scholarly journals Neuroimaging Findings in Patients with EBF3 Mutations: Report of Two Cases

2021 ◽  
pp. 1-8
Author(s):  
Mar Jiménez de la Peña ◽  
Ana Jiménez de Domingo ◽  
Pilar Tirado ◽  
Beatriz Calleja-Pérez ◽  
Luis A. Alcaraz ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Intellectual Disability ◽  
Neurodevelopmental Disorders ◽  
Autosomal Dominant ◽  
De Novo ◽  
Diffusion Tensor ◽  
Loss Of Function ◽  
Normal Range ◽  
Early B Cell Factor ◽  
And Diffusion

Early B cell factor 3 (EBF3) is a transcription factor involved in brain development. Heterozygous, loss-of-function mutations in <i>EBF3</i> have been reported in an autosomal dominant neurodevelopmental syndrome characterized by hypotonia, ataxia, and developmental delay (sometimes described as “HADD”s). We report 2 unrelated cases with novel de novo <i>EBF3</i> mutations: c.455G&#x3e;T (p.Arg152Leu) and c.962dup (p.Tyr321*) to expand the genotype/phenotype correlations of this disorder; clinical, neuropsychological, and MRI studies were used to define the phenotype. IQ was in the normal range and diffusion tensor imaging revealed asymmetric alterations of the longitudinal fasciculus in both cases. Our results demonstrate that <i>EBF3</i> mutations can underlie neurodevelopmental disorders without intellectual disability. Long tract abnormalities have not been previously recognized and suggest that they may be an unrecognized and characteristic feature in this syndrome.

scholarly journals Identification of SETBP1 Mutations by Gene Panel Sequencing in Individuals With Intellectual Disability or With “Developmental and Epileptic Encephalopathy”

2020 ◽  
Vol 11 ◽  
Author(s):  
Emanuela Leonardi ◽  
Elisa Bettella ◽  
Maria Federica Pelizza ◽  
Maria Cristina Aspromonte ◽  
Roberta Polli ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Neurodevelopmental Disorders ◽  
De Novo ◽  
Hot Spot ◽  
Genetic Diagnosis ◽  
Epileptic Encephalopathy ◽  
Gene Panel ◽  
Loss Of Function ◽  
Speech Impairment ◽  
Mild Intellectual Disability

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).

scholarly journals A de novo variant in CASK gene causing intellectual disability and brain hypoplasia: A Case Report and Literature Review

2021 ◽  
Author(s):  
Ying Zhang ◽  
Yanyan Nie ◽  
Yu Mu ◽  
Jie Zheng ◽  
Xiaowei Xu ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Mental Disorders ◽  
De Novo ◽  
Clinical Symptoms ◽  
Clinical Manifestations ◽  
De Novo Mutation ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Whole Exome ◽  
De Novo Variant

Abstract Background：The pathogenic variation of CASK gene can cause CASK related mental disorders. The main clinical manifestations are microcephaly with pontine and cerebellar hypoplasia, X-linked mental disorders with or without nystagmus and FG syndrome. The main pathogenic mechanism is the loss of function of related protein caused by mutation. We reported a Chinese male newborn with a de novo variant in CASK gene. Case presentation：We present an 18-day-old baby with intellectual disability and brain hypoplasia. Whole-exome sequencing was performed, which detected a hemizygous missense mutation c.764G>A of CASK gene. The mutation changed the 255th amino acid from Arg to His. Software based bioinformatics analyses were conducted to infer its functional effect.Conclusions：In this paper, a de novo mutation of CASK gene was reported. Moreover, a detailed description of all the cases described in the literature is reported.CASK mutations cause a variety of clinical phenotypes. Its diagnosis is difficult due to the lack of typical clinical symptoms. Genetic testing should be performed as early as possible if this disease is suspected. This case provides an important reference for the diagnosis and treatment of future cases.

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.

A Novel SETBP1 Gene Disruption by a De Novo Balanced Translocation in a Patient with Speech Impairment, Intellectual, and Behavioral Disorder

2020 ◽  
Author(s):  
Ivona Vrkić Boban ◽  
Futoshi Sekiguchi ◽  
Mirela Lozić ◽  
Noriko Miyake ◽  
Naomichi Matsumoto ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Autosomal Dominant ◽  
De Novo ◽  
Chromosomal Abnormalities ◽  
Chromosome Translocation ◽  
Behavioral Disorder ◽  
Behavioral Difficulties ◽  
Speech Impairment ◽  
Balanced Translocation ◽  
Severe Intellectual Disability

