ATXN2 and autosomal dominant cerebellar ataxia: Type 2 spinocerebellar ataxia (SCA2) is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in ATXN2. We present the first case of Moyamoya syndrome in a patient with a previous diagnosis of TS and GD who tested positive for SCA2 and had imaging findings compatible with an overlap of SCA2 and Moyamoya.