We differentiated participants genetically into five populations (see Methods, Supplementary Fig. 1) and removed outliers. There was a high degree of concordance (Supplementary Fig. 2) between the genetically defined populations and the self-reported groups for European Americans (EAs, 95.6% were self-reported Non-Hispanic white) and African Americans (AAs, 94.5% were self-reported Non-Hispanic black). Concordance ranged from 53.1% to 81.6% in the other three population groups.
