Hereditary or Not? Understanding Serrated Polyposis Syndrome

Purpose of review: To present the current understanding of the diagnosis, management, and potential genetic causes of serrated polyposis syndrome.

Recent findings: The clinical criteria for serrated polyposis syndrome was recently updated and now includes individuals with five or more serrated polyps proximal to the rectum that are 5 mm in size or greater and at least two that are 10 mm in size of greater as well as individuals with 20 or more serrated polyps throughout the colon with at least five proximal to the rectum. There is a significant risk for colon cancer in first-degree relatives of individuals with serrated polyposis syndrome. However, less than 3% of serrated polyposis syndrome cases are explained by identifiable germline mutations, with mutations in RNF43 being the only currently validated genetic cause. Serrated polyposis syndrome is rarely explained by identifiable germline mutations, but there remains an increased risk for colorectal cancer in first-degree relatives. Referral for genetic counseling and testing is recommended for individuals with serrated polyposis syndrome and a personal history of coexisting adenomatous polyposis or with a concerning family history and can be considered for all individuals with serrated polyposis syndrome. Close endoscopic surveillance of those with serrated polyposis syndrome and their first-degree relatives is recommended. Continued efforts at identifying hereditary causes of serrated polyposis are needed.