Although the pathophysiology of classic SPS remains to be fully elucidated, there are known immunological markers for SPS and an autoimmune link between diabetes mellitus (type 1) and SPS involving the neuroendocrine autoantibody specific for glutamic acid decarboxylase (65 kD isoform; GAD65) has been demonstrated [2–4]. The gene discussed is GAD2; the disease is stiff-person syndrome.