Adenomatous Polyposis Syndromes: Familial Adenomatous Polyposis and MutYH-Associated Polyposis

The purpose of this review is to provide an overview of the etiology, diagnosis, and clinical management of the two most common polyposis; change adenomatous to polyposis hereditary colorectal cancer syndromes, familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). The syndromes are caused by inherited genetic variants in the APC and MutYH genes, respectively. Both syndromes carry significant increased risk of colorectal and extracolonic cancers. Intense surveillance is required to reduce this risk, and colectomy or proctocolectomy is frequently the ultimate form of colorectal cancer risk reduction. The colorectal phenotype and extracolonic manifestations continue to evolve as more is learned about the natural history of the diseases, particularly MAP.