Interphase Fluorescence In Situ Hybridization (FISH)
The presence of certain clonal abnormalities in the bone marrow of cytopenic patients strongly supports the diagnosis of MDS, even in cases with absence of diagnostic morphology findings. The MDS FISH Panel is used to ascertain common recurrent genetic abnormalities that are frequently observed in MDS. Multiple studies have demonstrated the added value of MDS FISH on bone marrow is extremely low when a satisfactory karyotype is obtained (20 interpretable metaphases). MDS FISH panel is recommended to be performed post hoc in the event of an unsatisfactory karyotype. The MDS FISH panel includes tests for the following chromosome abnormalities using probes for the specific gene locus: EGR1/D5S23 probe set to detect monosomy 5 and 5q deletion, D7S486/CEP7 probe set to detect monosomy 7 and 7q deletion, and 20q12/20qter/8cen probe set to detect trisomy 8 and/or deletion of 20q.
1. American Society for Clinical Pathology, Choose Wisely. https://www.choosingwisely.org/clinician-lists/american-society-clinica…
2. Bunting CT, Senior T, Susson Y, Rivera A, Saxe D, Bunting ST. Utility of Fluorescence In Situ Hybridization Panel for Myelodysplastic Syndrome in Evaluation of Cytopenia in a Pediatric Hospital: A 5-Year Retrospective Review and Utilization Management. Lab Med. 2017;48(3):266-270. PMID: 28934515
3. Yang W, Stotler B, Sevilla DW, Emmons FN, Murty VV, Alobeid B, Bhagat G. FISH analysis in addition to G-band karyotyping: utility in evaluation of myelodysplastic syndromes? Leuk Res. 2010;34(4):420-5. PMID: 19800120
4. Coleman JF, Theil KS, Tubbs RR, Cook JR. Diagnostic yield of bone marrow and peripheral blood FISH panel testing in clinically suspected myelodysplastic syndromes and/or acute myeloid leukemia: a prospective analysis of 433 cases. Am J Clin Pathol. 2011;135(6):915-20.PMID: 21571964
Interpretive report provided.
*Reference ranges may change over time. Please refer to the original patient report when evaluating results.
5 days after chromosome analysis is completed with an inadequate result.
- Myelodysplastic Syndrome (MDS), FISH
- FISH for Myelodysplastic Syndrome
Collect bone marrow using aseptic technique. Place 1 - 3 mL bone marrow aspirate in a green top (sodium heparin) tube. Invert the tube several times to prevent clotting. Send at room temperature as soon as possible. Do not allow specimen to overheat or freeze. Clotted samples, samples containing <5 million dividing cells, and samples that are greater than 24 hours old are suboptimal.
Formalin fixed, frozen or grossly contaminated specimens.
This FISH testing is a reflex test used when standard chromosome analysis is inadequate or has less than 20 normal metaphase cells.