scholarly journals Rare case of a heterozygous microdeletion 9q21.11-q21.2: Clinical and genetic characteristics

2018 ◽  
Vol 21 (2) ◽  
pp. 59-62
Author(s):  
HY Ivanov ◽  
V Stoyanova ◽  
I Ivanov ◽  
A Linev ◽  
R Vazharova ◽  
...  

Abstract Intellectual disability is affecting 3.0-4.0% of the general population. Copy number variants (CNVs) are a significant cause leading to neurodevelopmental disorders such as intellectual disability, epilepsy, autism spectrum disorders and developmental delay. The use of single nucleotide polymorphism (SNP)-array and array comparative genomic hybridization (aCGH) as diagnostic tools has led to the recognition of new microdeletion/microduplication syndromes associated with neurodevelopmental disorders. It is also useful for further characterization of marker chromosomes. Here, we report a girl with mild intellectual disability and mild facial dysmorphisms. Cytogenetic analysis showed a marker chromosome in some percent of the cells and was followed by SNP-array karyotyping that detected, in addition, a 9655 Mb de novo interstitial deletion at 9q21.1-9q21.2.

2016 ◽  
Vol 19 (2) ◽  
pp. 85-90 ◽  
Author(s):  
I Görker ◽  
H Gürkan ◽  
S Demir Ulusal ◽  
E Atlı ◽  
E Ikbal Atlı

AbstractPhelan McDermid Syndrome (PHMDS) (OMIM #606232), is a contiguous gene disorder resulting from deletion of the distal long arm of chromosome 22. The 22q13.3 deletions and mutations that lead to a loss of a functional copy of SHANK3 (OMIM *606230) cause the syndrome, characterized by moderate to profound intellectual disability, severely delayed or absent speech, hypotonia, and autism spectrum disorder (ASD) or ASD traits. In this study, we present the case of a 9-year-old girl who had earlier been diagnosed with an ASD. Our findings were a clinically mild intellectual disability, rounded face, pointed chin but no autistic findings. We learned that her neuromotor development was delayed and she had neonatal hypotonia in her history. A heterozygous deletion of MLC1, SBF1, MAPK8IP2, ARSA, SHANK3 and ACR genes, located on 22q13.33, was defined by multiplex ligation-dependent probe amplification (MLPA). Deletion of 22q13.3 (ARSA) region was confirmed by a fluorescent in situ hybridization (FISH) technique. The 22q13.3 deletion was found to be de novo in our patient, and she was diagnosed with PHMDS. We confirmed the 22q13.3 deletion and also determined a gain of 8p23.3-23.2 by array comparative genomic hybridization (aCGH). Fluorescent in situ hybridization was performed to determine whether the deletion was of parental origin and to identify regions of chromosomes where the extra 8p may have been located. The parents were found to be normal. The extra copy of 8p was observed on 22q in the patient. She is the first case reported in association with the 22q deletion of 8p duplications in the literature.


2021 ◽  
pp. 1-5
Author(s):  
Ayberk Turkyilmaz ◽  
Erdal Kurnaz ◽  
Atilla Cayir

Intellectual disability (ID) is characterized by limited or insufficient development of mental abilities, including intellectual functioning impairments, such as learning and understanding cause-effect relationships. Some cases have ID as the only finding and are called isolated cases. Conversely, cases accompanied by facial dysmorphism, microcephaly, autism spectrum disorder, epilepsy, obesity, and congenital anomalies are called syndromic developmental delay (DD)/ID. Isolated and syndromic DD/ID cases show extreme genetic heterogeneity. Genetic etiology can be detected in approximately 40% of the cases, whereas chromosomal abnormalities are observed in 25%. Obesity is a multifactorial disease in which both genetic and environmental factors play important roles. The role of heredity in obesity has been reported to be between 40 and 70%. Array-based comparative genomic hybridization (array-CGH) can detect CNVs in the whole genome at a higher resolution than conventional cytogenetic methods. Array-CGH is currently recommended as the first-tier genetic test for ID cases worldwide. In the present study, we aimed to evaluate clinical, radiological, and genetic analyses of a 12-year and 4-month-old girl with microcephaly, ID, and obesity. In the array-CGH analysis, a 3.1-Mb deletion, arr[GRGh37] 10q23.31g23.33 (92745793_95937944)×1 was detected, and this alteration was evaluated to be pathogenic. We consider that haploinsufficiency of the candidate genes (<i>GPR120</i>, <i>KIF11</i>, <i>EXOC6</i>, <i>CYP26A1</i>, <i>CYP26C1</i>, and <i>LGI1</i>) in the deletion region may explain microcephaly, ID, obesity, seizures, and ophthalmological findings in our patient. The investigation of 10q23.31q23.33 microdeletion in cases with syndromic obesity may contribute to molecular genetic diagnosis.


