A practical question is how to construct polygenic scores for recently admixed individuals or individuals who are genetically distant from those in the largest existing GWAS. Use of trans-ancestry meta-analytic results to weight alleles can increase prediction accuracy (Grinde et al., 2019), and MultiPred is an approach that combines PRS based on European training data with PRS based on training data from the target population (Márquez-Luna et al., 2017). Current methods development is focused on improving handling of allele frequency differences and LD within and across populations. Given current limitations in understanding similarities and differences in polygenic risk across populations, caution is advised in interpreting differences in PRS across ancestries (Novembre and Barton, 2018).
