PRNP and Creutzfeldt Jacob disease: More specifically, GSS affected subjects carrying the most common GSS mutation (P102L) may either show a rapidly progressive CJD-like phenotype with both spongiform changes and amyloid plaques correlating with the cooccurrence PrPSc type 1 and the 8 kDa fragments or show a more slowly progressive “pure” GSS phenotype correlating with the presence of amyloid plaques and the 8 kDa PrP fragment [102, 146].