RRC ID 70331
Author Hayashi K, Teramoto R, Nomura A, Asano Y, Beerens M, Kurata Y, Kobayashi I, Fujino N, Furusho H, Sakata K, Onoue K, Chiang DY, Kiviniemi TO, Buys E, Sips P, Burch ML, Zhao Y, Kelly AE, Namura M, Kita Y, Tsuchiya T, Kaku B, Oe K, Takeda Y, Konno T, Inoue M, Fujita T, Kato T, Funada A, Tada H, Hodatsu A, Nakanishi C, Sakamoto Y, Tsuda T, Nagata Y, Tanaka Y, Okada H, Usuda K, Cui S, Saito Y, MacRae CA, Takashima S, Yamagishi M, Kawashiri MA, Takamura M.
Title Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases.
Journal Cardiovasc Res
Abstract AIMS:The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them.
METHODS AND RESULTS:We performed WES of 23 probands diagnosed with early-onset (<65 years) CCSD and analysed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency < 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as 'pathogenic' by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that two variants in KCNH2 and SCN5A, four variants in SCN10A, and one variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from 'Uncertain significance' to 'Likely pathogenic' in six probands.
CONCLUSION:Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD.
Volume 116(13)
Pages 2116-2130
Published 2020-11-1
DOI 10.1093/cvr/cvaa010
PII 5715576
PMID 31977013
PMC PMC8453299
MeSH Action Potentials / genetics Adult Age of Onset Aged Animals Cardiac Conduction System Disease / epidemiology Cardiac Conduction System Disease / genetics* Cardiac Conduction System Disease / metabolism Cardiac Conduction System Disease / physiopathology Case-Control Studies Computer Simulation ERG1 Potassium Channel / genetics Exome Sequencing* Female Gene Frequency Genetic Association Studies Genetic Predisposition to Disease Genetic Variation* Heart Rate / genetics* Humans Japan / epidemiology Lamin Type A / genetics Male Membrane Proteins / genetics Middle Aged Models, Cardiovascular Myocytes, Cardiac / metabolism NAV1.5 Voltage-Gated Sodium Channel / genetics NAV1.8 Voltage-Gated Sodium Channel / genetics Nuclear Proteins / genetics Phenotype Predictive Value of Tests Risk Assessment Risk Factors Young Adult Zebrafish / genetics Zebrafish / metabolism Zebrafish Proteins / genetics Zebrafish Proteins / metabolism
IF 8.168
Zebrafish Tg(cmlc2:Mermaid)