Fig. 4. Partial r² for PGS_EUR, PGS_dual, and PGS_AFR on 15 traits in UK Biobank.

Predictive performance on an African-ancestry (AFR) test set is shown by the solid lines. The dashed lines correspond to predictive performance on a European-ancestry (EUR) test set using PGS_EUR. The single-ancestry scores were estimated using a standard, unweighted LASSO. The dual-ancestry scores were constructed using an importance weighted LASSO with various degrees of reweighting γ. Traits are ordered according to partial r² of PGS_EUR on the European-ancestry test set (note the varying y-axes). Error bars correspond to the range across five cross-validation rounds of training set construction and PGS estimation. Phenotype acronyms: mean platelet volume (MPV), mean corpuscular volume (MCV), body mass index (BMI), atrial fibrillation (AFib), diverticular disease of the intestine (DDI), female genital prolapse (FGP).