A rare mitochondrial disease with characteristics of a variable clinical phenotype with the core features of optic atrophy, ataxia and hypotonia. Additional common manifestations include global developmental delay with or without regression, neuropathy, spasticity, and microcephaly, less frequently seizures, movement disorder, hearing loss and respiratory failure. Brain imaging may show abnormalities of the corpus callosum, basal ganglia and midbrain, cerebral or cerebellar atrophy, or white matter abnormalities. The condition is frequently fatal at an early age. [from
SNOMEDCT_US]