14 days from receipt of specimen in performing lab
Methodology
The cobas® Factor II and Factor V Test uses real-time PCR analysis of genomic DNA samples isolated from K2EDTA whole blood to determine the genotype of the Factor II gene at position 20210 and/or the genotype of the factor V gene at position 1601. The test is performed on the cobas z 480 analyzer. A positive and negative control are included in each run to confirm the validity of the run.
Use
Thrombophilia is a condition with a predisposition to develop thrombosis (eg, blood clots) due to either an inherited or acquired defect in the coagulation system. Blood clots may form in either the venous or arterial vascular system and can lead to Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE). Collectively, DVT and PE are known as Venous Thromboembolism (VTE). VTE is the third most common cause of cardiovascular death after acute coronary syndrome and stroke. Inherited thrombophilia is most frequently caused by a Factor V or Factor II (Prothrombin) variant. The factor V Leiden variant is a single nucleotide change (G to A at position 1601) of the human Factor V gene (F5) that results in substitution of arginine to glutamine at position 534 in the Factor V protein. The factor V Leiden variant renders the protein partially resistant to inactivation by activated protein C (APC). APC resistance is regarded as the most prevalent coagulation abnormality associated with VTE. Genetic analysis has demonstrated that the factor V Leiden variant, which has a relatively high prevalence in the general population (eg, about 5% in Caucasians), may account for 85% to 95% of APC resistance cases. Evaluation of a patient’s risk for hereditary thrombophilia through a Factor V genotyping test is critical for diagnosis and clinical management of patients with thrombophilia.
See Also
86728 Factor V Activity
Limitations
There are many other causes of thrombotic disease, including heritable variants in the genes encoding proteins C, S, and antithrombin III. This test result does not exclude the possibility that this individual also carries some other variant or defect in the coagulation/anticoagulation system, in addition to the factor V Leiden variant. The presence of one or more of these other defects can have a synergistic interaction with the factor V Leiden variant to produce an even higher risk of thrombosis. Though rare, other variants within the genomic DNA regions of the Factor V gene covered by the primers or probes used in the cobas® Factor II and Factor V Test may result in failure to detect the presence of the Factor V c.1601G>A variant
No F5 c.1601G>A (p.Arg534Gln) variant detected (previously known as G1691A or R506Q)
Test Information
CPT Codes
81241
Synonyms
Leiden Mutation
Factor V mutation
Test Includes
Detection of Factor V Leiden (G1691A) mutation
Performing Laboratory / Facility
UCLA Medical Center Clinical Laboratory (CHS)
Performing Section
Molecular Pathology
Availability
Monday through Friday, 0700-1700
Turnaround Time
14 days from receipt of specimen in performing lab
Methodology
The cobas® Factor II and Factor V Test uses real-time PCR analysis of genomic DNA samples isolated from K2EDTA whole blood to determine the genotype of the Factor II gene at position 20210 and/or the genotype of the factor V gene at position 1601. The test is performed on the cobas z 480 analyzer. A positive and negative control are included in each run to confirm the validity of the run.
Use
Thrombophilia is a condition with a predisposition to develop thrombosis (eg, blood clots) due to either an inherited or acquired defect in the coagulation system. Blood clots may form in either the venous or arterial vascular system and can lead to Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE). Collectively, DVT and PE are known as Venous Thromboembolism (VTE). VTE is the third most common cause of cardiovascular death after acute coronary syndrome and stroke. Inherited thrombophilia is most frequently caused by a Factor V or Factor II (Prothrombin) variant. The factor V Leiden variant is a single nucleotide change (G to A at position 1601) of the human Factor V gene (F5) that results in substitution of arginine to glutamine at position 534 in the Factor V protein. The factor V Leiden variant renders the protein partially resistant to inactivation by activated protein C (APC). APC resistance is regarded as the most prevalent coagulation abnormality associated with VTE. Genetic analysis has demonstrated that the factor V Leiden variant, which has a relatively high prevalence in the general population (eg, about 5% in Caucasians), may account for 85% to 95% of APC resistance cases. Evaluation of a patient’s risk for hereditary thrombophilia through a Factor V genotyping test is critical for diagnosis and clinical management of patients with thrombophilia.
See Also
86728 Factor V Activity
Limitations
There are many other causes of thrombotic disease, including heritable variants in the genes encoding proteins C, S, and antithrombin III. This test result does not exclude the possibility that this individual also carries some other variant or defect in the coagulation/anticoagulation system, in addition to the factor V Leiden variant. The presence of one or more of these other defects can have a synergistic interaction with the factor V Leiden variant to produce an even higher risk of thrombosis. Though rare, other variants within the genomic DNA regions of the Factor V gene covered by the primers or probes used in the cobas® Factor II and Factor V Test may result in failure to detect the presence of the Factor V c.1601G>A variant
