Lab Test

JAK2 Exon 12 Mutation Detection

JAK2 Exon 12 Non-V617F Mutation Detection, erythrocytosis, Polycythemia Vera

Test Codes

EPIC: LAB6911, Code: GJ12G


Molecular Pathology

Specimen Collection Criteria

Collect: Blood OR Bone Marrow.

  • Blood: 10 mL whole blood in Lavender-top EDTA tubes or Yellow-top ACD tubes. (Minimum: 5.0 mL)
  • Bone Marrow: 1.0 mL bone marrow aspirate in a Lavender-top EDTA tube. (Minimum: 0.5 mL)

Physician Office/Draw Specimen Preparation

Do not freeze specimens. Maintain specimens at room temperature (20-26°C or 68-78.8°F) or refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport: 10.0 mL whole blood or 1.0 mL bone marrow, at room temperature (20-26°C or 68-78.8°F) or refrigerated (2-8°C or 36-46°F). (Minimum: 5.0 mL whole blood or 0.5 mL bone marrow)

Rejection Criteria

  • Frozen specimens.
  • Unlabeled tubes.
  • Specimens collected in heparin (Green-top), clot tubes (Red-top), or SST tubes.

In-Lab Processing

Do not freeze specimens. Maintain specimen refrigerated (2-8°C or 36-46°F) prior to testing. 


Specimen Stability for Testing:

Room temperature (20-26°C or 68-78.8°F): 72 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Extracted DNA may be available for additional testing if clinically indicated. Contact the Molecular Pathology Laboratory for verification.


Royal Oak Clinical Molecular Pathology Laboratory


Once per week.
Results available in 7-10 days. 

Reference Range

Negative (no mutation).

Test Methodology

Polymerase Chain Reaction (PCR) Amplification of Exon 12 of the JAK2 gene with Mutation Analysis by High Resolution Capillary Electrophoresis and Size Analysis.


Somatic mutations in Exon 12 of the JAK2 gene are seen in Polycythemia Vera patients found to be negative for the JAK2 V617F mutation. The test is part of the WHO diagnostic algorithm for suspected Polycythemia Vera that is V617F negative. The Exon 12 mutation prevalence is less than 5% in Polycythemia Vera cases. Exon 12 Mutation Analysis is also useful in the workup of patients with erythrocytosis.

CPT Codes



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