Test BackgroundFISH involves the application of fluorescent DNA probes specific to genes or genetic regions of interest that highlight abnormalities involving these regions.
Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion supports the diagnosis of chronic eosinophilic leukemia (CEL) in patients with chronic hypereosinophilia. This abnormality is not detectable by conventional cytogenetic analysis. In cases where the diagnosis is conventional cytogenetic analysis may also be performed.
Sample Required See notes section
Sample Volume Samples would not be rejected on the basis of small volume, however, 5 mL is ideal.
Turnaround Time HES referrals are treated as routine; 95% should be reported within 21 calendar days according to national guidelines. Please note however that the average turn around for this category in our laboratory is approximately 4 days.
Bone marrow in cytogenetic transport medium (preferred) or lithium heparin is usually the sample of choice. EDTA samples are only suitable in cases requiring FISH only. If in doubt please use lithium heparin. Samples which are non-sterile, clotted or collected in sodium citrate, fixative or saline are not suitable.
To ensure appropriate analysis and interpretation it is important to provide clear and concise clinical information.