Abstract:Objective To discuss the correlations of CX40 gene (GJA5 ) single nucleotide polymorphism (SNP) with atrial fibrillation. Methods Two hundreds of patients were selected in the Department of Cardiovascular Medicine, the First Affiliated Hospital of University of South China from June 2012 to December 2012 and divided into atrial fibrillation group (98 cases with continuous fibrillation) and control group (102 cases with sinus rhythm). Clinic information of the patients was collected. Left atrial diameters of the patients were collected through chest and cardiac color ultrasonography. DNA was extracted from venous blood. The locus of SNP was detected through PCR and electrophoresis, and directly examined after PCR products were purified. Based on Hardy-Weinberg Equilibrium examination, the genotype and gene frequency of each group were compared. And non-conditional logistic regression analysis was carried out on the risk factors of atrial fibrillation. Results GJA5 gene rs10465885 had A/G polymorphism. The frequency of allele A and G of the atrial fibrillation group was 0.54 and 0.46 respectively, and that of the control group was 0.45 and 0.55 respectively. In accordance with Hardy -Weinberg Equilibrium examination, the groups complied with the equilibrium. The AA genotype of the arial fibrillation group was significantly higher than that of the control group. There was not significant difference in AG, GG genotype or allele frequency between the two groups. The AA genotype of rs10465885 locus of GJA5 gene (OR = 2.49) and left atrial diameter (OR = 1.29) were the risk factors of atrial fibrillation. The genotype of GJA5 gene (rs10465885) had no correlation with the left atrial diameter. Conclusions Gene polymorphism exists at rs10465885 locus GJA5 of gene.AA genotype and left atrial diameter are the risk factors of atrial fibrillation.