Our sample cohort clearly reveals a significant difference in disease expression among the three different phenotypic FAP groups; severe (APC MCR), intermediate (APC) and attenuated (APC AFAP) FAP, indicating that those individuals harbouring APC mutations in the MCR, should initiate screening/treatment at much earlier ages than other FAP or AFAP patients. The gene discussed is APC; the disease is attenuated familial adenomatous polyposis.