ACUTE MYELOID LEUKEMIA
Fluorescent in situ hybridization (FISH) test is offered to identify trisomy 8, the most common numerical aberration in Acute Myeloid Leukemia, and the translocation, t(15;17)(q22;q21.1), associated AML, subtype M3. Call the laboratory for the availability of FISH tests for other trisomies, inversions, and translocations that are being added.
REASONS FOR REFERRAL
· Individuals suspected of having a hematologic malignancy, specifically AML, in lieu of conventional chromosome analysis or when no metaphases are obtained for chromosome analysis
· Testing for residual disease or treatment response in a patient with a known trisomy 8, t(15;17)(q22;q21.1), or other aberrations
· Bone marrow or peripheral blood are cultured without mitogen for 24 to 48 hours.
· FISH is the application of fluorescently labeled DNA probes to metaphase chromosomes or interphase nuclei for the detection of abnormalities. The assay for trisomy 8 uses the centromeric probe for chromosome 8 and the assay for the 15;17 translocation uses dual probes that span the breakpoint regions on chromosomes 15q22 and 17q21.1. Dual fusion signals are produced when the translocation occurs. Analysis is based on fluorescent signals present in 200 or more interphase nuclei.
· Minimum of 0.5 mL of bone marrow in sodium heparin or bone marrow transport media (provided upon request). This is the preferred specimen.
· 5-10 mL peripheral blood in sodium heparin only if white blood count higher than 10,000 and at least 10% immature myeloid cells.
· A complete Cytogenetics/Biochemical Genetics Requisition Form must accompany the specimen.
· Transport in ambient temperature. Specimen cannot be frozen.
TURNAROUND TIME: 7 days
CPT CODES: 88271, 88275, 88237, 88291