MT-ND4 and Leber hereditary optic neuropathy: The m.3460G > A (A52T), m.11778G > A (R340H), m.14484 T > C (M64V) mitochondrial DNA (mtDNA) variants occurring in the MT-ND1, MT-ND4, and MT-ND6 genes, respectively, are the three most common primary mutations that are involved in the pathogenesis of LHON (8–10).