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Updated: Jun 17, 2026
13:08
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Asymptomatic factor VII deficiency: gene analysis and structure-function relationships
Dean Kirkel1, Ta-Wei Lin, Sidney W Fu
1Department of Medicine, Division of Hematology-Oncology, The George Washington University School of Medicine and Health Sciences and the Children's National Medical Center, Washington, District of Columbia 20037, USA.
Summary
Factor VII Padua deficiency can cause prolonged prothrombin times with specific reagents. Identifying this benign condition prevents unnecessary treatments for factor VII deficiency.
Area of Science:
- Hematology
- Genetics
Background:
- Factor VII deficiency is a rare bleeding disorder.
- Factor VII Padua is a specific variant associated with prolonged prothrombin time (PT) using certain thromboplastins.
Observation:
- A case of an asymptomatic African-American woman with factor VII deficiency is presented.
- Her PT was prolonged with rabbit brain thromboplastin but normal with human, ox brain, or recombinant tissue factor reagents.
Findings:
- The patient exhibited factor VII activity levels of 5-8% with rabbit brain thromboplastin.
- Recombinant human thromboplastin assays revealed normal PT and factor VII activity.
- The characteristic R304Q amino acid substitution of Factor VII Padua was identified.
Implications:
- Accurate diagnostic methods are crucial for differentiating Factor VII Padua from other forms of factor VII deficiency.
- Correct identification avoids unnecessary and potentially harmful treatments like plasma-derived products or recombinant activated factor VII.
- This case highlights the importance of reagent selection in diagnosing factor VII variants.
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