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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


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


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.

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 NGS

Specimen Type


Specimen 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


Report Available

21 to 28 days

Performing 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


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