The control group of MON without MM was composed by 16 LHON patients who carried the 11778/ND4 (14 patients), 3460/ND1 (1 patient) and 3890/ND1 (1 patient) mtDNA mutations and 20 DOA patients, who carried an OPA1 mutation. The gene discussed is OPA1; the disease is Leber hereditary optic neuropathy.