(Lai et al., 2022a). PRS-CS (Ge et al., 2019) was used to estimate the posterior effect sizes of each variant through a Bayesian regression framework using continuous shrinkage priors. European samples from 1000 Genomes Project were used as the LD reference panel. For AA participants, the discovery GWAS was from the meta-analysis of GWAS of problematic alcohol use in EA cohorts (EA-PAU) (Zhou et al., 2020) and the AA GWAS of AUD from the Million Veteran Program (AA-AUD) (Kranzler et al., 2019). Both GWAS results are available through dbGaP (https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs001672.v11.p1). As described above, only variants with the same direction of effects in both EA-PAU and AA-AUD were retained (Lai et al., 2022b). PRS-CSx (Ruan et al., 2022) was used to estimate the posterior effect sizes of each variant with African and European samples from 1000 Genomes Project as the LD reference panel for AA and EA participants respectively. PLINK (Chang et al., 2015, Purcell et al., 2007) was used to calculate PGSAUD using imputation dosages. PGSAUD was standardized (Mean =0, SD =1) for ease of interpretation. The lists of variants and their weights used to calculate PGSAUD are available at the PGS catalog (EA: https://www.pgscatalog.org/publication/PGP000345/; AA: https://www.pgscatalog.org/publication/PGP000346/).
