ATXN2 and spinocerebellar ataxia type 2: SCA2 is a polyglutamine disorder causing neurodegeneration at different levels, including cerebellar Purkinje cells, thalamic and cholinergic basal forebrain neurons, brainstem pontine, and olivary neurons, spinal and cortical motor neurons, as a result of mutant Ataxin-2 expression [4].