De novo missense variants in MEIS2 recapitulate the microdeletion phenotype of cardiac and palate abnormalities, developmental delay, intellectual disability and dysmorphic features

2018 ◽  
Vol 176 (9) ◽  
pp. 1845-1851 ◽  
Author(s):  
Ganka Douglas ◽  
Megan T. Cho ◽  
Aida Telegrafi ◽  
Susan Winter ◽  
Jason Carmichael ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
De Novo ◽  
Missense Variants ◽  
Dysmorphic Features

scholarly journals Rare GABRA3 variants are associated with epileptic seizures, encephalopathy and dysmorphic features

Brain ◽  
2017 ◽  
Vol 140 (11) ◽  
pp. 2879-2894 ◽  
Author(s):  
Cristina Elena Niturad ◽  
Dorit Lev ◽  
Vera M Kalscheuer ◽  
Agnieszka Charzewska ◽  
Julian Schubert ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Gabaa Receptor ◽  
Xenopus Laevis Oocytes ◽  
Incomplete Penetrance ◽  
Single Mutation ◽  
Loss Of Function ◽  
Missense Variants ◽  
Dysmorphic Features ◽  
Α3 Subunit

Abstract Genetic epilepsies are caused by mutations in a range of different genes, many of them encoding ion channels, receptors or transporters. While the number of detected variants and genes increased dramatically in the recent years, pleiotropic effects have also been recognized, revealing that clinical syndromes with various degrees of severity arise from a single gene, a single mutation, or from different mutations showing similar functional defects. Accordingly, several genes coding for GABAA receptor subunits have been linked to a spectrum of benign to severe epileptic disorders and it was shown that a loss of function presents the major correlated pathomechanism. Here, we identified six variants in GABRA3 encoding the α3-subunit of the GABAA receptor. This gene is located on chromosome Xq28 and has not been previously associated with human disease. Five missense variants and one microduplication were detected in four families and two sporadic cases presenting with a range of epileptic seizure types, a varying degree of intellectual disability and developmental delay, sometimes with dysmorphic features or nystagmus. The variants co-segregated mostly but not completely with the phenotype in the families, indicating in some cases incomplete penetrance, involvement of other genes, or presence of phenocopies. Overall, males were more severely affected and there were three asymptomatic female mutation carriers compared to only one male without a clinical phenotype. X-chromosome inactivation studies could not explain the phenotypic variability in females. Three detected missense variants are localized in the extracellular GABA-binding NH2-terminus, one in the M2-M3 linker and one in the M4 transmembrane segment of the α3-subunit. Functional studies in Xenopus laevis oocytes revealed a variable but significant reduction of GABA-evoked anion currents for all mutants compared to wild-type receptors. The degree of current reduction correlated partially with the phenotype. The microduplication disrupted GABRA3 expression in fibroblasts of the affected patient. In summary, our results reveal that rare loss-of-function variants in GABRA3 increase the risk for a varying combination of epilepsy, intellectual disability/developmental delay and dysmorphic features, presenting in some pedigrees with an X-linked inheritance pattern. 10.1093/brain/awx236_video1 awx236media1 5636589232001

scholarly journals De novo PHIP-predicted deleterious variants are associated with developmental delay, intellectual disability, obesity, and dysmorphic features

2016 ◽  
Vol 2 (6) ◽  
pp. a001172 ◽  
Author(s):  
Emily Webster ◽  
Megan T. Cho ◽  
Nora Alexander ◽  
Sonal Desai ◽  
Sakkubai Naidu ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
De Novo ◽  
Dysmorphic Features

Exome reports A de novo GNB2 variant associated with global developmental delay, intellectual disability, and dysmorphic features

2020 ◽  
Vol 63 (4) ◽  
pp. 103804 ◽  
Author(s):  
Tokiko Fukuda ◽  
Takuya Hiraide ◽  
Kaori Yamoto ◽  
Mitsuko Nakashima ◽  
Tomoko Kawai ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
De Novo ◽  
Global Developmental Delay ◽  
Dysmorphic Features

scholarly journals De Novo Missense Variants in TRAF7 Cause Developmental Delay, Congenital Anomalies, and Dysmorphic Features

