The official name of MSH2 gene is “mutS homolog 6 (E. coli)". The MSH6 gene provides instructions for making a protein that plays an essential role in repairing DNA. This protein fixes mistakes that are made when DNA is copied (DNA replication) in preparation for cell division. The MSH6 protein joins with another protein, the MSH2 protein, to form an active protein complex. This active protein complex identifies places on the DNA where mistakes have been made during DNA replication. Another group of proteins, the MLH1-PMS2 protein complex, then takes over to help with the actual repair. The MSH6 gene is a member of a set of genes known as the mismatch repair (MMR) genes.
MSH2 gene is present in human chromosome 2 and its coded from region 47,863,789 to 47,887,595 base pairs with 16 exons, the cytogenetic location 2p16.
Mutations in the MSH6 gene have been reported in about 10 percent of families with Lynch syndrome that have an identified gene mutation. All of these mutations cause the production of an abnormally short, nonfunctional MSH6 protein or a partially active version of the protein. When the MSH6 protein is absent or ineffective, the number of mistakes that are left unrepaired during cell division increases substantially. If the cells continue to divide, errors accumulate in DNA; the cells become unable to function properly and may form a tumor in the colon or another part of the body. People with mutations in the MSH6 gene also have an increased risk of developing cancers of the ovary, stomach, small intestine, liver, gallbladder duct, upper urinary tract, brain, and skin.