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Clinical System Name



FLT3 Internal Tandem Duplication


A mutation in the FLT3 gene on chromosome 13 results from internal tandem duplications (ITD) in exons 14 and 15 of the juxtamembrane portion of the gene and causes activation of the FLT3 protein.  This test should be performed on 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

Specimen:  Whole Blood or Bone Marrow

Container(s):  Lavender/EDTA (preferred) or Dk Green/Sodium Heparin

Preferred Vol:  6 mL blood; 1-2 mL bone marrow

Minimum Vol:  no micro collection


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.


Specimen Type Temperature Time
  Room temp 1 day
  Refrigerated 4 days
  Frozen NO



STAT Performed TAT
N M - F 2 weeks from day after receipt


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:  Send Outs


Phone Number:  (206) 987-2563


Reference Range

none specified


Method:  PCR amplification of the juxtamembrane portion of the FLT3 gene

Analytical Volume: 1.0 mL bone marrow

Limitations:  None specified

CPT Codes



Place test orders in CIS.

For bone marrow, use CIS 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 by PCR
Reference Test Number: None specified
Instructions: Send on next available shuttle to UW Molecular Hematopathology 825 Eastlake Ave. If provider desires for same day set up sample must reach UW Hematopath by 830 am.