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MUTYH gene

mutY DNA glycosylase

Normal Function

The MUTYH gene provides instructions for making an enzyme called MYH glycosylase, which is involved in the repair of DNA. This enzyme corrects particular errors that are made when DNA is copied (DNA replication) in preparation for cell division. DNA is made up of building blocks called nucleotides, each of which has a specific partner. Normally, adenine pairs with thymine (written as A-T) and guanine pairs with cytosine (written as G-C). During normal cellular activities, guanine sometimes becomes altered by oxygen, which causes it to pair with adenine instead of cytosine. MYH glycosylase fixes this error so mutations do not accumulate in the DNA and lead to tumor formation. This type of repair is known as base excision repair.

Health Conditions Related to Genetic Changes

Familial adenomatous polyposis

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 errors made during DNA replication. In individuals who have autosomal recessive familial adenomatous polyposis, both copies of the MUTYH gene in each cell are mutated. Most mutations in this gene result in the production of a nonfunctional or low-functioning MYH glycosylase. When base excision repair in the cell is impaired, mutations in other genes build up, leading to cell overgrowth and possibly tumor formation. Two mutations that change the sequence of the building blocks of proteins (amino acids) in MYH glycosylase are common in people of European descent. One mutation replaces the amino acid tyrosine with the amino acid cysteine at position 179 (written as Tyr179Cys or Y179C). The other mutation switches the amino acid glycine with the amino acid aspartic acid at position 396 (written as Gly396Asp or G396D).

More About This Health Condition

Other Names for This Gene

  • hMYH
  • mutY (E. coli) homolog
  • mutY homolog
  • mutY homolog (E. coli)
  • MYH

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Cheadle JP, Sampson JR. Exposing the MYtH about base excision repair and human inherited disease. Hum Mol Genet. 2003 Oct 15;12 Spec No 2:R159-65. doi: 10.1093/hmg/ddg259. Epub 2003 Aug 5. Citation on PubMed
  • Croitoru ME, Cleary SP, Di Nicola N, Manno M, Selander T, Aronson M, Redston M, Cotterchio M, Knight J, Gryfe R, Gallinger S. Association between biallelic and monoallelic germline MYH gene mutations and colorectal cancer risk. J Natl Cancer Inst. 2004 Nov 3;96(21):1631-4. doi: 10.1093/jnci/djh288. Citation on PubMed
  • Farrington SM, Tenesa A, Barnetson R, Wiltshire A, Prendergast J, Porteous M, Campbell H, Dunlop MG. Germline susceptibility to colorectal cancer due to base-excision repair gene defects. Am J Hum Genet. 2005 Jul;77(1):112-9. doi: 10.1086/431213. Epub 2005 May 3. Citation on PubMed or Free article on PubMed Central
  • Fleischmann C, Peto J, Cheadle J, Shah B, Sampson J, Houlston RS. Comprehensive analysis of the contribution of germline MYH variation to early-onset colorectal cancer. Int J Cancer. 2004 Apr 20;109(4):554-8. doi: 10.1002/ijc.20020. Citation on PubMed
  • Jones S, Emmerson P, Maynard J, Best JM, Jordan S, Williams GT, Sampson JR, Cheadle JP. Biallelic germline mutations in MYH predispose to multiple colorectal adenoma and somatic G:C-->T:A mutations. Hum Mol Genet. 2002 Nov 1;11(23):2961-7. doi: 10.1093/hmg/11.23.2961. Citation on PubMed
  • Jones S, Lambert S, Williams GT, Best JM, Sampson JR, Cheadle JP. Increased frequency of the k-ras G12C mutation in MYH polyposis colorectal adenomas. Br J Cancer. 2004 Apr 19;90(8):1591-3. doi: 10.1038/sj.bjc.6601747. Citation on PubMed or Free article on PubMed Central
  • Kambara T, Whitehall VL, Spring KJ, Barker MA, Arnold S, Wynter CV, Matsubara N, Tanaka N, Young JP, Leggett BA, Jass JR. Role of inherited defects of MYH in the development of sporadic colorectal cancer. Genes Chromosomes Cancer. 2004 May;40(1):1-9. doi: 10.1002/gcc.20011. Citation on PubMed
  • Lipton L, Halford SE, Johnson V, Novelli MR, Jones A, Cummings C, Barclay E, Sieber O, Sadat A, Bisgaard ML, Hodgson SV, Aaltonen LA, Thomas HJ, Tomlinson IP. Carcinogenesis in MYH-associated polyposis follows a distinct genetic pathway. Cancer Res. 2003 Nov 15;63(22):7595-9. Citation on PubMed
  • Lipton L, Tomlinson I. The multiple colorectal adenoma phenotype and MYH, a base excision repair gene. Clin Gastroenterol Hepatol. 2004 Aug;2(8):633-8. doi: 10.1016/s1542-3565(04)00286-1. Citation on PubMed
  • Russell AM, Zhang J, Luz J, Hutter P, Chappuis PO, Berthod CR, Maillet P, Mueller H, Heinimann K. Prevalence of MYH germline mutations in Swiss APC mutation-negative polyposis patients. Int J Cancer. 2006 Apr 15;118(8):1937-40. doi: 10.1002/ijc.21470. Citation on PubMed
  • Sampson JR, Dolwani S, Jones S, Eccles D, Ellis A, Evans DG, Frayling I, Jordan S, Maher ER, Mak T, Maynard J, Pigatto F, Shaw J, Cheadle JP. Autosomal recessive colorectal adenomatous polyposis due to inherited mutations of MYH. Lancet. 2003 Jul 5;362(9377):39-41. doi: 10.1016/S0140-6736(03)13805-6. Citation on PubMed
  • Sampson JR, Jones S, Dolwani S, Cheadle JP. MutYH (MYH) and colorectal cancer. Biochem Soc Trans. 2005 Aug;33(Pt 4):679-83. doi: 10.1042/BST0330679. Citation on PubMed
  • Sieber OM, Lipton L, Crabtree M, Heinimann K, Fidalgo P, Phillips RK, Bisgaard ML, Orntoft TF, Aaltonen LA, Hodgson SV, Thomas HJ, Tomlinson IP. Multiple colorectal adenomas, classic adenomatous polyposis, and germ-line mutations in MYH. N Engl J Med. 2003 Feb 27;348(9):791-9. doi: 10.1056/NEJMoa025283. Citation on PubMed
  • Venesio T, Molatore S, Cattaneo F, Arrigoni A, Risio M, Ranzani GN. High frequency of MYH gene mutations in a subset of patients with familial adenomatous polyposis. Gastroenterology. 2004 Jun;126(7):1681-5. doi: 10.1053/j.gastro.2004.02.022. Citation on PubMed
  • Wang L, Baudhuin LM, Boardman LA, Steenblock KJ, Petersen GM, Halling KC, French AJ, Johnson RA, Burgart LJ, Rabe K, Lindor NM, Thibodeau SN. MYH mutations in patients with attenuated and classic polyposis and with young-onset colorectal cancer without polyps. Gastroenterology. 2004 Jul;127(1):9-16. doi: 10.1053/j.gastro.2004.03.070. Erratum In: Gastroenterology. 2004 Nov;127(5):1651. Citation on PubMed

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