• Test Code:
  • Department:
  • Test Synonyms:
    15;17 translocation PCRAcute Promyelocytic Leukemia (APL) PCRM3 leukemia diagnosis and monitoring
  • CPT Code(s):

Acute promyelocytic leukemia (APL) accounts for 5% to 10% of acute myeloid leukemia, and generally has a good prognosis with current treatment protocols.   APL cells contain a characteristic translocation fusion gene comprised of the downstream sequences of the retinoic acid receptor alpha gene (RARA) fused to the promoter region and upstream sequences of the promyelocytic leukemia gene (PML).   The fusion gene is designated PML/RARA and is the consequence of the t(15;17)(q22;q12) translocation.   Messenger RNA (PML/RARA) produced from the fusion gene can be quantitatively detected using a PCR-based assay, and indicates the presence and relative amount of leukemia cells.   The PCR-based assay has greater sensitivity than standard methods such as morphology, karyotyping, or FISH.

Clinical Utility:
PML-RARA RNA expression in a patient with acute leukemia is indicative of a diagnosis of acute promyelocytic leukemia, for which specific targeted therapies may be indicated.  Serial quantitative PCR-based monitoring of APL patients during their course of treatment is important because patients who remain PCR-positive, become PCR-positive again following treatment, or having rising levels of PCR-detectable disease may relapse and could benefit from early intervention for residual/recurrent disease.


Quantitative real-time RT-PCR amplification of the PML-RARA fusion RNA and the ABL reference gene RNA. The final reported result is a ratio of PML-RARA to ABL.   The assay uses consensus PCR primers for PML and RARA that have been extensively validated by the Europe Against Cancer (EAC) consortium (Gabert 2003). There are three possible PML/RARA isoforms based on the locations of the translocation breakpoints in PML: long (L, or bcr1) at intron 6, variant (V, or bcr2) at exon 6, and short (S, or bcr3) at intron 3, involving 55%, 5%, and 40% of all t(15;17)-positive APL cases, respectively.  RARA breakpoints always occur in intron 2. This assay will detect all 3 isoforms of PML-RARA.

The limit of detection for this assay is 4 copies of PML-RARA per PCR reaction.

Specimen Requirements:

  • Blood or Bone Marrow: 5-10 mL  purple (EDTA) or yellow (ADC) tube (unspun)
  • If sample is to be shipped overnight, pour blood/bone marrow into RPMI media at a 1:1 ratio (1 mL of RPMI to 1 mL of blood/bone marrow) and mix thoroughly.
  • 2-5mL Blood or bone marrow in a Paxgene tube is also acceptable.
  • Deliver to lab at shipping address above within 24 hours of collection, if sample cannot arrive within 24 hours, refrigerate until sample can be transported, then transport on ice packs; do not freeze.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please provide detailed clinical information.

Test Performed (Days):


Turn Around Time:

7-10 days

Shipment Sensitivity Requirements:

  • Maintain specimen at refrigerator temperature - do not freeze. 
  • Blood must arrive in lab within 36 hours of collection. 
  • Ship via overnight express, using the cold pack provided to keep the specimen cool, not frozen. 
  • Contact Client Services at (855) 535-1522 for shipping kits and instructions.


Gabert, J. et al.  Standardization and quality control studies of ‘real-time’ quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia – A Europe Against Cancer Program.  Leukemia 2003, 17:2318-2357

Additional Info:

The Knight Cancer Institute at Oregon Health & Science University is a pioneer in the field of precision cancer medicine. The institute's director, Brian Druker, M.D., helped prove it was possible to shut down just the cells that enable cancer to grow. This breakthrough has made once-fatal forms of the disease manageable and transformed how cancer is treated. The OHSU Knight Cancer Institute is the only National Cancer Institute-designated Cancer Center between Sacramento and Seattle – an honor earned only by the nation's top cancer centers. It is headquarters for one of the National Cancer Institute's largest research collaboratives, SWOG, in addition to offering the latest treatments and technologies as well as hundreds of research studies and clinical trials.

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