the European and African samples from the 1000 Genomes Project (Phase 3, version 5, NCBI GRCh37) were considered as EA and AA samples, respectively. Before imputation, variants with palindromic alleles, missing rate >5%, MAF <3%, and HWE P-value < 0.0001 were excluded. We used SHAPIT2 (Delaneau et al., 2013) and Minimac3 (Das et al., 2016) for phasing the genotypes and for imputation, respectively. Imputation to 1000 Genomes Project was performed separately by array due to different array contents. Variants with imputation quality score R2 ≥0.3 and MAF ≥0.01 were retained for analysis.
