scholarly journals Heterozygous De Novo Truncating Mutation of Nucleolin in an ASD Individual Disrupts Its Nucleolar Localization

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 51
Author(s):  
Taimoor I. Sheikh ◽  
Ricardo Harripaul ◽  
Nasim Vasli ◽  
Majid Ghadami ◽  
Susan L. Santangelo ◽  
...  
Keyword(s):  
De Novo ◽  
Critical Role ◽  
Autism Spectrum ◽  
Terminal Sequence ◽  
Chromatin Decondensation ◽  
Indel Mutation ◽  
Truncating Mutation ◽  
Whole Exome ◽  
Multiple Processes ◽  
B23 Protein

Nucleolin (NCL/C23; OMIM: 164035) is a major nucleolar protein that plays a critical role in multiple processes, including ribosome assembly and maturation, chromatin decondensation, and pre-rRNA transcription. Due to its diverse functions, nucleolin has frequently been implicated in pathological processes, including cancer and viral infection. We recently identified a de novo frameshifting indel mutation of NCL, p.Gly664Glufs*70, through whole-exome sequencing of autism spectrum disorder trios. Through the transfection of constructs encoding either a wild-type human nucleolin or a mutant nucleolin with the same C-terminal sequence predicted for the autism proband, and by using co-localization with the nucleophosmin (NPM; B23) protein, we have shown that the nucleolin mutation leads to mislocalization of the NCL protein from the nucleolus to the nucleoplasm. Moreover, a construct with a nonsense mutation at the same residue, p.Gly664*, shows a very similar effect on the location of the NCL protein, thus confirming the presence of a predicted nucleolar location signal in this region of the NCL protein. Real-time fluorescence recovery experiments show significant changes in the kinetics and mobility of mutant NCL protein in the nucleoplasm of HEK293Tcells. Several other studies also report de novo NCL mutations in ASD or neurodevelopmental disorders. The altered mislocalization and dynamics of mutant NCL (p.G664Glufs*70/p.G664*) may have relevance to the etiopathlogy of NCL-related ASD and other neurodevelopmental phenotypes.

scholarly journals SENP1 in the retrosplenial agranular cortex regulates core autistic-like symptoms in mice

2021 ◽  
Author(s):  
Kan Yang ◽  
Yuhan Shi ◽  
Xiujuan Du ◽  
Yuefang Zhang ◽  
Shifang Shan ◽  
...  
Keyword(s):  
Social Interaction ◽  
De Novo ◽  
Fragile X ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Repetitive Behaviors ◽  
Genetic Components ◽  
Truncating Mutation ◽  
Synaptic Functions ◽  
Core Symptoms

AbstractAutism spectrum disorder (ASD) is a highly heritable complex neurodevelopmental disorder. While the core symptoms of ASD are defects of social interaction and repetitive behaviors, over 50% of ASD patients have comorbidity of intellectual disabilities (ID) or developmental delay (DD), raising the question whether there are genetic components and neural circuits specific for core symptoms of ASD. Here, by focusing on ASD patients who do not show compound ID or DD, we identified a de novo heterozygous gene-truncating mutation of the Sentrin-specific peptidase1 (SENP1) gene, coding the small ubiquitin-like modifiers (SUMO) deconjugating enzyme, as a potentially new candidate gene for ASD. We found that Senp1 haploinsufficient mice exhibited core symptoms of autism such as deficits in social interaction and repetitive behaviors, but normal learning and memory ability. Moreover, we found that the inhibitory and excitatory synaptic functions were severely affected in the retrosplenial agranular (RSA) cortex of Senp1 haploinsufficient mice. Lack of Senp1 led to over SUMOylation and degradation of fragile X mental retardation protein (FMRP) proteins, which is coded by the FMR1 gene, also implicated in syndromic autism. Importantly, re-introducing SENP1 or FMRP specifically in RSA fully rescued the defects of synaptic functions and core autistic-like symptoms of Senp1 haploinsufficient mice. Taken together, these results elucidate that disruption of the SENP1-FMRP regulatory axis in the RSA may cause core autistic symptoms, which further provide a candidate brain region for therapeutic intervene of ASD by neural modulation approaches.

scholarly journals Identification of a β-Arrestin 2 Mutation Related to Autism by Whole-Exome Sequencing

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yunfei Tang ◽  
Yamei Liu ◽  
Lei Tong ◽  
Shini Feng ◽  
Dongshu Du ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Developmental Stages ◽  
De Novo ◽  
Repetitive Behavior ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Potential Contribution ◽  
De Novo Mutations ◽  
Whole Exome

