It is also similar to the phenotype of OPA1 mutations causing autosomal dominant optic neuropathy and deafness, however, in general these mutations cause a more extensive phenotype that includes ptosis, ophthalmoplegia, ataxia, axonal sensory-motor polyneuropathy, mitochondrial myopathy, macrocytic anemia, and hypogonadism [6,14–16]. Here, OPA1 is linked to cerebellar ataxia.