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Epic Test Code LAB346 Factor V Leiden (R506Q) Mutation, Blood

Additional Codes

MML Code: F5DNA

LIS Code: F5L

NY State Approved

Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Factor V Leiden (R506Q) Mutation, B

Method Name

Direct Mutation Analysis

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Ambient (preferred) 7 days
  Frozen  14 days
  Refrigerated  14 days


Specimen Required


Container/Tube: 

Preferred: Yellow top (ACD)

Acceptable: EDTA or sodium citrate

Specimen Volume: Full tube

Collection Instructions: 

1. Invert several times to mix blood.

2. Send specimen in original tube.

Additional Information: Can be combined with other molecular coagulation tests;

-MTHAC 5,10-Methylenetetrahydrofolate Reductase A1298C, Mutation, Blood

-PTNT Prothrombin G20210A Mutation, Blood

-MTHFR 5,10-Methylenetetrahydrofolate Reductase C677T, Mutation, Blood

-MTHP 5,10-Methylenetetrahydrofolate Reductase C677T and A1298C Mutations, Blood


Specimen Type

Whole blood

Specimen Minimum Volume

1 mL blood in a 3-mL ACD tube

Reference Values

Negative

Analytic Time

3 days

Day(s) and Time(s) Performed

Monday through Friday; 12 p.m.

CPT Code Information

81241-F5 (coagulation factor V) (eg, hereditary hypercoagulability) gene analysis, Leiden variant

 

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross OK

Icterus

NA

Other

Green top (heparin) tube or Extracted DNA

Disease States

  • Factor V Leiden

Interpretation

The interpretive report will include specimen information, assay information, background information, and conclusions based on the test results (normal, heterozygous FV R506Q, homozygous FV R506Q).

Cautions

This direct mutation analysis will not detect individuals with activated protein c (APC)-resistance caused by mechanisms other than the FV R506Q.

 

Special Coagulation Clinic and/or Medical Genetics consultations are available for DNA diagnosis cases, and may be especially helpful in complex cases or in situations where the diagnosis is atypical or uncertain.

Genetics Test Information

Tests for R506Q mutation only.

Specimen Retention Time

Whole blood stored 2 weeks

Clinical Information

Venous thromboembolism includes deep vein thrombosis and its complication, pulmonary embolism. Plasma from 12% to 20% of venous thromboembolism patients is resistant to the anticoagulant effect of activated protein C (APC resistance). Essentially all patients with hereditary APC resistance have a single nucleotide mutation of the coagulation factor V gene (F5 rs6025), which encodes for an arginine (R) to glutamine (Q) substitution at position 506 of the factor V protein (FV R506Q). The factor V Leiden (R506Q) gene mutation test is a direct mutation analysis of patient blood leukocyte genomic DNA.

 

We recommend the coagulation-based activated protein C (APC)-resistance ratio (mixing with factor V-deficient plasma) as the initial screening assay for APC-resistance. Depending on the assay system, the APC-resistance ratio may be indeterminate for patients with a lupus anticoagulant or extremely high heparin levels.

Useful For

Factor V Leiden mutation testing should be reserved for patients with clinically suspected thrombophilia and: 1) APC-resistance proven or suspected by a low or borderline APC-resistance ratio, or 2) a family history of factor V Leiden.

Forms

1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing form (T576) is available in Special Instructions.

2. Coagulation Patient Information (T675) in Special Instructions

3. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.