scholarly journals Whole-Exome Sequencing Implicates SCN2A in Episodic Ataxia, but Multiple Ion Channel Variants May Contribute to Phenotypic Complexity

2018 ◽  
Vol 19 (10) ◽  
pp. 3113 ◽  
Author(s):  
Neven Maksemous ◽  
Robert Smith ◽  
Heidi Sutherland ◽  
Hugo Sampaio ◽  
Lyn Griffiths
Keyword(s):  
Sodium Channel ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Complex Disease ◽  
Molecular Genetic ◽  
Gene Mutations ◽  
Episodic Ataxia ◽  
Causative Mutation ◽  
Whole Exome ◽  
Cacna1a Gene

Although the clinical use of targeted gene sequencing-based diagnostics is valuable, whole-exome sequencing has also emerged as a successful diagnostic tool in molecular genetics laboratories worldwide. Molecular genetic tests for episodic ataxia type 2 (EA2) usually target only the specific calcium channel gene (CACNA1A) that is known to cause EA2. In cases where no mutations are identified in the CACNA1A gene, it is important to identify the causal gene so that more effective treatment can be prioritized for patients. Here we present a case of a proband with a complex episodic ataxias (EA)/seizure phenotype with an EA-affected father; and an unaffected mother, all negative for CACNA1A gene mutations. The trio was studied by whole-exome sequencing to identify candidate genes responsible for causing the complex EA/seizure phenotype. Three rare or novel variants in Sodium channel α2-subunit; SCN2A (c.3973G>T: p.Val1325Phe), Potassium channel, Kv3.2; KCNC2 (c.1006T>C: p.Ser336Pro) and Sodium channel Nav1.6; SCN8A (c.3421C>A: p.Pro1141Thr) genes were found in the proband. While the SCN2A variant is likely to be causal for episodic ataxia, each variant may potentially contribute to the phenotypes observed in this family. This study highlights that a major challenge of using whole-exome/genome sequencing is the identification of the unique causative mutation that is associated with complex disease.

scholarly journals The identification of novel gene mutations for degenerative lumbar spinal stenosis using whole-exome sequencing in a Chinese cohort

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Jiang ◽  
Dong Chen
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Spinal Stenosis ◽  
Lumbar Spinal Stenosis ◽  
Gene Mutations ◽  
Specific Gene ◽  
Single Nucleotide ◽  
Degenerative Lumbar Spinal Stenosis ◽  
Whole Exome ◽  
Lumbar Spinal

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.

Identification of a novel causative mutation in KRT1 in diffuse palmoplantar keratoderma, facilitated by whole-exome sequencing

2021 ◽  
Vol 31 (2) ◽  
pp. 264-265
Author(s):  
So Takeuchi ◽  
Takuya Takeichi ◽  
Yasutoshi Ito ◽  
Kana Tanahashi ◽  
Yoshinao Muro ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Causative Mutation ◽  
Palmoplantar Keratoderma ◽  
Whole Exome

scholarly journals Whole-exome sequencing associates novel CSMD1 gene mutations with familial Parkinson disease

2017 ◽  
Vol 3 (5) ◽  
pp. e177 ◽  
Author(s):  
Javier Ruiz-Martínez ◽  
Luis J. Azcona ◽  
Alberto Bergareche ◽  
Jose F. Martí-Massó ◽  
Coro Paisán-Ruiz
Keyword(s):  
Parkinson Disease ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genome Wide Association Study ◽  
Single Gene ◽  
Gene Mutations ◽  
Complement Control Protein ◽  
Genome Wide ◽  
Whole Exome ◽  
A Genome