2018 ◽  
Vol 103 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Mari J. Tokita ◽  
Chun-An Chen ◽  
David Chitayat ◽  
Ellen Macnamara ◽  
Jill A. Rosenfeld ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Congenital Anomalies ◽  
De Novo ◽  
Missense Variants ◽  
Dysmorphic Features

IL1RAPL1 Gene Deletion in a Female Patient with Developmental Delay and Continuous Spike-Wave during Sleep

2021 ◽  
Author(s):  
Evan Jiang ◽  
Mark P. Fitzgerald ◽  
Katherine L. Helbig ◽  
Ethan M. Goldberg
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Synapse Formation ◽  
De Novo ◽  
Interleukin 1 ◽  
Autism Spectrum ◽  
Neurological Dysfunction ◽  
Behavioral Disorder ◽  
Clinical Genetic ◽  
Severe Intellectual Disability

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.

Recurrent de novo missense variants in GNB2 can cause syndromic intellectual disability

2021 ◽  
pp. jmedgenet-2020-107462
Author(s):  
Natalie B Tan ◽  
Alistair T Pagnamenta ◽  
Matteo P Ferla ◽  
Jonathan Gadian ◽  
Brian HY Chung ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
G Proteins ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Missense Variant ◽  
Cellular Functions ◽  
Missense Variants ◽  
Neurodevelopmental Disease ◽  
Genes Encoding ◽  
International Data

PurposeBinding proteins (G-proteins) mediate signalling pathways involved in diverse cellular functions and comprise Gα and Gβγ units. Human diseases have been reported for all five Gβ proteins. A de novo missense variant in GNB2 was recently reported in one individual with developmental delay/intellectual disability (DD/ID) and dysmorphism. We aim to confirm GNB2 as a neurodevelopmental disease gene, and elucidate the GNB2-associated neurodevelopmental phenotype in a patient cohort.MethodsWe discovered a GNB2 variant in the index case via exome sequencing and sought individuals with GNB2 variants via international data-sharing initiatives. In silico modelling of the variants was assessed, along with multiple lines of evidence in keeping with American College of Medical Genetics and Genomics guidelines for interpretation of sequence variants.ResultsWe identified 12 unrelated individuals with five de novo missense variants in GNB2, four of which are recurrent: p.(Ala73Thr), p.(Gly77Arg), p.(Lys89Glu) and p.(Lys89Thr). All individuals have DD/ID with variable dysmorphism and extraneurologic features. The variants are located at the universally conserved shared interface with the Gα subunit, which modelling suggests weaken this interaction.ConclusionMissense variants in GNB2 cause a congenital neurodevelopmental disorder with variable syndromic features, broadening the spectrum of multisystem phenotypes associated with variants in genes encoding G-proteins.

Genomic Syndromes in Schizophrenia

2013 ◽  
pp. 247-255
Author(s):  
George Kirov ◽  
Michael C. O’Donovan ◽  
Michael J. Owen
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Neurodevelopmental Disorders ◽  
Copy Number ◽  
De Novo ◽  
Copy Number Variants ◽  
Individual Risk ◽  
Genomic Deletions ◽  
Pathogenic Cnvs ◽  
Cognition And Learning

Several submicroscopic genomic deletions and duplications known as copy number variants (CNVs) have been reported to increase susceptibility to schizophrenia. Those for which the evidence is particularly strong include deletions at chromosomal segments 1q21.1, 3q29, 15q11.2, 15q13.3, 17q12 and 22q11.2, duplications at 15q11.2-q13.1, 16p13.1, and 16p11.2, and deletions atthe gene NRXN1. The effect of each on individual risk is relatively large, but it does not appear that any of them is alone sufficient to cause disorder in carriers. These CNVs often arise as new mutations(de novo). Analyses of genes enriched among schizophrenia implicated CNVs highlight the involvement in the disorder of post-synaptic processes relevant to glutamatergicsignalling, cognition and learning. CNVs that contribute to schizophrenia risk also contribute to other neurodevelopmental disorders, including intellectual disability, developmental delay and autism. As a result of selection, all known pathogenic CNVs are rare, and none makes a sizeable contribution to overall population risk of schizophrenia, although the study of these mutations is nevertheless providing important insights into the origins of the disorder.

Sign in / Sign up

Export Citation Format

Share Document