We estimated polygenic scores (PGS, aggregate measures of risk alleles weighted by GWAS effect sizes) using PRS-CSx51, which integrates GWAS summary statistics across multiple populations to improve the predictive power of PGS in the populations that typically lack well-powered GWAS results. Because of variation in allele frequencies and LD, PGS lose predictive accuracy when there is mismatch between the population of the discovery GWAS and target sample, even within relatively homogenous clusters52. PRS-CSx employs a Bayesian approach to correct GWAS summary statistics for the non-independence of SNPs in the genome. We converted PGS into Z-scores.
