Platelet receptor gain-of-function single nucleotide polymorphisms in carotid and vertebral stenosis patients.

The role of platelet receptor gain-of-function single nucleotide polymorphisms (SNP) in cardiovascular disease is controversial. We hypothesised that certain SNPs may accelerate the development of carotid artery stenosis. The intronic PAR-1 receptor intervening sequence-14 A/T (IVSn-14 A/T) polymorphism and three additional platelet receptor polymorphisms, i.e. GPIa (807C/T), GPIbα (5T/C) and HPA-1a/HPA-1b (Pl (A1/A2)) of GPIIIa were studied. The interaction of SNPs with conventional risk factors including male gender, hypertension, high cholesterol, diabetes, advanced age and smoking were investigated. The hypothesis was tested in 114 well-characterised patients with symptomatic carotid or vertebral stenosis from the British CAVATAS population and compared the results with 97 unrelated controls. The allele frequency of the platelet gain-of-function SNP was not significantly different in the CAVATAS population as compared to controls (PAR-1A/T (P = 0.13), GPIa C/T (P = 0.25), GPIIIa HPA-1a/HPA-1b (PlA1/A2) (P = 0.66) and GPIb T/C (P = 0.20)). In the subgroup of smokers, however, the prothrombotic GPIbα C mutated allele was found in a significantly higher frequency in the patient as compared to the control group (P = 0.04). Contrary to the primary hypothesis, the PAR-1A/T SNP as well as the other SNPs tested were not over- or underrepresented in the CAVATAS population. However, a significantly increased prevalence of GPIb-α (5C/T) was found in the subgroup of smokers and may represent an important cofactor in this patient group of our hypothesis-generating study.