[Familial adenomatous polyposis].

Familial adenomatous polyposis (FAP) is an autosomally dominant disease characterized by early development of up to thousands of colorectal adenomas and colorectal carcinoma in untreated patients. Extra-colonic manifestations include duodenal adenomatosis and desmoid development. Due to identification of gene carriers by DNA analysis or endoscopy the prognosis is good after early colectomy, but life-long surveillance of the rectum and the duodenum is necessary. The Danish Polyposis Register coordinates prophylactic examination and treatment in the families, and serves as basis for research.