| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
BCR-ABL1 Gene Rearrangement, Quantitative, PCR
Test Code91065
CPT Codes
⁠⁠⁠⁠⁠⁠⁠If P190 transcript expression was previously documented, only P190 BCR-ABL1 will be performed (CPT code(s): 81207).<br>If P210 transcript expression was previously documented, only P210 BCR-ABL1 will be performed (CPT code(s): 81206).<br>If no prior positive is documented, P190 BCR-ABL1 and P210 BCR-ABL1 will be performed (CPT code(s): 81206, 81207).
Preferred Specimen
4 mL whole blood or 3 mL bone marrow collected in an EDTA (lavender-top) tube
Minimum Volume
3 mL whole blood
1 mL bone marrow
20 uL extracted RNA
1 mL bone marrow
20 uL extracted RNA
Other Acceptable Specimens
Whole blood or bone marrow collected in sodium heparin (green-top) tube • 50 uL of 10 ng/uL extracted RNA submitted in a microcentrifuge tube
Instructions
Do not reject specimens, send to laboratory for screening.
Collect 4 mL of whole blood or 3 mL bone marrow in an EDTA (lavender-top) tube. Whole blood or bone marrow is shipped at room temperature or refrigerated (cold packs). Do not freeze whole blood or bone marrow.
After collection of the sample, draw date and time, as well as sample type, must be written on the tube and included as requested information. If the stability of the sample cannot be determined, delay in result or cancellation of test may occur. Clotted specimens are unacceptable.
Only accept extracted RNA when extraction or isolation is performed in an appropriately qualified laboratory such as a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/ or CMS.
Collect 4 mL of whole blood or 3 mL bone marrow in an EDTA (lavender-top) tube. Whole blood or bone marrow is shipped at room temperature or refrigerated (cold packs). Do not freeze whole blood or bone marrow.
After collection of the sample, draw date and time, as well as sample type, must be written on the tube and included as requested information. If the stability of the sample cannot be determined, delay in result or cancellation of test may occur. Clotted specimens are unacceptable.
Only accept extracted RNA when extraction or isolation is performed in an appropriately qualified laboratory such as a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/ or CMS.
Transport Temperature
Room temperature
Specimen Stability
Whole blood & bone marrow:
Room temperature: 5 days
Refrigerated: 5 days
Frozen: Unacceptable
Extracted RNA:
Room temperature: Unacceptable
Refrigerated: Preferred
Frozen: Acceptable
Methodology
Quantitative Real-Time Polymerase Chain Reaction (PCR)
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
A.M. Sets up 6 days a week.
Clinical Significance
The Philadelphia Chromosome (Ph) is a translocation between chromosome 9 and 22 t(9; 22) (q34; Q11) that is found in more than 90-95% of chronic myeloid leukemia (CML), and in 20-25% of adult and 2-10% of childhood acute lymphoblastic leukemia (ALL). In CML, most translocations fall in the major breakpoint cluster region of the BCR gene, and result in either of two BCR-ABL1 mRNA molecules having an e13a2 junction (fusion of BCR exon 13 with ABL1 exon 2) or an e14a2 junction (fusion of BCR exon 14 with ABL1 exon 2) that encodes the p210 BCR-ABL1 fusion protein. In all, about two thirds of the BCR breakpoints fall in the minor breakpoint cluster region of the BCR gene, and the hybrid BCR-ABL1 transcript contains an e1a2 junction (fusion of BCR exon1 with AB11 exon2) which is translated as a p190 BCR-ABL1 fusion protein. Quantitative measurement of the changes of BCR-AB1 expression levels over time is important to monitor disease progression and response to targeted therapies. This test is a reverse-transcription pcr-based quantitative assay which detects these two major BCR-AB11 mRNA transcripts produced by the t(9; 22) chromosomal translocation (p210 and p190). BCR-ABL1 transcript levels are expressed as a percent ratio of BCR-ABL1 to the normalizing ABL1 transcript levels. For the p210 transcript associated with CML, quantitation is further adjusted to the international scale (IS) to allow comparison with other IS-compliant BCR-ABL1 assays. Optimal therapy in CML is associated with transcript levels below the major molecular response (MMR) milestone indicated by a BCR-ABL1/ABL1% (is) below 0.1.
