TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: MPAML    
MatePair, Acute Myeloid Leukemia (AML) Panel

Useful For Suggests clinical disorders or settings where the test may be helpful

Detecting a neoplastic clone associated with the common chromosome abnormalities seen in patients with acute myeloid leukemia or myelodysplasia or other myeloid malignancies

 

Evaluating specimens when standard cytogenetic or FISH analysis is unsuccessful

 

Determining the size, precise breakpoints, gene content, and any unappreciated complexity of abnormalities detected by other methods such as conventional chromosome and FISH studies

 

Providing important diagnostic, prognostic, and therapeutic information critical to proper patient management

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

This assay detects targeted chromosome abnormalities observed in the blood and bone marrow of patients with acute myeloid leukemia.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Acute myeloid leukemia (AML) is one of the most common adult leukemias, with almost 10,000 new cases diagnosed per year. AML also comprises 15% of pediatric acute leukemia and accounts for the majority of infant (<1 year old) leukemia. Several subtypes of AML have been recognized based on the cell morphology and myeloid lineage involved.

 

In addition to morphology, several recurrent chromosomal abnormalities have been linked to specific subtypes of AML. The most common chromosome abnormalities associated with AML include t(8;21), t(15;17), inv(16), +8, t(6;9), t(8;16), t(1;22), t(9;22), t(3;5), and abnormalities of the KMT2A (MLL) gene at 11q23. The most common genes juxtaposed with KMT2A (MLL) through translocation events in AML include AFF1 t(4;11), MLLT4 t(6;11), MLLT3 t (9;11), MLLT10 t(10;11), CREBBP t(11;16), ELL t(11;19p13.1), and MLLT1 t(11;19p13.3).

 

AML can also evolve from myelodysplasia (MDS). Thus, the common chromosome abnormalities associated with MDS can also be identified in AML, which include: inv(3), -5/5q-, -7/7q-, +8, 13q-, 17p-, 20q-, t(1;3), and t(3;21). In combination, the multiple recurrent chromosome abnormalities identified in patients with AML are observed in approximately 60% of diagnostic AML cases.

 

Conventional chromosome analysis is the gold standard for identification of the common, recurrent chromosome abnormalities in AML; however, some of the subtle rearrangements can be missed (eg, inv[16] and KMT2A [MLL] abnormalities). FISH analysis of nonproliferating (interphase) cells can be used to detect the common chromosome abnormalities observed in patients with AML, however, only a few KMT2A (MLL) gene partners are detected. The abnormalities have diagnostic and prognostic relevance and this testing can also be used to track response to therapy.

 

Mate-pair sequencing (MPS) is a next-generation sequencing technology that can aid in the further characterization of chromosome abnormalities by sequencing the entire genome and bioinformatically mapping short fragments of the genome to create a structural map of the genome. This technique enables the mapping of chromosome rearrangements to a resolution of approximately 2 kilobases or less, which allows for determination of genes at or near the breakpoints. MPS, similar to FISH analysis, can also be used on nonproliferating cells to detect common chromosome abnormalities observed in patients with AML. In addition, MPS is able to detect all gene partners for all the genes included on the panel, for example KMT2A (MLL) gene partners.

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

The interpretation describes the common chromosome abnormalities observed in patients with acute myeloid leukemia (AML) and the abnormalities have diagnostic and prognostic relevance. Mate-pair sequencing (MPS) is also able to further characterize previously identified acquired abnormalities. When possible the interpretation will state how the finding might be associated with the hematologic process and any potential information on diagnosis, prognosis, and treatment options given the finding.

 

The continual discovery of novel structural rearrangements and published clinical reports means that the interpretation of any finding may evolve with increased scientific understanding.

 

Although the presence of a clonal abnormality usually indicates a neoplasia, in some situations it may reflect a benign or constitutional genetic change. If a genetic change is identified that is likely constitutional and clearly pathogenic, follow-up with a medical genetics consultation may be suggested.

 

The absence of an abnormal clone may be the result of specimen collection from a site that is not involved in the neoplasm or may indicate that the genetic abnormality is not detectable by this assay.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not approved by the US Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.

 

This test is not appropriate when the reason for referral indicates acute promyelocytic leukemia (APL). FISH testing for t(15;17) is more appropriate.

 

This test does not detect point mutations, small deletions or insertions below the resolution of the assay, or other types of mutations such as epigenetic changes.

 

Low level abnormal clones may not be detected by this test; as such it is not recommended for minimal residual disease monitoring.

 

The results of this test may reveal incidental findings not related to the original reason for referral.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Grimwade D, Hills RK, Moorman AV, et al: Refinement of cytogenetics classification in acute myeloid leukemia: determination of prognostic significance or rare recurring chromosomal abnormalities among 5879 younger adult patients treated in the United Kingdom Research Council trials. Blood 2010 Jul;116(3):354-365

2. International Agency for Research on Cancer (IARC): World Health Organization (WHO) classification of tumour of haematopoietic and lymphoid tissues. Edited by SH Swerdlow, E Campo, NL Harris, et al. IARC Press, Oxford: Oxford University Press (distributor), 2008

Special Instructions Library of PDFs including pertinent information and forms related to the test