Comprehensive genetic analysis by whole exome sequencing in 352 Korean pediatric patients with unknown neurodevelopmental disorders

AbstractImportanceAccurate diagnosis of pediatric patients with complicated neurological problems demands a well-coordinated combination of robust genetic analytic capability and delicate clinical evaluation. It should be tested whether this challenge can be augmented by whole exome sequencing (WES).ObjectiveTo evaluate the utility of WES-based diagnosis and discovery of novel variants of undiagnosed patients with complex neurodevelopmental problems in a country with a centralized medical system.Design, setting, and participantsA cohort of 352 Korean patients, believed to cover a major portion of the entire country from July 2014 to April 2017, with a broad spectrum of neurodevelopmental disorders without any pathogenic variants revealed by conventional methods were evaluated by trio-based WES at Seoul National University Children’s Hospital.ExposuresWES of patients and parents and subsequent evaluation of genetic variants.Main outcomes and measuresGenetic variants from each patient were evaluated for known disease association and novel variants were assessed for possible involvement with neurodevelopment process.ResultsWe identified disease-causing variants, including newly discovered variants, in 57.4% of the probands, who had underwent a mean of 5.6 years of undiagnosed periods and visited mean of 2.3 tertiary hospitals. The cohort included 112 patients with variants that were previously reported as pathogenic (31.8%), 16 patients with copy number variants (4.5%) and 27 patients with variants that were associated with different clinical symptoms (7.7%). We also discovered potentially pathogenic variants from 47 patients that required further functional assessments (13.4%) and demonstrated potential implications in neurodevelopmental disorders. Following the genetic analysis, we provided more precise treatments to selected patients. A few clinical vignettes are presented that illuminate the potential diagnostic pitfalls that one could have encountered without this approach.Conclusions and relevanceOur results highlight the utility of WES-based diagnosis for improved patient care in a country with a centralized medical system and discovery of novel pathophysiology mechanisms.Key pointsQuestionWhat is the advantage of whole exome sequencing based diagnosis of pediatric neurology patients with unknown rare symptoms in a large tertiary clinic in a country with a centralized medical system?FindingsWhole exome sequencing of 352 Korean patients, with a mean of 5.7 years of undiagnosed period, yielded 44.0% of conservative diagnostic yield. A number of cases were directly benefitted by trio-based WES via termination of diagnostic odyssey, genetic counseling for next offspring, or suggestion of more effective and customized treatment options.MeaningWe report on the establishment of a national-level whole exome-based diagnosis system, with emphasis on deliberate integration of clinical interpretation and genetic analysis. Whole exome sequencing should be a choice of diagnostic tools for pediatric neurologic patients with ambiguous symptoms.

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Whole-Exome Sequencing Identifies Novel Variants for Tooth Agenesis

Journal of Dental Research ◽

10.1177/0022034517724149 ◽

2017 ◽

Vol 97 (1) ◽

pp. 49-59 ◽

Cited By ~ 16

Author(s):

N. Dinckan ◽

R. Du ◽

L.E. Petty ◽

Z. Coban-Akdemir ◽

S.N. Jhangiani ◽

...

Keyword(s):

Exome Sequencing ◽

Whole Exome Sequencing ◽

Permanent Teeth ◽

Tooth Agenesis ◽

Disease Genes ◽

Nonsense Mediated Decay ◽

Pathogenic Variants ◽

Whole Exome ◽

Novel Variants ◽

Complex Inheritance

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.

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Whole‐Exome Sequencing of a Saudi Epilepsy Cohort Reveals Association Signals in Known and Potentially Novel Loci

10.21203/rs.3.rs-915593/v1 ◽

2021 ◽

Author(s):

Amein Kadhem AlAli ◽

Abdulrahman Al-Enazi ◽

Ahmed Ammar ◽

Mahmoud Hajj ◽

Cyril Cyrus ◽

...

