As the efforts to diversify the samples in genomic research start to grow, the scale of non-European genomic resources has been expanded in recent years. Although the sample sizes of most non-European GWAS remain considerably smaller than European studies, they provide critical information on the variation of genetic effects across populations. Initial studies have indicated that the genetic architectures of many complex traits and diseases are largely concordant between populations – both at the single-variant level and at the genome-wide level15–18, suggesting that the transferability of PRS may be improved by integrating GWAS summary statistics from diverse populations. However, current PRS construction methods have been designed primarily for applications within one homogeneous population19–23. Existing methods that can take GWAS summary statistics from multiple populations use meta-analysis to summarize genetic effects across training datasets24,25, but this approach does not model population-specific allele frequencies and linkage disequilibrium (LD) patterns. Alternatively, independent analysis can be performed on each discovery GWAS and the resulting PRS can be linearly combined26,27, but this approach does not make full use of the genetic overlap between populations to inform PRS construction.
