scholarly journals Whole Exome Sequencing Reveals Pathogenic Variants in MYO3A, MYO15A and COL9A3, and Differential Frequencies in Ancestral Alleles in Hearing Impairment Genes Among Individuals from Cameroon

2020 ◽  
Author(s):  
Ambroise Wonkam ◽  
Noluthando Manyisa ◽  
Christian D Bope ◽  
Collet Dandara ◽  
Emile R Chimusa

Abstract There is scarcity of known gene variants of Hearing Impairment (HI) in African populations. This knowledge deficit is ultimately affecting the development of genetic diagnoses. We used whole exome sequencing to investigate gene variants, pathways of interactive genes, and the fractions of ancestral over derived alleles for 159 HI genes, among 18 Cameroonian patients with non-syndromic HI (NSHI), and 129 ethnically matched controls. Pathogenic and likely pathogenic (PLP) variants were found in MYO3A, MYO15A and COL9A3, with a resolution rate of 50% (9/18 patients). The study identified significant genetic differentiation in novel population specific gene variants at FOXD4L2, DHRS2L6, RPL3L and VTN, between HI patients and controls. These gene variants are found in functional/co-expressed interactive networks with other known HI associated genes; and in the same pathways with VTN being a hub protein, i.e. focal adhesion pathway and regulation of the actin cytoskeleton (p values < 0.05). The results suggest that these novel population specific gene variants are possible modifiers of the HI phenotypes. We found a high proportion of ancestral allele vs derived at low HI patients-specific minor allele frequency in range of 0.0 to 0.1. The results showed a relatively low pick up rate of PLP variants in known genes in this group of Cameroonian patients with NSHI. In addition, findings may signal an evolutionary enrichment of some variants of HI genes in patients, as the result of polygenic adaptation, and suggest the possibility of multigenic influence on the phenotype of congenital HI, which deserves further investigations.

Author(s):  
Adam L. Numis ◽  
Gilberto da Gente ◽  
Elliott H. Sherr ◽  
Hannah C. Glass

Abstract Background The contribution of pathogenic gene variants with development of epilepsy after acute symptomatic neonatal seizures is not known. Methods Case–control study of 20 trios in children with a history of acute symptomatic neonatal seizures: 10 with and 10 without post-neonatal epilepsy. We performed whole-exome sequencing (WES) and identified pathogenic de novo, transmitted, and non-transmitted variants from established and candidate epilepsy association genes and correlated prevalence of these variants with epilepsy outcomes. We performed a sensitivity analysis with genes associated with coronary artery disease (CAD). We analyzed variants throughout the exome to evaluate for differential enrichment of functional properties using exploratory KEGG searches. Results Querying 200 established and candidate epilepsy genes, pathogenic variants were identified in 5 children with post-neonatal epilepsy yet in only 1 child without subsequent epilepsy. There was no difference in the number of trios with non-transmitted pathogenic variants in epilepsy or CAD genes. An exploratory KEGG analysis demonstrated a relative enrichment in cell death pathways in children without subsequent epilepsy. Conclusions In this pilot study, children with epilepsy after acute symptomatic neonatal seizures had a higher prevalence of coding variants with a targeted epilepsy gene sequencing analysis compared to those patients without subsequent epilepsy. Impact We performed whole-exome sequencing (WES) in 20 trios, including 10 children with epilepsy and 10 without epilepsy, both after acute symptomatic neonatal seizures. Children with post-neonatal epilepsy had a higher burden of pathogenic variants in epilepsy-associated genes compared to those without post-neonatal epilepsy. Future studies evaluating this association may lead to a better understanding of the risk of epilepsy after acute symptomatic neonatal seizures and elucidate molecular pathways that are dysregulated after brain injury and implicated in epileptogenesis.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Jiang ◽  
Dong Chen

