ATXN3 and cerebellar ataxia: SCA1 and SCA3 symptoms include a spinocerebellar syndrome, leading to imbalance and speech difficulties (Jacobi et al. 2015), non-ataxia signs or symptoms such as hyperreflexia and sensory symptoms (Jacobi et al. 2015; Schmitz-Hubsch et al. 2008), and cognitive impairment may also play a role (Schmitz-Hubsch et al. 2008).