August 5, 2010

Genome Scan Reveals Genes Affecting Cholesterol

Researchers have uncovered 95 genes that are believed to affect blood cholesterol, including a few that are affected by drugs and others that might be the basis of new drugs.

The findings show that regulating cholesterol levels is even more complex than many people knew but also point to some short-cuts to prevent heart disease.

The variations account for a quarter to a third of the inherited variation in cholesterol levels and triglycerides, the researchers said.

"These results help refine our course for preventing and treating heart disease, a health problem that affects millions of Americans and many more people worldwide," Dr Francis Collins, director of the National Institutes of Health, told Rueters Health.

Collins promised to direct the NIH to try to more quickly translate such basic scientific findings into developing drugs and other treatments. The NIH funds and conducts scientific research, which is frequently licensed to commercial drug companies to develop products.

The team of researchers mapped the DNA of more than 100,000 people to identify the genes affecting various forms of cholesterol, including high density lipoprotein (HDL), low density lipoprotein (LDL) and triglycerides.

Doctors know that some people inherit high levels of cholesterol, some inherit low levels, and some people also vary in whether the food they eat makes their cholesterol go up or down.

A variety of drugs are manufactured to help control cholesterol, such as Lipitor, but with heart disease the number one killer of people in the industrialized world, doctors want to know more.

The researchers said their findings prove right a labor-intensive approach called a genome-wide association study, which involves studying the entire genetic map for clues that scientists would otherwise have no way of finding.

Daniel Rader of the University of Pennsylvania and colleagues found one DNA sequence that affects a gene called SORT1. 20 percent of people have a genetic variation that predisposes them to having low levels of LDL and VLDL -- very low density lipoprotein. These people have a 40 percent lower than average risk of heart attack.

Rader's team linked this variation to SORT1 and said it may represent a way to design a new drug to prevent heart disease, by imitating the naturally low LDL levels of people who have the gene.

The results of the study have been published this week in the journal Nature.


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