Late-Onset Alzheimer Disease Susceptibility Genes in Black Americans

The incidence of late-onset Alzheimer disease (LOAD) is higher in blacks than in whites living in the same area of the U.S. To investigate the cause of this difference, a collaborative group of researchers has undertaken the largest genome-wide association study of LOAD in black Americans to date. They used data from 1968 blacks with LOAD and 3928 healthy controls (aged 60 or older) collected from 1989 to 2011 to conduct both undirected assessments and targeted assessments of genes identified as risk variants for LOAD in other populations.

APOE genotype increased the risk for LOAD most substantially (odds ratio, 2.31), reflecting findings in other ethnic groups. After adjusting for APOE, the gene ABCA7, a risk locus for LOAD of marginal effe…