The role of preoperative factor V Leiden screening in different geographic populations

Patients harboring a specific mutation in the coagulation factor V gene have been identified as being at significantly increased risk for venous thrombosis. A simple genetic test that identifies carriers of this mutation (the factor V Leiden allele) is available and may have utility in various clinical settings, including preoperative risk assessment for thromboembolic complications. In this regard, it is generally agreed that prospective studies addressing the role of preoperative factor V Leiden mutational analysis are needed to clearly define the clinical prognostic/diagnostic significance of the presence of this mutation in surgical patients. This report questions the role that population dynamics (genetic and environmental backgrounds of individual populations) plays in the analysis of factor V genotypic data in relation to postsurgical thromboembolic complications. We have determined that the frequency of individuals carrying the factor V Leiden allele is 7.9 per cent for our South Central Pennsylvania population (395 wild type, 32 heterozygotes, 2 homozygotes) using a polymerase chain reaction-restriction fragment length polymorphism technique that specifically detects the factor V Leiden mutation. This baseline population information is useful from both a clinical and a basic science viewpoint. However, considering the various unknown genetic and environmental differences between geographically distinct populations, the significance of this result, in terms of clinical management of our surgical patients, is yet to be determined.