While there are many things associated with vampire lore, an interesting new article at the Liberty Voice supposes that the mythology behind vampires may not have come only from the excitable minds of Middle Age peasants. Instead, writes the site, a rare genetic disorder called porphyria might have started the tales, according to biochemist Dr. David H. Dolphin of the University of British Columbia and other scientists.

“Porphyria is a rare group of at least eight blood disorders. A patient is diagnosed with porphyria if any of the eight different enzymes that create porphyrin, a body chemical which transforms into heme (another chemical the body needs) when in contact with iron, are affected. A patient lacking in any one of the eight enzymes is not able to produce heme, which is responsible for items such as cell differentiation and protein synthesis. In people with porphyria, the build-up of unprocessed porphyrin and the overall lack of heme is what leads to the onset of symptoms. These can include severe, non-diagnosable stomach pain; additional discomfort in the chest, legs or back; vomiting; and diarrhea or constipation. A urine test is needed to provide a definitive diagnosis.

Porphyria is a chronic condition. There is no cure. However, symptoms can be managed. Porphyria flare-ups usually last a week or two, with symptoms decreasing as the attack draws to a close. The more care someone takes in managing their condition, the fewer flares they will likely experience.

Patients with this disease are highly sensitive to sunlight. Those who are able to go outside during the day must wear a high SPF sunscreen. Others must wait for cloudy days or nightfall to venture out. Therefore, many exhibit the paleness and nocturnal tendencies historically associated with vampires.

Bloodsucking behavior, which is typical of vampire myths, may have been a way for the porphyria patient to manage their disease. Today, a significant treatment is injecting man-made heme. In the Middle Ages, there was no way to create heme, so people were forced to drink blood.

This had an unintended side effect in some cases. The cause of porphyria is entirely genetic. People either acquire a disease-carrying gene from one of their parents or disease-carrying genes from both parents. Some people have what is called latent porphyria, in which they have the disease, but are not having symptoms. If someone with the latent form of porphyria allowed a relative to regularly blood-let them for the purposes of disease management, they were taking a great risk. Stress is one of the trigger mechanisms for a porphyria attack. Bloodletting is stressful to the body and might cause a person with latent porphyria to become a person with the active form.

This may explain why the myths incorporated the fact that if someone was bitten, they would also become a vampire. This was not a supernatural event; it was due to a change in disease status. This occurred, not because of dark forces, but due to an asymptomatic person having inflicted too much stress on their body. The person desired to help a family member, using the only treatment available. Neither party may have comprehended the risks involved.

So, while the mythos expanded over the years – invisible in mirrors, allergic to garlic, etc – it’s hypothesized that it could be originally from the above disease. And Vlad the Impaler, well, he could still be one of the reasons vampires became so feared throughout the ages.