NDUFS2 and optic nerve disorder: In contrast to the infrequently described nuclear DNA abnormalities with “LHON-like” visual loss, such as in patients with Charcot-Marie-Tooth disease, in optic atrophy associated with dominant mutations in OPA1 (36), and in a single report of recessive “LHON-like” optic neuropathy due to mutations in NDUFS2 (37), our findings argue for the frequent occurrence of arLHON.