The three most common causative mutations, described by several authors as the “primary variants” for the disease, are m.11778G>A in MT‐ND4 (by far the most common, accounting for 70% of all LHON cases worldwide), m.14484T>C in MT‐ND6 and m.3460G>A in MT‐ND1 [9]. This evidence concerns the gene MCAT and Leber hereditary optic neuropathy.