Genetics may underlie some kidney failure in blacks
Gene variants protect against African sleeping sickness but may increase renal risk
By Nathan Seppa
In a case of natural selection with a twist, genetic variants that confer protection against disease in Africa seem to place African Americans half a world away at elevated risk of kidney failure, a new study finds.
U.S. blacks are three times as likely as whites to develop chronic kidney disease. “We think this explains perhaps most of it,” says study coauthor Martin Pollak, a nephrologist and geneticist at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston.
The gene in question is called APOL-1, short for apolipoprotein L-1. Among people of African descent, APOL-1 can appear in two variant forms that protect against African sleeping sickness but also increase susceptibility to kidney failure, Pollak and his colleagues report online July 15 in Science.
Each parent provides one gene copy to offspring. The team analyzed blood from more than 1,400 African Americans and found that more than 30 percent carried at least one variant copy of APOL-1. About 10 percent harbored two variant copies.