MSH2

About MSH2

MSH2 on chromosome 2p21 encodes a core component of the DNA mismatch repair system, which corrects errors such as mispaired bases and small insertions or deletions that arise during DNA replication. MSH2 partners with MSH6 or MSH3 to recognize these errors. Inherited variants in MSH2 are one of the main causes of Lynch syndrome, along with MLH1, MSH6, PMS2, and deletions in EPCAM that silence MSH2. Lynch syndrome is the most common inherited colorectal cancer syndrome and also raises the risk of endometrial, ovarian, stomach, urinary tract, and other cancers. Tumors that lose mismatch repair show microsatellite instability, a pattern of length changes in repetitive DNA, and often respond well to immune checkpoint inhibitors because they carry many mutations. Testing tumors for mismatch repair deficiency is widely used to identify people who may have Lynch syndrome.