Venous thromboembolism (VTE) occurs in 1-2 individuals per 1000. There are approximately 10 million cases worldwide, with between 100,000 and 300,000 VTE related deaths in the US, and 544,000 in Europe each year. This is a major health economic burden. There are many factors that increase the risk of thrombophilia such as surgery, pregnancy, the use of oral contraceptives and prolonged immobilisation (economy class syndrome).
Genetic factors also contribute to an individual’s risk of VTE. Factor V Leiden is the most common inherited form of thrombophilia, occurring in 3.8% of the general US and European population in a heterozygous state. Heterozygous individuals are 7-fold more likely to develop a VTE, while homozygous individuals have an 80-fold increased risk.