It also agrees with the fact that genetic CJD forms share common neuropathological traits with sporadic cases, particularly a classification in very similar histotypes, which depend on the polymorphism at codon 129 of PRNP and the biochemical PrPres type [4], although some differences exist, mainly at the level of immunohistochemical PrP deposition patterns [27]. Here, PRNP is linked to Creutzfeldt Jacob disease.