We obtained genome-wide summary statistics for HbA1c,15 asthma,16,17 and prostate cancer18,19 calculated in European and African ancestry individuals (Table S1). Summary statistic variants that were not present in both the UK Biobank European and African ancestry testing populations were removed. PRSs for each phenotype were constructed from associated and independent GWAS variants within each training population by p value thresholding (p = [5 × 10−8, 1 × 10−7, 5 × 10−7, 1 × 10−6, 5 × 10−6, 1 × 10−5, 5 × 10−5, 1 × 10−4, 5 × 10−4, 1 × 10−3, 5 × 10−3, 0.01, 0.05, 0.1, 0.5, 1]) and clumping (LD r2 < 0.2) of variants within 1 Mb with PLINK.20 Additionally, a fixed-effects meta-analysis of the two populations was performed using METASOFT v2.0.1.21 The selected PRS variants exhibited limited heterogeneity between the European and African ancestry training set summary statistics. In particular, of all possible European (African) ancestry selected PRS variants, only 5.4% (9.4%), 6.9% (5.7%), and 7.0% (4.8%) were heterogeneous between the two groups for HbA1c, asthma, and prostate cancer, respectively (i.e., I2 > 25% and Q p value < 0.05).
