Table 1

Examples of genetic mutations associated with inherited thrombophilia

Approximate prevalence in unselected patients with deep vein thrombosis is shown in brackets where this is known.
ACE, angiotensin converting enzyme; TFPI, tissue factor pathway inhibitor.
Antithrombin (1%)Mutations causing raised factor VIII (25%)Other mutations causing APC resistance
Protein C (3%)Mutations causing raised fibrinogen levels
Protein S (3%)Mutations causing reduced thrombomodulin activity
Factor V Leiden (20%)Mutations causing reduced TFPI activity
F2G20210A (6%)Deletion/insertion polymorphism of the ACE gene
Mutations causing high plasma homocysteine (unknown)
Mutations causing dysfibrinogenaemia (very rare)