Adult-Onset Bilateral Optic Neuropathy in a Patient with Non-Familial Childhood-Onset Generalized Dystonia Associated with Mitochondrial DNA 14459G>A Mutation: A Case Report and Review of Literature

The occurrence of Leber Hereditary Optic Neuropathy in association with dystonia is exceedingly rare. There have been only a few previously reported cases describing this clinical phenotype with the mitochondrial DNA 14459 G>A/ND6 mutation. This mutation has been described to also manifest as isolated Leber Hereditary Optic Neuropathy or Leigh Syndrome/Leigh-like Syndrome in a very small number of patients. We report the case of a 27-year-old female who presented with bilateral sequential optic neuropathy on a background of non-familial generalized dystonia. Magnetic resonance imaging performed during childhood had shown bilateral high signal changes in the basal ganglia. Extensive testing for a possible autoimmune etiology was unrevealing. Her vision did not improve with aggressive steroid and plasma exchange treatment. Targeted genetic testing revealed a mitochondrial DNA 14459 G>A/ND6 mutation. Genetic analysis for the mitochondrial DNA 14459 G>A/ND6 mutation should be tested in a patient presenting with bilateral sequential optic neuropathy with co-morbid dystonia.