A case of sporadic Creutzfeldt-Jakob disease with a Gerstmann-Sträussler-Scheinker phenotype but no alterations in the PRNP gene.

We report here an unusual sporadic case of Creutzfeldt-Jakob disease (CJD) characterized by an abundance of prion protein (PrP)-immunopositive kuru and multicentric but not florid plaques. Molecular genetic analysis of the PRNP open reading frame region spanning codons 8-221 was performed. Neither deletion nor insertion mutations were detected in the repeat area of the PRNP. No pathogenic mutation was found in the sequenced region between codon 108-221. Restriction analysis of the amplified fragment using restriction endonucleases DdeI, PvuII and AluI did not show any of the previously described pathogenic mutations at codon 102, 105, and 117 associated with Gerstmann-Sträussler-Scheinker (GSS). The patient was heterozygous for the methionine/valine coding triplet at polymorphic codon 129 of the PRNP gene by sequence, restriction endonuclease analysis and hybridization with allele-specific nucleotides. Furthermore, hybridization with 32P-labeled allele-specific oligonucleotides confirmed the absence of pathogenic mutations at codons 102, 200 and 178. Such a case may present a missing "link" between sporadic CJD and familial GSS.