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HelpTest ID F5NGS F5 Gene, Next-Generation Sequencing, Varies
Ordering Guidance
If bleeding is the indication for testing, genetic testing for factor V deficiency (F5D) should only be considered if there is an isolated reduction of factor V activity in plasma using a specific prothrombin (PT)-based factor V assay(1) and acquired causes of a low factor V are excluded.
If thrombophilia is the indication for testing, the vast majority (approximately 95%) of individuals with thrombophilia due to hereditary APC resistance have a specific point alteration in the F5 gene called factor V Leiden (c.1601G>A, p.Arg534Gln; historically known as "R506Q" or "1691G>A"), which can be assayed directly and more cost-effectively by targeted alteration testing. If testing for factor V Leiden is desired instead of full-gene sequencing, order F5DNA / Factor V Leiden (R506Q) Mutation, Blood.
Shipping Instructions
Ambient and refrigerate specimens must arrive within 7 days (168 hours of draw), and frozen specimens must arrive within 14 days (336 hours of draw).
Collect and package specimens as close to shipping time as possible.
Necessary Information
Rare Coagulation Disorder Patient Information is required, see Special Instructions. Testing may proceed without the patient information, however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Peripheral blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD) or green top (sodium citrate)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Specimen Stability: Ambient (preferred)/Refrigerated/Frozen
Specimen Type: Extracted DNA
Container/Tube: 1.5- to 2-mL tube
Specimen Volume: Entire specimen
Collection Instructions:
1. Label specimen as extracted DNA and source of specimen.
2. Provide indication of volume and concentration of the DNA.
Specimen Stability: Frozen (preferred)/Refrigerated/Ambient
Forms
1. Rare Coagulation Disorder Patient Information (T824) is required, see Special Instructions. Fax the completed form to 507-284-1759.
2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
3. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Useful For
Genetic confirmation of factor V deficiency with the identification of an alteration in the F5 gene known or suspected to cause the condition
Carrier testing for close family members of an individual with a factor V deficiency diagnosis
This test is not intended to evaluate for the factor V Leiden mutation.
This test is not intended for prenatal diagnosis.
Genetics Test Information
This test detects pathogenic alterations in the F5 gene to delineate the underlying molecular defect in a patient with a laboratory diagnosis of coagulation factor V deficiency. This test may also detect rare alterations in F5 that cause activated protein C (APC) resistance, resulting in thrombophilia.
The gene target for this test is:
Gene name (transcript): F5 (GRCh37 [hg19] NM_000130)
Chromosomal location: 1q23-24
Testing Algorithm
If the patient appears to have a bleeding disorder, the clinical workup for factor V deficiency (F5D) begins with special coagulation testing for factor V activity. See FACTV / Coagulation Factor V Activity Assay, Plasma.
Genetic testing for F5D is indicated if:
-Factor V activity is reduced and acquired causes of FV deficiency have been excluded
-The FVIII activity is normal (low factor V levels with concurrently low factor VIII levels suggest combined deficiency of factor V and FVIII [F5F8D], a condition with a genetic etiology different from that of F5D)
If the patient appears to have thrombophilia, the results of an activated protein C (APC) resistance assay indicate presence of resistance to APC, and factor V Leiden genotype does not correlate with the severity of thrombophilia or clinical presentation, full-gene sequencing of F5 may be warranted. If testing for factor V Leiden is desired instead of full-gene sequencing, please order "Factor V Leiden (R506Q) Mutation, Blood" (Mayo test ID F5DNA).
Special Instructions
Method Name
Custom Sequence Capture and Targeted Next-Generation Sequencing (NGS) followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing when appropriate
Reporting Name
F5 Gene, Full Gene NGSSpecimen Type
VariesSpecimen Minimum Volume
Blood: 1 mL
Extracted DNA: 100 mcL at 50 ng/mcl
concentration
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | 7 days | |
| Frozen | 14 days | ||
| Refrigerated | 7 days |
Reference Values
An interpretive report will be provided
Day(s) Performed
Varies
Report Available
21 to 28 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81479
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| F5NGS | F5 Gene, Full Gene NGS | 94236-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 113027 | F5NGS Result | 50397-9 |
| 113021 | Alterations Detected | 82939-0 |
| 113020 | Interpretation | 69047-9 |
| 113022 | Additional Information | 48767-8 |
| 113023 | Method | 85069-3 |
| 113024 | Disclaimer | 62364-5 |
| 113025 | Panel Gene List | 21669-7 |
| 113026 | Reviewed By | 18771-6 |