DALLAS, May 15 -- A gene that helps keep bad cholesterol at bay -- and may reduce heart disease risk by 50 percent -- has been discovered by researchers reporting in this month's Arteriosclerosis, Thombosis and Vascular Biology: Journal of the American Heart Association.
A research group from the Karolinska Hospital in Sweden found that the variation in the gene called microsomal triglyceride transfer (MTP) protein was linked to low levels of low-density lipoprotein, or LDL, in a study of 184 healthy men. LDL is the form of cholesterol that helps create the fatty deposits that can clog blood vessels and cause a heart attack or stroke.
The gene for MTP provides the blueprint for production of the protein that helps assemble LDL. Individuals who carry two copies of the variant form of the gene had LDL cholesterol levels 22 percent lower than those who had one copy or no copies of the variant.
"This kind of reduction would correspond to 50 percent lowering of risk of future heart disease in a 40-year-old man," says the study's lead author, Dr. Fredrik Karpe, of the Atherosclerosis Research Unit, King Gustaf V Research Institute, Karolinska Hospital, Stockholm, Sweden.
Individuals who carry a double copy of the gene variant would have a 25 percent reduced risk.
"The variant of the MTP, found in six percent of the individuals, is of functional importance in regulating expression of the MTP and influences LDL cholesterol concentration," says Karpe. "These findings add to our understanding of how the LDL cholesterol level is regulated and suggest that genetic variation in the MTP expression may have important implications for the development of cardiovascular disease."
The MTP gene was cloned in 1993, but this is the first report on a common
genetic variant within the gene. The variant changes the promoter region of the
MTP gene. The promoter region acts like a start button that signals the
Contact: Carole Bullock
American Heart Association