Prion diseases: A concern for mankind

Abstract

Abnormal prion proteins are known to cause slowly progressive, invariably fatal neurodegenerative diseases in animals and humans. They are characterized by having prolonged incubation period and a clinically silent phase during which the normal cellular prion protein (PrPc) is misfolded into an abnormal form (PrPsc). This can occur sporadically, genetically or can be acquired by either oral or iatrogenic routes of transmission. Majority of human prion diseases are sporadic in occurrence and are termed as sporadic Creutzfeldt-Jakob disease (sCJD), whereas familial forms include familial or genetic CJD, fatal familial insomnia (FFI) and Gerstmann-Straussler-Scheinker syndrome (GSSS). About 5% of cases of human prion disease are infectious in origin, variant CJD (vCJD), iatrogenic CJD (iCJD) and a now extinct form “Kuru”, being the manifestations. Though Prion diseases are rare in humans, being invariably fatal and difficult to diagnose especially in ageing population, they have become an area of active interest. This chapter will focus on various aspects of human prion diseases including epidemiology, clinical features, pathogenesis, treatment and prevention.