FLT3 ITD

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General Information

Lab Name
FLT3
Lab Code
FLT3
Epic Ordering
FLT3 ITD Mutation DNA Screen
Description

In our 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.
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 for detecting minimal residual disease in AML.

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. Approximately 20-30% of patients with acute myeloid leukemia have this mutation which has been associated with adverse prognosis.

Please complete a Hematopathology test request form found at Request Form

Analytical Sensitivity/Limit of Detection: signal ratio of 0.0035 ITD
Precision near LOD (CV): 5%

Synonyms
Acute Myeloid Leukemia, AML, FLT, FLT 3, FLT-3, FLT3-ITD, FLT3ITD, FMS-like tyrosine kinase 3, Internal Tandem Duplication, ITD
Components

Interpretation

Method

PCR amplification of the juxtamembrane portion of the FLT3 gene. Specific for internal tandem duplication mutations

Reference Range
See individual components
Ref. Range Notes

Not applicable

Guidelines

Ordering & Collection

Specimen Type
Blood, Bone Marrow, Fresh or Frozen Tissue, Fluids, Slides, Sorted cells
Collection

Preferred:

Blood: 6mL in Lavender Top (EDTA)

Bone Marrow: 1-2mL in Lavender Top (EDTA)

Tissue, Fluids or Sorted cells: Sterile container in RPMI

Slides: 10 unstained

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

Forms & Requisitions

Hematopathology Requisition

Handling Instructions
  • Deliver samples to Hematopathology as soon as possible.
  • If sample is older than 48 hours, please store at 2-6°C upon receipt and send refrigerated.
  • Samples stored at room temperature or refrigerated older than 7 days will be rejected.
  • Frozen samples should be shipped on dry ice.
Quantity
requested: Blood: 6mL EDTA/BMA: 1-2mL EDTA/Slides: 10 unstained
minimum: Blood: 1mL EDTA/ BMA: 0.5mL EDTA/ Slides: 5 slides

Processing

Processing

Send specimens to Hematopathology – Molecular department for processing.

The stability limit for Blood and Bone Marrow is 7 days, samples beyond this limit will be rejected.

Performance

LIS Dept Code
Molecular Hematopathology (MHP)
Performing Location(s)
Other Hematopathology, Molecular
206-606-7060

UW Hematopathology Laboratory, G7-800
Fred Hutchinson Cancer Center
825 Eastlake Avenue E.
Seattle, WA 98109

Hematopathology, Molecular hours:
7:00 am - 5:30 pm M-F
8:00 am - 4:30 pm Saturday, closed on Sunday, and with reduced staffing on major holidays

Frequency
Testing daily Monday - Saturday, results available within 24hrs. EVALHD reflexed or add-on orders may take up to 5 days to complete.
Available STAT?
No

Billing & Coding

CPT codes
81245
LOINC
47958-4
Interfaced Order Code
UOW958