BCR-ABL t(9;22) Translocation Assay by PCR
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You can download the Test Requisition form (106k) in portable document format (.pdf).
About the Disorder | Indications | Specimen l Testing Methodology l Sensitivity l Turnaround Time l Cost l CPT Codes l Shipping l Results l Contact Us
About the Disorder
BCR/ABL t(9;22)(q34.1;q11.2) translocations are associated with a variety of hematologic malignancies. Approximately 90-95% of patients with chronic myelogenous leukemia (CML) have this chromosomal rearrangement results in the formation of a fusion protein (p210) between the ABL gene on chromosome 9 and the BCR gene on chromosome 22. This same translocation also has been reported in some patients with ALL (acute lymphocytic leukemia), as well as in some patients with CNL (chronic neutrophilic leukemia). However, the breakpoints within the BCR and ABL genes for each of these leukemias are different. These different breakpoints result in the production of fusion protein products of different sizes. Molecular methods have been used to map the breakpoints from the cells of patients with this translocation. Typically, patients with CML will have breakpoints in either introns 13 (b2) or 14 (b3) of the BCR gene (major breakpoint cluster region). This is fused to the a2 exon of the ABL gene, creating either a b2a2 or b3a2 fusion product. The resultant protein produced is 210kD and is denoted p210. In patients with acute leukemia, they typically have a breakpoint in the minor breakpoint cluster region of the BCR gene resulting in the formation of the e1a2 fusion product of 190kD and is denoted p190. Patients with CNL typically have breakpoints within exon 19 (-breakpoint cluster region) of the BCR gene and a2 exon of the ABL gene, resulting in the formation of a fusion protein product of 230kD and is denoted p230. This assay detects and identifies the variety of p190,p210 and p230 type transcripts produced from all known BCR/ABL translocations.
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Indications
- Establishing an initial diagnosis of CML, ALL and CNL
- Detection of residual disease
- Monitoring disease recurrence
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Specimen
This procedure requires 1-3 ml of whole blood or bone marrow in purple top (EDTA) tube. Label tube with patient's name, birthdate, and date of collection. Sample must be received within 24-48 hours after collection.
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Testing Methodology
Total RNA was isolated from either whole blood or bone marrow. RNA was then used to generate cDNA by reverse transcriptase. Locus specific primers were used for polymerase chain reaction to amplify the BCR / ABL translocation region.
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Sensitivity
RT-PCR based test for BCR/ABL translocation is more sensitive than standard cytogenetic techniques or fluorescence in situ hybridization analyses in the detection of the t(9;22) when it is present in low levels. According to the manufacturer, this assay cannot reliably detect fewer than one cell containing a fusion transcript per 1,000,000 normal cells.
This methodology was designed to perform qualitative analysis of the t(9;22) translocation, and does not at the present time offer quantitative measurements. Further, this methodology cannot identify what, if any, additional chromosomal abnormalities may be present. Standard cytogenetic analyses would be required. In addition, this assay is sensitive to RNA degradation and to the quality and quantity of starting RNA template.
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Turnaround Time
6 business days
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Cost
Please call 866-450-4198 for current pricing.
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CPT Codes
88391, 83902, 83898(x9), 83894, 83912
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Shipping Instructions
Please enclose test requisition with sample. All information must be completed before sample can be processed. Place samples in Styrofoam mailer and ship at room temperature by overnight Federal Express to arrive Monday through Friday.
Ship to
Cytogenetics and Molecular Genetics Laboratories
3333 Burnet Avenue NRB 1042
Cincinnati, OH 45229
513-636-4474
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Results
Results will be reported to the referring physician or genetic counselor as specified on the requisition form.
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Contact Us
For additional inquiries, contact us:
Phone 513-636-4474
Fax 513-636-4373
Email moleculargenetics@cchmc.org
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