African-Americans who inherit the sickle cell gene have an increased risk for chronic kidney disease, according to a study co-led by Alexander Reiner, research professor of epidemiology at the University of Washington School of Public Health.

Reiner and colleagues at collaborating institutions examined data from nearly 16,000 people from five large studies. Results, published in the Journal of the American Medical Association, show that African-Americans with the trait were nearly 60 percent more likely to have chronic kidney disease.

"These findings suggest that sickle cell trait, which is present in about 8 percent of African-Americans, appears to be one factor that contributes to the higher burden of kidney disease among that population," said Reiner, also a member of the Fred Hutch research center in Seattle. "This study highlights the need for additional research into the health consequences of sickle cell trait."

Sickle cell trait, where an individual inherits the sickle cell gene from one parent, was long considered benign. Full-blown sickle cell disease is a genetic condition where crescent-shaped red blood cells can block blood flow, causing pain.

"Since screening for the sickle cell mutation is already widely performed in the U.S., these findings present additional public health and policy implications, including the role of genetic counseling, community awareness and education around genetic findings such as sickle cell trait," Reiner added.

Participating institutions included Johns Hopkins University, the University of North Carolina, the University of Mississippi and the University of Wisconsin. University of Washington co-authors included Bessie Young, associate professor of nephrology and adjunct associate professor of epidemiology and health services; Ronit Katz, a biostatistician and research associate professor at the Kidney Research Institute; and Joshua D. Smith, research consultant for the UW’s Department of Genome Sciences.