Schere's Disease is a form of acute hepatic porphyria. Symptoms include severe anaemia, sterility, difficulty digesting most foods, and extreme sensitivity to sunlight. The sensitivity is so acute that direct exposure to sunlight can cause third-degree burns, or even kill. Sufferers maintain a youthful appearance, but often don't live past 50.
First proposed in 1898, Schere's is a disease engineered in 1905 by the Tremere Dr. Harold Schere for the express purpose of reinforcing the Masquerade. It mimics vampirism, serving the dual purpose of explaining historical "vampirism" as a myth based on a medical condition, as well as providing cover for modern Kindred. As it is hereditary, vampires who have themselves registered as Schere's Disease sufferers can disappear for a while and then reappear as their own children.
According to the foundation's statistics, Schere's affects 0.0002% of the population, or one out of every 500000.