Autism spectrum disorder (ASD) is a complex neurological disease characterized by impaired social communication and interaction skills, rigid behavior, decreased interest, and repetitive activities. The disease has a high degree of genetic heterogeneity, and the genetic cause of ASD in many autistic individuals is currently unclear. In this study, we report a patient with ASD whose clinical features included social interaction disorder, communication disorder, and repetitive behavior. We examined the patient’s genetic variation using whole-exome sequencing technology and found new de novo mutations. After analysis and evaluation, ARRB2 was identified as a candidate gene. To study the potential contribution of the ARRB2 gene to the human brain development and function, we first evaluated the expression profile of this gene in different brain regions and developmental stages. Then, we used weighted gene coexpression network analysis to analyze the associations between ARRB2 and ASD risk genes. Additionally, the spatial conformation and stability of the ARRB2 wild type and mutant proteins were examined by simulations. Then, we further established a mouse model of ASD. The results showed abnormal ARRB2 expression in the mouse ASD model. Our study showed that ARRB2 may be a risk gene for ASD, but the contribution of de novo ARRB2 mutations to ASD is unclear. This information will provide references for the etiology of ASD and aid in the mechanism-based drug development and treatment.

A method to delineate de novo missense variants across pathways prioritizes genes linked to autism

2021 ◽  
Vol 13 (594) ◽  
pp. eabc1739
Author(s):  
Amanda Koire ◽  
Panagiotis Katsonis ◽  
Young Won Kim ◽  
Christie Buchovecky ◽  
Stephen J. Wilson ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Protein Function ◽  
De Novo ◽  
Autism Spectrum ◽  
Homologous Gene ◽  
Fitness Effect ◽  
Missense Variants ◽  
Whole Exome ◽  
New Gene ◽  
The Impact

Genotype-phenotype relationships shape health and population fitness but remain difficult to predict and interpret. Here, we apply an evolutionary action method to de novo missense variants in whole-exome sequences of individuals with autism spectrum disorder (ASD) to unravel genes and pathways connected to ASD. Evolutionary action predicts the impact of missense variants on protein function by measuring the fitness effect based on phylogenetic distances and substitution odds in homologous gene sequences. By examining de novo missense variants in 2384 individuals with ASD (probands) compared to matched siblings without ASD, we found missense variants in 398 genes representing 23 pathways that were biased toward higher evolutionary action scores than expected by random chance; these pathways were involved in axonogenesis, synaptic transmission, and neurodevelopment. The predicted fitness impact of de novo and inherited missense variants in candidate genes correlated with the IQ of individuals with ASD, even for new gene candidates. Taking an evolutionary action method, we detected those missense variants most likely to contribute to ASD pathogenesis and elucidated their phenotypic impact. This approach could be applied to integrate missense variants across a patient cohort to identify genes contributing to a shared phenotype in other complex diseases.

scholarly journals Case Report: Christianson Syndrome Caused by SLC9A6 Mutation: From Case to Genotype-Phenotype Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yueyun Lan ◽  
Sheng Yi ◽  
Mengting Li ◽  
Jinqiu Wang ◽  
Qi Yang ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Autism Spectrum ◽  
Frontal Pole ◽  
Motor Delay ◽  
Distal Muscle ◽  
Whole Exome ◽  
Phenotype Analysis ◽  
Genetics And Genomics ◽  
Core Symptoms

Christianson syndrome (CS) is an X-linked neurodevelopmental syndrome characterized by microcephaly, epilepsy, ataxia, and severe generalized developmental delay. Pathogenic mutations in the SLC9A6 gene, which encodes the Na+/H+ exchanger protein member 6 (NHE6), are associated with CS and autism spectrum disorder in males. In this study, whole exome sequencing (WES) and Sanger sequencing revealed a novel de novo frameshift variant c.1548_1549insT of SLC9A6 in a 14-month-old boy with early-onset seizures. According to The American College of Medical Genetics and Genomics (ACMG)/the Association for Molecular Pathology (AMP) guidelines, the variant was classified as pathogenic. The proband presented with several core symptoms of typical epilepsy, including microcephaly, motor delay, distal muscle weakness, micrognathia, occasional unprovoked laughter, swallowing and speech difficulties. Electroencephalography (EEG) showed spikes-slow waves in frontal pole, frontal, anterior temporal and frontal midline point areas. Gesell development schedules (GDS) indicated generalized developmental delay. We also summarized all the reported variants and analyzed the correlation of genotype and phenotype of CS. Our study extends the mutation spectrum of the SLC9A6 gene, and it might imply that the phenotypes of CS are not correlated with SLC9A6 genotypes.

scholarly journals Whole exome sequencing reveals inherited and de novo variants in autism spectrum disorder: a trio study from Saudi families

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Bashayer Al-Mubarak ◽  
Mohamed Abouelhoda ◽  
Aisha Omar ◽  
Hesham AlDhalaan ◽  
Mohammed Aldosari ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Whole Exome

scholarly journals Low load for disruptive mutations in autism genes and their biased transmission

