CHEK2 and ovarian carcinoma: The most frequent mutations (3.9% of the patients) were found in PALB2, CHEK2 and ATM. In another group of 377 patients with a personal history of breast and/or ovarian cancer who were negative for BRCA1/2-mutations (BRCAx), 5% of the subjects carried a mutation in genes other than BRCA1/2 [38].