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SCN5A mutation status increases the risk of major arrhythmic events in Asian populations with Brugada syndrome: systematic review and meta-analysis.
Rattanawong, P, Chenbhanich, J, Mekraksakit, P, Vutthikraivit, W, Chongsathidkiet, P, Limpruttidham, N, Prasitlumkum, N, Chung, EH
Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc. 2019;(1):e12589
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Abstract
BACKGROUND Brugada syndrome (BrS) is an inherited arrhythmic disease linked to SCN5A mutations. It is controversial whether SCN5A mutation carriers possess a greater risk of major arrhythmic events (MAE). We examined the association of SCN5A mutations and MAE in BrS patients. METHODS We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Included studies were published cohort and case-control studies that compared MAE in BrS patients with and without SCN5A mutations. Data from each study were combined using the random-effects model. Generic inverse variance method of DerSimonian and Laird was employed to calculate the risk ratios (RR) and 95% confidence intervals (CI). RESULTS Seven studies from March 2002 to October 2017 were included (1,049 BrS subjects). SCN5A mutations were associated with MAE in Asian populations (RR = 2.03, 95% CI: 1.37-3.00, p = 0.0004, I2 = 0.0%), patients who were symptomatic (RR = 2.66, 95% CI: 1.62-4.36, p = 0.0001, I2 = 23.0%), and individuals with spontaneous type-1 Brugada pattern (RR = 1.84, 95% CI: 1.05-3.23, p = 0.03, I2 = 0.0%). CONCLUSIONS SCN5A mutations in BrS increase the risk of MAE in Asian populations, symptomatic BrS patients, and individuals with spontaneous type-1 Brugada pattern. Our study suggests that SCN5A mutation status should be an important tool for risk assessment in BrS patients.
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KCND3 potassium channel gene variant confers susceptibility to electrocardiographic early repolarization pattern.
Teumer, A, Trenkwalder, T, Kessler, T, Jamshidi, Y, van den Berg, ME, Kaess, B, Nelson, CP, Bastiaenen, R, De Bortoli, M, Rossini, A, et al
JCI insight. 2019;(23)
Abstract
BACKGROUNDThe presence of an early repolarization pattern (ERP) on the surface ECG is associated with risk of ventricular fibrillation and sudden cardiac death. Family studies have shown that ERP is a highly heritable trait, but molecular genetic determinants are unknown.METHODSTo identify genetic susceptibility loci for ERP, we performed a GWAS and meta-analysis in 2,181 cases and 23,641 controls of European ancestry.RESULTSWe identified a genome-wide significant (P < 5 × 10-8) locus in the potassium voltage-gated channel subfamily D member 3 (KCND3) gene that was successfully replicated in additional 1,124 cases and 12,510 controls. A subsequent joint meta-analysis of the discovery and replication cohorts identified rs1545300 as the lead SNP at the KCND3 locus (OR 0.82 per minor T allele, P = 7.7 × 10-12) but did not reveal additional loci. Colocalization analyses indicate causal effects of KCND3 gene expression levels on ERP in both cardiac left ventricle and tibial artery.CONCLUSIONSIn this study, we identified for the first time to our knowledge a genome-wide significant association of a genetic variant with ERP. Our findings of a locus in the KCND3 gene provide insights not only into the genetic determinants but also into the pathophysiological mechanism of ERP, discovering a promising candidate for functional studies.FUNDINGThis project was funded by the German Center for Cardiovascular Research (DZHK Shared Expertise SE081 - STATS). For detailed funding information per study, see the Supplemental Acknowledgments.