DALLAS, Jan. 20 -- A gene that appears to provide protection against coronary artery disease (CAD), the cause of heart attacks, has been identified by Japanese researchers, according to a report in today's Circulation: Journal of the American Heart Association.
In a study of more than 400 people in Japan, individuals with a variant form of the p22 phox gene were found to be at lower risk for CAD, say the report's authors Nobutaka Inoue, M.D., and Seinosuke Kawashima, M.D., of the Kobe University School of Medicine, Kobe, Japan.
The p22 phox gene is expressed in the blood vessel, and it has some variation, that is polymorphism, at four sites including active site. The gene affects production of free radicals that oxidize low-density lipoproteins (LDL), the bad form of cholesterol. Oxidized LDL can stick to and damage the artery walls and create plaque buildup. Over time, the plaque build-up can clog blood vessels, setting the stage for a heart attack or stroke.
Researchers found that the variant type of the gene may help prevent oxidation, rather than promote it.
The prevalence of the variant form of the active site was studied in 201 patients with CAD and in 201 "controls," individuals without CAD. It was found in 53 healthy individuals and 28 individuals with CAD.
Compared to individuals with CAD, healthy controls were 49 percent more likely to have the variant form of the active site of this gene, reports the researchers, "indicating that the gene might have a protective effect on heart attack risk." The polymorphism of the other sites occurred at equal rates among healthy individuals and patients.
Studies on a larger population and other ethnic groups will be required to determine whether the variant form of the gene might provide a genetic marker and help determine which individuals are more prone to develop CAD.
Co-authors of the study include Kenji Kanazawa, M.D.; Shinichiro Yamada, M.D.; Hozuka Akita, M.D., and Mitshuhiro Yokoyama, M.D.
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