PRNP and Creutzfeldt Jacob disease: These non-CJD subjects included two cases homozygous for methionine (M) at polymorphic codon 129 of the PrP gene (PrP-129MM) termed MM#1 and MM#2, and a case homozygous for valine (V) at codon 129 (PrP-129VV) designated VV#1.