Background:
Myelodysplastic syndrome (MDS) describes a group of clonal haematopoietic disorders resulting in ineffective production of one or more of the myeloid cell lineages; risk for transformation to AML is increased. MDS may occur de novo or may arise as a secondary malignancy associated with treatment. This FISH panel is designed to detect the most common, and/or prognostically-significant abnormalities in MDS (Swerdlow et al. 2008). FISH studies are useful adjuncts to complete chromosome studies, particularly when following an abnormal clone, assessing relapse and progression, or when material is inadequate for chromosomal analysis. Please note: routine chromosome analysis will detect many of the changes that are assessed by FISH, below; thus, chromosome analysis is recommended either as an initial test for MDS or at least in conjunction with FISH.
The MDS FISH panel includes:
1. EGR1/5q33/5p15 probe set, to detect monosomy 5 and 5q deletion.
2. D7S522/CEP 7 probe set, to detect monosomy 7 and 7q deletion.
3. CEP 8, to detect trisomy 8.
4. D20S108/20qtel probe set, to detect monosomy 20 and 20q deletion.
5. MLL break-apart probe, to detect MLL (11q23.1-q23.3) rearrangement.
6. TP53/NF1 locus-specific probe, to detect monosomy 17 and deletion of TP53 (17p13.1).
7. GATA2/MECOM dual fusion probe, to detect t(3;3) and inverted 3q.
Note: Reflex testing may include MLLT3/MLL t(9;11), MLL/MLLT1 t(11;19), and/or AFF1 break-apart when relevant. Additional charges apply. Interphase FISH analysis is not intended to stand alone, but rather to provide supplemental information to routine cytogenetic studies.
Methodology:
Slides are prepared per standard protocols and 100-200 interphase cells are scored per probe.
*Please note: it is our laboratory policy to analyze at least one metaphase cell from every hybridization if possible, including both normal and abnormal cells if both exist.
Specimen Requirements:
The MDS FISH Panel can be performed on the following specimen types. After collection, keep at room temperature until shipping. Contact Client Services at (855) 535-1522 for shipping kits and instructions.
Bone Marrow:
- Shortly before aspiration add 0.2 cc of Sodium Heparin (1,000 units/ml) to tube of transport medium (please contact lab to arrange for transport medium to be sent). Add at least 1 cc of bone marrow aspirate to the tube and suspend well. Allow no clots to form.
Peripheral blood:
- May be used if bone marrow is inaspirable and blasts (.5%) are present. Send in Sodium Heparin tube.
Bone core biopsy: May also provide cells in cases where marrow is severely packed. Send in transport medium with Sodium Heparin.
FFPE Slides: Specimen Requirements:**
- If sending slides, please include H&E stained slide cut from same block
- Preferred slice thickness is 4-5 microns on positively charged slides.
- Please submit 6-12 slides. Store at room temperature.
- Contact Client Services at (855) 535-1522 for shipping supplies and instructions
- **Note: cutoffs for copy number probes are insensitive to low-level mosaicism
A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please provide detailed clinical information.
Test Performed (Days):
Mon - Sat
Turn Around Time:
5 – 10 days Contact Lab at 855-KDL-1LAB (535-1522). Time varies depending on number of tests performed per specimen.
Shipment Sensitivity Requirements:
- Please contact Client Services at (855) 535-1522 for shipping kits and instructions.
- Do not use the cold pack provided in the KDL shipping kit.
- Ship the specimen overnight express, using the FedEx priority overnight label provided.
- The specimen must arrive at the lab no more than 24 hours after collection.
References:
Swerdlow et al. (Eds.): WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues. IARC: Lyon 2008
Additional Info: