Genetic loci on chromosomes 4q25, 7p31, and 12p12 are associated with onset of lone atrial fibrillation before the age of 40 years

Background

Three distinct genetic loci on chromosomes 1q21, 4q25, and 16q22 have been associated with atrial fibrillation (AF) in genome-wide association studies (GWAS). Five additional loci have been associated primarily with the PR interval and subsequently with AF. We aimed to investigate if 8 single nucleotide polymorphisms (SNPs), representing the 8 genomic loci previously linked with AF in genome-wide association studies, were associated with early-onset lone AF.

Methods

We included 209 patients with early-onset lone AF, and a control group consisting of 534 individuals free of AF. The 8 SNPs were genotyped using TaqMan assays (Applied Biosystems, Foster City, CA).

Results

Three SNPs were found to be significantly associated with early-onset lone AF: rs2200733 closest to PITX2 (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.16-2.27; P = 0.004), rs3807989 near to CAV1 (OR 1.35; 95% CI, 1.06-1.72; P = 0.015), and rs11047543 near to SOX5 (OR 1.70; 95% CI, 1.18-2.44; P = 0.004). When correcting for multiple testing, rs2200733 and rs11047543 were still significantly associated with AF.

Conclusions

Three SNPs, rs2200733 (4q25), rs3807989 (7p31), and rs11047543 (12p12), were associated with early-onset lone AF. All 3 SNPs are positioned close to genes that in previous studies have been demonstrated to be important for cardiac morphology/development, thereby suggesting a link between these SNPs and structural heart disease. Our results however, indicate that variants in these 3 loci are associated with AF through mechanisms that do not involve major structural abnormalities in the heart.