PMS2 and Huntington disease: Inactivation of DNA mismatch repair (MMR) genes (MSH3, MSH2, MLH1, PMS2, and MLH3) in cellular and animal models of neurological conditions such as Huntington’s disease (HD), myotonic dystrophy type1 (DM1), and fragile-X related disorders (FXDs) has been shown to attenuate triplet repeat expansion (reviewed in ref. 9).