Scientists in Canada and the United States claim to have found the evolutionary origin of prions, the deadly killer responsible for a family of fatal brain-wasting illnesses: chronic wasting disease in deer; scrapie in sheep; mad cow disease in cows; and human mad cow disease, kuru and Creutzfeldt-Jakob disease in people.
In each disease, the prion, a misfolded protein, leaves behind the same grim calling card: spongelike holes in otherwise healthy brains. FULL STORY
