Emotional stress and sensory stimulation may elicit spasms of the legs and trunk or exacerbate clinical manifestations of the disease.[1,2] Although the exact pathogenesis is unclear, between 60% and 80% of patients with SPS have serum antibodies to glutamic acid decarboxylase (GAD), the rate-limiting enzyme for the synthesis of gammaaminobutyric acid (GABA), an important inhibitory neurotransmitter of the brain and spinal cord. The gene discussed is GAD1; the disease is stiff-person syndrome.