Dr. Penton prepared her family for her death. After a catheter was inserted during the initial hours in intensive care, Penton noticed that Lyon's urine bag filled with what appeared to be dark blood. Penton suspected that Lyon had porphyria, a genetic disease he had studied in medical school but had never seen in a patient. Porphyrins are complex molecules in the body that combine with iron to produce heme, which is responsible for giving blood its red color and combines with globin to form hemoglobin. Besides delivering oxygen through the body's circulatory system, heme is important in metabolism and human physiology.
Porphyria is a genetic disease that is caused by an enzyme deficiency in heme production.
Heme is synthesized from smaller molecules through several enzyme-catalyzed steps in a biochemical pathway. An enzyme deficiency in any of these steps inhibits heme production, causing porphyrins to accumulate and clog the pathway. The high level of porphyrins is responsible for the physical symptoms, such as port-colored urine, sensitivity to sunlight, and the mental instability that sometimes accompanies this disease. Attacks occur when porphyrins become elevated, depending on the patient's tolerance. Alcohol, smoking, or prescription drugs that cause the body to respond by accumulating porphyrins can precipitate attacks.