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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


Forms

If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

Useful For

Aiding in the distinction between a reactive cytosis and a myeloproliferative neoplasm

Method Name

Sanger Sequencing

Reporting Name

MPL Exon 10 Mutation Detection, V

Specimen Type

Varies

Specimen 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

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.

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

Day(s) Performed

Monday through Friday

Report Available

5 to 8 days

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
Mayo Clinic Laboratories | Hematology Catalog Additional Information:

mml-myeloproliferative-disorders