Porphyria and the Biological Basis of Vampire Lore
Porphyias are inherited or acquired disorders effecting porphyrin production in the body. Porphyrins are the primary precursors to heme, the prosthetic group required for the binding of oxygen to the hemoglobin in red blood cells, the proper function of catalase and peroxidase (important to removing cellular peroxides), and the reductive capacity of cytochrom P450 (a component of the electron transport chain). There are a number of genetic mutations that can affect production of enzymes in the porphyrin pathway, any of which may lead to an inadequate supply of heme, resulting in a myriad of physiological problems. The symptoms often include:
* Light sensitivity
* Neurological attacks- seizures and severe back and abdominal pain
* Mental instability- psychosis, hallucination, and paranoia
* Receding gums leading to a fanged appearance
* Increased hair and nail growth
In addition to all these hardships, in the Middle Ages some porphyrics took to drinking blood, as modern treatments were not yet available. Although inefficient, in large enough quantities the additional heme in the blood-based diet could reduce symptoms.
Does this not sound like the fabled creatures of the night? Perhaps it does not describe the dashing and frightening Dracula, who is believed to be based off of Vlad the second, the brutal Hungarian king also known as "Dracul" (the dragon), but it does describe a more eerie creature of legend. The German adaptation of Dracula, Nosferatu, may have borrowed some from the poryphyria-based lore to create their own variety of vampire with elongated nails and hair, rotting flesh, and rat-like features. Not nearly as glamorous as those vampires popularized by the modern novelists like Anne Rice, these "vampires" had a more gritty lifestyle, often ending in pain and insanity. They were based off of a a tragic disease, for which there was no cure.
Luckily, today there are better treatments available for people with porphyria. Hematin and haem arginate are used to treat acute porphyria. If given early enough in an attack, they can limit the nausea, seizure, and neuropathy. In most cases of porphyria, direct heme injections can help relieve disease symptoms as well.
Juan, Stephen (2006). The Odd Brain: Mysteries of Our Weird and Wonderful Brains Explained. Andrews and McMeel Publishing.
Wikipedia (2006). "Porphyria."