A novel OPA1 mutation causing variable age of onset autosomal dominant optic atrophy plus in an Australian family.

Abstract

Pathogenic mutations in the OPA1 gene can be associated with Autosomal Dominant Optic Atrophy (ADOA). In approximately 20 % of patients with OPA1 mutations, a more complex neurodegenerative disorder with extraocular manifestations, known as ADOA Plus, can arise. 12 members of a multigenerational family were assessed clinically and screened for a genetic mutation in OPA1. Eight family members displayed manifestations consistent with ADOA Plus and four did not. Affected members of the oldest available generation displayed the most severe phenotype, which included severe optic atrophy, deafness, ptosis, ophthalmoplegia, proximal myopathy, neuropathy and ataxia. The next generation was less severely affected but several members displayed manifestations only after the fifth decade. Genetic analysis revealed a heterozygous variant in the OPA1 gene (c.1053T>A, p.Asp351Glu) that segregated with disease. The affected family members described here exhibited visual loss later than is typical for OPA1-related disease, as well as later onset of other neurological abnormalities in the fifth or sixth decades of life that progressed to severe neurological disability by the seventh decade. These findings expand the clinical spectrum of OPA1-related disease associated with a novel OPA1 mutation.