Prion Diseases A Short Review What is a Prion? Learn Below 1. What is a prion? A prion is an infectious (transmissible) protein able to replicate by transforming other proteins into a copy of the prion. The mechanism of copying is not yet understood by science. The hypothesis come out from research about a nervous system disease known as Creutzfeldt-Jacob disease, epidemiologically associated to a bovine disease called bovine spongiform encephalitis (the mad cow disease). Research discovered that the infectious agent that causes those diseases, suprisingly, was a protein capable of copying itself and of being transmitted by ingestion (the reason why meat from contaminated animals cannot be consumed), inoculation and even heredity. Image Diversity: prion 2. What are the main human diseases caused by prions? The main known human diseases of such type are the Creutzfeldt-Jacob disease (CJD), the kuru and the Gerstmann-Sträussle-Scheinken disease (GSS). The hypothesis that many other diseases of unknown etiological agents are actually caused by self-replicating infectious proteins is strong. Image Diversity: mad cow disease