Hematologic Diseases

Internal Tandem Duplication (ITD) and Tyrosine Kinase Domain (TKD). FLT3 ITD and TKD regions are analyzed by polymerase chain reaction (PCR) and fluorescent fragment size analysis. The signal ratio of the FLT3 ITD region compares the signal intensity of the mutation to the wild-type.

disease state indication(s)
Acute myeloid leukemia (AML)

clinical use
While FLT3 ITD mutations are associated with an unfavorable risk status in cytogenetically normal acute myeloid leukemia (AML), there is controversy as to whether FLT3 TKD mutations carry an equally unfavorable prognosis. Patients with FLT3 mutation-positive AML (ITD or TKD mutation) may benefit from treatment with tyrosine kinase inhibitors. [1]

References:
1. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Acute Myeloid Leukemia. Version 3.2017

methodology/product platform
Polymerase chain reaction (PCR) / Fragment analysis (FA)

specimen type and requirements
Preferred:
Bone marrow: 2-3 mL in EDTA (purple-top) tube
Peripheral blood: 2-3 mL in EDTA (purple-top) tube

Acceptable Alternative:
Bone marrow: 2-3 mL in sodium heparin (green-top) tube
Peripheral blood: 2-3 mL in sodium heparin (green-top) tube

Note: Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact with specimen.
DO NOT FREEZE.

turnaround time
Global: 5-7 days

cpt code(s)
81245 (x1)
81246 (x1)

medicare moldx cpt code
81479 (x1)

regulatory classification
Laboratory developed test (LDT)

ordering option
Global