AbstractBalanced chromosomal abnormalities (BCAs) can disrupt gene function resulting in disease. To date, BCA disrupting the SET binding protein 1 (SETBP1) gene has not been reported. On the other hand, de novo heterozygous variants in the highly conserved 11-bp region in SETBP1 can result in the Schinzel–Giedion syndrome. This condition is characterized by severe intellectual disability, a characteristic face, and multiple-system anomalies. Further other types of mutations involving SETBP1 are associated with a different phenotype, mental retardation, autosomal dominant 29 (MRD29), which has mild dysmorphic features, developmental delay, and behavioral disorders. Here we report a male patient who has moderate intellectual disability, mild behavioral difficulties, and severe expressive speech impairment resulting from a de novo balanced chromosome translocation, t(12;18)(q22;q12.3). By whole genome sequencing, we determined the breakpoints at the nucleotide level. The 18q12.3 breakpoint was located between exons 2 and 3 of SETBP1. Phenotypic features of our patient are compatible with those with MRD29. This is the first reported BCA disrupting SETBP1.

Bilateral Calcification of Basal Ganglia in a Patient with Duplication of Both 11q13.1q22.1 and 4q35.2 with New Phenotypic Features

2019 ◽  
Vol 159 (3) ◽  
pp. 130-136
Author(s):  
Maha S. Zaki ◽  
Ola M. Eid ◽  
Maha M. Eid ◽  
Amal M. Mohamed ◽  
Inas S.M. Sayed ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Autosomal Dominant ◽  
De Novo ◽  
Susceptibility Loci ◽  
Loss Of Function ◽  
Subunit C ◽  
Autistic Behavior ◽  
Basal Ganglia Calcification ◽  
Severe Intellectual Disability ◽  
Brain Calcification

We report on a female patient who presented with severe intellectual disability and autistic behavior, dysmorphic features, orodental anomalies, and bilateral calcification of basal ganglia. Using a high-density oligonucleotide microarray, we have identified a de novo duplication of 11q13.1q22.1 involving the dosage sensitive genes FGF3 and FGF4, genes related to autosomal dominant disorders KMT5B, GAL, SPTBN2, and LRP5, susceptibility loci SCZD2, SLEH1, and SHANK2, mitochondrial genes NDUFV1, NDUFS8, and TMEM126B, and many loss of function genes, including PHOX2A, CLPB, MED17, B3GNT1, LIPT2, and CLPB. However, the duplication did not involve Ribonuclease H2, subunit C (RNASEH2C) which is considered to be located in the critical region for Aicardi-Goutières syndrome. In combination with the duplication at 11q13.1, a 1.849-Mb heterozygous duplication at 4q35.2 was also identified. Although this duplicated region does not contain causative genes related to brain calcification, the duplication at 4q35 was reported previously in a patient with basal ganglia calcification, coats' like retinopathy, and glomerulosclerosis. Our patient's presentation and genomic findings indicate that duplication of 4q35.2 could be a novel genetic cause of calcification of basal ganglia. Our report also underscores the clinical significance of rearrangements in 11q13.1q22.1 in the pathogenesis of basal ganglia calcification.

CASZ1 loss-of-function mutation contributes to familial dilated cardiomyopathy

2017 ◽  
Vol 55 (9) ◽  
Author(s):  
Xing-Biao Qiu ◽  
Xin-Kai Qu ◽  
Ruo-Gu Li ◽  
Hua Liu ◽  
Ying-Jia Xu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Autosomal Dominant ◽  
Cardiac Development ◽  
Index Patient ◽  
Loss Of Function ◽  
Zinc Finger Transcription Factor ◽  
Complete Penetrance ◽  
Familial Dilated Cardiomyopathy ◽  
Postnatal Adaptation

AbstractBackground:The zinc finger transcription factor CASZ1 plays a key role in cardiac development and postnatal adaptation, and in mice, deletion of theMethods:The coding exons and splicing junction sites of theResults:A novel heterozygous CASZ1 mutation, p.K351X, was identified in an index patient with DCM. Genetic analysis of the mutation carrier’s family showed that the mutation co-segregated with DCM, which was transmitted in an autosomal dominant pattern with complete penetrance. The nonsense mutation, which was absent in 400 referential chromosomes, altered the amino acid that was highly conserved evolutionarily. Biological investigations revealed that the mutant CASZ1 had no transcriptional activity.Conclusions:The current study reveals

scholarly journals Consequences of NMDA receptor deficiency can be rescued in the adult brain

2017 ◽  
Author(s):  
Catharine A. Mielnik ◽  
Mary A. Binko ◽  
Adam J. Funk ◽  
Emily M. Johansson ◽  
Katheron Intson ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Nmda Receptor ◽  
Neurodevelopmental Disorders ◽  
Gene Editing ◽  
Adult Brain ◽  
Loss Of Function ◽  
Cognitive Behaviors ◽  
Adult Mice ◽  
Activity Dependent ◽  
Nmdar Subunits

