MSH2 and Leigh syndrome: According to the American College of Medical Genetics and Genomics classification criteria, these two mutants were considered pathogenic for LS, with the MSH2 mutant (NM_000251.2:c.1486delT:p.L496*) meeting the criteria for PVS1, PM2, PM6, and PP4, and the MLH1 mutant (NM_001258271.1:c.884 + 4A > G) being confirmed as pathogenic.