The exact incidence of thrombophilia is unknown. However, the epidemiology of heritable thrombophilia is well documented.
Inherited thrombophilia affects up to 10% of the population. Up to 50% of white people with venous thromboembolism (VTE) will have a heritable thrombophilia. Up to 6% of the white population are reported to be affected by factor V Leiden (genetic mutation in factor V) and 2% by prothrombin gene mutations.[5]Ridker PM, Hennekens CH, Lindpaintner K, et al. Mutation in the gene coding for coagulation factor V and the risk of myocardial infarction, stroke and venous thrombosis in apparently healthy men. N Engl J Med. 1995 Apr 6;332(14):912-7.
http://www.ncbi.nlm.nih.gov/pubmed/7877648?tool=bestpractice.com
[6]Poort SR, Rosendaal FR, Reitsma PH, et al. A common genetic variation in the 3'-untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increase in venous thrombosis. Blood. 1996 Nov 15;88(10):3698-703.
http://www.bloodjournal.org/content/bloodjournal/88/10/3698.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/8916933?tool=bestpractice.com
These mutations are rare in other ethnic groups.[7]Rees DC, Cox M, Clegg JB. World distribution of factor V Leiden. Lancet. 1995 Oct 28;346(8983):1133-4.
http://www.ncbi.nlm.nih.gov/pubmed/7475606?tool=bestpractice.com
[8]Dilley A, Austin H, Hooper WC, et al. Prevalence of the prothrombin 20210 G-to-A variant in blacks: infants, patients with venous thrombosis, patients with myocardial infarction and control subjects. J Lab Clin Med. 1998 Dec;132(6):452-5.
http://www.ncbi.nlm.nih.gov/pubmed/9851733?tool=bestpractice.com
[9]Dowling NF, Austin H, Dilley A, et al. The epidemiology of venous thromboembolism in Caucasians and African-Americans: the GATE study. J Thromb Haemost. 2003 Jan;1(1):80-7.
http://www.ncbi.nlm.nih.gov/pubmed/12871543?tool=bestpractice.com
However, most carriers of these mutations remain asymptomatic.
Antithrombin, protein C, and protein S deficiencies are less common and affect up to 0.02% (antithrombin), 0.4% (protein C), and 0.13% (protein S) of the population.[10]Franco RF, Reitsma PH. Genetic risk factors of venous thrombosis. Hum Genet. 2001 Oct;109(4):369-84.
http://www.ncbi.nlm.nih.gov/pubmed/11702218?tool=bestpractice.com
These deficiencies are commonly found in Southeast Asian people and are rare in black people.[11]Sakata T, Okamoto A, Mannami T, et al. Protein C and antithrombin deficiency are important risk factors for deep vein thrombosis in Japanese. J Thromb Haemost. 2004 Mar;2(3):528-30.
http://www.ncbi.nlm.nih.gov/pubmed/15009480?tool=bestpractice.com
[12]Sakata T, Okamoto A, Mannami T, et al. Prevalence of protein S deficiency in the Japanese general population: the Suita study. J Thromb Haemost. 2004 Jun;2(6):1012-3.
http://www.ncbi.nlm.nih.gov/pubmed/15140145?tool=bestpractice.com
[13]Shen MC, Lin JS, Tsay W. High prevalence of antithrombin III, protein C and protein S deficiency, but no factor V Leiden mutation in venous thrombophilic Chinese patients in Taiwan. Thromb Res. 1997 Aug 15;87(4):377-85.
http://www.ncbi.nlm.nih.gov/pubmed/9271815?tool=bestpractice.com
An elevated coagulation factor VIII level is the most common cause of thrombophilia in black people (found in up to 35% of black people with VTE).[14]Patel RK, Ford E, Thumpston J, et al. Risk factors for venous thrombosis in the black population. Thromb Haemost. 2003 Nov;90(5):835-8.
http://www.ncbi.nlm.nih.gov/pubmed/14597978?tool=bestpractice.com