EndLeukemia RNA Translocation Assay Analysis (Sequencing)

Indication:  

The current World Health Organization classification of hematopoietic and lymphoid tissues (WHO Classification of Tumors, 4th ed., 2008) defines distinct subtypes of acute myeloid leukemia (AML) and B-lymphoblastic leukemia (previously B-ALL) based on the presence of recurrent reciprocal chromosomal translocations that produce fusion proteins associated with oncogenesis. For example, t(8;21)(q22;q22), inv(16)(p13.1q22), t(15;17)((q22;q12) in AML and t(12;21)(p13;q22) in B-lymphoblastic leukemia are generally associated with a favorable prognosis, while t(9;22)(q34;q11.2), in B-lymphoblastic leukemia portends a poor outcome. Therapeutic approaches may be tailored according to the presence or absence of one of these disease-associated translocations. For example, targeted therapies already exist for treatment of B-lymphoblastic leukemia with t (9;22) (imatinib) and AML with t(15;17) (all-trans retinoic acid or ATRA). Significantly, the minimum blast count requirement of 20% for the diagnosis of AML is waived when one of the predefined recurrent balanced translocations is present. A next generation sequencing (NGS)-based analysis was performed for the detection of fusion transcripts using custom RNA Fusion Panel (ArcherDX, Boulder, CO, USA). To sequence specific regions of interest, a custom panel was designed using the Anchored Multiplex PCR (AMP™)-based Target Enrichment System from Archer (Invitae). This panel screens for translocation and fusion partners from 108 genes. This assay will replace the currently used Acute Leukemia Translocation Panel Screen by Nanofluidic at the MDL.

Methodology:  

Anchored multiplex PCR technology was used to amplify fusion genes in RNA extracted from the sample in our CLIA-certified molecular diagnostics laboratory.

Test Parameters:

Clinical specimens were reviewed for following fusion transcripts.

Turnaround Time:

10 days

Sample Requirements:

10 ml peripheral blood (PB) in purple-top (lavender top) tube (EDTA Vacutainer), sent on wet ice

or

2-5 ml of bone marrow aspirate (BM), sent on wet ice

CPT Codes:

81206; 81207; 81315, 81401 (x5); 81479

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.