2015 ◽  
Vol 112 (41) ◽  
pp. E5600-E5607 ◽  
Author(s):  
Ivan Iossifov ◽  
Dan Levy ◽  
Jeremy Allen ◽  
Kenny Ye ◽  
Michael Ronemus ◽  
...  
Keyword(s):  
Negative Selection ◽  
De Novo ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Mutational Load ◽  
Whole Exome ◽  
Strong Negative Selection ◽  
Low Load ◽  
Spectrum Disorders ◽  
Exome Sequence

We previously computed that genes with de novo (DN) likely gene-disruptive (LGD) mutations in children with autism spectrum disorders (ASD) have high vulnerability: disruptive mutations in many of these genes, the vulnerable autism genes, will have a high likelihood of resulting in ASD. Because individuals with ASD have lower fecundity, such mutations in autism genes would be under strong negative selection pressure. An immediate prediction is that these genes will have a lower LGD load than typical genes in the human gene pool. We confirm this hypothesis in an explicit test by measuring the load of disruptive mutations in whole-exome sequence databases from two cohorts. We use information about mutational load to show that lower and higher intelligence quotients (IQ) affected individuals can be distinguished by the mutational load in their respective gene targets, as well as to help prioritize gene targets by their likelihood of being autism genes. Moreover, we demonstrate that transmission of rare disruptions in genes with a lower LGD load occurs more often to affected offspring; we show transmission originates most often from the mother, and transmission of such variants is seen more often in offspring with lower IQ. A surprising proportion of transmission of these rare events comes from genes expressed in the embryonic brain that show sharply reduced expression shortly after birth.

scholarly journals De Novo PORCN and ZIC2 Mutations in a Highly Consanguineous Family

2021 ◽  
Vol 22 (4) ◽  
pp. 1549
Author(s):  
Laura Castilla-Vallmanya ◽  
Semra Gürsoy ◽  
Özlem Giray-Bozkaya ◽  
Aina Prat-Planas ◽  
Gemma Bullich ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
De Novo ◽  
Phenotypic Traits ◽  
Gorlin Syndrome ◽  
Consanguineous Family ◽  
Indel Mutation ◽  
Whole Exome ◽  
Heterozygous Variant ◽  
Skeletal Defects ◽  
Turkish Family

We present a Turkish family with two cousins (OC15 and OC15b) affected with syndromic developmental delay, microcephaly, and trigonocephaly but with some phenotypic traits distinct between them. OC15 showed asymmetrical skeletal defects and syndactyly, while OC15b presented with a more severe microcephaly and semilobal holoprosencephaly. All four progenitors were related and OC15 parents were consanguineous. Whole Exome Sequencing (WES) analysis was performed on patient OC15 as a singleton and on the OC15b trio. Selected variants were validated by Sanger sequencing. We did not identify any shared variant that could be associated with the disease. Instead, each patient presented a de novo heterozygous variant in a different gene. OC15 carried a nonsense mutation (p.Arg95*) in PORCN, which is a gene responsible for Goltz-Gorlin syndrome, while OC15b carried an indel mutation in ZIC2 leading to the substitution of three residues by a proline (p.His404_Ser406delinsPro). Autosomal dominant mutations in ZIC2 have been associated with holoprosencephaly 5. Both variants are absent in the general population and are predicted to be pathogenic. These two de novo heterozygous variants identified in the two patients seem to explain the major phenotypic alterations of each particular case, instead of a homozygous variant that would be expected by the underlying consanguinity.

scholarly journals Whole Exome Sequencing Identifies Novel De Novo Variants Interacting with Six Gene Networks in Autism Spectrum Disorder

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Namshin Kim ◽  
Kyoung Hyoun Kim ◽  
Won-Jun Lim ◽  
Jiwoong Kim ◽  
Soon Ae Kim ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genetic Factors ◽  
De Novo ◽  
Genetic Network ◽  
Autism Spectrum ◽  
Network Analyses ◽  
Functional Relationships ◽  
Whole Exome

