Leber's Hereditary Optic Neuropathy Phenotype in a Male Adolescent with Paternally Transmitted Autosomal NSUN3 Mutation

Leber's hereditary optic neuropathy (LHON) is clinically characterized by subacute progressive vision impairment and optic nerve atrophy in both eyes without other symptoms. After the initial visual decline, some patients show a recovery of visual function either spontaneously, or more often treatment-induced. The disease is usually caused by maternally inherited point mutations in mitochondrial genes encoding for subunits of complex I of the mitochondrial respiratory chain, leading to an imbalance in mitochondrial energy generation and increased oxidative stress in retinal ganglion cells. Visual recovery in LHON is attributed to a reactivated signal transduction in dysfunctional ganglion cells and nerve fibers that survived the energetic and oxidative crisis of the acute phase.