Pediatric Factor VII Deficiency Workup

  • Author: Helge Hartung, MD; Chief Editor: Max J Coppes, MD, PhD, MBA   more...
 
Updated: Mar 25, 2011
 

Laboratory Studies

The prothrombin time (PT) is prolonged in factor VII (FVII) deficiency and the international normalized ratio (INR) is elevated. The activated partial thromboplastin time (aPTT) is within the reference range in isolated factor VII deficiency.

Specific factor VII assays are required for diagnosis.

  • Factor VII assays are performed by using a tissue factor (TF; thromboplastin)–dependent one-stage clotting assay.
  • The sensitivity of the assay depends on the choice of assay reagents. The less sensitive animal-derived thromboplastins cannot be used to accurately measure levels less than 5%.
  • The more sensitive thromboplastins, usually recombinant human thromboplastin, are preferred for measuring factor VII activity in the very low range.
  • When the deficiency is due to mutations that affect formation of the TF/factor VIIa/FX complex, the measured factor VII levels may significantly vary depending on the type of reagent used (ie, rabbit vs human thromboplastin).

Genetic studies, including genotyping, may be warranted for counseling and prenatal diagnosis.

Factor assays in family members are indicated to identify other affected individuals.

Although factor VII levels are statistically lower in "bleeders" than in "nonbleeders," they may not predict bleeding risk in individual patients.

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Imaging Studies

Appropriate imaging studies may be useful in the evaluation of suspected bleeding. For instance, CT scanning or MRI of the brain is indicated for suspected CNS hemorrhage.

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Contributor Information and Disclosures
Author

Helge Hartung, MD  Attending Physician, Division of Hematology, Center for Cancer and Blood Disorders

Disclosure: Nothing to disclose.

Specialty Editor Board

Gary R Jones, MD  Associate Medical Director, Clinical Development, Berlex Laboratories

Gary R Jones, MD is a member of the following medical societies: American Academy of Pediatrics, American Society of Pediatric Hematology/Oncology, and Western Society for Pediatric Research

Disclosure: Nothing to disclose.

Mary L Windle, PharmD  Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Pharmacy Editor, eMedicine

Disclosure: Nothing to disclose.

James L Harper, MD  Associate Professor, Department of Pediatrics, Division of Hematology/Oncology and Bone Marrow Transplantation, Associate Chairman for Education, Department of Pediatrics, University of Nebraska Medical Center; Assistant Clinical Professor, Department of Pediatrics, Creighton University; Director, Continuing Medical Education, Children's Memorial Hospital; Pediatric Director, Nebraska Regional Hemophilia Treatment Center

James L Harper, MD is a member of the following medical societies: American Academy of Pediatrics, American Association for Cancer Research, American Federation for Clinical Research, American Society of Hematology, American Society of Pediatric Hematology/Oncology, Council on Medical Student Education in Pediatrics, and Hemophilia and Thrombosis Research Society

Disclosure: Nothing to disclose.

Helen SL Chan, MBBS, FRCP(C), FAAP  Senior Scientist, Research Institute; Professor, Division of Hematology/Oncology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Canada

Helen SL Chan, MBBS, FRCP(C), FAAP is a member of the following medical societies: American Academy of Pediatrics, American Association for Cancer Research, American Society of Hematology, and Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Chief Editor

Max J Coppes, MD, PhD, MBA  Senior Vice President, Center for Cancer and Blood Disorders, Children's National Medical Center; Professor of Medicine, Oncology, and Pediatrics, Georgetown University School of Medicine; Clinical Professor of Pediatrics, George Washington University School of Medicine and Health Sciences

Max J Coppes, MD, PhD, MBA is a member of the following medical societies: American Association for Cancer Research, American Society of Pediatric Hematology/Oncology, and Society for Pediatric Research

Disclosure: Nothing to disclose.

References

  1. Mandhyan R, Tiwari A, Cherian G. Congenital factor VII deficiency. Br J Anaesth. Feb 2010;104(2):267-8. [Medline].

  2. Mariani G, Herrmann FH, Dolce A, et al. Clinical phenotypes and factor VII genotype in congenital factor VII deficiency. Thromb Haemost. Mar 2005;93(3):481-7. [Medline].

  3. Peyvandi F, Mannucci PM. Rare coagulation disorders. Thromb Haemost. Oct 1999;82(4):1207-14. [Medline].

  4. Mariani G, Bernardi F. Factor VII Deficiency. Semin Thromb Hemost. Jun 2009;35(4):400-6. [Medline].

  5. Levi M, Levy JH, Andersen HF, Truloff D. Safety of recombinant activated factor VII in randomized clinical trials. N Engl J Med. Nov 4 2010;363(19):1791-800. [Medline].

  6. Todd T, J Perry D. A review of long-term prophylaxis in the rare inherited coagulation factor deficiencies. Haemophilia. Nov 11 2009;[Medline].

  7. Di Paola J, Nugent D, Young G. Current therapy for rare factor deficiencies. Haemophilia. Jan 2001;7 Suppl 1:16-22. [Medline].

  8. Giansily-Blaizot M, Schved JF. Potential predictors of bleeding risk in inherited factorVII deficiency. Clinical, biological and molecular criteria. Thromb Haemost. Nov 2005;94(5):901-6. [Medline].

  9. Mariani G, Dolce A, Marchetti G, Bernardi F. Clinical picture and management of congenital factor VII deficiency. Haemophilia. Oct 2004;10 Suppl 4:180-3. [Medline].

  10. Mariani G, Lapecorella M, Dolce A. Steps towards an effective treatment strategy in congenital factor VII deficiency. Semin Hematol. Jan 2006;43(1 Suppl 1):S42-7. [Medline].

  11. Perry DJ. Factor VII Deficiency. Br J Haematol. Sep 2002;118(3):689-700. [Medline].

  12. Tuddenham EG, Pemberton S, Cooper DN. Inherited factor VII deficiency: genetics and molecular pathology. Thromb Haemost. Jul 1995;74(1):313-21. [Medline].

 
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Intrinsic and extrinsic pathways of coagulation. Factor VII/tissue factor complex activates factor IX and factor X. Factor IXa along with factor VIIIa results in formation of more factor Xa. Factor Xa along with factor Va converts prothrombin to thrombin.
 
 
 
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