Porphobilinogen is a chemical compound produced in the body during the synthesis of heme, a component of hemoglobin. Elevated levels of porphobilinogen in the urine can be indicative of certain medical conditions, particularly those related to porphyria, a group of rare genetic disorders that affect the production of heme. To rule out acute intermittent porphyria (AIP) and other acute attack types of porphyrias associated with neurologic and/or psychiatric symptoms