Codon 129 polymorphism of the PRNP gene in normal Polish population and in Creutzfeldt-Jakob disease, and the search for new mutations in PRNP gene

Polymorphism at codon 129 of the prion protein gene (PRNP) is implicated both in susceptibility and phenotype of human prion diseases. We characterized the valine and methionine allele frequency at codon 129 in 109 individuals representing the normal Polish population and in 15 Polish CJD cases. The distribution of the genotype was 45% Met/Met, 39% Met/Val, and 16% Val/Val in the control group whereas, of the CJD cases, 73.3% were homozygous for methionine, 13.3% homozygous for valine and 13.3% were heterozygous. The novel missense mutation (ATG __ACG) at codon 232 was identified in one of the samples with a GSS phenotype.