The key elements that influence the accuracy of a PRS for a specific trait are its SNP heritability, genetic architecture, and sample size of the discovery GWAS (Table S1, see also Supplemental Note). SNP heritability is estimated as the additive contribution of common genetic variation to trait variability (8; 18–22) (Table 1). It is typically a fraction of family-based heritability, which captures contributions from all types of genetic variation.
