Genetic Ancestry Better Predictor of Bleeding Stroke Risk Than Race and Ethnicity

Traditional self-reported measures of race, ethnicity and cultural identity may not be sufficient at helping physicians predict an individual’s risk for bleeding stroke. The finding is according to a study presented at the American Stroke Association’s International Stroke Conference 2018, which suggested that a genetic ancestry test may be a better way to assess risk.

A combination of inherited and environmental factors contributes to an individual’s risk of suffering a stroke. While a person might be able to lower their risk by not smoking, eating right and exercising regularly, a family history of stroke still raises the chances you’ll experience one yourself. In addition, African Americans have been found to be at a greater risk of stroke compared to Caucasian people, which may be explained by the higher incidence of obesity, elevated blood pressure and diabetes within this group.

“Treatment and prevention of risk factors represent the most crucial components of efforts to limit the burden of stroke,” said study lead author Dr. Sandro Marini, post-doctoral research fellow in the Center for Genomic Medicine at Massachusetts General Hospital in Boston. “Accurate identification of patients at higher risk is the first step towards tailored prevention strategies.”

Data from nearly 5,000 patients who participated in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study was analyzed by the researchers. Intracerebral hemorrhage is a type of stroke characterized by bleeding in the brain caused by a ruptured blood vessel. Participants in the trial ranged in age from 49 to 79, 35 percent of which were Caucasian, 35 percent were African American, and 30 percent were Hispanic.

The study investigators found that genetic ancestry markers in 15 loci in the genome were better than self-reports of race and ethnicity at identifying patients with risk factors for stroke, including high cholesterol, irregular heartbeat, arterial plaque buildup and diabetes. This finding was particularly striking in the Hispanic population, suggesting the genetic test could be a better way to assess stroke risk in the future.

“Genetic ancestry represents an accurate way to control for both genetic and environmental exposures that vary across races and ethnicities, in association with risk factors for intracerebral hemorrhage,” said Marini. “Limiting our definitions of race and ethnicity to standard self-reports leaves out valuable information that could be used to better predict risk of at least some complex diseases.”

Stroke is among the top five leading causes of death in the US. It is also a major cause of long-term disability with damage occurring when the brain is deprived from oxygen and other nutrients carried by the blood.