Genetic testing for the coagulation factor V gene Leiden (G1691A) is performed to assess the risk of thrombosis in asymptomatic patients with a severe family history or in patients who have already had a thromboembolic episode.
Several genetic mutations are associated with an increased risk of thromboembolic complications. Some patients with recurrent venous thrombosis have resistance to activated protein C (APC) despite having normal levels of protein S and no other detectable abnormalities in the coagulation cascade. This is due to a mutation in the substrate for APC, the factor V (FV). The resistant APC phenotype is associated with heterozygotes or homozygotes for a point mutation at nucleotide 1691, where guanine (G) has been replaced by adenine (A) in the factor V gene (factor V Leiden mutation). This mutation occurs at the binding site of APC and results in the replacement of the arginine amino acid at position 506 (Arg506) by glutamine, producing the mutant FV Leiden (FVQ506).
The FV Leiden mutation is the most common mutation associated with an increased risk of recurrent venous thrombosis and can be detected by molecular analysis. The FV Leiden mutation is an important predisposing factor for the occurrence of thrombosis. It is a significant risk factor for gynecological-obstetric complications associated with abnormalities in the fetal-maternal circulation.
Factor V with the Leiden mutation is more common in women with severe preeclampsia, placental abruption, delayed fetal development, and stillbirth.
Thrombophilia is an acquired or congenital disorder associated with thrombosis. The clinical appearance of an underlying thrombophilia mainly involves venous thromboembolism, manifested as deep vein thrombosis, pulmonary embolism, or superficial vein thrombosis. Other events associated with thrombophilia include prolonged (recurrent) miscarriages and complications of pregnancy, such as severe preeclampsia, placental abruption, and fetal endometrial death. The demographic and environmental characteristics that contribute to the risk of venous thromboembolism in people predisposed to thrombophilia include old age, gender (more commonly in men), obesity, surgery, trauma, hospitalization, malignant neoplasms, prolonged immobility (such as long plane trips), use of certain medications (such as contraceptives, estrogens, tamoxifen and raloxifene) and certain drugs used to treat hypoglycemia equality.
Important Note
Laboratory test results are the most critical parameter for diagnosing and monitoring all pathological conditions. Between 70 to 80% of diagnostic decisions are based on laboratory tests. Correctly interpreting laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be analyzed based on each case and family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
