It’s the time of year when vampires appear to lurk everywhere, from childrens’ costumes to greeting cards to haunted houses. Some scientists believe vampire myths originated from stories about real people suffering from a blood disease known as erythropoietic protoporphyria (EPP).
EPP, one of a group of blood disorders known as porphyrias, affects the body’s ability to make heme, the hemoglobin component that gives blood its red color. Researchers recently reported in Proceedings of the National Academy of Sciences the discovery of a genetic mutation that triggers EPP. People born with the disorder suffer chronic anemia that makes them exhausted and causes pale skin and extreme sensitivity to light.
“Even on a cloudy day, there’s enough ultraviolet light to cause blistering and disfigurement of the exposed body parts, ears, and nose,” Barry Paw, a physician with the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, said in a statement. Even trace amounts of sunlight passing through window glass can cause swelling, burning and inflammation of exposed skin.
The researchers said people in ancient times with the disorder possibly emerged only at night and drank animal blood to help alleviate some of the symptoms, contributing to myths about vampires.
Paw said he hoped the study would assist medical researchers in developing methods that correct the faulty genes. “Although vampires aren’t real, there is a real need for innovative therapies to improve the lives of people with porphyrias,” he said. —J.B.