Autosomal dominant
- Multiple characteristic juvenile polyps mostly colon, also upper GI.
- Other features sometimes associated are macrocephaly, hereditary haemorrhagic telangiectasia and congeni- tal heart disease.
- Some have SMAD4 or BMPR1A gene mutations
- Risk of colorectal cancer ~40%. Increased risk of gastric cancer.
- Surveillance: regular upper and lower GI scopes + polypectomy.
- Occasionally prophylactic colectomy or gastrectomy required