BCR/ABL, mRNA Detection, Reverse Transcription-PCR (RT-PCR), Qualitative, Diagnostic Assay
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Aids in the diagnostic workup for patients with bcr/abl-positive neoplasms, predominantly chronic myeloid leukemia and acute lymphocytic leukemia
When positive, the test identifies which mRNA fusion variant is present to guide selection of an appropriate monitoring assay.
If a quantitative monitoring assay is not available for a rare fusion variant, this assay may be of some value for monitoring, as it is quite sensitive and can provide a positive or negative result.
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
The following algorithms are available in Special Instructions:
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Reverse Transcription-Polymerase Chain Reaction (RT-PCR) with Fluorescent-Bead Array Analysis
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
BCR/ABL, RNA-Qual, Diagnostic
Philadelphia Chromosome Ph1 Bone Marrow/Blood
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
The following information is required:
1. Pertinent clinical history-confirm that this test is being ordered for the purposes of making an initial diagnosis
2. Date of collection
3. Specimen source (blood or bone marrow)
1. Hematopathology Patient Information Sheet (Supply T676) in Special Instructions
2. If not ordering electronically, please submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
Specimen must arrive within 72 hours of collection.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 4 mL
1. Invert several times to mix blood.
2. Send specimen in original tube.
3. Label specimen as blood.
Specimen Type: Bone marrow
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 3 mL
1. Invert several times to mix bone marrow.
2. Send specimen in original tube.
3. Label specimen as bone marrow.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Varies||Ambient (preferred)||72 hours|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
mRNA transcribed from BCR/ABL (fusion of the breakpoint cluster region gene [BCR] at chromosome 22q11 to the Abelson gene [ABL] at chromosome 9q23) is detected in all chronic myelogenous leukemia (CML) patients and a subset of both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) patients. Although breakpoints in the BCR and ABL genes may occur in a variety of locations, splicing of the primary RNA transcripts result in only 8 fusion site variants (e1/a2, e6/a2, e13/a2, e14/as, e19/a2, e1/a3, e13/a3, e14/a3) which incorporate the entire sequence of the exons on both sides of the fusion site. Although not reported in the literature, additional fusion variants (e20/a2, e6/a3, e12/a3, e19/a3, e20/a3) could theoretically result in disease-promoting bcr/abl proteins. Very rare, single-case reports of patients with fusions sites within the exons of BCR or ABL are also present in the literature.
In CML, >95% of patients have either an e13/a2 or e14/a2 fusion, both of which produce a 210-kDa protein (p210). More than 50% of patients with BCR/ABL-positive ALL have the e1/a2 fusion, which produces a 190-kDa protein (p190), and the majority of the remaining patients have either the e13/a2 or e14/a2 variants. Other fusions are very rare in any of the neoplasms known to harbor BCR/ABL.
When looking for the presence of mRNA from BCR/ABL (bcr/abl) at the time of diagnosis, it is important to use an assay that detects as many of the fusions as possible and identifies which fusion is present. This avoids false-negative results at diagnosis and assures the test subsequently selected for monitoring during therapy will detect the appropriate fusion product in each patient. This assay is designed to detect essentially all reported and theoretical BCR/ABL mRNA fusion variants.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
A qualitative result is provided that indicates the presence or absence of BCR/ABL mRNA. When positive, the fusion variant is also reported.
An interpretive report will be provided.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is only qualitative and should not be used for routine monitoring. Monitoring of most chronic myeloid leukemia (CML) patients should be performed using BCRAB/89007 BCR/ABL, p210 mRNA Detection, Reverse Transcription-PCR (RT-PCR), Quantitative, Monitoring Chronic Myelogenous Leukemia (CML). Monitoring of patients known to carry a p190 fusion should be performed using BA190/83336 BCR/ABL, p190, mRNA Detection, Reverse Transcription-PCR (RT-PCR), Quantitative, Monitoring Assay. If a patient is known to have a rare fusion variant that is not covered by 1 of these monitoring assays, contact Dr. McClure or Dr. Viswanatha at 1-800-533-1710 extension 6-5323 to discuss whether this qualitative assay can be used for monitoring.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Hochhaus A, Reiter A, Skladny H, et al: A novel BCR-ABL fusion gene (e6a2) in a patient with Philadelphia chromosome-negative chronic myelogenous leukemia. Blood 1996 September 15;88(6):2236-2240
Method Description Describes how the test is performed and provides a method-specific reference
RNA is extracted from the patient’s blood or bone marrow obtained at the time of diagnosis and is converted into complementary DNA (cDNA) for ease of analysis. The cDNA is then subjected to PCR using 2 separate reactions: the first contains primers designed to amplify all fusions containing the ABL a2 exon. The second contains primers designed to amplify all fusions containing the ABL a3 exon. The reverse primer in each tube contains a fluorescent label such that all amplified products will be fluorescently labeled. If a bcr/abl fusion product is present in the original sample, this product will be amplified in one or both of these PCR reactions.
The PCR products are then added to a mixture of beads (Luminex Corp.), which is made as follows: for each possible bcr/abl fusion product, a uniquely colored bead is selected and multiple copies of a capture oligonucleotide are bound to its surface. The capture oligonucleotide contains sequence from the BCR portion of the fusion (from the exon closest to the fusion point) such that only a fusion product containing that exon will bind. All of the beads, each coated with their target’s capture probe, are mixed together and an aliquot is mixed with each of the 2 PCR reactions under annealing conditions. If an amplified bcr/abl target is in the PCR reaction mix, it will bind to its corresponding capture oligonucleotides on its uniquely colored bead. Following annealing, the beads are washed to remove all unbound products and analyzed by the Luminex instrument.
The Luminex instrument uses the principle of flow cytometry and analyzes 1 bead at a time using 2 separate lasers. The first laser identifies the color of the bead, and the second measures the amount of fluorescence on the bead. Any bead coated with captured, fluorescently labeled PCR product will register as high fluorescence. The machine is set to count a specific number of each bead color and a bar graph is generated showing the average fluorescence per bead in each uniquely colored bead set.(Unpublished Mayo method)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 2 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
RNA: Up to 3 months
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
81206-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; major breakpoint, qualitative or quantitative
81207-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; minor breakpoint, qualitative or quantitative
81208-BCR/ABL1 (t(9;22)) (eg, chronic myelogenous leukemia) translocation analysis; other breakpoint, qualitative or quantitative
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|