MT-ND6 and Leber hereditary optic neuropathy: The majority of LHON cases globally results from one of three mitochondrial DNA (mtDNA) mutations (ND1 3460G > A, ND4 11778G > A, and ND6 14484T > C), which affects the essential subunits of complex I (NADH: ubiquinone oxidoreductase) [7–13].