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Myelodysplastic Syndrome (MDS) Mutations, Sequencing

Test code(s) 91396

This test can be used to aid in the diagnosis of MDS. It can help strengthen a low-grade MDS diagnosis when the karyotype is uninformative.

Blood samples can be tested at the time of initial presentation or relapse. Bone marrow samples can be tested whenever the morphologic and flow cytometric evaluation is equivocal or nondiagnostic.

This assay is a next-generation sequencing (NGS), DNA-based assay that targets the frequently mutated areas of 7 genes (ASXL1, EXH2, IDH1, IDH2, KRAS, NRAS, and TET2). These are genes that are commonly mutated in the earlier stages of MDS. Mutation(s) detected in the NGS screen are confirmed by another sequencing method prior to reporting. Results of most assays are reported within 7 working days.

This assay can detect the presence of a mutant allele when it constitutes at least 5% of the population. Our studies1 show that this test will detect an MDS-related mutation in most MDS cases exhibiting increased blasts. Additionally, this test will detect an MDS-related mutation in 20% to 30% of cases presenting with cytopenias(s) that have a normal or equivocal flow cytometry study and/or normal karyotype but no increase in blasts.1 A negative test result (ie, no mutation detected) does not completely exclude the diagnosis of MDS.

Blood and bone marrow samples yield similar diagnostic sensitivities in this NGS-based assay.

We provide a text-based report of the mutations detected. A graphical report is also available via Care360. Contact the HelpDesk for assistance in accessing the graphical report.

Detection of a mutation indicates the presence of a clonal hematopoietic neoplasm. Determination of the precise type of clonal neoplasm requires correlation with the immunophenotype and morphologic findings. Mutations targeted in this test can be found in all types of myeloid neoplasms including MDS, myeloproliferative neoplasms, and acute myeloid leukemia.

Chromosomal Microarray, Oncology, ClariSure® Oligo-SNP (test code 90961) is a microarray assay that provides complementary genomic data.1 It includes a comprehensive analysis of chromosomal deletions and amplifications as well as copy number neutral SNP changes at MDS-associated loci. Such changes may be some of the earliest changes in the development of MDS.2 The test may be a useful adjunct to the MDS mutation panel when morphologic changes are nondiagnostic; it is preferred over FISH tests owing to the greater diagnostic yield in MDS. Blood or bone marrow samples are acceptable.

References

  1. Slovak ML, Hsu Y-H, Chen H-H, et al. Comprehensive workup of myelodysplastic syndromes: comparing targeted DNA sequencing, oligo/SNP microarray and higher dimensional flow cytometry [ASH abstract 2519]. Blood. 2012;120(21);2519.
  2. Gondek LP, Tiu R, O’Keefe CL, et al. Chromosomal lesions and uniparental disomy detected by SNP arrays in MDS, MDS/MPD, and MDS-derived AML. Blood. 2008;111(3):1534-1542.

 

This FAQ is provided for informational purposes only and is not intended as medical advice. A clinician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

 

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