A polymorphism (M129V) at codon 129 of the prion protein gene (PRNP) results in either a methionine residue (Met) or a valine residue (Val) and is known to determine susceptibility for the development of sporadic or acquired Creutzfeldt-Jakob disease (CJD). The distributions of M129V genotypes and alleles in various general populations have been reported and there are clear differences between Western Europeans and East Asians. We analysed the coding sequence of the PRNP gene in 100 healthy Turkish subjects to determine whether the distributions of the M129V genotypes and alleles or other PRNP gene variants in the Turkish population differ from those in other normal populations. Three known polymorphisms but no other gene variants were detected in the PRNP coding sequence of the Turkish individuals. Genotype frequencies at codon 129 were 57% Met/Met, 34% Met/Val and 9% Val/Val, with an allele frequency of 0.740 : 0.260 Met:Val. These distributions are considerably different from those reported for other normal populations residing in Western Europe and East Asia, except in Crete. The higher frequency of 129 Met-homozygotes in Turkey than in Western Europe suggests that the Turkish are at greater risk of developing CJD. European Journal of Human Genetics (2001) 9, 965 ± 968.

At sites of vascular injury, the platelet collagen receptor Glycoprotein Ia/IIa (GPIa/IIa) acts as an important mediator of platelet adhesion to ®brillar collagens. Two silent polymorphisms (807C/T and 873G/A) within the glycoprotein Ia gene have been implicated in increased risk of developing thrombosis and myocardial infarction in affected individuals. To provide basis for future studies, we examined the frequency of these GPIa polymorphisms for people in Turkey. We analyzed 118 unrelated individuals for their genotypes of the GPIa gene using a multiplexed allele speci®c-PCR based method. The allelic frequencies were found to be 34% for 807T/873A and 66% for 807C/873G; the genotypic frequencies were 13% for 807TT/873AA, 44% for 807CT/873GA, and 43% for 807CC/873GG. Am.