Abstract Background Degenerative lumbar spinal stenosis (DLSS) is a common lumbar disease that requires surgery. Previous studies have indicated that genetic mutations are implicated in DLSS. However, studies on specific gene mutations are scarce. Whole-exome sequencing (WES) is a valuable research tool that identifies disease-causing genes and could become an effective strategy to investigate DLSS pathogenesis. Methods From January 2016 to December 2017, we recruited 50 unrelated patients with symptoms consistent with DLSS and 25 unrelated healthy controls. We conducted WES and exome data analysis to identify susceptible genes. Allele mutations firstly identified potential DLSS variants in controls to the patients’ group. We conducted a site-based association analysis to identify pathogenic variants using PolyPhen2, SIFT, Mutation Taster, Combined Annotation Dependent Depletion, and Phenolyzer algorithms. Potential variants were further confirmed using manual curation and validated using Sanger sequencing. Results In this cohort, the major classification variant was missense_mutation, the major variant type was single nucleotide polymorphism (SNP), and the major single nucleotide variation was C > T. Multiple SNPs in 34 genes were identified when filtered allele mutations in controls to retain only patient mutations. Pathway enrichment analyses revealed that mutated genes were mainly enriched for immune response-related signaling pathways. Using the Novegene database, site-based associations revealed several novel variants, including HLA-DRB1, PARK2, ACTR8, AOAH, BCORL1, MKRN2, NRG4, NUP205 genes, etc., were DLSS related. Conclusions Our study revealed that deleterious mutations in several genes might contribute to DLSS etiology. By screening and confirming susceptibility genes using WES, we provided more information on disease pathogenesis. Further WES studies incorporating larger DLSS patient cohorts are required to comprehend the genetic landscape of DLSS pathophysiology fully.


Author(s):  
J Fonseca ◽  
C Melo ◽  
C Ferreira ◽  
M Sampaio ◽  
R Sousa ◽  
...  

AbstractEarly infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 (RHOBTB2) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.


PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0124178 ◽  
Author(s):  
Selene M. Virk ◽  
Richard M. Gibson ◽  
Miguel E. Quinones-Mateu ◽  
Jill S. Barnholtz-Sloan

2015 ◽  
Vol 3 (4) ◽  
pp. 283-301 ◽  
Author(s):  
Jesse M. Hunter ◽  
Mary Ellen Ahearn ◽  
Christopher D. Balak ◽  
Winnie S. Liang ◽  
Ahmet Kurdoglu ◽  
...  

Author(s):  
Marzia De Bortoli ◽  
Alex V. Postma ◽  
Giulia Poloni ◽  
Martina Calore ◽  
Giovanni Minervini ◽  
...  

2017 ◽  
Vol 97 (1) ◽  
pp. 49-59 ◽  
Author(s):  
N. Dinckan ◽  
R. Du ◽  
L.E. Petty ◽  
Z. Coban-Akdemir ◽  
S.N. Jhangiani ◽  
...  

Tooth agenesis is a common craniofacial abnormality in humans and represents failure to develop 1 or more permanent teeth. Tooth agenesis is complex, and variations in about a dozen genes have been reported as contributing to the etiology. Here, we combined whole-exome sequencing, array-based genotyping, and linkage analysis to identify putative pathogenic variants in candidate disease genes for tooth agenesis in 10 multiplex Turkish families. Novel homozygous and heterozygous variants in LRP6, DKK1, LAMA3, and COL17A1 genes, as well as known variants in WNT10A, were identified as likely pathogenic in isolated tooth agenesis. Novel variants in KREMEN1 were identified as likely pathogenic in 2 families with suspected syndromic tooth agenesis. Variants in more than 1 gene were identified segregating with tooth agenesis in 2 families, suggesting oligogenic inheritance. Structural modeling of missense variants suggests deleterious effects to the encoded proteins. Functional analysis of an indel variant (c.3607+3_6del) in LRP6 suggested that the predicted resulting mRNA is subject to nonsense-mediated decay. Our results support a major role for WNT pathways genes in the etiology of tooth agenesis while revealing new candidate genes. Moreover, oligogenic cosegregation was suggestive for complex inheritance and potentially complex gene product interactions during development, contributing to improved understanding of the genetic etiology of familial tooth agenesis.


