Creutzfeldt-Jakob Disease (CJD)

Creutzfeldt-Jakob disease (CJD) is a rare, rapidly fatal neurodegenerative disorder caused by prions.

CJD is caused by prions, the only known infectious agents that lack nucleic acids (eg, DNA, RNA).  Prion protein (PrP) is found in both neuronal and nonneuronal brain cells and normally exists in an alpha-helical structure (PrPC).  Prion diseases occur after a domain in this protein undergoes a conformational change from an alpha helix into a beta pleated sheet isoform (PrPSC), which confers the ability to induce similar conformational changes in other proteins.  This beta sheet conformation is resistant to proteases and forms long, highly neurotoxic fibrils that accumulate intracellularly in neurons and form extracellular deposits.  This results in noninflammatory spongiform neurodegeneration with widespread loss of neurons throughout the cerebrum and cerebellum.