Genetics of Coronary Artery Disease

Coronary heart disease affects ≈15.4 million individuals in the United States1 and is one of the main causes of mortality and morbidity.1 A familial component contributes to cardiovascular disease (CVD) susceptibility,2 but it was not until the emergence of genomewide association studies (GWAS) that genetic loci were identified that displayed consistent associations with coronary artery disease (CAD) across multiple cohorts. The present article describes recent advances in the understanding of the genetic basis of CAD.Family2 and twin3 studies provided convincing evidence that CAD clusters in families and has a heritable component2–5; however, the delineation of the specific genetic architecture that predisposes to CAD has been challenging, with initial candidate gene approaches yielding inconsistent results.6 In contrast to candidate gene approaches that focus on genetic variation in genes whose gene products are known to play an important role in cardiovascular physiology, GWAS simultaneously assess the association with CAD of hundreds of thousands of genetic variants distributed across the whole genome. Therefore, GWAS represent an essentially unbiased approach that is not limited by the current (patho)physiological understanding of CVD and bears the potential of discovering completely new molecular mechanisms that predispose to CAD.In 2007, the first GWAS for CAD were published.7–9 The main finding was a locus on chromosome 9p21, which is still the most consistently associated CAD locus to date.10 Subsequent studies revealed that this locus is related to a broad spectrum of vascular phenotypes, including CAD and myocardial infarction,7–9 coronary artery calcification,11 peripheral artery disease,12,13 and abdominal aortic aneurysm.14 To increase power for the detection of genetic variants with smaller effect sizes, large consortia have been built that combine genetic-epidemiological data from multiple cohorts and tens …