2020 ◽  
Author(s):  
Elliott Rees ◽  
Hugo Creeth ◽  
Hai-Gwo Hwu ◽  
Wei Chen ◽  
Ming Tsuang ◽  
...  

Abstract Genes enriched for rare disruptive coding variants in schizophrenia overlap those in which disruptive mutations are associated with neurodevelopmental disorders (NDDs), particularly autism spectrum disorders and intellectual disability. However, it is unclear whether this implicates the same specific variants, or even variants with the same functional effects on shared risk genes. Here, we show that de novo mutations in schizophrenia are generally of the same functional category as those that confer risk for NDDs, and that the specific de novo mutations in NDDs are enriched in schizophrenia. These findings indicate that, in part, NDDs and schizophrenia have shared molecular aetiology, and therefore likely overlapping pathophysiology. We also observe pleiotropic effects for variants known to be pathogenic for several syndromic developmental disorders, suggesting that schizophrenia should be included among the phenotypes associated with these mutations. Collectively, our findings support the hypothesis that at least some forms of schizophrenia lie within a continuum of neurodevelopmental disorders.


2020 ◽  
Author(s):  
Elliott Rees ◽  
Hugo D. J. Creeth ◽  
Hai-Gwo Hwu ◽  
Wei J. Chen ◽  
Ming Tsuang ◽  
...  

AbstractGenes enriched for rare disruptive coding variants in schizophrenia overlap those in which disruptive mutations are associated with neurodevelopmental disorders (NDDs), particularly autism spectrum disorders and intellectual disability. However, it is unclear whether this implicates the same specific variants, or even variants with the same functional effects on shared risk genes. Here, we show that de novo mutations in schizophrenia are generally of the same functional category as those that confer risk for NDDs, and that the specific de novo mutations in NDDs are enriched in schizophrenia. These findings indicate that, in part, NDDs and schizophrenia have shared molecular aetiology, and therefore likely overlapping pathophysiology. We also observe pleiotropic effects for variants known to be pathogenic for several syndromic developmental disorders, suggesting that schizophrenia should be included among the phenotypes associated with these mutations. Collectively, our findings support the hypothesis that at least some forms of schizophrenia lie within a continuum of neurodevelopmental disorders.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Julie Chow ◽  
Matthew Jensen ◽  
Hajar Amini ◽  
Farhad Hormozdiari ◽  
Osnat Penn ◽  
...  

Abstract Background Neurodevelopmental disorders (NDDs) such as autism spectrum disorder, intellectual disability, developmental disability, and epilepsy are characterized by abnormal brain development that may affect cognition, learning, behavior, and motor skills. High co-occurrence (comorbidity) of NDDs indicates a shared, underlying biological mechanism. The genetic heterogeneity and overlap observed in NDDs make it difficult to identify the genetic causes of specific clinical symptoms, such as seizures. Methods We present a computational method, MAGI-S, to discover modules or groups of highly connected genes that together potentially perform a similar biological function. MAGI-S integrates protein-protein interaction and co-expression networks to form modules centered around the selection of a single “seed” gene, yielding modules consisting of genes that are highly co-expressed with the seed gene. We aim to dissect the epilepsy phenotype from a general NDD phenotype by providing MAGI-S with high confidence NDD seed genes with varying degrees of association with epilepsy, and we assess the enrichment of de novo mutation, NDD-associated genes, and relevant biological function of constructed modules. Results The newly identified modules account for the increased rate of de novo non-synonymous mutations in autism, intellectual disability, developmental disability, and epilepsy, and enrichment of copy number variations (CNVs) in developmental disability. We also observed that modules seeded with genes strongly associated with epilepsy tend to have a higher association with epilepsy phenotypes than modules seeded at other neurodevelopmental disorder genes. Modules seeded with genes strongly associated with epilepsy (e.g., SCN1A, GABRA1, and KCNB1) are significantly associated with synaptic transmission, long-term potentiation, and calcium signaling pathways. On the other hand, modules found with seed genes that are not associated or weakly associated with epilepsy are mostly involved with RNA regulation and chromatin remodeling. Conclusions In summary, our method identifies modules enriched with de novo non-synonymous mutations and can capture specific networks that underlie the epilepsy phenotype and display distinct enrichment in relevant biological processes. MAGI-S is available at https://github.com/jchow32/magi-s.


