The variation, described in the journal Cell Host & Microbe, is one of the first genetic risk factors for HIV to be identified only in those of African descent, and puts a spotlight on the differences in our genetic makeup that play a critical role in susceptibility to HIV-AIDS.
The gene in question expresses the Duffy antigen receptor. People who do not express this gene are known to be less susceptible to the malaria as a result of Plasmodium vivax. However, the Duffy antigen influences levels of chemokines, which play a role in defending the body against HIV infection. HIV affects 25 million people in sub-Saharan Africa today, an HIV burden greater than any other region of the world. Sexual behavior and other social factors do not fully explain the large discrepancy in HIV prevalence compared to populations worldwide.
"In sub-Saharan Africa, the vast majority of people do not express Duffy on their red blood cells," said senior lead author Robin Weiss, of University College London. "This is one of the first genetic factors particularly common in Africans that has been shown to confer more susceptibility to HIV."
