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PML/RARA - t(15;17) RT-PCR - Quantitative

CPT 81315
Synonyms
  • 15;17 Translocation Detection by RT-PCR
  • APL

Test Details

Technology Used

Molecular

Turnaround Time

4 - 7 days

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.

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.

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)

Specimen Requirements

Information on collection, storage, and volume

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