Genetic and metabolic medicine
Familial adenomatous polyposis
APC genetics and genotype-phenotype links, classic versus attenuated FAP, colectomy timing and choice, duodenal surveillance with Spigelman staging, desmoids, and MUTYH-associated polyposis.
Tier 1Condition
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Autosomal dominant germline variant in the APC tumour suppressor gene (5q21). About 1 in 10,000 people; 20 to 25% are de novo.
- Classic FAP: hundreds to thousands of colorectal adenomas from the teens, with colorectal cancer in nearly 100% (average age 39) without colectomy.
- Prophylactic colectomy is the standard of care. After it, duodenal cancer and desmoid tumours are the leading causes of death.
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Sources
- eviQ. APC (familial adenomatous polyposis): risk management. Version 12, June 2026AU/NZCancer Institute NSW, 2026
- Clinical practice guidelines for the prevention, early detection and management of colorectal cancerAU/NZCancer Council Australia, 2017, chapters updated
- Zaffaroni G et al. Updated European guidelines for clinical management of familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), gastric adenocarcinoma, proximal polyposis of the stomach (GAPPS) and other rare adenomatous polyposis syndromes: a joint EHTG-ESCP revision. Br J Surg 2024;111:znae070European Hereditary Tumour Group and European Society of Coloproctology, 2024
- NCCN Clinical Practice Guidelines in Oncology. Genetic/Familial High-Risk Assessment: Colorectal, Endometrial, and GastricNational Comprehensive Cancer Network, 2026
- Baloch ZW et al. Overview of the 2022 WHO Classification of Thyroid Neoplasms. Endocr Pathol 2022 (cribriform-morular thyroid carcinoma no longer a subtype of papillary carcinoma)Endocrine Pathology, 2022
- Last updated
- 14 November 2026
What changed
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