PROTHROMBIN GENE G20210-]A TRANSITION IS A RISK FACTOR FOR CEREBRAL VENOUS THROMBOSIS

Background and Purpose-It has been recently reported that a G-->A tran sition at nucleotide position 20210 in the 3'-untranslated region of t he prothrombin gene is associated with elevated plasma prothrombin lev els and an increased risk of deep venous thrombosis. To date, it is un known whether this polymorphism also represents a risk factor for cere bral venous thrombosis (CVT). Methods-Venous blood samples were collec ted from 45 patients with CVT and from 354 healthy blood donors as con trols. A second control group consisted of 131 subjects with acute isc hemic stroke or transient ischemic attack (TIA). Genomic DNA was isola ted from peripheral blood leukocytes. Amplification of DNA was perform ed by polymerase chain reaction (PCR). The G-->A transition at nucleot ide position 20210 of the prothrombin gene was detected by allele-spec ific restriction digestion. Results-The G(20210)-->A transition in the prothrombin gene was found in a heterozygous form in 4 of 45 patients with CVT (8.9%) and in 8 of 354 healthy control subjects (2.3%). This difference was statistically significant (P=0.010). The G(20210)-->A transition increased the relative risk for CVT approximately 5-fold (a ge-adjusted odds ratio 5.7; 95% CI 1.5 to 21.5). In contrast, in the g roup of patients with acute cerebral ischemia, only 3 of 131 subjects (2.3%) were heterozygous for the G(20210)-->A transition, which corres ponded to the prevalence in the group of healthy blood donors. Conclus ions-The recently described G(20210)-->A transition in the 3'-untransl ated region of the prothrombin gene is an inherited risk factor for CV T but obviously not for acute ischemic stroke or TIA.