Microsatellite Instability | MSI | Lynch Syndrome |

Microsatellite instability (MSI) is the condition of genetic hypermutability that results from impaired DNA mismatch repair (MMR).

Microsatellites are regions of repeated DNA that change in length or in other words show instability when mismatch repair is not working properly.


The presence of MSI represents phenotypic evidence that MMR is not functioning normally.