Genome-wide Complex Trait Analysis was used (Yang et al., 2011) (GCTA) to estimate the proportion of phenotypic variance attributable to observed (non-imputed) genetic variants [V(G)/Vp, or h2SNP]. Genetic relationship matrices (GRMs) were derived for each ancestry group. Within ancestry group, only unrelated individuals were included in the GRM as in the GWAS, resulting in the following sample sizes: AFR: N = 1339; AMR: N = 582; EAS: N = 557; EUR: N = 3018; SAS: N = 455. An ancestry group-specific MAF cutoff of 0.01 was applied. The same ancestry PCs used in the GWAS analyses were included in the heritability analyses.
