MSH6 and colonic neoplasm: Guidelines published by professional associations and expert groups in the US and Europe (e.g. 59,60,61,62) and a systematic review by an independent expert group63 recommend colonoscopic surveillance every 1-2 years, beginning at age 20-25, or 10 years younger than the age of the youngest person diagnosed in the family (or 2-5 years before the earliest colon cancer if it is diagnosed at age <25 years).56 Lindor et al. suggest that screening may begin later (age 30) in those with MSH6 mutations.63