Researchers analyzed the DNA of close to 12,400 people who had coronary artery disease (CAD) and 7,400 people who did not. In an effort to identify genes specific for heart attack, they also compared the DNA of almost 5,800 CAD patients who had a history of heart attack with 3,600 patients who had no such history.
The initial analysis led to the discovery of ADAMTS7, a gene linked to the buildup of plaque in the arteries leading to the heart, says study researcher Muredach P. Reilly, MD, of the University of Pennsylvania. The secondary analysis led to the identification of an association at the ABO blood group gene.
When arterial plaque was present, the same enzyme found in people with type O blood appeared to offer protection against heart attack. But this does not mean people with type O blood can ignore other risk factors for heart disease, Reilly says.
The research appears online in the Jan. 15 issue of The Lancet.
“People with this blood type appear to have some mild protection against heart attack, but genes are just one part of the story,” he tells WebMD.
The newly discovered gene variant ADAMTS7 is one of about a dozen genes associated with heart disease risk identified within the last few years, Reilly says.
“Most are associated with plaque buildup [known medically as atherosclerosis] and not with other known heart disease risk factors,” he says. “This suggests we may have a more targeted approach to preventing this risk factor in the future.”