Vienna Stroke Registry. Impact of the platelet glycoprotein Ib alpha Kozak polymorphism on the risk of ischemic cerebrovascular events: a case-control study.

We performed a multicenter case-control study to evaluate the impact of the glycoprotein 1b alpha (-5)T/C Kozak polymorphism on the risk of ischemic cerebrovascular events. The genetic analysis in 1399 patients (745 men; median age, 70 years; interquartile ratio, 58-78) and 1066 control subjects (549 men; median age, 47 years; interquartile ratio, 39-59) was carried out with mutagenically separated polymerase chain reaction. Homozygous C/C genotype carriers had a 3.5-fold increased risk for ischemic cerebrovascular events (95% confidence interval, 1.5-7.9, P = 0.003) over T/T or T/C genotype carriers together. The effect was independent of well-established atherosclerotic risk factors. Our findings could be explained by the reported gene dose effect of the Kozak polymorphism on the density of the glycoprotein 1b alpha/IX/V receptors on platelets. According to our data, the (-5)C Kozak allele may represent a candidate genetic susceptibility factor for ischemic cerebrovascular events.