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26038 JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood (JAKXB)

JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood (JAKXB)
Test Code: JAKXBSO
Synonyms/Keywords
​JAK2 Exon 12
JAK2 Exon 13
JAK2 Exon 14
JAK2 Exon 15
Janus Kinase 2 Gene
Janus Kinase 2 Gene Sequencing
Tyrosine Kinase Gene Sequencing
Tyrosine Kinase Mutuation
Test Components
JAKXB / JAK2 Exon 12 and Other Non-V617F Mutation Detection
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
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No ​Whole Blood ​EDTA Lavendar Top Tube (LTT) ​ACD Yellow Top Tube (YTT) ​10 mL ​4 mL
Collection Processing Instructions

Invert several times to mix blood.  Send specimen in original tube.

Specimen must arrive within 5 days (120 hours) of collection.

Specimen Stability Information
Specimen Type Temperature Time
​Whole Blood ​ ​Refrigerate (preferred) ​5 days
​Ambient ​5 days
Interference

​A positive result is not specific for a particular diagnosis and clinico-pathologic correlation is necessary in all cases. A negative result does not exclude the presence of a myeloproliferative or other neoplasm. 

If this test is ordered in the setting of erythrocytosis and suspicion of polycythemia vera, interpretation requires correlation with a concurrent or recent prior bone marrow evaluation.

Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Friday ​5-8 days Mutation Detection in cDNA Using Sanger Sequencing
Reference Lab
Test Information

DNA sequence mutations in the Janus kinase 2 gene (JAK2) are found in the hematopoietic cells of several myeloproliferative neoplasms (MPN), most frequently polycythemia vera (close to 100%), essential thrombocythemia (approximately 50%), and primary myelofibrosis (approximately 50%). Mutations in JAK2 have been reported at much lower frequency in other MPN, chronic myelomonocytic leukemia and mixed MPN/myelodysplastic syndromes, but essentially never in chronic myelogenous leukemia (CML), reactive cytoses, or normal patients. Mutations are believed to cause constitutive activation of the JAK2 protein, which is an intracellular tyrosine kinase important for signal transduction in many hematopoietic cells. Since it is often difficult to distinguish reactive conditions from the non-CML MPN, identification of a JAK2 mutation has diagnostic value. Potential prognostic significance of JAK2 mutation detection in chronic myeloid disorders has yet to be clearly established.

The vast majority of JAK2 mutations occur as base pair 1849 in the gene, resulting in a JAK2 V617F protein change. In all cases being evaluated for JAK2 mutation status, the initial test that should be ordered is JAK2B / JAK2 V617F Mutation Detection, Blood, a sensitive assay for detection of the mutation. However, if no JAK2 V617F mutation is found, further evaluation of JAK2 may be clinically indicated. Over 50 different mutations have now been reported within exons 12 through 15 of JAK2 and essentially all of the non-V617F mutations have been identified in polycythemia vera. These mutations include point mutations and small insertions or deletions. Several of the exon 12 mutations have been shown to have biologic effects similar to those caused by the V617F mutation such that it is currently assumed other nonpolymorphic mutations have similar clinical effects. However, research in this area is ongoing. 

This assay for non-V617F/alternative JAK2 mutations is designed to obtain the sequence for JAK2 exons 12 through the first 90% of exon 15, which spans the region containing all mutations reported to date.

Reference Range Information
Interpretive Report
Interpretation
The results will be reported as 1 of 2 states:
1. Negative for JAK2 mutation
2. Positive for JAK2 mutation
 

If the result is positive, a description of the mutation at the nucleotide level and the altered protein sequence is reported.

Positive mutation status is highly suggestive of a myeloproliferative neoplasm, but must be correlated with clinical and other laboratory features for a definitive diagnosis. Negative mutation status does not exclude the presence of a myeloproliferative or other neoplasm.

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
0027U

​1

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.
Synonyms/Keywords
​JAK2 Exon 12
JAK2 Exon 13
JAK2 Exon 14
JAK2 Exon 15
Janus Kinase 2 Gene
Janus Kinase 2 Gene Sequencing
Tyrosine Kinase Gene Sequencing
Tyrosine Kinase Mutuation
Test Components
JAKXB / JAK2 Exon 12 and Other Non-V617F Mutation Detection
Ordering Applications
Ordering Application Description
​Centricity

JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood (JAKXB)

​Cerner ​ 

JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood (JAKXB)

​COM ​ 

JAK2 Exon 12 and Other Non-V617F Mutation Detection, Blood (JAKXB)

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​No ​Whole Blood ​EDTA Lavendar Top Tube (LTT) ​ACD Yellow Top Tube (YTT) ​10 mL ​4 mL
Collection Processing

Invert several times to mix blood.  Send specimen in original tube.

Specimen must arrive within 5 days (120 hours) of collection.

Specimen Stability Information
Specimen Type Temperature Time
​Whole Blood ​ ​Refrigerate (preferred) ​5 days
​Ambient ​5 days
Interference

​A positive result is not specific for a particular diagnosis and clinico-pathologic correlation is necessary in all cases. A negative result does not exclude the presence of a myeloproliferative or other neoplasm. 

If this test is ordered in the setting of erythrocytosis and suspicion of polycythemia vera, interpretation requires correlation with a concurrent or recent prior bone marrow evaluation.

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
Test Components
JAKXB / JAK2 Exon 12 and Other Non-V617F Mutation Detection
Reference Range Information
Interpretive Report
Interpretation
The results will be reported as 1 of 2 states:
1. Negative for JAK2 mutation
2. Positive for JAK2 mutation
 

If the result is positive, a description of the mutation at the nucleotide level and the altered protein sequence is reported.

Positive mutation status is highly suggestive of a myeloproliferative neoplasm, but must be correlated with clinical and other laboratory features for a definitive diagnosis. Negative mutation status does not exclude the presence of a myeloproliferative or other neoplasm.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Mayo Clinic Laboratories ​Monday through Friday ​5-8 days Mutation Detection in cDNA Using Sanger Sequencing
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
0027U

​1

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.
For most current information refer to the Marshfield Laboratory online reference manual.