Tracking the Familial Adenomatous Polyposis Gene Carriers by Indirect Ophthalmoscopy

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease with delayed expression, in which multiple polyps develop throughout the colon with a malignant potential of 100%. Genetic counselling and follow-up of patients at risk is essential for presymptomatic diagnosis. Prophylaxis of cancer arising from this condition would greatly improve if a genetic or a congenital phenotypic marker of gene carriers were available.