AbstractN-methyl-D-aspartate receptors (NMDARs) are required to shape activity-dependent connections in the developing and adult brain. Impaired NMDAR signaling through genetic or environmental insults causes a constellation of neurodevelopmental disorders that manifest as intellectual disability, epilepsy, autism, or schizophrenia. It is not clear whether the developmental impacts of NMDAR dysfunction can be overcome by interventions in adulthood. This question is paramount for neurodevelopmental disorders arising from mutations that occur in the GRIN genes, which encode NMDAR subunits, and the broader set of mutations that disrupt NMDAR function. We developed a mouse model where a congenital loss-of-function allele of Grin1 is restored to wildtype by gene editing with Cre recombinase. Rescue of NMDARs in adult mice yields surprisingly robust improvements in cognitive behaviors, including those that are refractory to treatment with current medications. These results suggest that neurodevelopmental disorders arising from NMDAR deficiency can be effectively treated in adults.

scholarly journals Mapping Autosomal Recessive Intellectual Disability: Combined Microarray and Exome Sequencing Identifies 26 Novel Candidate Genes in 192 Consanguineous Families

2016 ◽  
Author(s):  
Ricardo Harripaul ◽  
Nasim Vasli ◽  
Anna Mikhailov ◽  
Muhammad Arshad Rafiq ◽  
Kirti Mittal ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Autosomal Recessive ◽  
De Novo ◽  
Clinical Diagnostics ◽  
High Yield ◽  
Disease Genes ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Whole Exome

Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations(ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7,andUSP44),and missense mutations include the first reports of variants inBDNForTET1associated with ID. The genes identified also showed overlap withde novogene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.

scholarly journals Biophysical classification of a CACNA1D de novo mutation as a high-risk mutation for a severe neurodevelopmental disorder

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadja T. Hofer ◽  
Petronel Tuluc ◽  
Nadine J. Ortner ◽  
Yuliia V. Nikonishyna ◽  
Monica L. Fernándes-Quintero ◽  
...  
Keyword(s):  
High Risk ◽  
Neurodevelopmental Disorders ◽  
Developmental Disorder ◽  
De Novo ◽  
Disease Risk ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
De Novo Mutation ◽  
Loss Of Function ◽  
Gain Of Function

Abstract Background There is increasing evidence that de novo CACNA1D missense mutations inducing increased Cav1.3 L-type Ca2+-channel-function confer a high risk for neurodevelopmental disorders (autism spectrum disorder with and without neurological and endocrine symptoms). Electrophysiological studies demonstrating the presence or absence of typical gain-of-function gating changes could therefore serve as a tool to distinguish likely disease-causing from non-pathogenic de novo CACNA1D variants in affected individuals. We tested this hypothesis for mutation S652L, which has previously been reported in twins with a severe neurodevelopmental disorder in the Deciphering Developmental Disorder Study, but has not been classified as a novel disease mutation. Methods For functional characterization, wild-type and mutant Cav1.3 channel complexes were expressed in tsA-201 cells and tested for typical gain-of-function gating changes using the whole-cell patch-clamp technique. Results Mutation S652L significantly shifted the voltage-dependence of activation and steady-state inactivation to more negative potentials (~ 13–17 mV) and increased window currents at subthreshold voltages. Moreover, it slowed tail currents and increased Ca2+-levels during action potential-like stimulations, characteristic for gain-of-function changes. To provide evidence that only gain-of-function variants confer high disease risk, we also studied missense variant S652W reported in apparently healthy individuals. S652W shifted activation and inactivation to more positive voltages, compatible with a loss-of-function phenotype. Mutation S652L increased the sensitivity of Cav1.3 for inhibition by the dihydropyridine L-type Ca2+-channel blocker isradipine by 3–4-fold. Conclusions and limitations Our data provide evidence that gain-of-function CACNA1D mutations, such as S652L, but not loss-of-function mutations, such as S652W, cause high risk for neurodevelopmental disorders including autism. This adds CACNA1D to the list of novel disease genes identified in the Deciphering Developmental Disorder Study. Although our study does not provide insight into the cellular mechanisms of pathological Cav1.3 signaling in neurons, we provide a unifying mechanism of gain-of-function CACNA1D mutations as a predictor for disease risk, which may allow the establishment of a more reliable diagnosis of affected individuals. Moreover, the increased sensitivity of S652L to isradipine encourages a therapeutic trial in the two affected individuals. This can address the important question to which extent symptoms are responsive to therapy with Ca2+-channel blockers.

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