Test Id : BARQ
BCR::ABL1, Rare Fusion Monitoring, Quantitative, Varies
Useful For
Suggests clinical disorders or settings where the test may be helpful
Quantitative monitoring of rare (non-p210 [non-E13/E14A2], non-p190 [non-E1A2]) BCR::ABL1 fusion transcript types occurring in myeloid neoplasms (eg, CML, myeloproliferative neoplasms) or B-cell acute lymphoblastic leukemias.
Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| BADX | BCR/ABL1, RNA-Qual, Diagnostic | Yes | No |
| BA190 | BCR/ABL1, p190, Quant, Monitor | Yes | No |
| BCRAB | BCR/ABL1, p210, Quant, Monitor | Yes | No |
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If a previous BCR::ABL1 rare fusion has not been identified by Mayo Clinic Laboratories (MCL), the qualitative, diagnostic assay for BCR::ABL1 will be performed at an additional charge to identify the fusion form.
If MCL has previously identified a p190 or p210 BCR::ABL1 fusion form, the appropriate quantitative testing will be performed and this test will be canceled.
Method Name
A short description of the method used to perform the test
Droplet Digital Polymerase Chain Reaction (ddPCR)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Acute lymphoblastic leukemia (ALL)
Acute myeloid leukemia (AML)
B lymphoblastic leukemia (B-ALL)
BCR ABL
BCR-ABL1
BCR/ABL
BCR::ABL1
Chronic myelogenous leukemia (CML)
Chronic myeloid leukemia (CML)
Philadelphia chromosome Ph bone marrow/blood
T lymphoblastic leukemia (T-ALL)
t(9;22)
BCR::ABL1-positive myeloproliferative neoplasm
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If a previous BCR::ABL1 rare fusion has not been identified by Mayo Clinic Laboratories (MCL), the qualitative, diagnostic assay for BCR::ABL1 will be performed at an additional charge to identify the fusion form.
If MCL has previously identified a p190 or p210 BCR::ABL1 fusion form, the appropriate quantitative testing will be performed and this test will be canceled.
Specimen Type
Describes the specimen type validated for testing
Varies
Ordering Guidance
This test should not be used to screen for BCR::ABL1 fusions at the time of diagnosis. For diagnostic evaluation, please order BADX / BCR/ABL1, Qualitative, Diagnostic Assay, Varies; or BCRFX / BCR/ABL1 Qualitative Diagnostic Assay with Reflex to BCR/ABL1 p190 Quantitative Assay or p210 Quantitative Assay, Varies.
For measurable residual disease (MRD) monitoring of patients with chronic myeloid leukemia (CML) or, less commonly, B-cell acute lymphoblastic leukemia (B-ALL) or acute myeloid leukemia (AML) with a previously identified p210 (e13/e14-a2) fusion transcript, order BCRAB / BCR/ABL1, p210, mRNA Detection, Reverse Transcription-PCR (RT-PCR), Quantitative, Monitoring Chronic Myelogenous Leukemia (CML), Varies.
For MRD monitoring of B-ALL or rare CML or AML patients with a previously identified p190 (e1-a2) fusion transcript, order BA190 test / BCR/ABL1, p190, mRNA Detection, Reverse Transcription-PCR (RT-PCR), Quantitative, Monitoring Assay, Varies.
For more information, see BCR/ABL1 Ordering Guide for Blood and Bone Marrow
Shipping Instructions
Ambient specimens must arrive within 3 days (72 hours) of collection. Refrigerated specimens must arrive within 5 days of collection. Collect and package specimens 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 leukemia, B-cell acute lymphoblastic leukemia, or other BCR::ABL1-positive neoplasm
2. Specific fusion transcript if previously determined
3. Date of collection
4. Specimen source (blood or bone marrow)
ORDER QUESTIONS AND ANSWERS
| Question ID | Description | Answers |
|---|---|---|
| MP097 | Specimen Type |
Peripheral blood Bone marrow |
| MP098 | BCRABL Fusion |
E19A2 E13/E14A3 E1A3 E6A2 E19A3 E8A2 E12A2 E6A3 E8A3 E12A3 Unknown |
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 10 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
