[Genetic counseling, surgical prophylaxis and treatment for familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer].

FAP is an autosomal dominant disorder characterized by the appearance of thousands of adenomatous polyps. FAP is associated with a deletion of chromosome 5q21 (known as the APC gene). Surgical prophylaxis in FAP consists of resection of the entire large bowel, to prevent malignant transformation. Hereditary Nonpolyposis Colorectal Cancer(HNPCC), like FAP, is an autosomal dominant disorder. In contrast to FAP, HNPCC is associated with an unusually high frequency of cancers in the proximal large bowel. If an adenoma or adenocarcinoma of the colon is identified, total abdominal colectomy with an ileorectal anastomosis is recommended.