Hematologic Diseases

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.

disease state indication(s)
Acute Lymphoblastic Leukemia (ALL)

clinical use
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

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.

methodology/product platform
Next-Generation Sequencing (NGS)

specimen type and 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)

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

turnaround time
Global (TC & PC): 14 days

cpt code(s)
81450 (x1)

medicare moldx cpt code
Not applicable

regulatory classification
Laboratory developed test (LDT)

ordering option
Global (TC & PC)