28th February 2025

A 34-year-old farmer presents to the GP with a 2-week history of intermittent bloating

A 34-year-old farmer presents to the GP with a 2-week history of intermittent bloating and rectal bleeding. Physical examination is unremarkable and blood tests show iron-deficiency anaemia. Faecal occult blood is positive and he is sent for endoscopy.

Colonoscopy shows multiple polyps in the colon and genetic testing confirms familial adenomatous polyposis. Which of the following genes is mutated in familial adenomatous polyposis (FAP)?

Select the SINGLE most appropriate option from the list below. Select ONE option only.