Juvenile polyposis syndrome
Juvenile polyposis syndrome is an autosomal dominant disorder in which multiple hamartomatous polyps with histology characteristic of juvenile polyps occur in the gastrointestinal tract. In distinction from isolated sporadic juvenile polyps, the generally accepted clinical criteria are at least 5 juvenile polyps in the colorectum or juvenile polyps elsewhere in the gastrointestinal tract. There is a 30–40% lifetime risk of colorectal cancer and an increased risk of other gastrointestinal cancers. There is no excess risk of extra-gastrointestinal cancers. Some patients may also manifest hereditary haemorrhagic telangiectasia.
No systematic reviews on this topic were undertaken in the development of this section. The guidance on juvenile polyposis syndrome is based on recent international guidelines. See Guidelines Development for more information.
Genetic testing[edit source]
Genetic testing is indicated to confirm the diagnosis and in relatives of known mutation carriers. Up to 60% of individuals with clinical juvenile polyposis syndrome have identifiable pathogenic mutations in SMAD4 or BMPR1A. In individuals with BMPR1A mutations polyps of mixed morphology can be present in addition to juvenile polyps.
In patients with a diagnosis of juvenile polyposis syndrome, colonoscopy should commence at age 12–15 or earlier if symptoms occur (Syngal et al., 2015; Cancer Institute NSW, 2016). It should be repeated every 1 to 3 years depending on polyp burden. Colectomy is indicated if polyps cannot be managed endoscopically (Syngal et al., 2015; Cancer Institute NSW, 2016).
- Syngal S, Brand RE, Church JM, Giardiello FM, Hampel HL, Burt RW, et al. ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes. Am J Gastroenterol 2015 Feb;110(2):223-62; quiz 263 Available from: http://www.ncbi.nlm.nih.gov/pubmed/25645574.
- Cancer Institute NSW. eviQ Cancer Genetics Referral Guidelines for Colorectal Cancer or Polyposis Risk Assessment and Consideration of Genetic Testing. [homepage on the internet] Sydney; 2016 [cited 2016 Sep 6]. Available from: https://www.eviq.org.au/Category/tabid/65/categoryid/6/Default.aspx.