FISH ANALYSIS, BCR/ABL1 TRANSLOCATION
Pseudonyms: t(9;22); 9;22 Translocation; BCR-ABL Translocation; BCR-ABL1 Translocation; ABL1-BCR Translocation; BCR-ABL Fusion; Chronic Myeloid Leukemia; CML; Acute Lymphocytic Leukemia; ALL; Acute Myeloid Leukemia; AML
TURNAROUND TIME: 7 to 10 days
TESTING METHODOLOGY: Fluorescence in situ hybridization
- Collect: 2 mL bone marrow aspirate in sodium heparin (green); 5 mL peripheral blood in sodium heparin (green) also acceptable.
- Minimum Collection: 1 mL bone marrow or 2 mL peripheral blood
- Transport: bone marrow or peripheral blood in sodium heparin (green) at 20-25°C; specimen should arrive in the laboratory within 24 hours of collection.
- Stability: Ambient: 24 hours; Refrigerated: 24 hours; Frozen: unacceptable
- Unacceptable Conditions: Frozen or clotted specimens; paraffin-embedded specimens; specimens; in anticoagulants other than sodium heparin.
A Cytogenetics/FISH Laboratory Test Requisition must accompany the specimen. Contact the Cytogenetics Laboratory at 918-502-1722 to obtain further information.
Test Summary: Test can detect the 9;22 translocation characteristic of CML and observed in some cases of ALL and AML; for diagnostic specimens, it is recommended that the test be performed with chromosome analysis
Methods: A dual-color dual-fusion FISH analysis performed on interphase cells using a probe for the BCR gene on chromosome 22q11.2 and a probe for the ABL1 gene on chromosome 9q34; analysis of 200 interphase cells; analysis of 500 interphase cells for minimal residual disease assessment
Interpretation: A positive result (BCR-ABL1 fusion) is reported when the percent of cells with an abnormality exceeds the normal reference range for the probes. The detection of an abnormal clone indicates a diagnosis of CML, ALL or AML with the 9;22 translocation. A negative result indicates no 9;22 translocation was observed but does not rule out the presence of a neoplastic disorder.
FDA Approval: This test is not approved by the FDA and it should used as an adjunct to other clinical and pathological information.
Indications for Use:
- Patients with CML; establishing the percentage of neoplastic cells at diagnosis
- Identifying patients with ALL or AML with a 9;22 translocation (BCR/ABL fusion)
- Monitoring the 9;22 translocation (BCR/ABL1 fusion) during treatment
- Detecting all forms of the 9;22 translocation (Ph chromosome) with various breakpoints