Factor V Leiden Gene Mutation and Thrombin Generation in Relation to the Development of Acute Stroke

To determine the prevalence of the factor V Leiden gene mutation in relation to the phenotypes of cerebral infarction and cerebral hemorrhage, we studied 386 randomly selected cases of acute stroke and 247 control subjects. Factor V genotype was determined by amplification of a 267-bp sequence of exon/intron 10 of the factor V gene. Levels of prothrombin fragment F1+2 , a marker of thrombin generation, were determined in both acute and convalescent stroke and related to factor V genotype. Prothrombin fragment F1+2 was assessed by using an enzyme-linked immunosorbent assay. Sixteen stroke cases (4.1%) were identified as having the mutation compared with 14 (5.6%) control subjects. Prothrombin fragment F1+2 levels were estimated in 191 cases and found to be elevated both acutely and after 3 months, but they were not related to factor V genotype. Prothrombin fragment F1+2 is elevated in acute stroke and requires further evaluation in relation to cerebrovascular disease. These results suggest that the factor V Leiden gene mutation is not a risk factor for arterial thrombosis causing stroke.