Since the diagnosis of MAP depends on the level of repair activity of the MUTYH variants encoded in the two MUTYH alleles of the patient and the presence of the clinical phenotype characteristic of MAP, even when MUTYH gene variations are present in a patient, information on the level of repair activity of the MUTYH variants is indispensable to making the diagnosis of MAP. Here, MUTYH is linked to mutyh-associated polyposis.