Genetic discovery explains skin-blistering 'Vampire' disease
US-based researchers have discovered a genetic mutation that leads to a condition called erythropoietic protoporphyria (EPP), which makes people look pale and highly sensitive to sunlight. On exposure to ultraviolet light, EPP causes the skin to develop blisters by triggering the release of an enzyme that accumulates in the red blood cells and produce chemicals which damage surrounding cells. 