Laboratory Test Information Guide

Details for Polycythemia Vera

Test Name: Polycythemia Vera
Alternate Name(s): JAK2(V617F)
Laboratory: Molecular Diagnostics
Specimen Type: Whole blood-1 x 4 mL Lavender EDTA top Vacutainer tube
Collection Information: Blood samples must be maintained at room temperature.
Requisition: JAK2 REQUISITION
Test Schedule: As required
Monday - Friday
0800 - 1600 h
Turnaround time from when specimen
is received in testing laboratory:
 
Routine
1 month
Stat
 
 
Reference Range: See report
Effective Date:  
Revised Date: 2016-04-27
Critical Value: N/A
Interpretive Comments: Human myeloproliferative disorders form a range of clonal haematological malignant diseases, the main members of which are polycythaemia vera, essential thrombocythaemia, and idiopathic myelofibrosis. The molecular pathogenesis of these disorders is unknown, but tyrosine kinases have been implicated in several related disorders 1,2. JAK2 is a widely expressed cytoplasmic tyrosine kinase, which plays a central role in the transduction of signals from multiple growth factor receptors. It has been reported1 that a single point mutation *JAK2:1849G>T predicting an amino acid substitution (Val617Phe) has been identified in the JAK2 gene in 71 (97%) of a panel of 73 patients with polycythaemia vera, 29 (57%) of 51 with essential thrombocythaemia, and eight (50%) of 16 with idiopathic myelofibrosis. This mutation, which is generally acquired, is present in a variable proportion of granulocytes, alters a highly conserved valine present in the negative regulatory JH2 domain, and is predicted to dysregulate kinase activity. To detect the above JAK2 mutation b.p. PCR-amplified fragment is generated from leukocyte-derived genomic DNA encompassing the corresponding region of the JAK2 gene. The forward primer contains two mismatched bases at its 3' end to create, by a process of site-directed mutagenesis, an Ac1I restirciton enzyme cut site which results, in the presence of the JAK2:1849G>T mutation, in two DNA fragments 176bp and 25 bp in length and which can be resolved by PAGE.

References

1. Baxter EJ et al. (2005) Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet. 365:1054-61.
2. Kravolics R.N. et al. (2005) A gain-of-function mutation of JAK2 in myeloproliferative disorders; 352:1779-90. N Engl J Med. 352:1744-6.
Special Processing:  
Comments: For more information click on:

Molecular Diagnostic Laboratory
Method of Analysis: RT-PCR
Critical Information Required:  
Storage & Shipment: Must be received in testing laboratory within 5 days of collection, shipped at room temperature by courier/overnight delivery.
System Codes: 
Cerner
 
 
Referred To:  

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