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Test Code BCRFX BCR/ABL1 Qualitative Diagnostic Assay with Reflex to BCR/ABL1 p190 Quantitative Assay or BCR/ABL1 p210 Quantitative Assay


Shipping Instructions


Specimen must arrive within 72 hours of draw. Draw and package specimen as close to shipping time as possible.



Necessary Information


The following information is required:

1. Pertinent clinical history including if the patient has a diagnosis of chronic myeloid/myelogenous leukemia or other BCR/ABL1 positive neoplasm

2. Date of collection

3. Specimen source (blood or bone marrow)



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: ACD

Specimen Volume: 10 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

3. Label specimen as blood.

 

Specimen Type: Bone marrow

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: ACD

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix bone marrow.

2. Send specimen in original tube.

3. Label specimen as bone marrow.


Forms

1. Hematopathology Patient Information (T676) in Special Instructions

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request Form (T726) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/hematopathology-request-form.pdf)

Secondary ID

65248

Useful For

Diagnostic workup of patients with high probability of BCR-ABL1-positive hematopoietic neoplasms, predominantly chronic myeloid/myelogenous leukemia and acute lymphoblastic leukemia

 

When positive, the test identifies which specific mRNA fusion variant is present to guide selection of an appropriate monitoring assay.

Testing Algorithm

When a positive p210 or p190 BCR/ABL1 result is identified by the qualitative assay, a reflex test will then be performed at an additional charge to determine the quantitative transcript level of BCR/ABL1 mRNA. A positive p210 or p190 result will specifically trigger either quantitative p210 (B210R) or p190 (B190R) testing to provide a normalized percentage of transcript level. For the p210 target, the value is additionally defined using the International Scale (IS) convention. The results are released in an integrated report and provide a baseline quantitative transcript to monitor treatment response. If the initial qualitative testing is negative, or an alternate rare form BCR/ABL1 detected, then no reflex testing will be pursued and the initial results will be reported.

Method Name

Reverse Transcription-Polymerase Chain Reaction (RT-PCR) multiplex PCR (PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)

Reporting Name

BCR/ABL1 Reflex, Qual/Quant

Specimen Type

Varies

Specimen Minimum Volume

Blood: 4 mL; Bone Marrow: 1 mL

Specimen Stability Information

Specimen Type Temperature Time
Varies Refrigerated (preferred) 72 hours
  Ambient  72 hours

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

NA

Icterus

NA

Other

Moderately to severely clotted

Clinical Information

The t(9;22)/BCR-ABL1 abnormality is associated with chronic myelogenous leukemia (CML) and "Philadelphia positive" acute lymphoblastic leukemia of B-cell lineage (Ph ALL). Very rarely, this abnormality has also been identified in cases of acute myeloid leukemia and T-lymphoblastic leukemia/lymphoma. The fusion gene on the derivative chromosome 22q11 produces a chimeric BCR-ABL1 mRNA transcript and corresponding translated oncoprotein. Despite substantial breakpoint heterogeneity at the DNA level, a consistent set of BCR-ABL1 mRNA transcripts are produced that can be readily and sensitively detected by reverse transcription PCR (RT-PCR) technique. In CML, breakpoints in BCR result in either exons 13 or 14 (e13, e14) joined to exon 2 of ABL1 (a2). The corresponding e13-a2 or e14-a2 BCR-ABL1 mRNAs produce a 210 kD protein (p210). Rare cases of CML are characterized by an e19-a2 type mRNA with a corresponding p230 protein. In Ph ALL, the majority of cases harbor an e1-a2 BCR-ABL1 mRNA transcript, producing a p190 protein. However, chimeric mRNA type is not invariably associated with disease type, as noted by the presence of p210-positive Ph ALL and very rare cases of p190-positive CML. Therefore, positive results from a screening (diagnostic) assay for BCR-ABL1 mRNA need to be correlated with clinical and pathologic findings.

 

In addition to the main transcript variants described above, rare occurrences of both CML and Ph ALL can have alternative break-fusion events resulting in unusual BCR-ABL1 transcript types. Examples include e6-a2 and BCR exon fusions to ABL1 exon a3 (eg, e13-a3, e14-a3, or e1-a3). In addition to detecting common BCR-ABL1 mRNA transcripts, this assay also can identify these rarer BCR-ABL1 transcript variants and is therefore a comprehensive screen for both usual and uncommon BCR-ABL1 gene fusions in hematopoietic malignancies. Given the nature of genetic events in tumors however, this assay will not identify extremely rare and unexpected BCR-ABL1 events involving other exons (eg, case report level) and is therefore not absolutely specific, but is predicted to detect greater than 99.5% of BCR-ABL1 events. Therefore, it is recommended that for diagnosis, RT-PCR plus a second method (eg, BCR-ABL1 FISH or cytogenetics) should be used. However, this RT-PCR assay is invaluable at diagnosis for identifying the precise BCR-ABL1 mRNA type (eg, for future quantitative assay disease monitoring), which complementary methods cannot.

 

This assay is intended as a qualitative method, providing information on the presence (and specific mRNA type) or absence of the BCR-ABL1 mRNA. Results from this test can be used to determine the correct subsequent assay for monitoring of transcript levels following therapy (eg, BCRAB, BA190). Because the assay is analytically sensitive, it compensates for situations such as partially degraded RNA quality, or low cell number but it is not intended for quantitative or monitoring purposes.

Reference Values

An interpretive report will be provided.

Interpretation

An interpretive report will be provided.

Clinical Reference

1. Burmeister T, Reinhardt R: A multiplex PCR for improved detection of typical and atypical BCR-ABL fusion transcripts. Leuk Res 2008 Apr;32(4):579-585

2. Melo JV: The diversity of BCR-ABL fusion proteins and their relationship to leukemia phenotype. Blood 1996;88(7):2375-2384

3. Melo JV: BCR-ABL gene variants. Baillieres Clin Haematol 1997;10(2):203-222

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

7 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test uses a standard method. Its performance characteristics were 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.

CPT Code Information

81208-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; other breakpoint, qualitative

81206-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; major breakpoint, qualitative

81207-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; minor breakpoint, qualitative

 

81206-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; major breakpoint, quantitative (If appropriate)

81207-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; minor breakpoint, quantitative (If appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BCRFX BCR/ABL1 Reflex, Qual/Quant In Process

 

Result ID Test Result Name Result LOINC Value
MP039 Specimen Type In Process
48389 BCR/ABL1 Reflex Result In Process
48388 Final Diagnosis In Process