[Paleopsych] NS: European Gene Deadly In African Americans: Increases Heart Risk

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European Gene Deadly In African Americans: Increases Heart Risk
Heart risk gene hits African Americans hardest
New Scientist, 14 November  2005
[Thanks to Laird for this.]

A gene commonly found in Americans of European descent can  be deadly when 
carried by African Americans, a new study has revealed. The gene  variant more 
than triples the risk heart attack in African American populations,  the 
researchers found.

African Americans are known to be more prone to heart attacks and the 
researchers suggest this may partly be due to European ancestry in those 
individuals, although environmental factors are certainly involved. Kári 
Stefansson at Decode Genetics in Reykjavik, Iceland, and colleagues, isolated a 
gene variant called HapK, which is found in 30% of European Americans and 6% of 
African Americans. The variant also occurs in about 35% of  people in Asia, but 
native Africans do not possess the gene. Stefansson proposes that the gene 
mutation must have occurred after the migration of human populations from 
Africa, about 50,000 years ago. HapK is involved in series of biochemical steps 
that leads to  inflammation in the body. Its role is not fully understood but 
it is believed to  increase the propensity of fatty deposits in the arteries 
– atherosclerotic  plaques – to rupture, leading to a heart attack. 250% 
increased risk
Stefansson studied the significance of the gene variant in more than 3000 
people in three groups, one at the Cleveland Clinic in Ohio, one at Emory 
University in Atlanta, and one at the University of Pennsylvania in 
Philadelphia, all in the US. In the study, published in Nature Genetics, they 
found that  HapK was associated with a slight increase in risk of heart attack 
for  participants of European descent – just 16% – while those of African 
descent  were 3.5 times more likely to suffer a heart attack (equivalent to a 
250%  increase in risk). “If you’re an African American with the variant 
gene you are close to certain  to have a heart attack if nothing is done about 
it,”"It’s very important to  screen and find this subgroup,” Stefansson 
says. His biopharmaceutical company  has two potential drug therapies in 
clinical trials which act by regulating the  inflammatory pathway that HapK is 
involved in. Micro-flora defence
Martin Godfrey, a physician at the British Cardiac Society, notes: “There are
  significant ethnic variations in heart attack risk. Black people in Britain 
and  America are particularly at risk and they have increased incidence of 
strokes  and high blood pressure.” Stefansson speculates that the variant is 
so dangerous in African Americans because, unlike European Americans, they have 
not had thousands of years to adjust to its presence in their genome. “The 
inflammatory pathway probably developed as a protective response to 
micro-organisms; and as populations inhabited very different areas, the 
micro-flora they encountered was vastly different,” he says. “That may be 
the  reason for the differences in frequency of the variant.” Journal 
reference: Nature  Genetics