testing (R2=0.002). A similar study found that PRS derived from a GWAS of neuroticism in 170,910 individuals participating in the European UK Biobank (Okbay et al., 2016) predicted variance in both depression (R2=0.001) and neuroticism (R2=0.083) in Han Chinese women (Docherty et al., 2016). Thus, with caution, one could experiment with projecting effect sizes from population A to population B. Of course, the most valuable resource in this regard would be large well-powered discovery GWAS conducted in homogenous populations from different ancestral origins, which are becoming more common (Duncan et al., 2017, Meyers et al., 2017, Xu et al., 2015). Related approaches combining results from large and readily available European or mixed-ethnicity cohorts with smaller training datasets of another ancestry to produce ancestry-adjusted PRS have also been proposed ((Marquez-Luna and Price, 2016, Coram et al., 2017).
