Double heterozygosity for Factor V Leiden and Factor V Cambridge mutations associated with low levels of activated protein C resistance in a Spanish thrombophilic family

Activated protein C resistance (APCR) is a recently discovered, medically important cause of venous thrombosis. More than 95% of cases are due to factor V Leiden (FVL), a mutated form of factor V that is resistant to degradation by activated protein C. The prevalence of this disorder, which is inherited in an autosomal dominant fashion, is approximately 5% among asymptomatic people of European heritage. In addition, 20 to 60% of patient cohorts with previous thrombosis demonstrate APCR, making it the most common known genetic cause of abnormal thrombophilia. Current laboratory techniques available for diagnosis include functional assays, such as the APC ratio, as well as DNA-based tests that detect the specific genetic anomaly responsible for FVL. A case report is presented, along with a review of the literature highlighting epidemiology, pathogenesis, clinical features and methods for laboratory diagnosis.

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Improved Distinction of Factor V Wild-Type and Factor V Leiden Using a Novel Prothrombin-Based Activated Protein C Resistance Assay

American Journal of Clinical Pathology ◽

10.1309/t8avvh7qwgl0qtf5 ◽

2004 ◽

Vol 122 (6) ◽

pp. 836-842 ◽

Cited By ~ 19

Author(s):

Marianne Wilmer ◽

Christoph Stocker ◽

Beatrice Bühler ◽

Brigitte Conell ◽

Andreas Calatzis

Keyword(s):

Protein C ◽

Activated Protein C ◽

Factor V Leiden ◽

Factor V ◽

Wild Type ◽

Activated Protein C Resistance

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Activated Protein C Resistance and Factor V Leiden in Mexico

Clinical and Applied Thrombosis/Hemostasis ◽

10.1177/1076029607306807 ◽

2007 ◽

Vol 14 (4) ◽

pp. 428-437 ◽

Cited By ~ 6

Author(s):

Abraham Majluf-Cruz ◽

Manuel Moreno-Hernández ◽

Adriana Ruiz-de-Chávez-Ochoa ◽

Rosario Monroy-García ◽

Karim Majluf-Cruz ◽

...

Keyword(s):

Protein C ◽

Activated Protein C ◽

Factor V Leiden ◽

Factor V ◽

Activated Protein C Resistance ◽

Factor V Leiden Mutation ◽

Common Cause ◽

Factor V Gene ◽

V Gene ◽

Low Prevalence

A common cause of hereditary thrombophilia is activated protein C resistance (APCR), and most cases result from factor V Leiden mutation. An APCR phenotype without association with factor V Leiden has been described. This transversal, observational, nonrandomized study evaluated these 2 phenomena in healthy indigenous and mestizo Mexican subjects (n = 4345), including 600 Mexican natives. No indigenous subjects had APCR, but 82 mestizo subjects did. After retesting, 50 subjects had a negative test. The remaining 32 subjects had factor V Leiden, giving a 0.85% prevalence of factor V Leiden in the mestizo Mexican population. Only 31% of APCR carriers had factor V Leiden. These results show a very low prevalence of APCR and factor V Leiden in Mexico. Except for factor V Leiden, there are no other mutations in the factor V gene responsible for the APCR phenotype. Acquired APCR is nearly twice as prevalent as the inherited variant.

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