Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder characterized by the early onset of hundreds to thousands of adenomas throughout in the rectum and colon. If left untreated, all patients with FAP develop colon cancer a decade after the appearance of the polyps. The genetic defect in FAP is a germline mutation in the adenomatous polyposis coli (APC) gene. In a subset of individuals, a MUTYH mutation causes a recessively inherited polyposis condition.
