TABLE 2.

Comparison of Hereditary Thrombophilias

Thrombophilia	General Prevalence, %	First VTE Prevalence, %	Relative Risk of First VTE	Annual Incidence of VTE, %
Factor V R506Q (FVL)	3–7	12–20	4.3	0.19–0.67
Factor II G20210A (PGM)	1–3	3–8	1.9	0.13
Combined FVL/PGM	0.1	—	32.4	0.57
Protein C deficiency	0.02–0.05	2–5	11.3	1–2
Protein S deficiency	0.01–1	1–3	32.4	1–2
Antithrombin deficiency	0.03	1–2	17.5	1.2

Data provided are for heterozygous deficiencies. Homozygous deficiencies carry significantly higher thrombotic risk but are too rare to be detected in population surveys. Prevalence data are as reported in white adults. FVL indicates factor V Leiden; PGM, prothrombin gene mutation G20210A.

Adapted from Heit JA. Thrombophilia: Clinical and laboratory assessment and management. In: Kitchens CS, Alving BM, Kessler CM, eds. Consultative Hemostasis and Thrombosis. 2nd ed. Philadelphia, PA: Saunders; 2007:213–244.