Gene linked to protease inhibitor–related cholesterol elevation

Researchers have identified a human gene that causes some HIV-infected people taking protease inhibitors to experience a dangerous rise in cholesterol, Reuters Health reports. Patients who have a small genetic variation in the cholesterol-regulating gene known as SREBP-1c—a single nucleotide switch among the several million that make up DNA strands—are significantly less likely to develop elevated cholesterol levels than those without the variation. Two copies of the SREBP-1c gene are inherited from each parent, and only a variation in both copies seems to protect against the drug-induced cholesterol increases. About 30% of patients taking protease inhibitors do not experience elevated cholesterol levels, researchers said. This nearly matches the estimated 25% of the population at large that carry the double-gene variation. Researchers suggest that testing for this genetic variation prior to antiretroviral treatment may help doctors identify which of their HIV-positive patients are likely to develop potentially serious protease inhibitor–related cholesterol problems.