prion disease

prion

 [pri´on]

any of several pathogenic, transmissible forms of the core of prion protein that cause a group of degenerative diseases of the nervous system known as prion diseases. Prions have a structure different from that of normal prion protein, lack detectable nucleic acid, and do not elicit an immune response.

prion disease any of a group of fatal degenerative diseases of the nervous system caused by abnormalities in the metabolism of prion protein. These diseases are unique in that they may be transmitted genetically as an autosomal dominant trait, or by infection with abnormal forms of the protein (prions). Inherited forms result from mutations in the gene that codes for prion protein; such mutations may also occur sporadically. Hereditary forms include some forms of Creutzfeldt-Jakob disease, Gerstmann-Sträussler syndrome, and fatal familial insomnia. Infectious forms of the disease result from ingestion of infected tissue or the introduction of infected tissue into the body (kuru and some forms of Creutzfeldt-Jakob disease). The latter has occasionally occurred during surgical procedures; it has also occurred as the result of injection of human growth hormone prepared from infected pituitary glands. Prion diseases also occur in animals. Called also transmissible neurodegenerative disease and subacute spongiform or transmissible spongiform encephalopathy.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

prion disease

See PRION PROTEIN, PRION PROTEIN DISEASE and CREUTZFELDT-JAKOB DISEASE.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005