Objective:Despite the enormous advancements made in deciphering the genetic architecture of Parkinson disease (PD), the majority of PD is idiopathic, with single gene mutations explaining only a small proportion of the cases.Methods:In this study, we clinically evaluated 2 unrelated Spanish families diagnosed with PD, in which known PD genes were previously excluded, and performed whole-exome sequencing analyses in affected individuals for disease gene identification.Results:Patients were diagnosed with typical PD without relevant distinctive symptoms. Two different novel mutations were identified in the CSMD1 gene. The CSMD1 gene, which encodes a complement control protein that is known to participate in the complement activation and inflammation in the developing CNS, was previously shown to be associated with the risk of PD in a genome-wide association study.Conclusions:We conclude that the CSMD1 mutations identified in this study might be responsible for the PD phenotype observed in our examined patients. This, along with previous reported studies, may suggest the complement pathway as an important therapeutic target for PD and other neurodegenerative diseases.

scholarly journals Searching for the missing genetic determinants of hereditary breast cancer risk by whole-exome sequencing of BRCA-negative patients: new candidate genes USP39, SLIT3, CREB3

2021 ◽  
Vol 67 (1) ◽  
pp. 111-116
Author(s):  
Kirill Zagorodnev ◽  
Aleksandr Romanko ◽  
Uliy Gorgul ◽  
Aleksandr Ivantsov ◽  
Anna Sokolenko ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Exome Sequencing ◽  
Candidate Genes ◽  
Whole Exome Sequencing ◽  
Hereditary Breast Cancer ◽  
Germ Line ◽  
Genetic Diagnosis ◽  
Clinical Signs ◽  
Causative Mutation ◽  
Whole Exome

The search for the new hereditary mutations and a precise molecular genetic diagnosis that determines the causative mutation in each specific case of hereditary breast cancer (BC) is a clinically important task since it helps to define the personal therapeutic approach and increase the effectiveness of preventive measures. Using whole-exome sequencing (WES) we analyzed the full spectrum of hereditary variations in 49 Russian patients with clinical signs of a hereditary disease which allowed us to compile a list of 229 candidate probably pathogenic germ-line variants. Then, the selected candidate mutations were validated by Sanger sequencing and molecular-epidemiological studies, the predisposing roles of three oncologically relevant mutations (USP39 c.*208G>C, SLIT3 p.Arg154Cys, and CREB3 p.Lys157Glu) were confirmed. Our candidate genes are first mentioned in connection with the hereditary risk of BC. The final proofs of the causative roles of these variants could be obtained through functional tests as well as via the analysis of the mutations segregation in BC families.

scholarly journals Whole-Exome Sequencing Identifies Causative Mutations in Families with Congenital Anomalies of the Kidney and Urinary Tract

2018 ◽  
Vol 29 (9) ◽  
pp. 2348-2361 ◽  
Author(s):  
Amelie T. van der Ven ◽  
Dervla M. Connaughton ◽  
Hadas Ityel ◽  
Nina Mann ◽  
Makiko Nakayama ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Congenital Anomalies ◽  
Causative Mutation ◽  
Deleterious Mutations ◽  
Whole Exome ◽  
Multiplex Families ◽  
High Fraction ◽  
Etiologic Diagnosis

BackgroundCongenital anomalies of the kidney and urinary tract (CAKUT) are the most prevalent cause of kidney disease in the first three decades of life. Previous gene panel studies showed monogenic causation in up to 12% of patients with CAKUT.MethodsWe applied whole-exome sequencing to analyze the genotypes of individuals from 232 families with CAKUT, evaluating for mutations in single genes known to cause human CAKUT and genes known to cause CAKUT in mice. In consanguineous or multiplex families, we additionally performed a search for novel monogenic causes of CAKUT.ResultsIn 29 families (13%), we detected a causative mutation in a known gene for isolated or syndromic CAKUT that sufficiently explained the patient’s CAKUT phenotype. In three families (1%), we detected a mutation in a gene reported to cause a phenocopy of CAKUT. In 15 of 155 families with isolated CAKUT, we detected deleterious mutations in syndromic CAKUT genes. Our additional search for novel monogenic causes of CAKUT in consanguineous and multiplex families revealed a potential single, novel monogenic CAKUT gene in 19 of 232 families (8%).ConclusionsWe identified monogenic mutations in a known human CAKUT gene or CAKUT phenocopy gene as the cause of disease in 14% of the CAKUT families in this study. Whole-exome sequencing provides an etiologic diagnosis in a high fraction of patients with CAKUT and will provide a new basis for the mechanistic understanding of CAKUT.

