During one of my final biochemistry lectures I learned something very interesting and unexpected… vampires might be based on a real disease!
What?! Why didn’t I hear about this disease before? Well, that’s probably because people who have this genetic disease would rather not be related to vampires, who are considered evil by many. The legend of vampires exists nevertheless, and there is a real medical explanation for how it may have originated.
It makes sense that before science was able to explain strange genetic diseases and symptoms, people assumed that they were connected with an evil spirit, or a result of certain behaviors like diet. In fact, when I lived in rural Ukraine, pregnant women refused to cut their hair or sit on anything cold, thinking these actions would cause birth defects.
Yet, now we know that genetic defects are often the result of a tiny mistake in the duplication and division of DNA. A single rearrangement or deletion can cause a lot of strange things to happen- it’s amazing that most of us come out looking “normal.”
The possible explanation of the vampire legend is one of seven types of porphyrias, which are all diseases in the synthesis of heme (the compound in blood which carries oxygen and carbon dioxide to keep us alive). Heme is synthesized in the liver and bone marrow. There are eight steps, four of which take place inside mitchondria and four in the cytoplasm. Therefore, there are multiple opportunities for defective enzymes and build-up of intermediate products.
The interesting thing about the intermediates in heme synthesis is that they contain many benzene rings. When these rings are oxidized, they can absorb light and appear to be colored (think of purple-yellow-brown-greenish bruising when heme breaks-down under the skin).
The type of porphyria believed to have started the legend of vampires is called porphyria cutanea tarda. It leads to a build up of products which cause a variety of problems. First, people suffer from extreme anemia, so they are very pale. Additionally they have red and fluorescent teeth, which can look pretty strange.
The intermediate products in their blood can oxidize to become insoluble when exposed to sunlight. This causes pain and blistering in the skin, so those with the disease will try to avoid sunlight. Also, drinking fresh blood, could relieve the neurological symptoms.
This type of porphyria was a genetic defect, so it stayed within families. Since these people were probably outcasts from society, they may have married relatives causing the disease to proliferate faster.
None of this is proven fact because nobody knows where any supposed “vampires” are buried. Otherwise, it might be possible to perform a genetic test. Also, this explanation doesn’t explain a fear of garlic or why you have to put a stake through the heart in order to kill a vampire.
This is an extremely rare disease. Yet, it’s interesting to begin to use modern knowledge and biochemistry to solve past medical mysteries. I never thought biochemistry would fascinate me this much.
Posted by Liz 
