Test Code LAB7547 BCR::ABL1 t(9;22) minor (p190), Quantitative
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Methodology
The quantitative BCR::ABL1 assay specific for the p190 isoform is performed on the GeneXpert (Cepheid) platform. RNA is extracted, converted to cDNA, and BCR::ABL1 and ABL1 cDNA targets are quantified by real-time PCR amplification.
The analytical sensitivity of this assay is 0.006% p190 BCR::ABL1. Due to assay non-linearity for % p190 values >10% or <0.02%, if p190 is detected, those values will be reported as "Positive, >10%" or “Positive, below the lower level of quantification”, respectively.
Note: Prior evidence of BCR::ABL1 fusion by FISH or PCR is required for testing. This test is not considered diagnostic and should only be used for monitoring patients known to have the p190 BCR::ABL1 fusion isoform or to identify the isoform following detection of BCR::ABL1 by FISH.
Specimen Requirements
Call Barnes-Jewish Hospital Molecular Diagnostics Laboratory at 314-454-8685 for collection instructions.
Forms: Molecular Diagnostics Requisition
Specimen Type: Whole blood
Container/Tube: EDTA (lavender or pink) vacutainer tube
Specimen Volume: 3-4 ml
Specimen Minimum Volume: 2 mL
Collection Instructions: Invert several times to mix blood. Clotted blood is not acceptable.
Additional Information:
1. RNA is extremely liable and subject to degradation, delay in shipping may compromise RNA viability and results.
2. Specimen cannot be frozen.
Specimen Type: Bone marrow
Container/Tube: EDTA (lavender or pink) vacutainer tube
Specimen Volume: 1-2 mL
Specimen Minimum Volume: 0.5 mL
Collection Instructions: Invert several times to mix bone marrow. Clotted sample is not acceptable.
Additional Information:
1. RNA is extremely liable and subject to degradation, delay in shipping may compromise RNA viability and results.
2. Specimen cannot be frozen.
Day(s) Test Set Up
Monday through Friday
Cut-off time: 1500 on days test performed
Turnaround Time:
STAT: not available
Routine: 1 to 4 business days
Test Classification and CPT Coding
81207
Reference Values
An interpretive report will be provided.
Literature Reference:
Faderl S. et al. Clinical Significance of Cytogenic Abnormalities in Adult Acute Lymphoblastic Leukemia. Blood. 1998; 91 (11): 3995-4019.
Dushyant, V. et al. Chronic myeloid leukemia (CML) with p190 BCR-ABL: analysis and characteristics, outcomes and prognostic significance. Blood. 2009; 114: 2232-2235.
Kurzrock, R. et al. The Molecular Genetics of Philadelphia Chromosome-Positive Leukemias. Mechanisms of Disease. NEJM 1998; 990-998.
Chan, L.C. et al. A novel abl protein expressed in Philadelphia chromosome positive acute lymphoblastic leukemia. Nature. 1987; 325: 635-637.
Deininger M.W. The molecular biology of chronic myeloid leukemia. Blood. 2000; 96: 3343-3356.
Cruz, S.S.D. et al. Chronic Myelogenous Leukemia with Double Philadelphia Chromosome and Coexpressio n of p210 and p190 Fusion Transcripts. Genes. 2022. 13:580..
Sample Transport Temperature
Samples must be sent at ambient or refrigerated temperatures. Do not send frozen.
Additional Information
For BJH Laboratory Use Only
Analyte Stability:
Blood and bone marrow are stable up to 4 hours at ambient temperature and up to 120 hours refrigerated.