MT-ND6 and Leber hereditary optic neuropathy: These LHON-associated mtDNA mutations, including NADH dehydrogenase subunit 1 gene (ND1) 3460G>A (A52T), ND4 11778G>A (R340H), ND6 14484T>C (M64V), and ND6 14600G>A (P25L) mutations, primarily affect the essential subunits of complex I (NADH: ubiquinone oxidoreductase) (11–19).