scholarly journals Proposal for Modification of Cahan's Criteria Utilizing Molecular Genetic Analyses for Cases without Baseline Histopathology: A Unique Method Applicable to Primary Radiosurgery

2018 ◽  
Vol 80 (01) ◽  
pp. 010-017
Author(s):  
Aaron Rusheen ◽  
James Smadbeck ◽  
Lisa Schimmenti ◽  
Eric Klee ◽  
Michael Link ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Vestibular Schwannoma ◽  
Radiation Treatment ◽  
Molecular Genetic ◽  
Secondary Malignancy ◽  
Whole Exome ◽  
Mate Pair ◽  
Generation Sequencing

Background Cahan's criteria have been utilized since 1948 to establish causality between prior radiation treatment and the development of secondary malignancy. One major criterion specifies that histological and radiographic evidence collected before and after radiation treatment must confirm separate tumor types; however, pretreatment biopsy is rarely obtained prior to radiosurgery for vestibular schwannoma and many other skull base and cranial lesions. Therefore, in these cases Cahan's criteria cannot be validly applied. Objective This article proposes an update to Cahan's criteria using modern molecular genetic analysis for cases lacking baseline histopathology. Methods Mate-pair sequencing and whole exome sequencing of a cerebellopontine angle undifferentiated high-grade pleomorphic sarcoma (UHGPS) that developed after stereotactic radiosurgery of a presumed benign vestibular schwannoma. Results Mate-pair sequencing and whole exome sequencing of the sarcoma revealed complex chromosomal aberrations. Notably, the tumor contained a deletion in the NF2 gene at 22q12 and an in-frame deletion on exon 5 of the remaining copy of NF2. Biallelic events impacting NF2 are atypical for UHGPS but are characteristic for vestibular schwannoma. These findings help support the conclusion that the UHGPS arose from a benign vestibular schwannoma all along. Conclusions Next-generation sequencing can be successfully applied to a radiation-induced sarcoma when both the original and malignant tumors harbor separate signature genetic markers. As our understanding of the genetic profile of various tumors expand, we believe that next-generation sequencing and other genomic tools will play an increasingly important role in establishing causality between radiation and the development of secondary malignancy.

scholarly journals Whole exome sequencing identifies compound heterozygous variants of CR2 gene in monozygotic twin patients with common variable immunodeficiency

2020 ◽  
Vol 8 ◽  
pp. 205031212092265
Author(s):  
Adiratna Mat Ripen ◽  
Hamidah Ghani ◽  
Chai Teng Chear ◽  
Mei Yee Chiow ◽  
Sharifah Nurul Husna Syed Yahya ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Complex Disease ◽  
Monozygotic Twins ◽  
Compound Heterozygous ◽  
Sequencing Analysis ◽  
Missense Mutations ◽  
Upper Respiratory Tract ◽  
Whole Exome ◽  
Tract Infections

Objectives: A pair of female Malay monozygotic twins who presented with recurrent upper respiratory tract infections, hepatosplenomegaly, bronchiectasis and bicytopenia were recruited in this study. Both patients were suspected with primary immunodeficiency diseases. However, the definite diagnosis was not clear due to complex disease phenotypes. The objective of this study was to identify the causative gene mutation in these patients. Methods: Lymphocyte subset enumeration test and whole exome sequencing were performed. Results: We identified a compound heterozygous CR2 mutation (c.1916G>A and c.2012G>A) in both patients. These variants were then confirmed using Sanger sequencing. Conclusion: Whole exome sequencing analysis of the monozygotic twins revealed compound heterozygous missense mutations in CR2.

