Abstract
Venous thrombosis, or venous thromboembolism, comprises deep vein thrombosis with
or without symptomatic pulmonary embolus. The development of symptomatic venous thrombosis
is highly dependent on gene–environment interaction. In most instances this interaction
results in hypercoagulability (the intermediate phenotype) sufficient to result in
intraluminal clot formation (the disease phenotype). The genetic framework underlying
venous thrombosis is complex, and there is a large material contribution from disease
and interaction with environmental factors. For example, venous thrombosis is related
to recent hospitalization in approximately half of all adult cases. After a first
episode of venous thrombosis patients are 40 times more likely to suffer a further
event compared with previously unaffected individuals. However, the risk differs between
patients. Duration of anticoagulation (lifelong or not) should be made with reference
to whether an episode of thrombosis was provoked and the presence of other risk factors.
The results of testing for heritable thrombophilia rarely influence duration of treatment.
Keywords
thrombosis - venous - deep vein thrombosis - pulmonary embolus - risk factors - thrombophilia
- inherited - acquired - hospital-acquired thrombosis - cancer - pregnancy
