The Genetic Control of Left Atrial Gene Expression Yields Insights into the Genetic Susceptibility for Atrial Fibrillation

Abstract

Background

Genome wide association studies have identified 23 loci for atrial fibrillation (AF), but the mechanisms responsible for these associations, as well as the causal genes and genetic variants, remain undefined.

Methods and Results

To identify the effect of common genetic variants on gene expression that might explain the mechanisms linking genome wide association loci with AF risk, we performed RNA sequencing of left atrial appendages from a biracial cohort of 265 subjects. Combining gene expression data with genome-wide single nucleotide polymorphism (SNP) data, we found that approximately two-thirds of the expressed genes were regulated in cis by common genetic variants at a false discovery rate of <0.05, defined as cis-expression quantitative trait loci ( cis-eQTLs). 12 of 23 reported AF genome wide association loci displayed genome-wide significant cis-eQTLs, at PRRX1 (chromosome 1q24), SNRNP27 (1q24), CEP68 (2p14), FKBP7 (2q31), KCNN2 (5q22), FAM13B (5q31), CAV1 (7q31), ASAH1 (8p22), MYOZ1 (10q22), C11ORF45 (11q24), TBX5 (12q24), and SYNE2 (14q23), suggesting that altered expression of these genes plays a role in AF susceptibility. Allelic expression imbalance was employed as an independent method to characterize the cis-control of gene expression. 1248 of 5153 queried genes had cis-SNPs that significantly regulated allelic expression at a false discovery rate of <0.05.

Conclusions

We provide a genome wide catalog of the genetic control of gene expression in human left atrial appendage. These data can be used to confirm the relevance of genome wide association loci and to direct future functional studies to identify the genes and genetic variants responsible for complex diseases such as AF.