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Test Code JAKXM JAK2 Exon 12 and Other Non-V617F Mutation Detection, Bone Marrow

Reporting Name

JAK2 Exon 12 Mutation Detection, BM

Useful For

Second-order testing to aid in the distinction between a reactive cytosis and a myeloproliferative neoplasm, particularly when a diagnosis of polycythemia is being entertained; for use with bone marrow specimens

Testing Algorithm

This is a second-order test that should be used when the test for the JAK2M / JAK2 V617F Mutation Detection, Bone Marrow test is negative.


See Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation in Special Instructions.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Bone Marrow

Advisory Information

The sensitivity of this assay is much less than that of JAK2M / JAK2 V617F Mutation Detection, Bone Marrow. This is because the sequencing technique is required to evaluate for many potential mutations. The sensitive JAK2M / JAK2 V617F Mutation Detection, Bone Marrow should always be performed first, as the JAK2 mutation burden may be very low in some specimens. If JAK2M / JAK2 V617F Mutation Detection, Bone Marrow is negative, then this assay, JAKXM / JAK2 Exon 12 and Other Non-V617F Mutation Detection, Bone Marrow, should be performed for detection of non-V617F JAK2 mutations.

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


Preferred: EDTA (lavender top)

Acceptable: ACD (yellow top)

Specimen Volume: 2 mL

Collection Instructions:

1. Invert several times to mix bone marrow.

2. Send specimen in original tube.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Bone Marrow Refrigerated (preferred) 5 days
  Ambient  5 days

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday

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.

CPT Code Information

0027U-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
JAKXM JAK2 Exon 12 Mutation Detection, BM 80186-0


Result ID Test Result Name Result LOINC Value
39468 JAK2 Sequencing Result 80186-0
20250 Final Diagnosis: 34574-4

Method Name

Mutation Detection in cDNA Using Sanger Sequencing


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 (