hereditary optic atrophy mitochondrial disease ACO2-related optic atrophy with or without extraocular features https://github.com/monarch-initiative/mondo/issues/9051 GARD:0028153 MONDO:1060120 An optic atrophy in which the cause of the disease is monoallelic or biallelic variants in the ACO2 gene. ACO2 is a mitochondrial protein and thus, in addition to the optic atrophy features, features of this disease include abnormal mitochondrial morphology and can affect other organ systems. Extraocular features can include ataxia, spastic paraplegia, CNS abnormalities, neurodevelopmental phenotypes, and retinal degeneration. infantile cerebellar-retinal degeneration ACO2-related optic atrophy with or without extraocular features optic atrophy 9