Thirty-one out of 100 investigated patients carried germline pathogenic or likely pathogenic variants in MLH1 (n = 8), MSH2 (n = 13), MSH6 (n = 5), PMS2 (n = 2) or EPCAM (n = 3) associated with LS (Fig. 1 and Table 1). This evidence concerns the gene MSH6 and Leigh syndrome.