About one-fourth of all black men and women carry a genetic mutation that dramatically reduces their risk for coronary artery disease, new research reveals.
The mutation is found on a gene that has been linked to a higher risk for heart disease among other races, the investigators noted. But their study found that in black men and women who carry this single variation, the risk for arterial narrowing or clogging drops fivefold.
"What we think we have here is the first confirmed hereditary link to cardiovascular disease among African Americans, and it is a protective one," epidemiologist Diane Becker, a professor at the Johns Hopkins University School of Medicine and Hopkin's Bloomberg School of Public Health and the study's senior investigator, said in a Hopkins news release.
Blacks face a greater risk for heart disease than any other racial group, the study authors noted.
For their study, reported in the Jan. 27 online issue of the Journal of Human Genetics, the researchers analyzed the blood of 548 black men and women, 26 to 60 years old, who lived in Baltimore. None had heart disease when their blood was drawn. For confirmation, blood sampling and analysis was done on several hundred comparable residents of Atlanta and Durham, N.C.
In addition to the shield against coronary artery disease that was found for those with a single mutation, the study also determined that people who had inherited the same mutation from both their mother and their father -- thus carrying two copies -- had a tenfold drop in their risk for coronary artery disease. About 6 percent of blacks in the United States fall into that category, the researchers said.