Prion diseases

Synonyms

Transmissible spongiform encephalopathy, transmissible neurodegenerative diseases.

Definition

Prion diseases are rare disorders that share common clinical features of progressive central nervous system dysfunction caused by neuronal degeneration. On histology, all prion diseases manifest spongiform degeneration of the CNS. The shared pathophysiology appears to be a pathological accumulation of the prion protein (PrP). Prions are infectious agents composed primarily or possibly exclusively by proteins. Most prion diseases are transmitted through genetic inheritance, or more commonly through exposure to prion-infected tissues (via tissue transplant or ingestion of contaminated tissue-particularly CNS). The best known example of transmissibility of prion-associated disease is Kuru, a spongiform encephalopathy that afflicted large numbers of indigenous tribal people from the Eastern Highlands of New Guinea. Kuru has largely disappeared since the banning of ritual cannibalism in...