A beta-sheet rich conformational isoform of PrPC, called PrPSc, has been considered to be the major constituent of infectious agent of the fatal neurodegenerative diseases such as Transmissible Spongiform Encephalopathies (TSE) and its hereditary from spongiform encephalopathies (SE) [1–3]. The gene discussed is PRNP; the disease is prion disease.