ATM and breast cancer: To evaluate the PRS3820 effect size relative to known high- and moderate-risk BC genes, we compared the OR for the top PRS3820 decile (PRS90) with that of pathogenic variants in TP53, BRCA1, BRCA2, PALB2, ATM, and CHEK2 genes plus the pathogenic variant R337H of the TP53 gene (Figure 5).