Researchers at NCI and other institutes have documented how a mutation in an African population may have made them susceptible to infection by the human immunodeficiency virus (HIV) and related viruses. This finding may indicate how HIV first jumped into human populations and also yield clues about how viral infections can lead to certain types of cancer.

The AIDS pandemic is thought to have arisen by transmission of viruses closely related to HIV - from chimpanzees in Central or Western Africa to humans, possibly when these animals were hunted. A regulatory protein, TRIM5-alpha, has been implicated in this transmission because it can affect the susceptibility of some mammals to infection from viruses such as HIV. Researchers found that approximately four percent of Baka pygmies in Cameroon had a version of the gene that does not restrict retrovirus infection. Genetic factors such as this, along with the high frequency of exposure to chimpanzee body fluids, may have predisposed the population in this region to the initial cross-species transmission of HIV. The results of this finding appeared online July 3, 2009. Title: A rare null allele potentially encoding a dominant-negative TRIM5α protein in Baka pygmies. Torimiro, et. al. Virology.

Back to Top