Alternative Name
Philadelphia – like acute lymphoblastic leukemia (Ph-Like ALL)
Methodology
Molecular
Test Description

Detection of gene fusion transcripts in Acute Lymphoblastic Leukemia (ALL) from ribonucleic acid (RNA). RNA is isolated from bone marrow aspirates or peripheral blood and the cDNA sequence of targeted regions of the ABL1, ABL2, BCR, CRLF2, CSF1R, ETV6, IL2RB, IL3, JAK2, KMT2A, MEF2D, MLLT10, NUP98, PAX5, PDGFRB, PTK2B, RUNX1 ,TAL1, TCF3, TLX1, TLX3, TYK2, and ZNF384 genes is determined using next-generation sequencing (NGS) technology. This test will be performed at our Carlsbad location.

For comprehensive Ph-like ALL assessment consider ordering CRLF2 FISH & EPOR FISH concurrently. See also the ALL FISH PROFILE (Ph-Like)

Clinical Significance

Diagnostic Evaluation, Risk Assessment and Therapy Selection

Chromosome aberrations, in particular translocations and the corresponding gene fusions, have an important role in the initial steps of tumorigenesis.1 The identification of gene fusions in B Cell Acute Lymphoblastic Leukemia (B-ALL) are being recognized as an essential part of the diagnostic evaluation, risk assessment and optimal therapy selection.[2,3] Within B-ALL, three major groups of fusions/rearrangements have been identified.

  • BCR-ABL1 (aka Philadelphia chromosome “Ph+”)[1-3]
  • Ph-Like (WHO 2016 Entity)[1-5]
    - ABL-class fusions: BCR, ABL1, ABL2, CSFR1, PDGFR-β
    - EPOR or JAK2 fusions
    - Cytokine receptor-like factor 2 (CRLF2) fusions
  • Other Ph-Like fusions [6,7]
    - B ALL: DUX4, ETV6, IR2RB, KMT2A(MLL), MEF2D, MLLT10, NUP98, PAX5, PTK2B, RUNX1, TCF3, TSLP, TYK2, ZNF384
    - T ALL: TAL1, TLX1, TLX3
Specimen Requirements

Preferred:

  • Peripheral blood: 2-3 mL in EDTA (purple-top) tube
  • Bone marrow: 2-3 mL in EDTA (purple-top) tube

Acceptable:

  • Peripheral blood: 2-3 mL in sodium heparin (green-top) tube
  • Bone marrow: 2-3 mL in in sodium heparin (green-top) tube
  • Fixed cell pellets (3:1 methanol and acetic acid fixative)
Storage and Transportation

Use cold pack for transport. Make sure cold pack is not in direct contact with specimen. DO NOT FREEZE.

CPT Code(s)*
81450x1, add 88377x2 if FISH is ordered.
Turnaround Time

15 days (NGS), 6 days (FISH)

References
  1. Mitelman F, et al. The impact of translocations and gene fusions on cancer causation. Nature Reviews Cancer. 7, 233-245 | doi:10.1038/nrc2091.
  2. NCCN Practice Guidelines in Oncology, Acute Lymphoblastic Leukemia--Version 1.2017. Accessed on 8/28/2017.
  3. Roberts KG, et al. Targetable Kinase-Activating Lesions in Ph-like Acute Lymphoblastic Leukemia. N Engl J Med. 2014;371:1005-15.
  4. Yokota T, et al. Genetic abnormalities associated with acute lymphoblastic leukemia. Cancer Sci. 107 (2016) 721–725.
  5. Arber, DA. et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016; 127(20):2391-2405.
  6. Roberts, KG, et al. High Frequency and Poor Outcome of Philadelphia Chromosome–Like Acute Lymphoblastic Leukemia in Adults. Journal of Clinical Oncology. 35:394-401.
  7. Iacobucci I, et al. Genetic Basis of Acute Lymphoblastic Leukemia. J Clin Oncol. 35:975-983.
Level of Service
Global

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.