FLT3 Mutation Analysis

Test Code
39786


CPT Codes
81245, 81246

Preferred Specimen
5 mL whole blood or 3 mL bone marrow aspirate collected in an EDTA (lavender-top) tube or sodium heparin (green-top) tube


Minimum Volume
3 mL whole blood • 1 mL bone marrow aspirate • 25 uL Extracted Genomic DNA


Other Acceptable Specimens
50 uL Extracted Genomic DNA (from CLIA lab only) in a sterile leak-proof container • Cell pellet


Instructions
Do Not Reject. Send to lab for evaluation. Submission of whole blood (preferred): Follow standard whole blood collection procedure. Collect 3-5 mL whole blood samples in EDTA tube. Blood samples are shipped at room temperature or 4°C. Do not freeze whole blood. Record the draw time and date on the tube. Ship immediately to maintain sample stability.

Cell Pellet Instructions: This assay is also designed for the remnant cell pellet from Cytogenetics. The cell pellet usually fixed should be transported refrigerated to the laboratory as soon as possible. Please provide a copy of the Cytogenetics report.


Transport Temperature
Refrigerated (cold packs)


Specimen Stability

Whole blood and bone marrow
Room temperature: 7 days
Refrigerated: 7 days
Frozen: Unacceptable

Extracted Genomic DNA
Room temperature: Unacceptable
Refrigerate: 5 years 
Frozen: 5 years


Cell Pellet
Room temperature: Unacceptable
Refrigerated: 30 days
Frozen: 30 days



Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Do Not Reject



Methodology
Polymerase Chain Reaction (PCR)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Daily; Report available: 3 days



Report Available
Reports in 3 days.


Clinical Significance
FLT3 (fms-like tyrosine kinase-3) is a receptor tyrosine kinase that plays a significant role in cell survival, proliferation, and differentiation of hematopoietic stem cells. Mutations of FLT3 represent one of the most frequent molecular mutations in acute myeloid leukemia (AML) and are reported in 25-30% of the patients. These mutations predominantly include FLT3 internal tandem duplications (ITD) which occur in the region of the gene encoding the Juxtamembrane region of the protein and point mutations in the tyrosine kinase domain (TKD). Patients with a high mutant allelic ratio (>0.5) are more likely to be responsive to FLT3 inhibition compared to those with low allelic ratio but also with poor prognosis due to high relapse risk. The TKD mutations most frequently involve mutation or deletion of codons D835 or I836. Both ITD and TKD mutations constitutively activate FLT3 kinase activity without the need for the ligand and hence promote malignancy. AML patients with FLT3 internal tandem duplication (ITD) mutations have poor prognosis, high relapse rates, and reduced overall survival. Patients with FLT3 mutations could be eligible for FLT3-targeted therapy regimens.




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.