Keyword(s):

Exome Sequencing ◽

Whole Exome Sequencing ◽

Rare Variants ◽

High Rate ◽

Variants Of Unknown Significance ◽

Pathogenic Variants ◽

Whole Exome ◽

Novel Variants ◽

Unknown Significance ◽

Rare Genetic Variants

Abstract Background Epilepsy, a serious chronic neurological condition effecting up to 100 million people globally, has clear genetic underpinnings including common and rare variants. In Saudi Arabia the prevalence of epilepsy is high and caused mainly by perinatal and genetic factors. No whole-exome sequencing (WES) studies have been performed to date in Saudi Arabian Epilepsy cohorts. This offers a unique opportunity for the discovery of rare genetic variants impacting this disease as there is a high rate of consanguinity amongst large tribal pedigrees. Results We performed WES on 144 individuals diagnosed with epilepsy, to interrogate known Epilepsy related genes for known and functional novel variants. We also used an American College of Medical Genetics (ACMG) guideline based variant prioritization approach in an attempt to discover putative causative variants. We identified a 32 potentially causative pathogenic variants across 30 different genes in 44/144 (30%) of these Saudi Epilepsy individuals. We also identified 232 variants of unknown significance (VUS) across 101 different genes in 133/144 (92%) subjects. Strong enrichment of variants of likely pathogenicity were observed in previously described epilepsy-associated loci, and a number of putative pathogenic variants in novel loci are also observed. Conclusion Several putative pathogenic variants known to be epilepsy-related loci were identified for the first time in our population, in addition to several potential new loci have been identified which may be prioritized for further investigation.

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GENE-30. PRELIMINARY STUDY ON WHOLE-EXOME SEQUENCING TECHNOLOGY IN THE GENETIC ANALYSIS OF PEDIATRIC PATIENTS WITH GLIOMAS

Neuro-Oncology ◽

10.1093/neuonc/noz175.432 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi104-vi104

Author(s):

Mingyao Lai ◽

Juan Li ◽

Junjie Zhen ◽

jiangfen zhou ◽

Qingjun Hu ◽

...

Keyword(s):

Genetic Analysis ◽

Signaling Pathways ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Pediatric Patients ◽

Genetic Mutation ◽

Pleomorphic Xanthoastrocytoma ◽

Pathological Examination ◽

Sequencing Technology ◽

Whole Exome

Abstract OBJECTIVE To analyze the genes related to the signaling pathways in pediatric gliomas and drug-related genes with whole-exome sequencing technology. METHODS The tumor tissues and matched blood samples of 17 enrolled patients were detected with whole-exome sequencing technology. There were 3 cases of diffuse midline gliomas, 2 cases of childhood glioblastomas, 3 cases of disffuse astrocytoma, 1 case of pleomorphic xanthoastrocytoma, 1 case of ganglioglioma, 6 cases of anaplastic ependymoma and 1 case of ependymoma in this study. All the enrolled patients who were no more than 14 years old received surgery in the Department of Neurosurgery, Guangdong Sanjiu Brain Hospital. The diagnosis was confirmed by pathological examination and the sample acquisition was approved by hospital ethics committee. RESULTS With the use of whole-exome sequencing technology, a total of 31 related genetic mutations were detected in 15 cases, while no genetic mutation was detected in the other 2 cases. The genes related to the signaling pathways in pediatric gliomas included ATRX, ASL1, BCOR, EP300, FGFR1, H3F3A, IGF1R, MED12, PIK3R1, PRKDC, RB1, SETD2, SMARCA4, SOX2, TGFBR2, and the drug-related genes included AKT1, BCL2, BRAF, BRCA2, CCND1, CCND2, CDK6, EGFR, FGF3, KRAS, MET, PDGFRA, PIK3CA, PTEN, TP53, TSC1. One patient only had genes related to the signaling pathways, and 14 patients had drug-related genes. CONCLUSION Applying whole-exome sequencing technology in the genetic analysis of pediatric patients with gliomas has remarkable guiding significance for revealing the mechanism of disease, searching for therapeutic targets and adopting individualized treatment, which can bring potential benefits to pediatric patients. However, more samples and further data analysis and verification are needed in future study.