Autism spectrum disorder (ASD) is a highly heritable condition caused by a combination of environmental and genetic factors such as de novo and inherited variants, as well as rare or common variants among hundreds of related genes. Previous genome-wide association studies have identified susceptibility genes; however, most ASD-associated genes remain undiscovered. This study aimed to examine rare de novo variants to identify genetic risk factors of ASD using whole exome sequencing (WES), functional characterization, and genetic network analyses of identified variants using Korean familial dataset. We recruited children with ASD and their biological parents. The clinical best estimate diagnosis of ASD was made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5TM), using comprehensive diagnostic instruments. The final analyses included a total of 151 individuals from 51 families. Variants were identified and filtered using the GATK Best Practices for bioinformatics analysis, followed by genome alignments and annotation to the reference genome assembly GRCh37 (liftover to GRCh38), and further annotated using dbSNP 154 build databases. To evaluate allele frequencies of de novo variants, we used the dbSNP, gnomAD exome v2.1.1, and genome v3.0. We used Ingenuity Pathway Analysis (IPA, Qiagen) software to construct networks using all identified de novo variants with known autism-related genes to find probable relationships. We identified 36 de novo variants with potential relations to ASD; 27 missense, two silent, one nonsense, one splice region, one splice site, one 5′ UTR, and one intronic SNV and two frameshift deletions. We identified six networks with functional relationships. Among the interactions between de novo variants, the IPA assay found that the NF-κB signaling pathway and its interacting genes were commonly observed at two networks. The relatively small cohort size may affect the results of novel ASD genes with de novo variants described in our findings. We did not conduct functional experiments in this study. Because of the diversity and heterogeneity of ASD, the primary purpose of this study was to investigate probable causative relationships between novel de novo variants and known autism genes. Additionally, we based functional relationships with known genes on network analysis rather than on statistical analysis. We identified new variants that may underlie genetic factors contributing to ASD in Korean families using WES and genetic network analyses. We observed novel de novo variants that might be functionally linked to ASD, of which the variants interact with six genetic networks.

scholarly journals Molecular Dysregulation in Autism Spectrum Disorder

2021 ◽  
Vol 11 (9) ◽  
pp. 848
Author(s):  
Pritmohinder S. Gill ◽  
Jeffery L. Clothier ◽  
Aravindhan Veerapandiyan ◽  
Harsh Dweep ◽  
Patricia A. Porter-Gill ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
De Novo ◽  
Genomic Analysis ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Nucleotide Polymorphisms ◽  
Common Variants ◽  
Treatment And Prevention ◽  
Whole Exome ◽  
Number Variation

Autism Spectrum Disorder (ASD) comprises a heterogeneous group of neurodevelopmental disorders with a strong heritable genetic component. At present, ASD is diagnosed solely by behavioral criteria. Advances in genomic analysis have contributed to numerous candidate genes for the risk of ASD, where rare mutations and s common variants contribute to its susceptibility. Moreover, studies show rare de novo variants, copy number variation and single nucleotide polymorphisms (SNPs) also impact neurodevelopment signaling. Exploration of rare and common variants involved in common dysregulated pathways can provide new diagnostic and therapeutic strategies for ASD. Contributions of current innovative molecular strategies to understand etiology of ASD will be explored which are focused on whole exome sequencing (WES), whole genome sequencing (WGS), microRNA, long non-coding RNAs and CRISPR/Cas9 models. Some promising areas of pharmacogenomic and endophenotype directed therapies as novel personalized treatment and prevention will be discussed.

Family-based Whole Exome Sequencing of Autism Spectrum Disorder Reveals Novel De Novo Variants in Korean Population

2017 ◽  
Vol 41 (S1) ◽  
pp. S309-S309 ◽  
Author(s):  
H. Yoo ◽  
S.A. Kim ◽  
M. Park ◽  
J. Kim ◽  
W.J. Lim ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Korean Population ◽  
De Novo Mutation ◽  
Whole Exome ◽  
Family Based

ObjectivesThe objective of this family-based whole exome sequencing (WES) is to examine genetic variants of autism spectrum disorder (ASD) in Korean population.MethodsThe probands with ASD and their biological parents were recruited in this study. We ascertained diagnosis based on DSM-5™ criteria, using Autism Diagnostic Observation Schedule and Autism Diagnostic Interview–Revised. We selected probands with typical phenotypes of ASD both in social interaction/communication and repetitive behaviour/limited interest domains, with intellectual disability (IQ < 70), for attaining homogeneity of the phenotypes. First, we performed WES minimum 50× for 13 probands and high-coverage pooled sequencing for their parents. We performed additional WES for 38 trio families, at least 100× depth. De novo mutations were confirmed by Sanger sequencing. All the sequence reads were mapped onto the human reference genome (hg19 without Y chromosome). Bioinformatics analyses were performed by BWA-MEM, Picard, GATK, and snpEff for variant annotation. We selected de novo mutation candidates from probands, which are neither detected in two pooled samples nor both parents.ResultsFifty-one subjects with ASD (5 females, 40∼175 months, mean IQ 42) and their families were included in this study. We discovered 109 de novo variants from 46 families. Twenty-nine variants are expected to be amino acid changing, potentially causing deleterious effects. We assume CELSR3, MYH1, ATXN1, IDUA, NFKB1, and C4A/C4B may have adverse effect on central nerve system.ConclusionsWe observed novel de novo variants which are assumed to contribute to development of ASD with typical phenotypes and low intelligence in WES study.Disclosure of interestThis work has been supported by Healthcare Technology R&D project (No: A120029) by Ministry of Health and Welfare, Republic of Korea.

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