Test Id : FLT
FLT3 Mutation Analysis, Varies
Useful For
Suggests clinical disorders or settings where the test may be helpful
Prognostic indication for some patients with acute myeloid leukemia
This test should not be used to monitor residual disease following treatment.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see:
-Acute Leukemias of Ambiguous Lineage Testing Algorithm
-Acute Myeloid Leukemia: Testing Algorithm
-Acute Myeloid Leukemia: Relapsed with Previous Remission Testing Algorithm
Method Name
A short description of the method used to perform the test
Polymerase Chain Reaction (PCR)/Capillary Electrophoresis
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
FLT
FLT3
FLT3-ITD
FLT3 coding for D835
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see:
-Acute Leukemias of Ambiguous Lineage Testing Algorithm
-Acute Myeloid Leukemia: Testing Algorithm
-Acute Myeloid Leukemia: Relapsed with Previous Remission Testing Algorithm
Specimen Type
Describes the specimen type validated for testing
Varies
Ordering Guidance
This test is intended to be used as a prognostic test at diagnosis and should not be used to monitor residual disease following treatment.
Shipping Instructions
Specimen must arrive within 7 days of collection.
Necessary Information
The following information is required:
1. Pertinent clinical history
2. Clinical or morphologic suspicion
3. Date and time of collection
4. Specimen source
ORDER QUESTIONS AND ANSWERS
| Question ID | Description | Answers |
|---|---|---|
| MP009 | Specimen Type |
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 3 mL
Collections Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube. Do not aliquot.
3. Label specimen as blood.
Specimen Stability Information: Ambient (preferred)/Refrigerate
Specimen Type: Bone marrow
Container/Tube: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 2 mL
Collections Instructions:
1. Invert several times to mix bone marrow.
2. Send specimens in original tube. Do not aliquot.
3. Label specimen as bone marrow.
Specimen Stability Information: Ambient (preferred)/Refrigerate
Specimen Type: Extracted DNA from blood or bone marrow
Container/Tube: 1.5- to 2-mL tube
Specimen Volume: Entire specimen
Collection Instructions:
1. Label specimen as extracted DNA from blood or bone marrow
2. Indicate volume and concentration of DNA on the label.
Specimen Stability Information: Frozen (preferred)/Refrigerate/Ambient
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Blood, Bone Marrow: 1 mL
Extracted DNA: 50 mcL at 20 ng/mcL concentration
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Bone marrow biopsies, slides, paraffin shavings Moderately to severely clotted | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | 7 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Prognostic indication for some patients with acute myeloid leukemia
This test should not be used to monitor residual disease following treatment.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see:
-Acute Leukemias of Ambiguous Lineage Testing Algorithm
-Acute Myeloid Leukemia: Testing Algorithm
-Acute Myeloid Leukemia: Relapsed with Previous Remission Testing Algorithm
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The FMS-like tyrosine gene (FLT3) codes for a transmembrane receptor/signaling protein (FLT3) of the tyrosine kinase group. Binding of FLT3 ligand to the FLT3 receptor ultimately leads to production of proteins that cause cell growth and inhibit cell death through apoptosis. Recently, variants in FLT3 have been found in some hematopoietic neoplasms and are particularly common in adult acute myeloid leukemia (AML) with an overall incidence of approximately 20% to 30%. The highest genetic variant rates are seen in adult patients with AML and normal- or intermediate-risk cytogenetics and in patients with acute promyelocytic leukemia.
The most common FLT3 variant consists of internal tandem duplication (ITD) of DNA sequences found in exons 14 or 15. In some subgroups of adults with AML, the presence of an FLT3 ITD variant has been found to be an adverse prognostic indicator. The second most common variant is a point alteration in the codon for an aspartate residue (D835) that resides in the activation loop of the FLT3 protein. D835 alterations have been identified in approximately 7% of AML cases but, at this time, it is not clear if the presence of this alteration has any prognostic significance. It is thought that both types of FLT3 variants lead to constitutive (always present, independent of internal or external stimuli) FLT3 activation.
Identification of an FLT3 variant in AML is clinically useful, not only because of the prognostic information it provides, but also because FLT3-inhibitory drugs have shown promise as useful therapeutic agents.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation
Provides information to assist in interpretation of the test results
An interpretive report will be issued indicating whether the FLT3 internal tandem duplication (ITD), D835 alteration, or both were detected.
Variant status will be indicated as positive or negative. If ITD positive, an allelic ratio will be reported.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not designed for monitoring residual disease following treatment and the following should be noted: the sensitivity of the test is less than other methods designed for residual disease testing, and there have been several reports of FLT3 variants being lost or gained in neoplastic cells following treatment.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Levis M, Small D. FLT3: ITDoes matter in leukemia. Leukemia. 2003;17:1738-1752
2. Gilliland DG, Griffin JD. The roles of FLT3 in hematopoiesis and leukemia. Blood. 2002;100(5):1532-1542
3. He R, Devine DJ, Tu ZJ, et al. Hybridization capture-based next generation sequencing reliably detects FLT3 mutations and classifies FLT3-internal tandem duplication allelic ratio in acute myeloid leukemia: a comparative study to standard fragment analysis. Mod Pathol. 2019;33:334-34
Method Description
Describes how the test is performed and provides a method-specific reference
This polymerase chain reaction (PCR)-based assay is designed to detect the presence of 2 separate variants in FLT3: internal tandem duplication (ITD) of coding sequence for the intracellular juxtamembrane domain and point alterations in the codon for Asp835 (D835). Genomic DNA is extracted from nucleated cells in the sample. A multiplex PCR is then performed using 2 sets of primers. One primer in each set is labeled with a fluorescent dye to aid in PCR-fragment analysis. The PCR products are then analyzed using capillary electrophoresis.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Saturday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
81245-FLT3 (fms-related tyrosine kinase) (eg, acute myeloid leukemia), gene analysis, internal tandem duplication (ITD) variants (ie, exons 14, 15)
81246-FLT3 (fms-related tyrosine kinase 3) (eg, acute myeloid leukemia), gene analysis; tyrosine kinase domain (TKD) variants (eg, D835, I836)
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| FLT | FLT3 Mutation Analysis, V | 79210-1 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| MP009 | Specimen Type | 31208-2 |
| 19236 | Final Diagnosis: | 34574-4 |
| 41935 | FLT3 Result | 79210-1 |