MUTYH

The MUTYH gene carries the instructions for cells to make an enzyme that is involved in the repair of DNA. This enzyme, MYH 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).

familial adenomatous polyposis - caused by mutations in the MUTYH gene

Mutations in the MUTYH gene cause an autosomal recessive form of familial adenomatous polyposis (also called MYH-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).

1p34.3-p32.1

The MUTYH gene is located on the short (p) arm of chromosome 1 between positions 34.3 and 32.1.

See How do geneticists indicate the location of a gene? in the Handbook.

You and your healthcare professional may find the following resources about MUTYH helpful.

• Gene Tests - DNA tests ordered by healthcare professionals

You may also be interested in these resources, which are designed for genetics professionals and researchers.

• PubMed - Recent literature
• OMIM - Genetic disorder catalog
• Research Resources - Tools for researchers (3 links)

See How are genetic conditions and genes named? in the Handbook.

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How does a gene make a protein?
• How can gene mutations cause disorders?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

amino acid ; autosomal ; autosomal recessive ; base excision repair ; base pair ; cancer ; cell division ; colorectal ; DNA ; DNA replication ; enzyme ; familial ; gene ; homologs ; mutation ; oxygen ; polyposis ; protein ; recessive ; tumor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.