Optic Atrophy 3 (OPA3) and Solute Carrier Family 25 Member 46 (SLC25A46) are associated with recessive inherited complex neurodegenerative disorders that include optic atrophy as a key feature (Costeff syndrome and CMT with cerebellar atrophy, respectively) [263,264,265]. The gene discussed is SLC25A46; the disease is Leber hereditary optic neuropathy.