Inherited Thrombophilia due to Factor V Leiden Mutation.
Inherited thrombophilia due to activated protein C resistance is now recognized as one of the major genetic risk factors in the development of venous thromboembolic disease. Activated protein C resistance is secondary to a point mutation in the factor V gene, factor V Leiden. The high prevalence of this mutation in the general population, mainly in Caucasians of European descent, is a major contributing factor to the high incidence of venous thromboembolic disease in the United States, affecting one in 1000 individuals annually. Heterozygosity and homozygosity for factor V Leiden increase the risk for thrombosis 5- to 10-fold and 50- to 100-fold, respectively, compared with genotypically normal individuals. Factor V Leiden is more common than all other known genetic risk factors for thrombosis, and its presence results in a compounded risk in patients with simultaneous inherited abnormalities such as protein C, protein S, antithrombin III deficiencies, hyperhomocysteinemia, and/or acquired risk factors. Therefore, detection of activated protein C resistance and genotyping for factor V Leiden are important for establishing risk for thrombosis and ultimately for patient management.
Mattson
JC
Divisions of Hematopathology and Molecular Pathology, Department of Clinical Pathology, William Beaumont Hospital, Royal Oak, Michigan
Crisan
D