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PML-RARA t(15;17) short and long form - Quantitative by Polymerase Chain Reaction

P PML-RARA

Test Synonym:

P PML-RARA l/s (long and short fusions), quantitative, APL (AML-M3)

CPT Code:

83891 – Molecular isolation
83892 – Enzymatic digestion
83902 – Reverse transcriptase
83894 – Separation by gel electrophoresis
83896 x4 – Nucleic acid probe each
83898 x4 – Amplification of patient nucleic acid, per primer pair

83912-26 – Interpretation and report

Turnaround Time:

3-5 days; specimens accepted Monday through 1:00PM on Friday. Assay run once/week

Methodology:

Quantitative reverse transcriptase Polymerase Chain Reaction (qRT-PCR)

Specimen Requirements:

pdf icon Technical Bulletin qPCR

  • 10.0ml (min. 9.0ml) peripheral blood in EDTA
  • 5.0ml (min. 2.5ml) bone marrow in EDTA

    • Causes for Rejection:

  • Specimen >48 hrs. old
  • Specimen clotted
  • Stored or shipped at incorrect temperature
  • Incorrect anticoagulant
  • Insufficient specimen volume

    • Specimen Stability:

  • Stable at 2-8°C
  • Specimen must be received by MPLN within 48 hrs. of collection

    • Storage and Handling:

    Ship peripheral blood and bone marrow at ambient temperature (do not ship on ice or cold pack; do not ship to arrive after 1:00PM on Friday, or on weekends)

    Reference Range:

    Positive: PML-RARA fusion detected and quantified
    Negative:  PML-RARA fusion not detected (<0.002% PML-RARA/ABL)

    Indication:

    Acute promyelocytic leukemia (AML-M3) is characterized by chromosomal rearrangements of 17q21.  Approximately 96% of patients carry the t(15;17) translocation which can be detected by conventional karyotyping and/or FISH analysis on interphase or metaphase cells.  This translocation fuses the PML gene to the retinoic acid receptor alpha (RARA) gene and, depending upon the position of the break-point in the PML gene, results in the formation of three differently spliced fusion types [PML-RARA long (L)], [PML-RARA short (S)], and [PML-RARA variable (V)], found in 55%, 35%, and 10% of t(15;17) positive patients respectively.  Detection of the PML-RARA fusion gene by quantitative reverse transcriptase PCR (qRT-PCR) is routinely utilized as a complement to cytogenetic / FISH studies, for diagnosis and for monitoring of minimal residual disease (MRD), with particular emphasis on the early identification of patients who are at high risk of relapse after treatment with all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy.

    This test will detect the presence of both the PML-RARA long and short fusion forms, accounting for ~90% of t(15;17) positive patients.

    References:

    1. Reiter et al. (2004). Pathogenesis, diagnosis and monitoring of residual disease in acute promyelocytic leukaemia. Acta Haematologica  112:55
    2. Mistry et al. (2003). The molecular pathogenesis of acute promyelocytic leukaemia: implications for the clinical management of the disease. Blood Reviews  17:71
    3. Gallagher et al. (1997). Association of PML-RARα fusion mRNA type with pretreatment hematologic characteristics but not treatment outcome in acute promyelocytic leukemia: an intergroup molecular study. Blood  90:1656