Researchers performed a genome-wide association study of African ancestry populations and examined if genetic risk factors for primary open-angle glaucoma differ based on ancestry. In this multistage, case-control, genome-wide association study, 26,295 participants were included. The analysis revealed a significant association of the amyloid-β A4 precursor protein-binding family B member 2 locus with primary open-angle glaucoma among the individuals of African ancestry (odds ratio, 1.19 per copy of the risk allele for single-nucleotide polymorphism rs59892895T>C), but not of European or Asian ancestry. This study thereby yielded a single-nucleotide polymorphism that showed differential association with primary open-angle glaucoma by ancestry.