2020 ◽  
Vol 11 ◽  
Author(s):  
Emanuela Leonardi ◽  
Elisa Bettella ◽  
Maria Federica Pelizza ◽  
Maria Cristina Aspromonte ◽  
Roberta Polli ◽  
...  

SETBP1 mutations are associated with the Schinzel-Giedion syndrome (SGS), characterized by profound neurodevelopmental delay, typical facial features, and multiple congenital malformations (OMIM 269150). Refractory epilepsy is a common feature of SGS. Loss of function mutations have been typically associated with a distinct and milder phenotype characterized by intellectual disability and expressive speech impairment. Here we report three variants of SETBP1, two novel de novo truncating mutations, identified by NGS analysis of an Intellectual Disability gene panel in 600 subjects with non-specific neurodevelopmental disorders, and one missense identified by a developmental epilepsy gene panel tested in 56 pediatric epileptic cases. The three individuals carrying the identified SETBP1 variants presented mild to severe developmental delay and lacked the cardinal features of classical SGS. One of these subjects, carrying the c.1765C&gt;T (p.Arg589*) mutation, had mild Intellectual Disability with speech delay; the second one carrying the c.2199_2203del (p.Glu734Alafs19*) mutation had generalized epilepsy, responsive to treatment, and moderate Intellectual Disability; the third patient showed a severe cognitive defects and had a history of drug resistant epilepsy with West syndrome evolved into a Lennox-Gastaut syndrome. This latter subject carries the missense c.2572G&gt;A (p.Glu858Lys) variant, which is absent from the control population, reported as de novo in a subject with ASD, and located close to the SETBP1 hot spot for SGS-associated mutations. Our findings contribute to further characterizing the associated phenotypes and suggest inclusion of SETBP1 in the list of prioritized genes for the genetic diagnosis of overlapping phenotypes ranging from non-specific neurodevelopmental disorders to “developmental and epileptic encephalopathy” (DEE).


Author(s):  
Meena Balasubramanian ◽  
Alexander J. M. Dingemans ◽  
Shadi Albaba ◽  
Ruth Richardson ◽  
Thabo M. Yates ◽  
...  

AbstractWitteveen-Kolk syndrome (OMIM 613406) is a recently defined neurodevelopmental syndrome caused by heterozygous loss-of-function variants in SIN3A. We define the clinical and neurodevelopmental phenotypes related to SIN3A-haploinsufficiency in 28 unreported patients. Patients with SIN3A variants adversely affecting protein function have mild intellectual disability, growth and feeding difficulties. Involvement of a multidisciplinary team including a geneticist, paediatrician and neurologist should be considered in managing these patients. Patients described here were identified through a combination of clinical evaluation and gene matching strategies (GeneMatcher and Decipher). All patients consented to participate in this study. Mean age of this cohort was 8.2 years (17 males, 11 females). Out of 16 patients ≥ 8 years old assessed, eight (50%) had mild intellectual disability (ID), four had moderate ID (22%), and one had severe ID (6%). Four (25%) did not have any cognitive impairment. Other neurological symptoms such as seizures (4/28) and hypotonia (12/28) were common. Behaviour problems were reported in a minority. In patients ≥2 years, three were diagnosed with Autism Spectrum Disorder (ASD) and four with Attention Deficit Hyperactivity Disorder (ADHD). We report 27 novel variants and one previously reported variant. 24 were truncating variants; three were missense variants and one large in-frame gain including exons 10–12.


