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Genetics Library / Genes / MSH2

GENE REFERENCE / HGNC:7325

MSH2

mutS homolog 2

protein-coding gene2p21-p16.3Gene information

What does this gene do?

The MSH2 gene provides instructions for making a protein that plays an essential role in repairing DNA. This protein helps correct errors that are made when DNA is copied in preparation for cell division, a process called DNA replication. The MSH2 protein joins with another protein to form a two-protein complex called a dimer. This complex identifies locations where errors have been made during DNA replication. The MSH2 dimer, together with another dimer and additional proteins, makes the repairs by replacing the section of DNA that contains an error with a corrected DNA sequence. The MSH2 gene is one of a set of genes called mismatch repair (MMR) genes.

Source: MedlinePlus, National Library of Medicine. Source publication: 2025-05-12. Source review: 2025-05.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

ConditionInheritanceEvidence
Lynch syndromeMONDO:0005835 · Evaluated 2022-06-20Autosomal dominantDefinitiveHereditary Cancer Gene Curation Expert Panel
mismatch repair cancer syndrome 1MONDO:0010159 · Evaluated 2018-10-09Autosomal recessiveDefinitiveHereditary Cancer Gene Curation Expert Panel
hereditary breast carcinomaMONDO:0016419 · Evaluated 2023-03-14Autosomal dominantRefutedHereditary Cancer Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles
8,636
Submissions for variants in or overlapping this gene
23,095
Submissions explicitly reporting this gene
22,889
Alleles reported pathogenic / likely pathogenic
2,479
VariationIDs with uncertain significance
2,382
VariationIDs with conflicting classifications
1,431

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about MSH2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 2,479 alleles in MSH2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in MSH2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-10-10.

HGNC Source details

Open source record ↗

Source release: Fri, 09 Oct 2026 13:40:45 GMT
Source record updated: 2023-01-20

SHA-256: e4cd9c6d7120051b80e5e61d2aeb98bd6a541ddd21f428a6eab922c11242e053

MedlinePlus Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 05:16:07 GMT
Source publication: 2025-05-12
Source review: 2025-05

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 04 Oct 2026 13:15:29 GMT

SHA-256: 126d9e5bded1d43c0380ac6684c86f9aab056d2ff2be93d743e408ed917ae558

ClinGen Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 09:49:14 GMT

SHA-256: 5bbc9404c72cc21d80e36ea4c49380231755850af5c34064262adceb74881af6

About the library sources · Latest validated release · Record 7caf02a2fdc4