MLH 1 and MSH2 mutations account for 90% of LS, MSH6 mutations for 10% and PMS2 mutations for 6%.[6] In previous studies, there are many reports about MLH1 and MSH2 mutations, occasionally MSH6 mutations can be reported in LS, while PMS2 mutations are very rare. This evidence concerns the gene MSH6 and Leigh syndrome.