The term “prions” refers to abnormal, pathogenic agents that are transmissible and are able to induce abnormal folding (or misfolding) of specific normal cellular proteins called prion proteins that are found most abundantly in the brain. The word prion derives from “proteinaceous infectious particle”. The abnormal folding of the prion proteins leads to brain damage and the characteristic signs and symptoms of the disease.  Prion diseases are usually rapidly progressive and always fatal.

Properties of prions

  • consist of a single type of protein molecule
  • arises from normal prion proteins that have completely unknown functions. The confusion arises from the fact that the prion protein and the gene that encodes it are also found in normal ‘uninfected’ cells
  • they have no nucleic acid
  • Present in nervous tissue

Transmission is through:

  • Consumption of infected meat/ nervous tissue
  • –Surgical instruments
Hypothesized mechanisms for the development of prion disease


The list of identified Prion-Spongiform diseases to date

Human Prion Diseases
Animal Prion Diseases