The MUTYH gene contains 16 exons spanning a region of 11147 bp.

The transcribed mRNA is 1854 bp long. There are three major classes of human MUTYH mRNAs: a, b and g. Each of these undergoes alternative splicing, suggesting a total of 10 possible mature transcripts. However, their distribution and abundance in different normal tissues have yet to be determined. The reference isoform is MutYa3.

Aminoacids: 535. Molecular Weight: 52 kDa. MUTYH is a protein involved in base excision repair (BER). It contains a DNA binding domain, an adenine binding motif and several interaction domains for APE1, PCNA, RPA and MSH6, located in different regions of the gene.

Ubiquitous.

Nuclear and mithocondrial.

MUTYH is involved in oxidative DNA damage repair. Human MutY is responsible for recognition and removal of inappropriately inserted adenine in Ao8-oxoG mispairs. If unrepaired, the Ao8-oxoG mispairs can result in C:G to A:T transversions. MUTYH functions in a postreplication repair pathway and is targeted to the newly synthesized daughter strand of DNA for removal of the adenine base.

MUTYH is homologous to the bacterial MutY gene, and MUTYH homologues are also present in eukaryote.

Biallelic germline mutations of MUTYH are associated with colorectal polyposis. The most common mutations in Caucasians are the missense substitutions Y165C (494A>G) and G382D (1145G>A). Functional analysis of C165 and D382 proteins has shown a severe decrease of catalytic activity. E466X and Y90X are the common mutations reported in Indian and Pakistani cases. Several other missense, nonsense, in-frame, frameshift and splicing mutations have been found in patients with colorectal polyposis.

To date, no MUTYH somatic mutation has been described.