Prions. The mysterious infectious agents.

Prions, a novel biological entity are causative agents of fatal neurodegenerative diseases. Such diseases gain importance because of its effect on both humans and animals and because of the unique biological features of the infectious agent. Since its discovery the agent responsible has remained mysterious in its mechanism of action, pathogenesis and the ability to produce disease. In this review, the considerable evidence regarding the molecular biology, pathogenesis, epidemiology, diagnosis and therapeutic approaches are being discussed. The advances in understandings of fundamental biology of prion diseases may open the possibilities for the prevention and treatment of these unusual diseases.