Of these, 77 (17%) had either a high-risk mutation in a breast cancer susceptibility gene or methylation of the promoter region of BRCA1 in peripheral blood DNA (31 BRCA1, 16 BRCA2, 1 ATM, 4 TP53, 25 BRCA1 promoter region methylation). Here, BRCA2 is linked to breast carcinoma.