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HelpTest Code LAB3049 FLT3 ITD
Clinical System Name
FLT3 ITD
Synonyms
FLT3 Internal Tandem Duplication
Description
Internal tandem duplications (ITD) in exons 14 and 15 of the FLT3 gene lead to constituitive activation of the FLT3 receptor tyrosine kinase protein. FLT3 ITDs frequently occur in AML and this test should be performed for all AML patients at diagnosis. FLT3 mutations tend to be unstable and can change with relapse, so this assay is not a reliable method fo detecting minimal residual disease in AML.
Sample Requirements
Preferred:
Blood: 6mL in Lavender Top (EDTA); minimum 1mL EDTA
Bone Marrow: 1-2mL in Lavender Top (EDTA), minimum 0.5mL EDTA
Tissue, Fluids or Sorted cells: Sterile container in RPMI
Slides: 10 unstained, minimum 5 slides (Requires consult from pathology)
Accepted:
Green Tops (Heparin), while green tops are accepted for testing, there is documentation that heparin can interfere with some PCR assays.
Extracted DNA will only be accepted from CLIA certified laboratories.
Tissue from stained or cover-slipped slides
Unacceptable:
Specimens received beyond stability limit.
Specimens with low volume or inadequate WBC
Formalin-fixed paraffin embedded tissue (FFPE/PET)
Decalcified or unacceptable fixatives
Note: Record specimen type and date/time of collection on label. While green top tubes are accepted for testing, there is documentation that heparin can interfere with some PCR assays.
For more detailed info for bone marrow testing, see separate Bone Marrow Aspirate listing .
Processing Instructions
Reject due to:
Spin: N
Aliquot: N
Temp: 2 - 4 C
Storage location: Place bone marrow sample in the Send Outs rack in the CPA fridge.
Off-site collection: Contact UW Hematopathology at (206) 288-7060 for instructions.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Room temp | 24 h | |
| Refrigerated | 72 h | |
| Frozen | Unacceptable |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | M, W, and F | 2 w |
Performing Laboratory
University of Washington
Dept of Laboratory Medicine
UW Molecular Hematopathology Lab
825 Eastlake Ave E, Room G7-800
Seattle, WA 98195
Phone Number: (206) 288-7060
Department
Department: Send Outs/Genetic
Phone Number: (206) 987-2563
Reference Range
None specified.
Methodology
Method: PCR amplification of the juxtamembrane portion of the FLT3 gene. Specific for internal tandem duplication mutations
Analytical Volume: 6.0 mL Whole Blood; 1.0 mL Bone Marrow
Limitations: This test is not intended to be used for minimal residual disease (MRD)
Special Instructions
Place test orders in EMR.
For bone marrow, use order "HemOnc Bone Marrow Requisition" or "Hematopoietic Transplant Marrow Requisition", as appropriate.
Clinical Utility
Approximately 20-30% of patients with acute myeloid leukemia have this mutation which has been associated with adverse prognosis. In this PCR assay, purified genomic DNA is amplified using flanking primers and then size fractionated by capillary electrophoresis. For positive patients, a FLT3 ITD to wild type allelic ratio is calculated and reported.
Send Out Instructions
| Reference Test Name: | FLT3 ITD |
| Reference Test Number: | FLT3 |
| Instructions: | Send Monday through Friday with the UW Courier. |