Although none of the 825 breast cancer cases were marked as familial breast cancer cases, 49 germline mutations in the classical predisposition genes of ATM, BRCA1, BRCA2, BRIPi, CHEK2, NBN, PTEN, RAD51C and TP53 were identified in 47 of 507 blood samples paired with breast cancer cases. This evidence concerns the gene CHEK2 and hereditary breast carcinoma.