CHEK2 and breast carcinoma: Belgian national guidelines for CHEK2 carriers recommend gynaecological follow-up from age 25 and breast cancer screening starting at age 35 in women, yearly PSA and digital prostate exam starting at age 50 in men, and colonoscopy every 5 years from age 40 (or 10y before youngest diagnosis of colorectal cancer in family) in both sexes.