Test ID F2NGS F2 Gene, Next-Generation Sequencing, Varies
Test Down Notes
This test is temporarily unavailable. There is not an alternative for this test. For additional details, see test update here
Ordering Guidance
The clinical workup for factor II deficiency (F2D) begins with special coagulation testing for factor II. Order F_2 / Coagulation Factor II Activity Assay, Plasma.
This test is not intended to evaluate for the F2 c.*97G>A alteration (historically known as G20210A) associated with prothrombin-related thrombophilia. If testing for the F2 c.*97G>A alteration (G20210A) is desired instead of full-gene sequencing, order PTNT / Prothrombin G20210A Mutation, Blood.
Shipping Instructions
Ambient and refrigerate specimens must arrive within 7 days of collection, and frozen specimens must arrive within 14 days.
Collect and package specimen as close to shipping time as possible.
Necessary Information
Rare Coagulation Disorder Patient Information is required. 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: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD) or light-blue top (3.2% sodium citrate)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
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
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:
-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
Ascertaining a causative alteration in F2 and the affected region of prothrombin protein in an individual clinically diagnosed with factor II deficiency
Carrier testing for close family members of an individual with a factor II deficiency diagnosis
This test is not intended for prenatal diagnosis.
Testing Algorithm
This genetic test should only be considered if clinical and family history, initial coagulation screens, and initial factor II (FII) tests (activity and antigen) indicate a diagnosis of factor II deficiency.
Genetic testing for F2D is indicated if:
-Prothrombin (factor II) activity is reduced (less than 80% of normal)
-Acquired causes of factor II deficiency have been excluded (eg, vitamin K deficiency, warfarin anticoagulation use, liver disease, etc)
Prothrombin antigen testing, to distinguish between type I and type II deficiencies, may be helpful in cases where genetic testing results yield variants of uncertain significance.
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
F2 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

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 |
---|---|---|
F2NGS | F2 Gene, Full Gene NGS | 94237-5 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
113019 | F2NGS Result | 50397-9 |
113013 | Alterations Detected | 82939-0 |
113012 | Interpretation | 69047-9 |
113014 | Additional Information | 48767-8 |
113015 | Method | 85069-3 |
113016 | Disclaimer | 62364-5 |
113017 | Panel Gene List | 24477-2 |
113018 | Reviewed By | 18771-6 |