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Spontaneous or near spontaneous bleeding caused by a defect in clotting mechanisms (blood coagulation disorders) or another abnormality causing a structural flaw in the blood vessels (hemostatic disorders).
No HPO annotations are available for this condition.
Venous thromboembolism (VTE) is the primary clinical manifestation of factor V Leiden thrombophilia . The most common site for VTE is the legs, but upper-extremity, cerebral, and superficial venous thrombosis may also occur. The relative risk for VTE is increased approximately three- to eightfold in factor V Leiden variant heterozygotes . Lower relative risks (four- to fivefold) were reported in two large meta-analyses . Despite the increase in relative risk, the overall annual incidence of a first VTE is low in heterozygotes, approximately 0.5% . The reported adjusted hazard ratio (HR) for VTE in heterozygotes compared with controls was 2.7 (95% confidence interval [CI] 1.8-3.8) .
Factor V Leiden thrombophilia should be suspected in individuals with the following clinical, laboratory, and family history findings:
Clinical findings. A history of one or recurrent venous thromboembolism (VTE) manifesting as deep vein thrombosis (DVT) or pulmonary embolism (PE), especially at a young age and in the absence of strong risk factors for VTE
Laboratory findings. Low activated protein C (APC) resistance on APC resistance qualitative and quantitative assays
No approved treatments are currently available for hemorrhagic disease. The disease remains an area of unmet medical need.
Gene therapy approaches for hemorrhagic disease have been reported in the published literature.
To assess the risk for venous thromboembolism (VTE) in an individual found to have a factor V Leiden variant, the following are recommended:
Individuals receiving long-term anticoagulation require periodic reevaluation of their clinical course to confirm that the benefits of anticoagulation continue to outweigh the risk of bleeding. Factor V Leiden heterozygotes who do not require long-term anticoagulation may benefit from evaluation prior to exposure to circumstantial risk factors such as surgery or pregnancy.
Source: GeneReviews — "Factor V Leiden Thrombophilia"
27 clinical trials registered, 16 recruiting. Interventions under study include other interventions, drug therapy, medical devices, and gene therapy. Pipeline includes 1 PHASE4, 1 PHASE1, 1 EARLY_PHASE1. Research is primarily sponsored by academic and government institutions.
NCT ID | Title | Phase | Sponsor | Status |
|---|---|---|---|---|
[NCT07183605](https://clinicaltrials.gov/study/NCT07183605) |
Data assembled from 4 of 12 sources · Last updated Sep 18, 2026, 8:53 PM UTC
Source: GeneReviews — "Factor V Leiden Thrombophilia"
Source: GeneReviews — "Factor V Leiden Thrombophilia"
The differential diagnosis of venous thromboembolism (VTE) includes several other inherited thrombophilic disorders, including those caused by other variants in F5, and acquired thrombophilic disorders (outside of the scope of this GeneReview). Prothrombin thrombophilia is characterized by VTE manifesting most commonly in adults as deep vein thrombosis (DVT) in the legs or pulmonary embolism. The clinical expression of prothrombin thrombophilia is variable; many individuals heterozygous or homozygous for the 20210GA F2 variant never develop thrombosis, and while most heterozygotes who develop thrombotic complications remain asymptomatic until adulthood, some have recurrent thromboembolism before age 30 years.
Source: GeneReviews — "Factor V Leiden Thrombophilia"
Biomarker and diagnostic research for hemorrhagic disease has been reported in the published literature.
DNA analysis for prothrombin thrombophilia (F2 variant c.*97GA, commonly known as 20210GA)
Multiple phospholipid-dependent coagulation assays for a lupus inhibitor
Serologic assays for anticardiolipin antibodies and anti-beta-2-glycoprotein 1 antibodies
For high-risk individuals (i.e., those with a history of recurrent VTE, especially at a young age, or those with strong family history of VTE at a young age), evaluation should also include assays of:
Protein C activity
Antithrombin activity
Protein S activity or free protein S antigen
Note: Measurement of the following is NOT recommended:
Plasma concentration of homocysteine, as no data support a change in duration of anticoagulation or the use of vitamin supplementation in individuals with hyperhomocysteinemia and a history of VTE
MTHFR variants, as no clinical rationale for this testing exists
Factor VIII and other clotting factor levels
Treatment of Manifestations
The management of individuals with factor V Leiden thrombophilia depends on the clinical circumstances. The first acute thrombosis should be treated according to current guidelines . For initial treatment of VTE, current guidelines suggest a direct oral anticoagulant (dabigatran, edoxaban, rivaroxaban, or apixaban) over warfarin because of a lower bleeding risk and gr...
