'Rare' Gene Found in Descendants of African Americans may Increase Risk of Heart Disease

Researchers from Weill Cornell Medical College looked at genetic variations that may explain why heart disease, type 2 diabetes, obesity and stroke are so much more common in those with African American ancestry than others.

"The prevalence of the ApoE mutation may put large numbers of Africans and African descendants worldwide at risk for a triglyceride--linked disorder," senior study author Dr. Ronald G. Crystal said, who is also the chairmen of genetic medicine at the school, via a press release. "But we don't yet know the extent of that risk or its health consequences.

"Inheriting this genetic variant does not mean a person is going to get heart disease and other diseases. It increases their risk, and screening for fats in the blood -- both cholesterol and triglycerides -- as well as maintaining a healthy lifestyle is important. There are many factors at work in these diseases. This may be one player."

It's estimated that the number of Africans and African descendants who may have this gene variant is significantly high. In fact, the researchers believe that close to 1.7 million African Americans in the United States and 36 million sub-Saharan Africans worldwide carry this variant that raises the risk of a lipid disorder.

Researchers studied a single point mutation that replaces one of the DNA amino acid with another in the ApoE gene. It also carries fats and other molecules through the blood.

Scientists have believed that more than 95 percent of the world's population has one of three common ApoE variants -- 2, 3, or 4. The rest have one of 38 rare ApoE mutations, among them the R145C variant studied in this research. In the three decades since the variant's discovery, only 32 instances of it have been reported in the scientific literature, Crystal adds.

Researchers evaluated the mutation in their work by studying the genetics of Qatari-people who have lived in the country for three generations or more.

To their surprise, investigators found that only 17 percent of the African-derived genetic subgroup had the rare ApoE variant, and none of the Arab or Persian participants carried the mutation.

More information regarding the study can be found via the American Journal of Cardiology.