Analysis of PRNP gene codon 129 polymorphism in the Greek population.

Creutzfeldt-Jakob disease (CJD) is a fatal transmissible neurodegenerative prion disease with a rapid progression comprising familial, sporadic, iatrogenic and variant forms. A polymorphism at codon 129 of PRNP gene has been implicated in the development of variant CJD. We examined Met/Val allele frequencies and the genotype distribution, with respect to the polymorphic codon 129 of PRNP gene in 348 healthy individuals from the region of Athens, Greece. The following genotype frequencies were observed in the Greek population: Met/Met 50%, Met/Val 39% and Val/Val 11%. The presence of the Methionine allele frequencies in various European populations, according to the published data, increases gradually from northwestern to southeastern countries, implying the presence of a cline. The distribution of genotypes of Met homozygotes displays random declination across the 10 compared populations. The observed higher frequency of Met homozygotes at codon 129 does not necessarily suggest that these populations are at increased risk of developing CJD.