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Whole-exome sequencing with targeted analysis and epilepsy after acute symptomatic neonatal seizures

Pediatric Research ◽

10.1038/s41390-021-01509-3 ◽

2021 ◽

Author(s):

Adam L. Numis ◽

Gilberto da Gente ◽

Elliott H. Sherr ◽

Hannah C. Glass

Keyword(s):

Exome Sequencing ◽

Whole Exome Sequencing ◽

De Novo ◽

List Type ◽

Sequencing Analysis ◽

Neonatal Seizures ◽

Pathogenic Variants ◽

Targeted Analysis ◽

Whole Exome ◽

Epilepsy Gene

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.

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Analysis workflow to assess de novo genetic variants from human whole-exome sequencing

STAR Protocols ◽

10.1016/j.xpro.2021.100383 ◽

2021 ◽

Vol 2 (1) ◽

pp. 100383

Author(s):

Nicholas S. Diab ◽

Spencer King ◽

Weilai Dong ◽

Garrett Allington ◽

Amar Sheth ◽

...

Keyword(s):

Exome Sequencing ◽

Whole Exome Sequencing ◽

Genetic Variants ◽

De Novo ◽

Whole Exome ◽

Analysis Workflow

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Novel MYO15A variants are associated with hearing loss in the two Iranian pedigrees

BMC Medical Genetics ◽

10.1186/s12881-020-01168-x ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Somayeh Khatami ◽

Masomeh Askari ◽

Fatemeh Bahreini ◽

Morteza Hashemzadeh-Chaleshtori ◽

Saeed Hematian ◽

...

Keyword(s):

Hearing Loss ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Genetic Diagnosis ◽

Clinical Genetic ◽

Large Size ◽

Whole Exome ◽

Novel Variants ◽

Syndromic Hearing Loss ◽

Traditional Approaches

Abstract Background Clinical genetic diagnosis of non-syndromic hearing loss (NSHL) is quite challenging. With regard to its high heterogeneity as well as large size of some genes, it is also really difficult to detect causative mutations using traditional approaches. One of the recent technologies called whole-exome sequencing (WES) has been thus developed in this domain to remove the limitations of conventional methods. Methods This study was a report on a research study of two unrelated pedigrees with multiple affected cases of hearing loss (HL). Accordingly, clinical evaluations and genetic analysis were performed in both families. Results The results of WES data analysis to uncover autosomal recessive non-syndromic hearing loss (ARNSHL) disease-causing variants was reported in the present study. Initial analysis identified two novel variants of MYO15A i.e. c.T6442A:p.W2148R and c.10504dupT:p.C3502Lfs*15 correspondingly which were later confirmed by Sanger validations and segregation analyses. According to online prediction tools, both identified variants seemed to have damaging effects. Conclusion In this study, whole exome sequencing were used as a first approach strategy to identify the two novel variants in MYO15A in two Iranian families with ARNSHL.

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Genetic analysis of impaired trimethylamine metabolism using whole exome sequencing

BMC Medical Genetics ◽

10.1186/s12881-017-0369-8 ◽

2017 ◽

Vol 18 (1) ◽

Cited By ~ 5

Author(s):

Yiran Guo ◽

Liang-Dar Hwang ◽

Jiankang Li ◽

Jason Eades ◽

Chung Wen Yu ◽

...

Keyword(s):

Genetic Analysis ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Whole Exome

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RHOBTB2 p.Arg511Trp Mutation in Early Infantile Epileptic Encephalopathy-64: Review and Case Report

Journal of Pediatric Genetics ◽

10.1055/s-0040-1722288 ◽

2021 ◽

Author(s):

J Fonseca ◽

C Melo ◽

C Ferreira ◽

M Sampaio ◽

R Sousa ◽

...

Keyword(s):

Case Report ◽

Intellectual Disability ◽

Status Epilepticus ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Epileptic Encephalopathy ◽

Btb Domain ◽

Pathogenic Variants ◽

Severe Intellectual Disability ◽

Whole Exome

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.

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