African-Americans Genetically Prone to HIV, AIDS

| Wed Jul. 16, 2008 1:53 PM EDT

New research shows that Africans and African-Americans bear a gene variant that helps protect them from malaria, but also makes them more vulnerable to HIV infection. The variant increases susceptability to HIV by 40 percent, says the San Francisco Chronicle.

The genetic trait is found in 90 percent of Africans and 60 percent of African-Americans. Thus far, it has protected against malaria by disabling a protein that some strains of malaria use to enter red blood cells. However, that same protein that's disabled in Africans to prevent malaria can actually protect against HIV by soaking up virus cells before they can invade white blood cells. With this sponge-like protein disabled, Africans lose a key pre-infection barrier.

This finding helps explain, in part, the high HIV infection rates among Sub-Saharan Africans and Americans of African descent. On the flipside, there is a genetic variant among people of Northern European heritage that actually makes them immune to HIV infection. Scientists think the mutation was passed down by ancestors who survived the Black Plague. In one test, a man's blood was exposed to 3,000 times the amount of HIV needed to infect a cell, but infection still didn't occur. The HIV virus simply had no gateway of entry.

Both the European and African genetic traits are currently being studied to see if they can shed light on a cure to HIV.

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