Definition

A gene that makes a protein involved in repairing DNA errors that can occur when DNA is copied in a cell. Mutations (changes) in the MLH1 gene may cause unrepaired errors in DNA to build up in the cell, which may lead to abnormal cell growth and cancer. MLH1 gene mutations have been found in the inherited conditions Lynch syndrome and Muir-Torre syndrome. People with these conditions have an increased risk of developing colorectal cancer and other types of cancer. The MLH1 gene is a type of DNA mismatch repair (MMR) gene.