Prion

A disease-causing agent that is neither bacterial nor fungal nor viral and contains no genetic material.

A prion is a protein that occurs normally in a harmless form.

By folding into an aberrant shape, the normal prion turns into a rogue agent.

It then coopts other normal prions to become rogue prions.</P> Prions have been held responsible for a number of degenerative brain diseases, including scrapie (a fatal disease of sheep and goats), mad cow disease, Creutzfeldt-Jacob disease, fatal familial insomnia, kuru, an unusual form of hereditary dementia known as Gertsmann-Straeussler-Scheinker disease, and possibly some cases of Alzheimer's disease.</P> Dr.

Stanley B.

Prusiner received the 1997 Nobel Prize in Physiology or Medicine for his discovery of prions.

See also: Prusiner, Stanley B..