Diminished Expression Is Associated With Increased Risk of Atrial Fibrillation and Shortening of the Cardiac Action Potential.
BACKGROUND: Atrial fibrillation (AF) affects over 33 million individuals worldwide. Genome-wide association studies have identified at least 30 AF loci, but the mechanisms through which individual variants lead to altered disease risk have remained unclear for the majority of these loci. At the 1q24 locus, we hypothesized that the transcription factor could be a strong candidate gene as it is expressed in the pulmonary veins, a source of AF in many individuals. We sought to identify the molecular mechanism, whereby variation at 1q24 may lead to AF susceptibility.
METHODS AND RESULTS: We sequenced a ≈158 kb region encompassing in 962 individuals with and without AF. We identified a broad region of association with AF at the 1q24 locus. Using in silico prediction and functional validation, we identified an enhancer that interacts with the promoter of in cells of cardiac lineage. Within this enhancer, we identified a single-nucleotide polymorphism, rs577676, which alters enhancer activity in a mouse atrial cell line and in embryonic zebrafish and differentially regulates expression in human left atria. We found that suppression of in human embryonic stem cell-derived cardiomyocytes and embryonic zebrafish resulted in shortening of the atrial action potential duration, a hallmark of AF.
CONCLUSIONS: We have identified a functional genetic variant that alters expression, ultimately resulting in electrophysiological alterations in atrial myocytes that may promote AF.
|Year of Publication
Circ Cardiovasc Genet
|PubMed Central ID
HHSN268201100037C / HL / NHLBI NIH HHS / United States
K24 HL105780 / HL / NHLBI NIH HHS / United States
R01 HL104156 / HL / NHLBI NIH HHS / United States
R01 HL092577 / HL / NHLBI NIH HHS / United States
R01 HL128914 / HL / NHLBI NIH HHS / United States
T32 HL007208 / HL / NHLBI NIH HHS / United States
K23 HL114724 / HL / NHLBI NIH HHS / United States