Breast cancer was more commonly reported in family members (up to third degree as available) of probands with a PV in MSH6 or PMS2 (average number of reported cancers per family = 1.46 and 1.52) whereas colon cancer was more commonly reported in family members of probands with a PV in MLH1 or MSH2 (2.62 and 2.12). Here, MSH6 is linked to breast cancer.