Immunoglobulin G Deficiency, also known as igg deficiency, is related to systemic lupus erythematosus and autoimmune disease. An important gene associated with Immunoglobulin G Deficiency is FCGRT (Fc Gamma Receptor And Transporter). The drugs Sulfamethoxazole and Trimethoprim have been mentioned in the context of this disorder. Affiliated tissues include spinal cord and bone marrow.