Factor V Leiden Prevalence in DVT Patients
Factor V Leiden is present in approximately 15-20% of patients with an initial episode of deep vein thrombosis, making it the most common known heritable thrombophilic risk factor. 1, 2
Prevalence Data
The prevalence of Factor V Leiden in DVT patients varies based on clinical presentation and population characteristics:
- Overall DVT population: 15-20% of individuals with an initial VTE episode carry Factor V Leiden 1, 2
- Selected high-risk populations: Up to 40% prevalence in patients under 50 years old and/or those with recurrent thrombosis 2
- Elderly patients with idiopathic DVT: 26% of men over age 60 with first episode of idiopathic VTE had Factor V Leiden 1
- Large vessel DVT: Higher prevalence (37.7%) in patients with iliofemoral or femoral DVT compared to calf DVT (13.3%) 3
Clinical Context and Comparison
The prevalence in DVT patients is substantially higher than in the general population:
- General Caucasian population: Approximately 5% carry Factor V Leiden in heterozygous form 2
- Non-Hispanic whites: 5.1% heterozygous prevalence 1
- Hispanic whites: 2.0% heterozygous prevalence 1
- African Americans: 1.2% heterozygous prevalence 1
Important Caveats
The prevalence differs by clinical presentation: Factor V Leiden is found more commonly in patients presenting with isolated deep vein thrombosis (17%) compared to those presenting with pulmonary embolism alone (9%) 4. This suggests Factor V Leiden may preferentially lead to manifest DVT rather than PE 4.
Geographic and ethnic variation exists: In Asian-Indian populations, Factor V Leiden contributes far less to activated protein C resistance in DVT patients than observed in Caucasians, with only 16 of 31 patients with activated protein C resistance carrying the mutation 5.
Age considerations: The American College of Medical Genetics notes that among Factor V Leiden carriers, the first lifetime episode of VTE usually occurs after age 50 years, indicating the mutation remains clinically relevant across all age groups 1.