The majority of LHON cases are caused by single-nucleotide point mutations of mtDNA located in NADH dehydrogenase subunit 1 (ND1) (G3460A), ND4 (G11778A), or ND6 (T14484C) genes, which result in a dysregulated complex I of OXPHOS [46]. The gene discussed is MT-ND1; the disease is Leber hereditary optic neuropathy.