2019 ◽  
Vol 27 (9) ◽  
pp. 1445-1455 ◽  
Author(s):  
Ron Nudel ◽  
Michael E. Benros ◽  
Morten Dybdahl Krebs ◽  
Rosa Lundbye Allesøe ◽  
Camilla Koldbæk Lemvigh ◽  
...  

AbstractHuman leukocyte antigen (HLA) genes encode proteins with important roles in the regulation of the immune system. Many studies have also implicated HLA genes in psychiatric and neurodevelopmental disorders. However, these studies usually focus on one disorder and/or on one HLA candidate gene, often with small samples. Here, we access a large dataset of 65,534 genotyped individuals consisting of controls (N = 19,645) and cases having one or more of autism spectrum disorder (N = 12,331), attention deficit hyperactivity disorder (N = 14,397), schizophrenia (N = 2401), bipolar disorder (N = 1391), depression (N = 18,511), anorexia (N = 2551) or intellectual disability (N = 3175). We imputed participants’ HLA alleles to investigate the involvement of HLA genes in these disorders using regression models. We found a pronounced protective effect of DPB1*1501 on susceptibility to autism (p = 0.0094, OR = 0.72) and intellectual disability (p = 0.00099, OR = 0.41), with an increased protective effect on a comorbid diagnosis of both disorders (p = 0.003, OR = 0.29). We also identified a risk allele for intellectual disability, B*5701 (p = 0.00016, OR = 1.33). Associations with both alleles survived FDR correction and a permutation procedure. We did not find significant evidence for replication of previously-reported associations for autism or schizophrenia. Our results support an implication of HLA genes in autism and intellectual disability, which requires replication by other studies. Our study also highlights the importance of large sample sizes in HLA association studies.


Author(s):  
Evan Jiang ◽  
Mark P. Fitzgerald ◽  
Katherine L. Helbig ◽  
Ethan M. Goldberg

AbstractInterleukin-1 receptor accessory protein-like 1 (IL1RAPL1) encodes a protein that is highly expressed in neurons and has been shown to regulate neurite outgrowth as well as synapse formation and synaptic transmission. Clinically, mutations in or deletions of IL1RAPL1 have been associated with a spectrum of neurological dysfunction including autism spectrum disorder and nonsyndromic X-linked developmental delay/intellectual disability of varying severity. Nearly all reported cases are in males; in the few reported cases involving females, the clinical presentation was mild or the deletion was identified in phenotypically normal carriers in accordance with X-linked inheritance. Using genome-wide microarray analysis, we identified a novel de novo 373 kb interstitial deletion of the X chromosome (Xp21.1-p21.2) that includes exons 4 to 6 of the IL1RAPL1 gene in an 8-year-old girl with severe intellectual disability and behavioral disorder with a history of developmental regression. Overnight continuous video electroencephalography revealed electrical status epilepticus in sleep (ESES). This case expands the clinical genetic spectrum of IL1RAPL1-related neurodevelopmental disorders and highlights a new genetic association of ESES.


2018 ◽  
Vol 89 (10) ◽  
pp. A29.4-A30 ◽  
Author(s):  
Ela M Akay ◽  
Ian S Schofield ◽  
Ming H Lai ◽  
Rhys H Thomas

We describe the seizure phenotype of a 26 year old lady who presented with a probable photic-induced convulsion on a background of mild intellectual disability, facial dysmorphia, fused cervical vertebrae and ventricular septal defect. There was no prior history of seizures.Routine EEG was polyrhythmic with a prominent photoparoxysmal response at 14 Hz and 40 Hz. CT head was normal. A SNP array demonstrated a rare 51 kb deletion at 12 p12.1 which disrupts the SOX5 gene.SOX5 is a developmentally important gene encoding a transcription factor that plays a role in multiple developmental pathways including of the nervous system. Loss of function of this gene is associated with Lamb-Shaffer syndrome, first characterised in 2012 with global developmental delay, intellectual disability, mild dysmorphic facies, language impairment and variable skeletal abnormalities.3 of the original cohort of 16 patients described experienced seizures and the nature of their epilepsy was not further defined. Only a further 7 cases have been reported to date, none of whom experienced seizures. Our case helps to broaden the phenotype of Lamb-Shaffer syndrome, highlights the importance of looking for copy number variation and poses questions regarding the neurobiology of photo-sensitivity.


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