Author(s):  
Qingwen Zeng ◽  
Yanjie Fan ◽  
Lili Wang ◽  
Zhuo Huang ◽  
Xuefan Gu ◽  
...  

AbstractBackground:Mucopolysaccharidosis IIIB (MPS IIIB) is a genetic disease characterized by mutations in theCase presentation:Whole exome sequencing (WES) was conducted and the putative pathogenic variants were validated by Sanger sequencing. The activity of MPS IIIB related enzyme in the patient’s blood serum was assayed. A heterozygous, non-synonymous mutation (c.1562C>T, p.P521L) as well as a novel mutation (c.1705C>A, p.Q569K) were found in theConclusions:Our results describe an atypical form of MPS IIIB and illustrate the diagnostic potential of targeted WES in Mendelian disease with unknown etiology. WES could become a powerful tool for molecular diagnosis of MPS IIIB in clinical setting.


2020 ◽  
Author(s):  
Chen Zhao ◽  
Hongyan Chai ◽  
Qinghua Zhou ◽  
Jiadi Wen ◽  
Uma M. Reddy ◽  
...  

Purpose: Pregnancy loss ranging from spontaneous abortion (SAB) to stillbirth can result from monogenic causes of Mendelian inheritance. This study evaluated the clinical application of whole exome sequencing (WES) in identifying the genetic etiology for pregnancy loss. Methods: A cohort of 102 specimens from products of conception (POC) with normal karyotype and absence of pathogenic copy number variants were selected for WES. Abnormality detection rate (ADR) and variants of diagnostic value correlated with SAB and stillbirth were evaluated. Results: WES detected six pathogenic variants, 16 likely pathogenic variants, and 17 variants of uncertain significance favor pathogenic (VUSfp) from this cohort. The ADR for pathogenic and likely pathogenic variants was 22% and reached 35% with the inclusion of VUSfp. The ADRs of SAB and stillbirth were 36% and 33%, respectively. Affected genes included those associated with multi-system abnormalities, neurodevelopmental disorders, cardiac anomalies, skeletal dysplasia, metabolic disorders and renal diseases. Conclusion: These results supported the clinical utility of WES for detecting monogenic etiology of pregnancy loss. The identification of disease associated variants provided information for follow-up genetic counseling of recurrence risk and management of subsequent pregnancies. Discovery of novel variants could provide insight for underlying molecular mechanisms causing fetal death.


2021 ◽  
Vol 13 ◽  
Author(s):  
Lin Sun ◽  
Jianye Zhang ◽  
Ning Su ◽  
Shaowei Zhang ◽  
Feng Yan ◽  
...  

Background: Sporadic dementias generally occur in older age and are highly polygenic, which indicates some patients transmitted in a poly-genes hereditary fashion.Objective: Our study aimed to analyze the correlations of genetic features with clinical symptoms in patients with degenerative dementia.Methods: We recruited a group of 84 dementia patients and conducted the whole exome sequencing (WES). The data were analyzed focusing on 153 dementia-related causing and susceptible genes.Results: According to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines, we identified four reported pathogenic variants, namely, PSEN1 c.A344G, APP c.G2149A, MAPT c.G1165A, and MAPT c.G742A, one reported likely pathogenic variant, namely, PSEN2 c.G100A, one novel pathogenic variants, SQSTM1 c.C671A, and three novel likely pathogenic variants, namely, ABCA7 c.C4690T, ATP13A2 c.3135delC, and NOS3 c.2897-2A > G. 21 variants with uncertain significance in PSEN2, C9orf72, NOTCH3, ABCA7, ERBB4, GRN, MPO, SETX, SORL1, NEFH, ADCM10, and SORL1, etc., were also detected in patients with Alzheimer’s disease (AD) and frontotemporal dementia (FTD).Conclusion: The new variants in dementia-related genes indicated heterogeneity in pathogenesis and phenotype of degenerative dementia. WES could serve as an efficient diagnostic tool for detecting intractable dementia.


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