The detection ratio of PMS2 in the Non-CNS LS-unrelated tumor group was significantly greater than that in the CNS LS-related tumor group (43.4% vs. 17.65%, p = 0.036) and Non-CNS LS-related tumor group (43.4% vs. 18.8%, p = 0.021). The gene discussed is PMS2; the disease is Leigh syndrome.