MLH1 (30%)

Key points

• Patients with HNPCC are also at a higher risk of other cancers, with endometrial cancer being the next most common association, after colon cancer. The Amsterdam criteria are sometimes used to aid diagnosis:
• at least 3 family members with colon cancer
• the cases span at least two generations
• at least one case diagnosed before the age of 50 years FAP is a rare autosomal dominant condition which leads to the formation of hundreds of polyps by the age of 30-40 years. Patients inevitably develop carcinoma.
• general population: transferrin saturation > ferritin