PRS are individual-level estimates of the relative genetic contribution to a phenotype, computed for each genotyped individual in a target sample based on GWAS results from a discovery sample. PRS are useful for validating GWAS results in external cohorts and have the potential to provide individualized risk prediction from genetic data (Khera et al., 2018; Martin et al., 2019). The predictive value of PRS profiling depends both on the statistical power of the discovery (training) dataset— specifically, enrichment in the genome-wide distribution of association test statistics that is attributable to aggregate, additive genetic effects — and the relevant characteristics of the target (testing) dataset.
