In Leber hereditary optic neuropathy (LHON) 10 genes are involved; these are MT-ND1, MT-ND4, MT-ND4L, MT-ND6, MT-CO1, MT-CO3, MT-CYB, MT-ND2, and MT-ND5. Here, MT-CO1 is linked to Leber hereditary optic neuropathy.