Detecting prions in eyes of patients with Creutzfeldt-Jakob disease

(c) NIH

Prions are abnormal forms of natural proteins. The misshapen proteins collect in brain tissue and cause cells to die, leaving sponge-like holes in the brain. Prion diseases include “mad cow” disease in cattle and Creutzfeldt-Jakob disease (CJD) in people. People can get CJD by eating infected beef, but most cases develop spontaneously. This rare disease, which affects about one in a million people, is untreatable and fatal.