3. Label specimen as blood.
Specimen Type: Bone marrow
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 4 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
3. Label specimen as bone marrow.
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Whole blood: 8 mL; Bone marrow: 2 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Moderately or severely clotted | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Refrigerated (preferred) | 5 days | PURPLE OR PINK TOP/EDTA |
| Ambient | 72 hours | PURPLE OR PINK TOP/EDTA |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Quantitative monitoring of rare (non-p210 [non-E13/E14A2], non-p190 [non-E1A2]) BCR::ABL1 fusion transcript types occurring in myeloid neoplasms (eg, CML, myeloproliferative neoplasms) or B-cell acute lymphoblastic leukemias.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If a previous BCR::ABL1 rare fusion has not been identified by Mayo Clinic Laboratories (MCL), the qualitative, diagnostic assay for BCR::ABL1 will be performed at an additional charge to identify the fusion form.
If MCL has previously identified a p190 or p210 BCR::ABL1 fusion form, the appropriate quantitative testing will be performed and this test will be canceled.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The t(9;22)/BCR::ABL1 abnormality is associated with chronic myeloid leukemia (CML) and "Philadelphia-positive" acute lymphoblastic leukemia of B-cell lineage (Ph+ B-ALL). Very rarely has this abnormality also been identified in cases of acute myeloid leukemia and T-lymphoblastic leukemia/lymphoma. The fusion genes on the derivative chromosome 22q11 produce a chimeric BCR::ABL1 messenger RNA (mRNA) transcript and corresponding translated oncoprotein. Because of substantial breakpoint heterogeneity at the genomic level, BCR::ABL1 mRNA transcripts are utilized for sensitive detection and quantification by reverse transcription-polymerase chain reaction (RT-PCR) techniques. Common BCR::ABL1 fusion transcript types include the p210 (E13/E14A2) product, which is associated with nearly all cases of CML and some cases of B-ALL, and the p190 (E1A2) product, which is associated primarily with B-ALL. However, rare alternate breaks in both BCR and ABL1 are described in CML, B-ALL and other rare myeloid neoplasms, resulting in a variety of alternate BCR::ABL1 fusion transcript types. These include, but are not limited to, the p230 (E19A2) fusion, BCR::ABL1 fusions involving ABL1 A3, and other rare types (eg, E6A2, E8A2). These alternate BCR::ABL1 fusion transcript types can be identified with a comprehensive diagnostic RT-PCR screening assay (see test ID: BCRFX / BCR/ABL1 Qualitative Diagnostic Assay with Reflex to BCR/ABL1 p190 Quantitative Assay or BCR/ABL1 p210 Quantitative Assay, Varies or BADX / BCR/ABL1, Qualitative, Diagnostic Assay, Varies); however, rare transcript targets cannot be monitored using specific quantitative assays that typically target the more common p210 or p190 events. To meet this need, this test was developed using a droplet digital PCR methodology (ddPCR). If a rare BCR::ABL1 fusion type is identified by diagnostic RT-PCR screening, this test can subsequently be used to monitor patients with the specific rare fusion form. This assay provides quantitative evaluation of 10 alternate rare BCR::ABL1 fusion transcripts and better individualizes treatment response monitoring and clinical management for these patients.
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.
An interpretive report will be provided
Interpretation
Provides information to assist in interpretation of the test results
An interpretative report will be provided.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Although this quantitative droplet digital polymerase chain reaction (ddPCR) assay is comprehensive for detecting and quantifying 10 rare alternative (non-p210, non-p190) BCR::ABL1 fusions, there are additional extremely rare fusions (eg, complex translocation/rearrangement events) that may produce highly unusual BCR::ABL1 products that may not be detectable by this assay
The precision of this assay at very low BCR::ABL1 levels is less reliable, such that inter-run results can be slightly variable. Significant changes during monitoring should be verified by testing a subsequent specimen.
