each SNP. The weighting by p value was used because it is robust to variations in sample size from SNP to SNP. Each PRS was tested at nine thresholds. A p value of 3.3 × 10−4 was considered significant for a PRS after Bonferroni correction (although this is probably conservative, because PRSs are correlated). Calculations were performed with PLINK (47). For comparison, we also ran PRS-CS (48) for EA subjects and PRS-CSx (49) for AA subjects. For these analyses, the Bonferroni correction was 1.6 × 10−2. All PRS results were standardized (mean = 0, SD = 1).
