MSH6 and Familial prostate cancer: A similar risk-modifying effect of PRS on carrier status was also observed for genes that were found to have weaker independent associations with overall prostate cancer and aggressive disease (BRCA1, RAD50, MLH1, and MSH6). While previous larger studies in men of European ancestry permitted finer stratification of PRS (deciles), the smaller sample size of the current study permitted testing only broad PRS strata (tertiles) when examining aggregate effects by carrier status.