GAD2 and paraneoplastic neurologic syndrome: As such, autoantibodies against GAD65 (GAD65-Abs) have been associated with not only several neuropsychiatric conditions, including stiff-person syndrome (SPS), epilepsy, limbic encephalitis, cerebellar ataxia, and paraneoplastic neurological syndromes (3), but also with type-1 diabetes mellitus (DM1) and latent autoimmune diabetes in adults (LADA), in which the presence of GAD65-Abs suggests autoimmune-induced destruction of the insulin-producing beta-cells in the pancreas.