The results showed an association between the 86-SNV PRS and breast cancer risk for each of the carrier populations: BRCA1 (OR 1.20; 95% CI 1.10–1.32), BRCA2 (OR 1.23; 95% CI 1.12–1.34), ATM (OR 1.37; 95% CI 1.21–1.55), and PALB2 (OR 1.34; 95% CI 1.16–1.55). This evidence concerns the gene BRCA1 and breast cancer.