From the Editor

The prion diseases are a group of neuro- degenerative conditions affecting both humans and animals. They are transmissible after inoculation, have long incubation periods, and have been known as the spongiform encephalopathies, slow virus diseases, or transmissible dementias. The human diseases include Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler- Scheinker disease (GSS), and kuru. All are associated with the deposition in the brain of an abnormal, partially protease resistant, isoform of a host encoded protein, the prion protein (PrP). An impressive body of exper- imental evidence now argues persuasively that this abnormal isoform of PrP central and conceivably component of transmissible agent types coding mutations diagnosis