Mutations in the optic atrophy 1 (OPAI) or Mitofusin 2 (MFN2) genes, which represent two mitochondrial dynamic regulators, lead to an impaired mitochondrial function and contribute to optic atrophy or charcot-marie-tooth disease type 2A (a familial neuropathy) [36, 37]. Here, MFN2 is linked to optic atrophy.