Significantly increased prevalence of factor V Leiden in patients with dural arteriovenous fistulas

Resistance to activated protein C (APCR) is the most common genetic risk fa ctor for venous thrombosis and is generally caused by a mutation in the fac tor V (FV) gene leading to FV Leiden. The recent finding of FV Leiden in th ree of seven patients with dural arteriovenous fistulas (DAVFs) prompted us to evaluate systematically the role of APCR due to FV Leiden in the pathog enesis of DAVFs in 22 patients and age- and sex-matched controls. We found a significantly higher frequency of APCR and FV Leiden in the patient group than among controls (5/22 vs. 0/22, P=0.048, Fisher's exact test). We conc lude that APCR due to FV Leiden is of pathogenetic significance in a subgro up of DAVFs.