Whereas normal alleles possess 12–43 repeats, pathogenic ATXN3 alleles contain 60–87 repeats with milder forms of ataxia and restless leg syndrome appearing in patients with mid-range repeats (Ranum et al., 1995; Paulson, 2012; Li et al., 2015; Nobrega et al., 2018; Matos et al., 2019). Here, ATXN3 is linked to cerebellar ataxia.