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Test Code JAKXB JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood

Reporting Name

JAK2 Exon 12 Mutation Detection, B

Useful For

Aiding in the distinction between a reactive cytosis and a myeloproliferative neoplasm, particularly when a diagnosis of polycythemia is being entertained; for use with blood specimens

Testing Algorithm

This is a second-order test that should be used when the test for the JAK2B / JAK2 V617F Mutation Detection, Blood test is negative. The sensitivity of this assay is much less than that of the JAK2B blood test. This is because the sequencing technique is required to evaluate for many potential mutations. The sensitive JAK2B blood test should always be performed first, as the JAK2 mutation burden may be very low in some specimens. If JAK2B blood test is negative, then this assay (JAKXB / JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood) should be performed for detection of non-V617F JAK2 mutations.

 

The following algorithms are available in Special Instructions:

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

-Erythrocytosis Evaluation Testing Algorithm

Method Name

Mutation Detection in cDNA Using Sanger Sequencing
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Whole blood


Additional Testing Requirements


The sensitive JAK2B / JAK2 V617F Mutation Detection, Blood should always be performed first, as the JAK2 mutation burden may be very low in some specimens.



Shipping Instructions


Specimen must arrive within 5 days (120 hours) of collection. Draw and package specimen as close to shipping time as possible.



Necessary Information


Date of collection is required.



Specimen Required


Container/Tube:

Preferred: EDTA (lavender top)

Acceptable: ACD (yellow top)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Refrigerated (preferred) 5 days
  Ambient  5 days

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

NA

Icterus

NA

Other

Moderately to severely clotted

 

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday

CPT Code Information

81403-JAK2 (Janus kinase 2) (eg, myeloproliferative disorder), exon 12 sequence and exon 13 sequence, if performed

LOINC Code Information

Test ID Test Order Name Order LOINC Value
JAKXB JAK2 Exon 12 Mutation Detection, B In Process

 

Result ID Test Result Name Result LOINC Value
39467 JAK2 Sequencing Result No LOINC Needed
20194 Final Diagnosis: 34574-4

Secondary ID

89189

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 U.S. Food and Drug Administration.

Forms

1. Hematopathology Patient Information (T676) in Special Instructions

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request Form (T726) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/hematopathology-request-form.pdf).