To adjust for genetic ancestry/population stratification when not using Bolt-LMM LOCO, we performed a PC analysis, as described45. The first 10 eigenvectors for non-Hispanic whites and the first 6 eigenvectors for all other race/ethnicity groups were included as covariates in the regression model described above. When we tested European vs. African ancestry percentages in African Americans, we used PC1 as a European admixture surrogate45.
