We examined polymorphism of prion protein open reading frame. We found out several point mutations and insertional polymorphism. At first, we reported that codon 102 or codon 117 point mutation was linked to Gerstmann-Straussler syndrome. We also found codon 129 mutation, codon 200 mutation and 168 bp insertion in the proline-glycine rich repetitive portion of prion protein. To examine the precise localization of prion protein, we established a new pretreatment. designated as hydrolytic autoclaving. This pretreatment could reveal abnormal prion protein accumulations in the gray matter of the central nervous system. This diffuse gray matter stainings were documented in all patients with Creutzfeldt-Jakob disease. Prion protein immunostainings were similar to synaptophysin immunostainings. To examine precisely, we performed double immunolabelling using anti-prion protein and anti-synaptophysin. Both immunoreactions were colocalized in the same synaptic structures. Therefore, we reported
that the major localization of abnormal prion protein is the synaptic structures in patients with sporadic Creutzfeldt-Jakob disease.
We immunohistochemically examined tissue sections from patients with prion protein polymorphism using hydrolytic autoclaving enhancement. Abnormal prion protein accumulations could be classified into plaque formations(plaque-type)and the diffuse gray matter stainings including synaptic structures(synaptic-type). Both insertional polymorphism and a point mutation in codon 102, 117/129, 129 result in plaque-type prion protein accumulations. The patients with codon 102 mutation also have synaptic type prion protein accumulations. However, a point mutation in codon 200 did not show plaque-type accumulations, and only showed synaptic-type prion protein accumulations. Likewise, sporadic Creutzfeldt-Jakob disease patients without any known mutations only have synaptic-type accumulations. These results imply that the primary structures of prion protein influence in the phenotype of prion protein disease, especially in abnormal prion protein distributions of the central nervous system. Less