The Center is supported by the CDC and sponsored by the American Association of Neuropathologists.

About Human Prion Diseases

Human Prion Diseases
Prion diseases are also referred to as transmissible spongiform encephalopathies (TSE). They occur in humans and animals, primarily affecting the central nervous system.  They can be sporadic (spontaneous), familial (genetic/inherited) or acquired (transmitted by infection).  The hallmark of these diseases is the presence of microscopic vacuolization of the brain tissue, called spongiform degeneration (meaning that the tissue deteriorates, developing a spongy texture), and an abnormal protein, called scrapie prion protein (PrPSc), prion or abnormal prion protein. The PrPSc, unlike other known infectious diseases, is believed to result from a change in the conformation or shape of a normal protein called cellular prion protein (PrPC), which is present in large amounts in the brain as well as in other tissues.  Since the abnormal prion protein cannot be broken down through the body’s normal process, it aggregates mostly in the brain causing degeneration and disease. The abnormal prion protein is often infectious and, under certain conditions, can transmit the disease. Currently, there are no cures for prion diseases. The average world-wide occurrence of prion diseases is approximately one case per million people per year. (For details, see Caughey B. British Medical Bulletin. 66: 109, 2003.)

Our classification of human prion diseases:


Phenotype (Clinical and Pathological Features)


Sporadic Creutzfeldt-Jakob Disease (sCJD), Sporadic Familial Insomnia (sFI)


Familial Creutzfeldt-Jakob Disease (fCJD), Fatal Familial Insomnia (FFI), Gerstmann-Sträussler-Scheinker Syndrome (GSS)


Iatrogenic Creutzfeldt-Jakob Disease (iCJD), variant Creutzfeldt-Jakob Disease (vCJD), Kuru

Creutzfeldt-Jakob Disease (CJD) is the most common of the human prion diseases. There are three types of CJD: 1) sporadic, also called spontaneous, for which the cause is not known; 2) familial, also called genetic or inherited, which is due to a defect in the prion protein gene; 3) and acquired, which is transmitted by infection due to exposure to the infectious prion from contaminated meat, or from transplant of contaminated tissues or use of contaminated instruments during surgical procedures.