Children were selected and categorized into three groups: beta cell autoantibody negative throughout follow-up (no autoimmunity); developing insulin autoantibodies as their first beta cell autoantibody prior to age 3 years (early insulin autoimmunity); and developing GAD autoantibodies as their first beta cell autoantibody (GAD autoimmunity). The gene discussed is GAD1; the disease is Autoimmunity.