07-18-2008, 07:47 AM
There's no doubt Africans have borne the brunt of the AIDS epidemic. Now researchers in London and Texas say it may have something to do with a single gene variant that could account for 11%, or about 2.5 million, of Africa's HIV cases.
Published in the journal Cell Host & Microbe, the findings center around one gene variation that blocks a receptor from being expressed on the surface of red blood cells. Scientists had previously studied this genetic variant — found almost exclusively in Africans and their descendants — because it also conferred protection against an early form of malaria. (The malaria parasite needed the receptor to infect blood cells; without the receptor, the parasite starved and died.)
More than 90% of sub-Saharan Africans lack the red-blood-cell receptor, along with two-thirds of African-Americans. But the variant that once saved its carriers from one disease now appears to make them more susceptible to another. According to the paper, people with the gene variant (that blocks a receptor from being expressed on the surface of red blood cells) were 40% more likely to become infected with HIV than people without it.
Read more: http://www.time.com/time/health/article/...19,00.html
Published in the journal Cell Host & Microbe, the findings center around one gene variation that blocks a receptor from being expressed on the surface of red blood cells. Scientists had previously studied this genetic variant — found almost exclusively in Africans and their descendants — because it also conferred protection against an early form of malaria. (The malaria parasite needed the receptor to infect blood cells; without the receptor, the parasite starved and died.)
More than 90% of sub-Saharan Africans lack the red-blood-cell receptor, along with two-thirds of African-Americans. But the variant that once saved its carriers from one disease now appears to make them more susceptible to another. According to the paper, people with the gene variant (that blocks a receptor from being expressed on the surface of red blood cells) were 40% more likely to become infected with HIV than people without it.
Read more: http://www.time.com/time/health/article/...19,00.html