Mitodyn/OPA1

---A database from the MITOchondrial DYNamics variation portal---
Autosomal dominant optic atrophy (DOA, Kjer type, MIM#165500) is characterized by moderate to severe loss of visual acuity with insidious onset in early childhood, blue-yellow dyschromatopsia and central scotoma. Mutations in the optic atrophy 1 gene (OPA1; MIM#605290) are responsible for about 60-80% of the cases of DOA. The spectrum of OPA1-related disorders is highly variable. The age of onset varies from birth to over 60 years, and the severity of the visual loss ranges from subclinical loss to severe blindness. Estimated disease prevalence is between 1:10,000 in Denmark due to a founder effect and 1:35,000 worldwide. Extra ocular features, involving the central, peripheral and autonomous nervous systems, complicating the optic neuropathy are reported in about 20% of the patients carrying OPA1 pathogenic variants, leading to conditions described as the "DOA plus" or "DOA+" syndromes (MIM#125250). A phenotype fully compatible with the Behr syndrome (MIM#210000), associating early onset and severe optic neuropathy with spinocerebellar ataxia and retarded development was also reported. This variety of phenotypes is attributed to differences in the OPA1 mutations effects (haplo-insufficiency or dominant negative effect), as well as to the mode of inheritance, which may be mono- or more rarely bi-allelic.