An additional 5.1% (95% CI: 2.4–8.5) are estimated to carry a pathogenic allele of a moderate-risk breast cancer susceptibility gene (i.e., ATM, BARD1, CHEK2, or NBN) bringing the total proportion of estimated carriers to 10.4% (95% CI: 6.5–14.9). This evidence concerns the gene CHEK2 and breast carcinoma.