Description
Why It’s Done
The PML-RARα t(15;17) – FISH test is used for:
• Diagnosing acute promyelocytic leukemia (APL): The presence of the PML-RARα fusion gene confirms the diagnosis of APL, which has unique treatment and prognostic implications.
• Confirming the Philadelphia chromosome: This test helps confirm the specific genetic alteration in APL patients, which is caused by the translocation between chromosomes 15 and 17.
• Monitoring treatment response: After treatment with all-trans retinoic acid (ATRA) and chemotherapy, the test can detect whether the PML-RARα fusion gene is still present, indicating the persistence of leukemia or relapse.
• Assessing minimal residual disease (MRD): FISH is a highly sensitive test for detecting small amounts of leukemia cells that remain after treatment, even if they are undetectable with other methods.
• Monitoring remission: A negative result may indicate that the disease is in remission, but the test is often repeated to ensure no relapse occurs.
The PML-RARα fusion gene plays a crucial role in the pathogenesis of APL, and detecting it provides critical information for diagnosis, treatment, and monitoring of the disease
Preparation
• No special preparation is required for this test.
• Sample collection: The test typically requires a blood sample drawn from a vein in your arm, but in some cases, a bone marrow aspiration may be needed. Bone marrow is taken from the hip bone using a needle.
• Medication considerations: Inform your doctor about any medications you are taking, especially if you are undergoing ATRA treatment or any other therapies for leukemia, as these may affect test results.
• Timing: The test may be performed at different stages during treatment to monitor response or detect relapse.
