MRC1 and Leigh syndrome: LS is an autosomal dominant disorder resulting from inherited mutations in MMR genes: MLH1, MutS homolog 2 (MSH2), MSH6 or PMS1 homolog 2, mismatch repair system component (PMS2), or through a rare deletion of the Epithelial cell adhesion molecule (EPCAM), which inactivates MSH2.3