Results of this assay cannot be directly compared with data generated from other polymerase chain reaction (PCR) assays, including similar assays performed in other laboratories.
The results of this assay cannot be directly compared with BCR::ABL1 results obtained using fluorescence in situ hybridization (FISH) technology. FISH measures the presence of rearrangements in single cells, whereas this ddPCR-based assay measures relative expression of messenger RNA (mRNA) transcripts. FISH is generally not as sensitive as ddPCR.
Blood or bone marrow can be used for disease monitoring. While BCR::ABL1 levels in blood and bone marrow drawn at the same time are generally similar, bone marrow may provide a slight increase in detection sensitivity (0.5-1 log).
Specimens with delayed transport or nearing the stability window as stated may result in sufficient RNA degradation to produce false-negative results. Thus, specimens should be shipped as quickly as possible. Ambient specimens over 3 days old and refrigerated specimens over 5 days old at the time of receipt are not acceptable.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Burmeister T, Reinhardt R. A multiplex PCR for improved detection of typical and atypical BCR-ABL fusion transcripts. Leuk Res. 2008;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
4. Baccarani M, Castagnetti F, Gugliotta G, et al. The proportion of different BCR-ABL1 transcript types in chronic myeloid leukemia. An international overview. Leukemia. 2019;33(5):1173-1183. doi:10.1038/s41375-018-0341-4
5. Petiti J, Lo Iacono M, Dragani M, et al. Novel multiplex droplet digital PCR assays to monitor minimal residual disease in chronic myeloid leukemia patients showing atypical BCR-ABL1 transcripts. J Clin Med. 2020;9(5):1457. Published 2020 May 13. doi:10.3390/jcm9051457
6. Schafer V, White HE, Gerrard G, et al. Assessment of individual molecular response in chronic myeloid leukemia patients with atypical BCR-ABL1 fusion transcripts: recommendations by the EUTOS cooperative network. J Cancer Res Clin Oncol. 2021;147(10):3081-3089. doi:10.1007/s00432-021-03569-8
Method Description
Describes how the test is performed and provides a method-specific reference
RNA is extracted from the blood or bone marrow specimen and reverse-transcribed to complementary DNA (cDNA). The cDNA template is amplified in a droplet digital PCR (ddPCR) platform using primers and fluorescent probes targeting specific BCR and ABL1 exon regions. Results are expressed quantitatively as BCR::ABL1 target transcript copies to control gene (ABL1) transcript copies. The analytical sensitivity of the assay is 0.1% BCR::ABL1/ABL1.(Lee SJ, Lee JM, Ahn A, et al. Analytical performance evaluation of a digital real-time PCR for quantifying major BCR::ABL1 transcripts. J Clin Lab Anal. 2024;38(7):e25034. doi10.1002/jcla.25034; Kockerols C, Valk PJM, Hogenbirk P, Cornelissen JJ, Westerweel PE. BCR::ABL1 deep molecular response quantification and transcript type identification in chronic myeloid leukemia using a US Food and Drug Administration-approved droplet-based digital PCR assay. J Mol Diagn. 2025;27(2):109-118. doi:10.1016/j.jmoldx.2024.11.003)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Weekly
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
81208
BADX: 81206, 81207, 81208 (if appropriate)
BA190: 81207 (if appropriate)
BCRAB: 81206 (if appropriate)
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| BARQ | BCR::ABL1 Rare fusion Quant Monitor | 75892-0 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| MP097 | Specimen Type | 31208-2 |
| MP098 | BCRABL Fusion | 75892-0 |
| 623494 | Signing Pathologist | 18771-6 |
| 623479 | Interpretation | 69047-9 |