs), but its utility in identification of clinical likely pathogenic variants needs to be further demonstrated and proved. In a family with two consecutive pregnancies affected with ventriculomegaly, a splicing likely pathogenic variant at the LAMA1 locus (NM_005559: c. 4663 + 1 G > C) inherited from the father was identified in the proband by whole-exome sequencing, and no other pathogenic variant associated with the clinical phenotypes was detected. SV analysis by BOM revealed an ~48 kb duplication at the LAMA1 locus in the maternal sample. Real-time quantitative PCR and Sanger sequencing further confirmed the duplication as c.859-153_4806 + 910dup. Based on these variants, we hypothesize that the fetuses have Poretti-Boltshauser syndrome (PBS) presenting with ventriculomegaly. With the ability to determine single nucleotide variants and SVs, the strategy adopted here might be useful to detect cases missed by current routine screening methods. In addition, our study may broaden the phenotypic spectrum of fetuses with PBS.
Background: Chromosomal deletion involving the 6p25 region results in a clinically recognizable syndrome characterized by anterior eye chamber anomalies with risk of glaucoma and non-ocular malformations (6p25 deletion syndrome). We report a newborn infant case of childhood glaucoma with a combination of partial monosomy 6p25 and partial trisomy 18p11 due to an unbalanced translocation.
Materials and methods: The patient was a 0-year-old girl. Both eyes showed aniridia and left eye Peters anomaly with multiple malformations. To identify the chromosomal aberrations in the patient with clinically suspected 6p25 deletion syndrome, we performed cytogenetic analysis (G-banding and multicolor fluorescent in-situ hybridization) and array-based comparative genomic hybridization (array-CGH) analysis.
Results: Cytogenetic analyses revealed a derivative chromosome 6 with its distal short arm replaced by an extra copy of the short arm of chromosome 18. Array-CGH analysis detected a 4.6-Mb deletion at 6pter to 6p25.1 and 8.9-Mb duplication at 18pter to 18p11.22. To determine the breakpoint of the unbalanced rearrangement at the single-base level, we performed a long-range PCR for amplifying the junctional fragment of the translocation breakpoint. By sequencing the junctional fragment, we defined the unbalanced translocation as g.chr6:pter_4594783delinschr18:pter_8911541.
Conclusions: A phenotype corresponding to combined monosomy 6p25 and trisomy 18p11 presented as childhood glaucoma associated with non-acquired (congenital) ocular anomalies consist of aniridia and Peters anomaly and other systemic malformations. To the best of our knowledge, this is the first report which demonstrated the breakpoint sequence of an unbalanced translocation in a Japanese infant with childhood glaucoma.
