title: Genetic variants of potassium voltage-gated channel genes (KCNQ1, KCNH2, and KCNE1) affected the risk of atrial fibrillation in elderly patients.
abstract: BACKGROUND
  Atrial fibrillation (AF) is a common type of cardiac arrhythmia and is a major healthcare burden. Around 20% of patients show no obvious clinical manifestations; this can lead to a delay of AF diagnosis and prevention. Genetic mutations are one of the important risk factors for AF. This study aimed to assess the associations between polymorphisms on KCNE1, KCNQ1, and KCNH2 with the risk of AF in a Chinese population.
  
  
  METHODS
  A case-control study comprised of 438 AF patients and 450 controls. The tag single-nucleotide polymorphisms (SNPs) were retrieved in the International HapMap database and Haploview software was used to capture all the polymorphisms on KCNE1, KCNQ1, and KCNH2. DNA was extracted from blood and polymerase chain reaction-based assays were used to genotype polymorphisms of the KCNE1, KCNQ1, and KCNH2 genes. Chi-square test and student t-tests were used to evaluate the differences in the clinical characteristics between AF cases and controls. Odds ratios (OR) and corresponding 95% confidence intervals (CIs) were calculated to assess the association between genetic variants of KCNQ1, KCNH2, KCNE1, and AF risk.
  
  
  RESULTS
  Among the nine tag SNPs, three were significantly associated with the risk of AF: the rs1805127*G allele on KCNE1, and the rs2283228*C and rs1057128*A alleles on KCNQ1. In contrast, rs1805120*T variant was correlated with lower risk of AF. However, the other five genetic variants (rs2237892, rs2237895, rs2237897, rs2070357, and rs2070356) showed no significant association with AF risk (all p>0.05).
  
  
  CONCLUSIONS
  Our study suggested that the rs1805127*G allele of KCNE1, and the rs2283228*C and rs1057128*A alleles on KCNQ1 are risk factors for AF, while the rs1805120*T allele on KCNH2 may serve as a protective factor for AF.
authors.affiliation: 1 Department of Geriatrics, Renmin Hospital of Wuhan University , Wuhan, China .
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: 2 College of Life Sciences, Wuhan University , Wuhan, China .
authors.forename: Chao
authors.initials: C
authors.lastname: Shen
authors.affiliation: 1 Department of Geriatrics, Renmin Hospital of Wuhan University , Wuhan, China .
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Yao
authors.affiliation: 3 Department of Cardiology, Renmin Hospital of Wuhan University , Wuhan, China .|4 Cardiovascular Research Institute, Wuhan University , Wuhan, China .
authors.forename: Jinjun
authors.initials: J
authors.lastname: Liang
authors.affiliation: 3 Department of Cardiology, Renmin Hospital of Wuhan University , Wuhan, China .|4 Cardiovascular Research Institute, Wuhan University , Wuhan, China .
authors.forename: Congxin
authors.initials: C
authors.lastname: Huang
mesh_terms: D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000235:genetics*; D016022:Case-Control Studies; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C489622:KCNE1 protein, human; C000606913:KCNH2 protein, human; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D024642:Potassium Channels, Voltage-Gated