MUTYH (mutY Homolog (E. coli)) is a human gene that carries the instructions for cells to make an enzyme that is involved in the repair of DNA. This enzyme, MUTYH glycosylase, corrects particular mistakes that are made when DNA is copied (replicated) in preparation for cell division. The building blocks of DNA (base pairs) have specific partners. Normally, adenine pairs with thymine (written as A-T) and guanine pairs with cytosine (G-C). During the normal cellular activities, guanine sometimes becomes altered by oxygen, which causes it to pair with adenine instead of cytosine. MYH glycosylase fixes these mistakes so mutations don't accumulate in the DNA and lead to tumor formation and possibly cancer. This type of repair is known as base excision repair (BER).
The MUTYH gene is located on the short (p) arm of chromosome 1 between positions 34.3 and 32.1, from base pair 45,464,007 to base pair 45,475,152.
Related conditions
Mutations in the MUTYH gene cause an
autosomal recessive form of
familial adenomatous polyposis (also called MUTYH-associated polyposis). Mutations in this gene affect the ability of cells to correct mistakes made during
DNA replication. Both copies of the MUTYH gene are mutated in individuals who have autosomal recessive familial adenomatous polyposis. Most reported mutations in this gene cause production of a nonfunctional or low functioning
glycosylase enzyme. When base excision repair in the cell is compromised, mutations in other genes build up, leading to cell overgrowth and possibly tumor formation. The two most common mutations in
Caucasian Europeans are exchanges of
amino acids (the building blocks of proteins) in the enzyme. One mutation replaces the amino acid
tyrosine with
cysteine at position 165 (also written as Tyr165Cys or Y165C). The other common mutation switches the amino acid
glycine with
aspartic acid at position 382 (also written as Gly382Asp or G382D).
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Genes