Familial adenomatous polyposis (FAP) is a genetic disease created by an abnormality of chromosome number five resulting in a generalized cellular growth disorder. The growth abnormality created by the genetic defect dictates the development of benign and malignant lesions in different organs of the body. Even the term familial adenomatous polyposis does not fully describe the defect because lesions other than polyps may occur in these patients. The major organ affected is the large intestine. Adenomas occur at an earlier age than normally seen in the general population, grow more numerously and more rapidly, and become malignant at an inordinately young age.
