The clinical and pathological presentations of sporadic Creutzfeldt-Jakob disease (sCJD) are strongly influenced by the polymorphism at codon 129 of the prion protein (PrP) gene (methionine [Met] or valine [Val]; Met/Met, Met/Val, or Val/Val) and the type of protease-resistant PrP (type 1 PrPSc or type 2 PrPSc) [1,2]. This evidence concerns the gene PRNP and sporadic Creutzfeldt-Jakob disease.