PML-RARA Transcript Detection for Acute Promyelocytic Leukemia, Quantitative
CPT:
81315
Synonyms
- 15;17 Translocation Detection by RT-PCR
- APL
Special Instructions
Specimens must arrive in laboratory within 48 hours of collection. Indicate date and time of collection on test request form. Please direct any questions regarding this test to customer service at 800-345-4363.
Expected Turnaround Time
4 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Specimen Requirements
Specimen
Whole blood, bone marrow, or cell pellet
Volume
3 to 5 mL whole blood or 1 to 2 mL bone marrow
Minimum Volume
3 mL whole blood or 1 mL bone marrow
Container
Lavender-top (EDTA) tube, green-top (sodium heparin) tube, yellow-top (ACD-A) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube
Storage Instructions
Ship at room temperature. If specimen is to be stored prior to shipment, store at 2°C to 8°C.
Causes for Rejection
Specimen does not meet collection criteria; frozen whole blood, marrow, or cell pellet; leaking tube; clotted blood or marrow; grossly hemolyzed specimen or otherwise visibly degraded; contamination by another specimen; specimens containing suspicious foreign material
Test Details
Use
The translocation t(15;17) (q22;q21) is the prototype rearrangement found in the vast majority of acute promyelocytic leukemia (APL), being found in >95% of APL cases. In this chromosomal rearrangement, the retinoic acid receptor (RARA) gene on chromosome 17 is fused with the PML gene on chromosome 15. There are three common breakpoints within the PML gene, bcr1 (intron 6), bcr2 (exon 6), and bcr3 (intron 3). All breakpoints fuse a portion of the PML gene to a consistent breakpoint region within the RARA gene. This assay will detect the PML-RARA transcripts associated with the bcr1, bcr2, and bcr3 breakpoints using real-time RT-PCR in order to assist in the diagnosis and monitoring of APL. The results are reported as a normalized ratio of %PML-RARA copies/ABL1 copies. In vitro studies have indicated that this assay has an analytical sensitivity that allows for the detection of 0.001% PML-RARA/ABL1.
Limitations
Absence of a detectable rearrangement does not exclude the possibility of the presence of low levels of transcript below the level of detection of this assay, or a rearrangement outside the analyzed breakpoint regions. Fluorescence in situ hybridization (FISH) is recommended to detect rare variant breakpoints or other translocations associated with APL.
This test was developed and its performance characteristic determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
TaqMan® quantitative polymerase chain reaction (Q-PCR)
References
Lo Coco F, Diverio D, Falini B, et al. Genetic diagnosis and molecular monitoring in the management of acute promyelocytic leukemia. Blood. 1999; 94(1):12-22.10381493
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 510840 | APL(PML-RARA) Quant | 510841 | PML bcr1-RARA transcript | % | 72216-5 | |
| 510840 | APL(PML-RARA) Quant | 510842 | PML bcr2-RARA transcript | % | 72215-7 | |
| 510840 | APL(PML-RARA) Quant | 510846 | PML bcr3-RARA transcript | % | 72214-0 | |
| 510840 | APL(PML-RARA) Quant | 510843 | Interpretation: | 62365-2 | ||
| 510840 | APL(PML-RARA) Quant | 510859 | Background: | 77202-0 | ||
| 510840 | APL(PML-RARA) Quant | 510845 | Methodology: | 49549-9 | ||
| 510840 | APL(PML-RARA) Quant | 510847 | References: | N/A | ||
| 510840 | APL(PML-RARA) Quant | 510848 | Director Review: | 72486-4 | ||
| 510840 | APL(PML-RARA) Quant | 511958 | 80563-0 |
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