Common gene variant linked to heart disease

Caucasians carrying a common genetic variant are up to 60 percent more likely to develop heart disease than those who don't, regardless of lifestyle, according to two new studies.

The studies, involving about 40 000 people in four countries, indicate that genetic factors can play a role in whether a person develops heart disease beyond smoking, diet, exercise or other well-established risk factors.

Heart disease is the leading cause of death in Western countries.

About 25 percent of people of European origin carry this genetic variant, which appears on a region of chromosome 9, the researchers reported.

"If we can identify genetic factors which influence heart disease risk over and above known risk factors, we can do a better job of identifying those people who will benefit most from early intervention to reduce their risk," said Ruth McPherson, director of the University of Ottawa Heart Institute Lipid Research Laboratory and lead author of one of the studies.

McPherson and colleagues scanned the DNA of 1 300 heart patients and 1 500 healthy people in Ottawa for genetic variants.

The results were checked against other large-scale genetic heart studies in the United States and Denmark involving 22 000 patients.

Of the Ottawa patients, about 33 percent of those with early onset heart disease had this genetic variant versus 24 percent of healthy elderly people, McPherson said.

In a separate study, researchers in Iceland reported that this same variant on chromosome 9 accounted for about one-fifth of the incident of heart attack in patients of European origin and one-third of early-onset cases, apart from other risk factors.

That study involved 17 000 people in Iceland and the United States, of whom more than 20 percent of participants carried two copies of the variant.

Patients with two copies of the variant had a more than 60 percent increase in risk of heart attack than those without the variant. Those with one copy had a more moderate risk, the researchers reported.

The variant is "one of the most significant genetic risk factors found to date for heart attack as a public health problem," wrote researchers at deCODE in Reykjavik, Iceland, who led the study.

Source : http://www.iol.co.za