MT-ATP6 and cerebellar ataxia: Within the last ten years a growing number of adult onset spinocerebellar ataxia (SCA) cases have been reported in association with MT-ATP6 variants; most cases exhibit complex phenotypes with a variable combination of neuropathy, spasticity, renal disease, psychiatric or cognitive dysfunction, and diabetes, but some of the phenotypes described were indistinguishable from the most known SCA due to nuclear mutations [16].