MSH6 and Leigh syndrome: Previous research has described that MSH2 can dimerize with MSH6, and the MSH2 mutation often leads to in deficiency in both MSH2 and MSH6 protein expression, whereas MSH6 gene mutation typically result in loss of MSH6 protein expression (31, 32); based on our IHC results, it is suggested that LS of this pedigree might be caused by MSH2 mutation.