Researchers have discovered that variants in the APOL1 gene that raise the risk for renal disease are common in individuals of recent African ancestry, occurring in more than 30% of African-American chromosomes. At one time, the disease-causing variants may have protected Africans against a deadly parasite.

Persons who have inherited two copies of these APOL1 variants may be approximately 10 times more likely to develop kidney disease as others, Martin Pollak, MD, Chief of Nephrology at Beth Israel Deaconess Medical Center in Boston, and colleagues reported online in Science.