The legend of blood-sucking vampires could have been based on real people, experts have revealed.
The mythical creatures could have actually been suffering from a rare blood disorder, a new study suggests.
Folklore portrays vampires as undead beings who feast on the blood of innocent people.
They’re notoriously allergic to daylight and can be repelled with garlic and a crucifix.
But, now a team of scientists at Boston Children’s Hospital believes there is another explanation.
They believe a rare genetic mutation could have caused some people to display traits of “vampires,” leading to the fictitious characters we know about today.
The condition erythropoietic protoporphyria (EPP), is a blood disorder that affects kids, causing their skin to become very sensitive to light.
Prolonged exposure to the sun can cause agonizing, disfiguring blisters.
The condition affects the body’s ability to make heme, which helps make hemoglobin, the part of our blood that helps carry oxygen.
And heme also helps make blood red, when it binds with iron.
People suffering EPP are “chronically anemic,” Dr. Barry Paw of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center explained.
It means their iron levels are too low.
“It makes them feel very tired and look very pale with increased photosensitivity because they can’t come out in the daylight,” Paw said.
“Even on a cloudy day, there’s enough ultraviolet light to cause blistering and disfigurement of the exposed body parts, ears and nose.”
Patients with EPP can stay inside and receive blood transfusions to combat their anemia.
But in ancient times drinking animal blood and emerging only at night may have been used to achieve the same effect, the researchers noted, adding further fuel to the legend of vampires.
Now, Paw and his team have identified a specific genetic mutation that they believe triggers EPP.
He said the mutation could potentially be responsible for the folklore of vampires.
Heme is produced in the liver and bone marrow, thanks to a process called porphyrin synthesis.
Any genetic defect that affects that process can stop the body producing heme.
Decreased levels of heme lead to a build up of a type of protoporphyrin called protoporphyrin IX, in the red blood cells, plasma and sometimes the liver.
When protoporphyrin IX is exposed to light, it produces chemicals that damage surrounding cells.
And it’s this damage that causes people with EPP to experience swelling, burning and redness of the skin after exposure to sunlight.
The reaction can even happen with a few rays of sunlight passing through a window.
Paw said: “This newly-discovered mutation really highlights the complex genetic network that underpins heme metabolism.”
“Loss of function mutations in any number of genes that are part of this network can result in devastating disfiguring disorders.”
Paw suggested that identifying the genetic mutations that cause porphyria could pave the way for future therapies that could correct the faulty genes.
He added: “Although vampires aren’t real, there is a real need for innovative therapies to improve the lives of people with porphyrias.”