Early-onset X-linked optic atrophy is a rare form of hereditary optic atrophy, seen in only 4 families to date, with an onset in early childhood, characterized by progressive loss of visual acuity, significant optic nerve pallor and occasionally additional neurological manifestations, with females being unaffected. The disease is Early-onset X-linked optic atrophy (Orphanet_98890). Also known as: Non-Leber type optic atrophy with early-onset, OPA2, Optic atrophy type 2.