In addition, genetic analysis of a large family with isolated optic atrophy disclosed the first dominant SPG7 mutation, c.1232A>C, p.D411A, affecting the AAA domain (Klebe et al., 2012), 56 amino-acids upstream of the conserved RPGR motif, in which we found the AFG3L2 mutation. The gene discussed is AFG3L2; the disease is Leber hereditary optic neuropathy.