Study: New Genetic Risks for Dementia in Black Americans

JAMA has published the largest African American genome-wide association study to date, and uncovered new racially-based genetic risk factors for Alzheimer's disease, reports Being Patient . The researchers analyzed the data of 8,006 African Americans, scanning their DNA to find genetic variations linked to Alzheimer's: 2,784 participants had Alzheimer's and 5,222 were controls, while their average age was 74. Although many of the genes differed from those identified in larger studies done in mainly white populations, there was substantial overlap in functions like immune response, processing of fatty acids, and the movement of molecules. The authors observed a novel genetic pathway involving kidney system development. "This finding is particularly interesting given the observation that African American individuals are three times more likely to experience kidney failure compared with the non-Hispanic White population, and along with Hispanic populations, have a higher rate of comorbidity for dementia and kidney disease," they wrote. The scientists added that their results have ramifications for predicting individuals' odds of developing Alzheimer's. "In the future, we think that polygenic risk scores — which take dozens of genetic risk factors into account — can help us identify those most at risk," said Columbia University Professor Christiane Reitz. "Our findings tell us that we likely will need different risk scores for different ethnicities, since the genetic risk factors vary somewhat from group to group."