Exposure of GAD antigen during synaptic vesicle secretion induces the body to produce GAD antibodies, which react immunologically with GAD in the nerve endings of GABAergic neurons, resulting in reduced GABA synthesis and impaired transport, leading to persistent muscle excitation.[4–6] In addition, SPS can be a sign of Paraneoplastic syndrome. Here, GAD1 is linked to stiff-person syndrome.