FLT3 ITD

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

Code	Name
FLTSD	FLT3 Specimen Description
FLTRES	FLT3 Result
FLTSIZ	FLT3 ITD Length
FLTARO	FLT3 ITD to Normal Ratio
FLTINT	FLT3 Interpretation
FLTMTH	FLT3 Method and Information
FLTGRN	FLT3 Case Number

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

Molecular Testing for Hematopoietic Disorders

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?

Billing & Coding

CPT codes: 81245
LOINC: 47958-4
Interfaced Order Code: UOW958