This test is a targeted next-generation sequencing (NGS) (panel) assay that encompasses 8 genes with variable full exon, partial region, or hot spot coverage (depending on specific locus). This test will therefore not detect other genetic abnormalities in genes or regions outside the specified target areas. The test detects single base substitutions (ie, translocations), gene fusions, copy number alterations, or large scale (segmental chromosome region) deletions or complex changes.
This assay does not distinguish between somatic and germ line alterations in analyzed regions, particularly with variant allele frequencies (VAF) near 50% or 100%. If nucleotide alterations in genes associated with germ line mutation syndromes are present and there is also a strong clinical suspicion or family history of malignant disease predisposition, additional genetic testing and appropriate counseling may be indicated. Mutations detected between 5% and 10% VAF may indicate low-level (ie, subclonal) tumor populations, although the clinical significance of these findings may not be clear. A low incidence of gene mutations associated with myeloid neoplasms can be detected in blood samples from individuals with advancing age who do not have a hematologic neoplasm (clonal hematopoiesis of indeterminate potential) and such alterations may not be clearly distinguishable from tumor-associated mutations, especially if detected as a sole abnormality. Some apparent mutations classified as variants of undetermined significance (VUS) may represent rare or low frequency polymorphisms.
Prior treatment for a hematologic malignancy could affect the results obtained in this assay. In particular, prior allogenic hematopoietic stem cell transplant (HSCT) may cause difficulties in resolving somatic or polymorphic alterations, or in assigning variant calls correctly to donor and recipient fractions, if pertinent clinical or laboratory information (eg, chimerism engraftment status) is not provided.
Correlation with clinical, histopathologic and additional laboratory findings is required for final interpretation of these results. The final interpretation of results for clinical management of the patient is the responsibility of the managing physician.
If this test is ordered in the setting of erythrocytosis and suspicion of polycythemia vera, interpretation requires correlation with a concurrent or recent prior bone marrow evaluation.