A great deal of evidence indicates that the prion protein (PrPC), encoded by the prnp gene, is involved in several neurodegenerative disorders, including Creutzfeldt-Jacob disease, Gerstmann-Sträussler-Scheinker syndrome, fatal familial insomnia, kuru, and possibly Alzheimer’s disease. This evidence concerns the gene PRNP and Creutzfeldt Jacob disease.