In SCA3, the polyQ-expanded protein is known as ataxin-3 and patients carry an expansion between 61 and 87 repeats on the affected allele resulting in the observed phenotype characterized by a disturbance of movement coordination (cerebellar ataxia), bulbar, pyramidal and extrapyramidal signs, and a possible occurrence of peripheral neuropathy or ophthalmoplegia (2). Here, ATXN3 is linked to cerebellar ataxia.