Phenotypic heterogeneity in inherited prion disease (P102L) is associated with differential propagation of protease-resistant wild-type and mutant prion protein.

Inherited prion diseases are caused by PRNP coding mutations and display marked phenotypic heterogeneity within families segregating the same pathogenic mutation. A proline-to-leucine substitution at prion protein (PrP) residue 102 (P102L), classically associated with the Gerstmann-Sträussler-Scheinker (GSS) phenotype, also shows marked clinical and pathological heterogeneity, including patients with a Creutzfeldt-Jakob disease (CJD) phenotype. To date, this heterogeneity has been attributed to temporal and spatial variance in the propagation of distinct protease-resistant (PrP(Sc)) isoforms of mutant PrP.

Characterization of two distinct prion strains derived from bovine spongiform encephalopathy transmissions to inbred mice.

Distinct prion strains can be distinguished by differences in incubation period, neuropathology and biochemical properties of disease-associated prion protein (PrP(Sc)) in inoculated mice. Reliable comparisons of mouse prion strain properties can only be achieved after passage in genetically identical mice, as host prion protein sequence and genetic background are known to modulate prion disease phenotypes. While multiple prion strains have been identified in sheep scrapie and Creutzfeldt-Jakob disease, bovine spongiform encephalopathy (BSE) is thought to be caused by a single prion strain.