TBP and autosomal dominant cerebellar ataxia: Parkinsonism is the most common nonataxic movement disorder phenotype in SCA and commonly associated with SCA2, SCA3, and SCA17 (van Gaalen, Giunti, & Warrenburg, 2011; Rossi, Perez‐Lloret, Cerquetti, & Merello, 2014).