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Test Code IN16Q CBFB::MYH11 Inversion(16), Quantitative Detection and Minimal Disease Risk Monitoring, qRT-PCR, Varies


Shipping Instructions


1. Refrigerated specimens must arrive within 5 days of collection, and ambient specimens must arrive within 3 days of collection.

2. Collect and package specimen as close to shipping time as possible.



Necessary Information


The following information is required:

1. Pertinent clinical history

2. Date of collection

3. Specimen source (blood or bone marrow)



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Blood

Container/Tube: Lavender top (EDTA) or yellow top (ACD-B)

Specimen Volume: 10 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

3. Label specimen as blood.

 

Specimen Type: Bone marrow

Container/Tube: Lavender top (EDTA) or yellow top (ACD-B)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix bone marrow.

2. Send bone marrow specimen in original tube. Do not aliquot.

3. Label specimen as bone marrow.


Forms

1. Hematopathology Patient Information (T676)

2. If not ordering electronically, complete, print, and send an Hematopathology/Cytogenetics Test Request (T726) with the specimen.

Secondary ID

610266

Useful For

Detection of CBFB::MYH11 gene fusion in patients recently diagnosed with acute myeloid leukemia (AML)

 

Minimal residual disease monitoring during the clinical and therapeutic course of patients with AML

Highlights

This test is a highly sensitive quantitative assay for the detection of inv(16)(p13.1q22) or t(16;16)(p13.1;q22) CBFB::MYH11 gene fusion. This detection is useful for patients with acute myeloid leukemia at the time of diagnosis as well as for minimal residual disease monitoring during the clinical and therapeutic course of these patients.

Method Name

Quantitative Real-Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR)

Reporting Name

Inv(16); CBFB-MYH11, Quant, V

Specimen Type

Varies

Specimen Minimum Volume

Blood: 8 mL; Bone marrow: 2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred) 5 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Bone marrow core biopsies
Paraffin-embedded bone marrow clots
Slides
Paraffin shavings
Moderately to severely clotted
Reject

Clinical Information

CBFB::MYH11 minimal residual disease (MRD) monitoring in patients with acute myeloid leukemia (AML) with inv(16) or t(16;16) is useful for evaluating disease response after therapy and identifying individuals with increased risk of relapse. Quantitative real-time reverse transcription polymerase chain reaction testing in neoplasms with known clonal genetic markers can achieve highly sensitive detection of neoplastic cells in peripheral blood or bone marrow specimens. It is one of the most mature technologies available for this purpose. In this assay, inversion or translocation of chromosome 16 resulting in fusion of two genes, CBFB and MYH11, will be evaluated. Quantitative results will provide physicians with an accurate and precise measurement of disease burden to guide patient intervention decisions. This assay can be used for post-therapy MRD monitoring as well as detection of CBFB::MYH11 fusion in AML patients at the time of diagnosis.

Reference Values

An interpretive report will be provided.

Interpretation

The assay is reported in the form of a normalized ratio of CBFB::MYH11 fusion transcript to the control gene ABL1 expressed as a percentage, which is an estimate of the level of CBFB::MYH11 fusion RNA present in the specimen, expressed in relation to the level of RNA from an internal control gene (ABL1). The normalized ratio has no units but is directly related to the level of CBFB::MYH11 detected (ie, larger numbers indicate higher relative levels of CBFB::MYH11, and smaller numbers indicate lower levels). A relative expression value minimizes variability in the RNA levels and cell numbers measured in separate specimens tested at different times.

 

The precision of the quantitative assay is excellent, but interassay variability can occur such that result changes should not be considered significant if 2 single measurements differ by less than 0.5 log. More critical results, such as a change in the status of positivity or greater or equal to 1 log increase between 2 positive samples should be repeated on a separate specimen with appropriate time interval to verify the result.

Method Description

Total RNA is extracted from blood or bone marrow and reverse transcribed to generate complementary DNA. Quantitative real-time reverse transcription polymerase chain reaction is performed using the LightCycler instrument platform, and the data analyzed using the dedicated software for relative quantification with calibrator normalization. Results are provided as a normalized relative value of CBFB::MYH11::ABL1 messenger RNA transcripts with a reproducible analytical sensitivity of 0.01%.(Unpublished Mayo method)
The normalized ratio is a relative quantification calculation as follows: 

Normalized ratio=

CBFB::MYH11 (sample)/ABL1 (sample)

CBFB::MYH11 (run calibrator)/ABL1 (run calibrator)

Day(s) Performed

Monday through Saturday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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

81401-CBFB-MYH11

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IN16Q Inv(16); CBFB-MYH11, Quant, V 101377-0

 

Result ID Test Result Name Result LOINC Value
MP057 Specimen Type 31208-2
610267 Interpretation 59465-5
614375 Signing Pathologist 19139-5