Source: GeneReviews — "Factor V Leiden Thrombophilia"
27 trials found
Comparison of Heparin Anti-Xa Activity From Central Venous Catheter Samples Using a 5 mL Syringe Flush or a Vacuum Tube Flush Versus Peripheral Vein Samples in ICU Patients |
NA |
Centre Hospitalier Régional d'Orléans |
RECRUITING |
[NCT04645199](https://clinicaltrials.gov/study/NCT04645199) | National Longitudinal Cohort of Hematological Diseases | — | Institute of Hematology & Blood Diseases Hospital, China | RECRUITING |
[NCT06740929](https://clinicaltrials.gov/study/NCT06740929) | Hormonal Management of Heavy Menstrual Bleeding in Adolescents | — | University Hospital, Geneva | RECRUITING |
[NCT06727669](https://clinicaltrials.gov/study/NCT06727669) | Longitudinal Cohort of Thrombosis and Hemostasis Diseases | — | Peking University People's Hospital | RECRUITING |
[NCT05916469](https://clinicaltrials.gov/study/NCT05916469) | Heavy Menstrual Bleeding Progestin Treatment in Bleeding Disorders Study | — | Oregon Health and Science University | RECRUITING |
405 publications have been identified in PubMed for hemorrhagic disease. Kisho has analyzed 297 by research type. Research spans Basic Science / Preclinical (36%), Epidemiology / Natural History (27%), and Review / Meta-Analysis (10%).
Research Type | Count | % of Total |
|---|---|---|
Laboratory research | 106 | 36% |
Disease patterns and progression | 80 | 27% |
Research summaries | 31 | 10% |
Patient case studies | 31 | 10% |
Testing and diagnosis research | 18 | 6% |
New treatment approaches | 16 | 5% |
Clinical study results | 12 | 4% |
Other research | 3 | 1% |
von Hundelshausen P (2026). [PMID: 41662453](https://pubmed.ncbi.nlm.nih.gov/41662453/). *Circulation*. [Review / Meta-Analysis]
Molini U (2026). [PMID: 41777070](https://pubmed.ncbi.nlm.nih.gov/41777070/). *Vet Ital*. [Basic Science / Preclinical]
Zanetto A (2026). [PMID: 41046210](https://pubmed.ncbi.nlm.nih.gov/41046210/). *Dig Liver Dis*. [Diagnostic / Biomarker]
Seye S (2026). [PMID: 42069546](https://pubmed.ncbi.nlm.nih.gov/42069546/). *BMC Infect Dis*. [Epidemiology / Natural History]
Erram D (2026). [PMID: 41759918](https://pubmed.ncbi.nlm.nih.gov/41759918/). *J Am Mosq Control Assoc*. [Epidemiology / Natural History]
Gao X (2026). [PMID: 41349619](https://pubmed.ncbi.nlm.nih.gov/41349619/). *Fish Shellfish Immunol*. [Basic Science / Preclinical]
Garros C (2026). [PMID: 42104528](https://pubmed.ncbi.nlm.nih.gov/42104528/). *Med Vet Entomol*. [Epidemiology / Natural History]
Hemry J (2026). [PMID: 41721655](https://pubmed.ncbi.nlm.nih.gov/41721655/). *J Investig Med High Impact Case Rep*. [Case Report / Case Series]
Owens LA (2026). [PMID: 42120057](https://pubmed.ncbi.nlm.nih.gov/42120057/). *J Wildl Dis*. [Epidemiology / Natural History]
Hiebner DW (2026). [PMID: 41701975](https://pubmed.ncbi.nlm.nih.gov/41701975/). *Blood Adv*. [Diagnostic / Biomarker]