scholarly journals Pathogenic variants identified by whole-exome sequencing in 43 patients with epilepsy

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Linlin Zhang ◽  
Jinshuang Gao ◽  
Hailiang Liu ◽  
Yuan Tian ◽  
Xiaoli Zhang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Treatment Options ◽  
Molecular Genetic ◽  
Epileptic Encephalopathy ◽  
Molecular Genetic Analysis ◽  
Specific Diagnosis ◽  
Whole Exome ◽  
Early Establishment

Abstract Background Epilepsy is a group of neurological disorders characterized by recurrent epileptic seizures. Epilepsy is affected by many factors, approximately 20–30% of cases are caused by acquired conditions, but in the remaining cases, genetic factors play an important role. Early establishment of a specific diagnosis is important to treat and manage this disease. Methods In this study, we have recruited 43 epileptic encephalopathy patients and the molecular genetic analysis of those children was performed by whole-exome sequencing (WES). Results Fourteen patients (32.6%, 14/43) had positive genetic diagnoses, including fifteen mutations in fourteen genes. The overall diagnostic yield was 32.6%. A total of 9 patients were diagnosed as pathogenic mutations, including 4 variants had been reported as pathogenic previously and 6 novel variants that had not been reported previously. Therefore, WES heralds promise as a tool for clinical diagnosis of patients with genetic disease. Conclusion Early establishment of a specific diagnosis, on the one hand, is necessary for providing an accurate prognosis and recurrence risk as well as optimizing management and treatment options. On the other hand, to unveil the genetic architecture of epilepsy, it is of vital importance to investigate the phenotypic and genetic complexity of epilepsy.

scholarly journals Clinical Application of Whole Exome Sequencing to Identify Rare but Remediable Neurologic Disorders

2020 ◽  
Vol 9 (11) ◽  
pp. 3724
Author(s):  
Min-Jee Kim ◽  
Mi-Sun Yum ◽  
Go Hun Seo ◽  
Yena Lee ◽  
Han Na Jang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genetic Diagnosis ◽  
Intractable Epilepsy ◽  
Episodic Ataxia ◽  
Treatment Modalities ◽  
Congenital Myasthenic Syndrome ◽  
Early Application ◽  
Whole Exome ◽  
Neurologic Disorders

Background: The aim of this study was to describe the application of whole exome sequencing (WES) in the accurate genetic diagnosis and personalized treatment of extremely rare neurogenetic disorders. Methods: From 2017 to 2019, children with neurodevelopmental symptoms were evaluated using WES in the pediatric neurology clinic and medical genetics center. The clinical presentation, laboratory findings including the genetic results from WES, and diagnosis-based treatment and outcomes of the four patients are discussed. Results: A total of 376 children with neurodevelopmental symptom were evaluated by WES, and four patients (1.1%) were diagnosed with treatable neurologic disorders. Patient 1 (Pt 1) showed global muscle hypotonia, dysmorphic facial features, and multiple anomalies beginning in the perinatal period. Pt 1 was diagnosed with congenital myasthenic syndrome 22 of PREPL deficiency. Pt 2 presented with hypotonia and developmental arrest and was diagnosed with autosomal recessive dopa-responsive dystonia due to TH deficiency. Pt 3, who suffered from intractable epilepsy and progressive cognitive decline, was diagnosed with epileptic encephalopathy 47 with a heterozygous FGF12 mutation. Pt 4 presented with motor delay and episodic ataxia and was diagnosed with episodic ataxia type II (heterozygous CACNA1A mutation). The patients’ major neurologic symptoms were remarkably relieved with pyridostigmine (Pt 1), levodopa (Pt 2), sodium channel blocker (Pt 3), and acetazolamide (Pt 4), and most patients regained developmental milestones in the follow-up period (0.4 to 3 years). Conclusions: The early application of WES helps in the identification of extremely rare genetic diseases, for which effective treatment modalities exist. Ultimately, WES resulted in optimal clinical outcomes of affected patients.

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