Dr. David H. Dolphin, in a lecture at an AAAS meeting, is
attributed to have proposed an alternative explanation for the
vampire myth that werewolves and vampires may have been
based on people suffering from a rare class of genetic diseases
known as porphyrias. He suggested that characteristics
commonly associated with vampirism such as protruding teeth,
avoidance of sunlight, drinking blood, and disfigurement could
have been the symptoms of people with a genetic disease known
as porphyria. Porphyrias are a group of rare genetic diseases that
primarily manifest their effects in blood disorders as a result of a
defect in the production and synthesis of the heme prosthetic
group in hemoglobin (Cox 1995) leading to anemia which means
“a lack of blood.” Anemia is a decrease in the normal number of
red blood cells or less than the normal quantity of hemoglobin in
the blood. Without the normal production of the functional heme prosthetic group, the
quantity of hemoglobin is reduced. The archetype vampire appears to be very anemic.