Familial adenomatous polyposis. | Read by QxMD (original) (raw)
Familial adenomatous polyposis (FAP) is an autosomal-dominant colorectal cancer syndrome, caused by a germline mutation in the adenomatous polyposis coli (APC) gene, on chromosome 5q21. It is characterized by hundreds of adenomatous colorectal polyps, with an almost inevitable progression to colorectal cancer at an average age of 35 to 40 yr. Associated features include upper gastrointestinal tract polyps, congenital hypertrophy of the retinal pigment epithelium, desmoid tumors, and other extracolonic malignancies. Gardner syndrome is more of a historical subdivision of FAP, characterized by osteomas, dental anomalies, epidermal cysts, and soft tissue tumors. Other specified variants include Turcot syndrome (associated with central nervous system malignancies) and hereditary desmoid disease. Several genotype-phenotype correlations have been observed. Attenuated FAP is a phenotypically distinct entity, presenting with fewer than 100 adenomas. Multiple colorectal adenomas can also be caused by mutations in the human MutY homologue (MYH) gene, in an autosomal recessive condition referred to as MYH associated polyposis (MAP). Endoscopic screening of FAP probands and relatives is advocated as early as the ages of 10-12 yr, with the objective of reducing the occurrence of colorectal cancer. Colectomy remains the optimal prophylactic treatment, while the choice of procedure (subtotal vs proctocolectomy) is still controversial. Along with identifying better chemopreventive agents, optimizing screening of extracolonic cancers and applying new radiological and endoscopic technology to the diagnosis and management of extracolonic features are the major challenges for the future.
Full text links
We have located links that may give you full text access.
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-
2024
by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our
and
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app