High concentrations of GAD65 antibodies associate with a limited set of clinically distinctive phenotypes, namely: SPSD, cerebellar ataxia, epilepsy and limbic encephalitis (Fig. 3B), suggesting some syndrome specificity.107, 110, 111 In addition, several patients with GAD65 antibodies do respond to immunotherapy. The gene discussed is GAD2; the disease is cerebellar ataxia.