MUTYH-associated polyposis D12.6

MUTYH-associated polyposis MAP is a hereditary colorectal carcinoma syndrome (see below polyposis syndromes, hereditary) that is inherited in an autosomal recessive manner. The clinical features of MAP include the presence of 10-100 adenomatous polyps in the colon and the early occurrence of colorectal carcinoma. It is suspected that there are ethnic and geographical differences in the pattern of MUTYH gene mutations (Yamaguchi S et al. 2014).

The age at onset of polyposis is significantly delayed in carriers of a biallelic MUTYH mutation compared to polyposis patients with an APC mutation.

Mutations in both alleles of the gene are required for the development of the disease, but carriers of monoallelic mutations are found to have an increased risk of developing colorectal cancer (Toboeva MK et al. 2019). In Caucasian patients, the mutations c.536A>G (Y179C) and c.1187G>A (G396D) are frequently detected. In the Asian population, Y179C and G396D are rare, while other variants are considered the main causes of MAP.

The polyposis syndrome often phenotypically resembles an attenuated form of familial adenomatous polyposis (FAP/D12.6).

1. Nielsen M et al. (2011) MUTYH-associated polyposis (MAP). Crit Rev Oncol Hematol 79:1-16.
2. Papp J et al. (2015) Contribution of APC and MUTYH mutations to familial adenomatous polyposis susceptibility in Hungary. Fam Cancer 15: 85-97.
3. Toboeva MK et al (2019) MutYH-associated polyposis. Ter Arkh 91:97-100.
4. Yamaguchi S et al. (2014) MUTYH-associated colorectal cancer and adenomatous polyposis. Surg Today 44:593-600.