Porphyria is an inherited rare disorder that affects the nervous system or skin and may cause abdominal pain. Cells of porphyria patients are unable to change body chemicals called porphyrins and its precursors into heme, the substance responsible for blood color. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the exact rates of porphyria are unknown and vary globally. Mehr anzeigen