FLT3 ITD

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%

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

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.