Prospective studies by Hadjivassiliou et al. [9] in the UK showed that the prevalence of immune-mediated CAs was 32 % in a group of 320 patients with sporadic ataxia (gluten ataxia 27 %, paraneoplastic cerebellar degeneration 3 %, and anti-GAD-Abs associated CA 3 %). This evidence concerns the gene GAD1 and paraneoplastic cerebellar degeneration.