ATXN3 and Spinocerebellar ataxia type 3: Spinocerebellar ataxia type 3 (SCA3) is caused by a dynamic cytosine‐adenine‐guanine (CAG) repeat expansion of the Ataxin‐3 gene (ATXN3) and is the most common SCA worldwide,1 which characterized by the presence of progressive cerebellar ataxia, associated with a wide range of nonataxic symptoms (pyramidal signs, extrapyramidal features, cognitive dysfunction, and dementia).