Background: Polymorphisms in platelet glycoprotein (GP) receptors Ia, Ib and IIIa may be heritable risk factors for platelet-dependent thrombosis leading to death. The precipitation of stroke by occlusive thrombi has led to the investigation of the platelet surface GP receptors, that are involved in critical steps in the activation of platelets. Three polymorphisms in the GP Iba gene and one in each of GPIIIa, GP Ia were selected based on the evidence of functional effects on structure or expression as candidates for risk. We also determined whether these polymorphisms were associated with in vivo expression levels of platelet GP receptors and the severity of the neurological deficit.
Methods: A Chinese hospital-based case-control study was conducted with 119 cases of atherothrombotic stroke and 166 age and sex matched controls. Genotyping was performed on lymphocyte DNA by standard methods and platelet GP expression levels were measured by flow-cytometry.
Results: Allele and genotype frequencies of the GP receptor polymorphisms differ considerably between ethnic populations. We found the D allele of the GP Iba VNTR polymorphism was significantly associated with atherothrombotic stroke in our Chinese cohort, however we did not find a relationship among these polymorphisms, the expression levels of GP receptors and severity of the neurological deficit.
Conclusions: In our Chinese cohort the D allele of the GP Iba VNTR polymorphism is associated with atherothrombotic stroke. The number of VNTR repeats alters the length of amino acid sequence, which might affect the structure and function of this receptor.