FISH ANALYSIS, CHROMOSOMES 4, 10 AND 17 ENUMERATION
Pseudonyms: Chromosome 4; Chromosome 10; Chromosome 17; Pediatric Acute Lymphocytic Leukemia; Pediatric ALL; B-cell ALL; ALL
TURNAROUND TIME: 7 to10 days
TESTING METHODOLOGY: Fluorescence in situ hybridization
- Collect: 2 mL bone marrow aspirate in sodium heparin (green) for children and adults; 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
Test Summary: Test can detect trisomies of chromosomes 4, 10 and 17 which can occur in acute lymphocytic leukemia in the pediatric age group
Methods: A triple-color FISH analysis performed on interphase cells using probes for the centromeres of chromosomes 4, 10 and 17; analysis of 200 interphase cells for diagnostic specimens and 500 interphase cells for minimal residual disease.
Interpretation: A positive result 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 ALL with a trisomy 4, 10 and/or 17. A negative result indicates no abnormality 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:
- Identifying patients with trisomies of chromosomes 4, 10 and/or 17
- Prognostic indicator for patients with B-cell ALL
- Monitoring the disease during treatment
- Detecting residual disease in patients with trisomies of chromosomes 4, 10 and/or 17