CHEK2 and breast carcinoma: Our study indicates very precocious and even metastatic BC in women with PVs in BRCA2 and ATM (patients 2 and 3) or BRCA2 and CHEK2 genes (patient 6), while a previous study evaluating 17 double-heterozygous patients with breast cancers failed to demonstrate a younger age at presentation in this group [13].