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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed October 2015

What is the official name of the MSH2 gene?

The official name of this gene is “mutS homolog 2.”

MSH2 is the gene's official symbol. The MSH2 gene is also known by other names, listed below.

What is the normal function of the MSH2 gene?

The MSH2 gene provides instructions for making a protein that plays an essential role in DNA repair. This protein helps fix mistakes that are made when DNA is copied (DNA replication) in preparation for cell division. The MSH2 protein joins with one of two other proteins, MSH6 or MSH3 (each produced from a different gene), to form a protein complex. This complex identifies locations on the DNA where mistakes have been made during DNA replication. Another group of proteins, the MLH1-PMS2 protein complex, then repairs the errors. The MSH2 gene is a member of a set of genes known as the mismatch repair (MMR) genes.

How are changes in the MSH2 gene related to health conditions?

Lynch syndrome - increased risk from variations of the MSH2 gene

About 40 percent of all cases of Lynch syndrome with an identified gene mutation are associated with inherited mutations in the MSH2 gene. Lynch syndrome increases the risk of many types of cancer, particularly cancers of the colon (large intestine) and rectum, which are collectively referred to as colorectal cancer. People with Lynch syndrome also have an increased risk of cancers of the endometrium (lining of the uterus), ovaries, stomach, small intestine, liver, gallbladder duct, upper urinary tract, and brain.

MSH2 gene mutations involved in Lynch syndrome may cause the production of an abnormally short or inactive MSH2 protein that cannot perform its normal function. When the MSH2 protein is absent or nonfunctional, the number of DNA mistakes that are left unrepaired during cell division increases substantially. The errors accumulate as the cells continue to divide, which may cause the cells to function abnormally, increasing the risk of tumor formation in the colon or another part of the body.

Some mutations in the MSH2 gene cause a variant of Lynch syndrome called Muir-Torre syndrome. In addition to colorectal cancer, people with this condition have an increased risk of developing several uncommon skin tumors. These rare skin tumors include sebaceous adenomas and carcinomas, which occur in glands that produce an oily substance called sebum (sebaceous glands). Multiple rapidly growing tumors called keratoacanthomas may also occur, usually on sun-exposed areas of skin.

ovarian cancer - increased risk from variations of the MSH2 gene

Inherited changes in the MSH2 gene increase the risk of developing ovarian cancer, as well as other types of cancer, as part of Lynch syndrome (described above). Women with Lynch syndrome have an 8 to 10 percent chance of developing ovarian cancer in their lifetimes, as compared with 1.6 percent in the general population.

Where is the MSH2 gene located?

Cytogenetic Location: 2p21

Molecular Location on chromosome 2: base pairs 47,403,067 to 47,564,579

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The MSH2 gene is located on the short (p) arm of chromosome 2 at position 21.

The MSH2 gene is located on the short (p) arm of chromosome 2 at position 21.

More precisely, the MSH2 gene is located from base pair 47,403,067 to base pair 47,564,579 on chromosome 2.

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

Where can I find additional information about MSH2?

You and your healthcare professional may find the following resources about MSH2 helpful.

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

What other names do people use for the MSH2 gene or gene products?

  • COCA1
  • HNPCC1
  • mutS (E. coli) homolog 2
  • mutS (E. coli) homolog 2 (colon cancer, nonpolyposis type 1)
  • mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli)

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

What glossary definitions help with understanding MSH2?

cancer ; cell ; cell division ; colon ; colorectal ; DNA ; DNA repair ; DNA replication ; duct ; E. coli ; endometrium ; gallbladder ; gene ; inherited ; intestine ; mutation ; ovarian ; population ; protein ; rectum ; stomach ; syndrome ; tumor

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


  • Bandipalliam P. Syndrome of early onset colon cancers, hematologic malignancies & features of neurofibromatosis in HNPCC families with homozygous mismatch repair gene mutations. Fam Cancer. 2005;4(4):323-33. Review. (
  • Cohen MM Jr. Molecular dimensions of gastrointestinal tumors: some thoughts for digestion. Am J Med Genet A. 2003 Nov 1;122A(4):303-14. Review. (
  • Gene Review: Lynch Syndrome (
  • Guillem JG, Moore HG, Palmer C, Glogowski E, Finch R, Nafa K, Markowitz AJ, Offit K, Ellis NA. A636P testing in Ashkenazi Jews. Fam Cancer. 2004;3(3-4):223-7. Review. (
  • Lützen A, de Wind N, Georgijevic D, Nielsen FC, Rasmussen LJ. Functional analysis of HNPCC-related missense mutations in MSH2. Mutat Res. 2008 Oct 14;645(1-2):44-55. doi: 10.1016/j.mrfmmm.2008.08.015. Epub 2008 Sep 4. (
  • Lynch HT, de la Chapelle A. Hereditary colorectal cancer. N Engl J Med. 2003 Mar 6;348(10):919-32. Review. (
  • Mitchell RJ, Farrington SM, Dunlop MG, Campbell H. Mismatch repair genes hMLH1 and hMSH2 and colorectal cancer: a HuGE review. Am J Epidemiol. 2002 Nov 15;156(10):885-902. Review. (
  • NCBI Gene (
  • Pande M, Wei C, Chen J, Amos CI, Lynch PM, Lu KH, Lucio LA, Boyd-Rogers SG, Bannon SA, Mork ME, Frazier ML. Cancer spectrum in DNA mismatch repair gene mutation carriers: results from a hospital based Lynch syndrome registry. Fam Cancer. 2012 Sep;11(3):441-7. doi: 10.1007/s10689-012-9534-6. (
  • Peltomäki P. Lynch syndrome genes. Fam Cancer. 2005;4(3):227-32. Review. (
  • Pennington KP, Swisher EM. Hereditary ovarian cancer: beyond the usual suspects. Gynecol Oncol. 2012 Feb;124(2):347-53. doi: 10.1016/j.ygyno.2011.12.415. Review. (
  • Rishi K, Font RL. Sebaceous gland tumors of the eyelids and conjunctiva in the Muir-Torre syndrome: a clinicopathologic study of five cases and literature review. Ophthal Plast Reconstr Surg. 2004 Jan;20(1):31-6. Review. Erratum in: Ophthal Plast Reconstr Surg. 2004 May;11(5):953. (
  • South CD, Hampel H, Comeras I, Westman JA, Frankel WL, de la Chapelle A. The frequency of Muir-Torre syndrome among Lynch syndrome families. J Natl Cancer Inst. 2008 Feb 20;100(4):277-81. doi: 10.1093/jnci/djm291. Epub 2008 Feb 12. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: October 2015
Published: February 1, 2016