Correlation Between The Polymorphisms Of Platelet Glycoprotein Ib Gene And Ischemic Cerebrovascular Disease

Objective: The platelet glycoprotein (GP) Ib is a major receptor for von Willebrand factor and important for platelet adhesion to the vessel wall, which plays a key role in the initial phase of platelet activation under high shear stress conditions.Platelets in flowing blood can be activated and aggregated by high shear strees without chemical agonists. Therefore,the role of GPIb in the development of atherosclerosis and arterial thrombosis is very important. The a chain of GPIb contains variable number of tandem repeats (VNTR)polymorphism. Several studies have suggested that the polymorphism may extend the GPIb binding sites for vWF,increasing the avidity between them and affecting the vulnerability for thromobotic diseases.This study is to investigate the distribution of alleles and genotypes of GPIb gene VNTR polymorphisms in Chinese population and the correlation between these polymorphisms and ischemic cerebrovascular diseases.Methods: One hundred and five patients with ischemic CVD, as confirmed by brain CT and/or MRI, and 100 age- and sex-matched control subjects without clinical evidence of CVD were analyzed for their genotype frequencies of the VNTR dimorphism of the a-chain of GPIb (GPIba). PCR method was used to determine genotypes in all these subjects enrolled in this study.. Calculation of odds ratio (OR) and 95% confidence intervals (95% CI) estimated the association strength between GPIba genotype and CVD. OR (95% CI) >1 was considered to be significant. A logistic regression analysis was performed to evaluate the interaction between the GPIba VNTR genotype and other variables in relation to the prevalence of CVD.Results: The presence of the B allele in Chinese population is less than 0.01.We have found the B allele frequencies and the BC genotype of GPIba VNTR were significantly higher in the ICVD group than in control group(5.7%vsl%,P=0.023; 6.7%vsl%, P=0.036,respectively). The odds ratio of the B allele and the BC genotype for ICVD were3.98 (95% confidence intervals, 1.106 to 14.32);7.071(95% confidence intervals,0.85 to 58.55),respectively. Logistic regression analysis revealed that the presence of VNTR B-allele frequently associated with CVD. OR=5.104,P=0.046, 95%CI:0.96-27.147.Conclusions Our study suggests that the platelet GPIba genotype is a genetic risk factor for ischemic CVD.