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

In 1998, we published a case of "sporadic Creutzfeld-Jakob disease with a G erstmann-Straussler-Scheinker phenotype but with no alterations in the PRNP gene" [3]. Our molecular analysis at that time covered codons 8-221; subse quently, we extended our analysis to include the entire C-terminal end of t he translated exon and found an ATG to ACG mutation at codon 232 (methionin e to threonine). This mutation was absent from 40 healthy Polish controls a nd from 16 other Polish Creutzfeldt-Jakob disease (CJD) cases, and we there fore believe that 232(Thr) is a new pathogenic mutation and not a benign po lymorphism. DNA was extracted twice from formalin-fixed and paraffin-embedded brain tis sue. The tissue was cut and transferred to 1.5-ml tubes and washed twice wi th xylene followed by washing with 95% ethanol twice and with 70% ethanol o nce. The pellet was dried and resuspended in 50 mu l of extraction buffer ( 1% SDS, 10 mM EDTA, 0.2 M TRIS pH 8.0) and digested with proteinase K (5 mg /ml) overnight at 56 degrees C. DNA was then isolated by phenol:chloroform extraction and salt-ethanol precipitation.