PML-RARA Transcript Detection for Acute Promyelocytic Leukemia, Quantitative

Whole blood, bone marrow, or cell pellet

3 to 5 mL whole blood or 1 to 2 mL bone marrow

3 mL whole blood or 1 mL bone marrow

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

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.

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.

TaqMan® quantitative polymerase chain reaction (Q-PCR)