Anti-malaria gene 'makes Africans more susceptible to HIV'

A gene found only in people of African ancestry which evolved to prevent malaria infection now increases the odds of contracting AIDS by up to 40 per cent, a new study has found.

The gene does, however, seem to protect against the progression of the disease, allowing those carrying it to live about two years longer.

Around 90 per cent of people in Africa carry this genetic variant and it may be responsible for 11 per cent of the infections there, the study published Wednesday in Cell Host and Microbe found.

"After thousands of years of adaptation, this Duffy variant rose to high frequency because it helped protect against malaria," said co-author Matthew Dolan of the Wilford Hall United States Air Force Medical Center.

"Now, with another global pandemic on the scene, this same variant renders people more susceptible to HIV."

The gene in question, the Duffy Antigen Receptor for Chemokines (DARC), encodes a protein found mainly at the surface of red blood cells.

About 68 per cent of people infected with HIV live in Sub-Saharan Africa, the United Nations says.

The US and British researchers who authored the study said sexual behavior and other social factors do not fully explain large discrepancies in HIV prevalence.

Earlier studies have shown that HIV can bind to red blood cells through this receptor. The receptor has also been found to bind a wide array of inflammatory molecules, including one which is highly effective in suppressing replication of HIV.