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HelpMayo Test ID MPLVS MPL Exon 10 Mutation Detection, Varies
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Peripheral blood
Container/Tube: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 3 mL
Collections Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube. Do not aliquot.
3. Label specimen as blood.
Specimen Stability: Ambient (preferred)/Refrigerate
Specimen Type: Bone marrow
Container/Tube: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 2 mL
Collections Instructions:
1. Invert several times to mix bone marrow.
2. Send specimens in original tube. Do not aliquot.
3. Label specimen as bone marrow.
Specimen Stability: Ambient (preferred)/Refrigerate
Specimen Type: Extracted DNA from blood or bone marrow
Container/Tube: 1.5- to 2- mL tube
Specimen Volume: Entire specimen
Collection Instructions: Label specimen as extracted DNA from blood or bone marrow and provide indication of volume and concentration of DNA.
Specimen Stability Information: Frozen (preferred)/Refrigerated/Ambient
Useful For
Aiding in the distinction between a reactive cytosis and a myeloproliferative neoplasm
Testing Algorithm
For more information see:
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation
Special Instructions
Method Name
Sanger Sequencing
Reporting Name
MPL Exon 10 Mutation Detection, VSpecimen Type
VariesSpecimen Minimum Volume
Blood, Bone marrow: 0.5 mL; Extracted DNA: 50 mcL at 20 ng/mcL concentration
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | 7 days |
Reject Due To
| Gross hemolysis | Reject |
| Bone marrow biopsies Slides paraffin shavings Moderately to severely clotted |
Reject |
Clinical Information
DNA sequence variants in exon 10 of the myeloproliferative leukemia virus oncogene (MPL) have been detected in approximately 5% of patients with primary myelofibrosis (PMF) and essential thrombocythemia (ET), which are hematopoietic neoplasms classified within the broad category of myeloproliferative neoplasms. MPL codes for a transmembrane tyrosine kinase, and the most common MPL variants are single base pair substitutions at codon 515. These alterations have been shown to promote constitutive, cytokine-independent activation of the JAK/STAT signaling pathway and contribute to the oncogenic phenotype. At least 8 different MPL exon 10 variants have been identified in PMF and ET to date, and variants outside of exon 10 have not yet been reported. The vast majority of MPL variants have been found in specimens testing negative for the most common variant identified in myeloproliferative neoplasms, JAK2 V716F, although a small number of cases with both types of variants have been reported. MPL variants have not been identified in patients with polycythemia vera, chronic myelogenous leukemia, or other myeloid neoplasms.
Identification of MPL variants can aid in the diagnosis of a myeloproliferative neoplasm and is highly suggestive of either PMF or ET.
Reference Values
An interpretive report will be provided.
Interpretation
The results will be reported as 1 of 2 states:
-Negative for MPL exon 10 variant
-Positive for MPL exon 10 variant
If the result is positive, a description of the variant at the nucleotide level and the altered protein sequence is reported.
Positive variant status is highly suggestive of a myeloproliferative neoplasm but must be correlated with clinical and other laboratory features for a definitive diagnosis. Negative variant status does not exclude the presence of a myeloproliferative or other neoplasm.
Cautions
A positive result is not specific for a particular diagnosis and clinicopathologic correlation is necessary in all cases.
A negative result does not exclude the presence of a myeloproliferative or other neoplasm.
Clinical Reference
1. Defour JP, Chachoua I, Pecquet C, Constantinescu SN. Oncogenic activation of MPL/thrombopoietin receptor by 17 mutations at W515: implications for myeloproliferative neoplasms. Leukemia. 2016;30(5):1214-1216. doi:10.1038/leu.2015.271
2. Pikman Y, Lee BH, Mercher T, et al. MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia. PLoS Med. 2006;3(7):e270
3. Pardanani AD, Levine RL, Lasho T, et al. MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients. Blood. 2006;108(10):3472-3476
4. Kilpivaara O, Levine RL. JAK2 and MPL mutations in myeloproliferative neoplasms: discovery and science. Leukemia. 2008;22(10):1813-1817. doi:10.1038/leu.2008.229
Method Description
Genomic DNA is extracted from the blood or bone marrow sample, and the MPL exon 10 amplified using standard polymerase chain reaction. The entire exon 10 sequence is obtained using Sanger sequencing with analysis on an automated genetic analyzer.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
5 to 8 daysSpecimen Retention Time
Whole blood/Bone marrow: 2 weeks; Extracted DNA: 3 monthsPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81339-MPL (myeloproliferative leukemia virus oncogene, thrombopoietin receptor, TPOR) (eg, myeloproliferative disorder), exon 10 sequence
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MPLVS | MPL Exon 10 Mutation Detection, V | 62948-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| MP051 | Specimen Type | 31208-2 |
| 602600 | Interpretation | 69047-9 |
| 602601 | Signing Pathologist | 19139-5 |