Detection of nucleophosmin (NPM1) mutation provides information for prognosis in patients with newly diagnosed acute myeloid leukemia. NPM1 mutation with absence of FLT3-ITD (FMS-like tyrosine kinase-3 internal tandem duplication) is associated with a better prognosis. This RNA based quantitative test detects about 95% of NPM1 mutations and can be used for monitoring measurable residual disease.
Quantitative Reverse Transcription-Polymerase Chain Reaction (RT-PCR)
NPM1
Nucleophosmin Mutation Analysis
Bone Marrow
Specimen must arrive within 72 hours of collection. Collect and package specimen as close to shipping time as possible. Specimens greater than 3 days old at the time of receipt will be considered unacceptable.
The following information is required:
1. Pertinent clinical history including if the patient has a diagnosis of chronic myeloid leukemia or other BCR/ABL-1-positive neoplasm
2. Date of collection
Container/Tube:
Preferred: Lavender top (EDTA)
Specimen Volume: 3 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.
1 mL
Gross hemolysis | Reject |
Moderately to severely clotted | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Bone Marrow | Refrigerated (preferred) | 72 hours | |
Ambient | 72 hours |
Detection of nucleophosmin (NPM1) mutation provides information for prognosis in patients with newly diagnosed acute myeloid leukemia. NPM1 mutation with absence of FLT3-ITD (FMS-like tyrosine kinase-3 internal tandem duplication) is associated with a better prognosis. This RNA based quantitative test detects about 95% of NPM1 mutations and can be used for monitoring measurable residual disease.
Acute myeloid leukemia (AML) is a heterogeneous disease of the blood and bone marrow, characterized by clonal expansion of hematopoietic stem and progenitor cells with impaired differentiation capacity, leading to bone marrow failure. Nucleophosmin (NPM1) mutated AML represents a distinct entity in the World Health Organization classification. NPM1 mutation occurs in 20% to 30% of AML cases. Most of these patients have a normal karyotype. Detection of an NPM1 mutation without coexisting FLT3-ITD (FMS-like tyrosine kinase-3 internal tandem duplication) suggests a more favorable prognosis. More than 50 different heterozygous mutations have been identified in NPM1 in exon 12. Three mutation types, A, B, and D, account for about 95% of the NPM1 mutations. NPM1 mutation detection has been utilized in monitoring measurable minimal residual disease.
An interpretive report will be provided.
Nucleophosmin (NPM1) mutation occurs in 20% to 30% of acute myeloid leukemia (AML) cases. AML with NPM1 mutation is a subtype of AML classification. Detection of an NPM1 mutation with absence of FLT3-ITD (FMS-like tyrosine kinase-3 internal tandem duplication) is associated with better outcomes, increased complete remission, and improved overall survival in AML. Concurrent NPM1 and FLT3-ITD mutations confer intermediate risk in AML.
Three mutation types, A, B, and D account for about 95% of the NPM1 mutations in AML. This RNA based quantitative test detects the transcripts of the type A, B, and D mutations and provides a useful target for measurable residual disease (MRD) monitoring.
The continued presence of NPM1 mutant transcripts is associated with a higher chance of relapse than those with non-detectable NPM1 mutant transcripts. Minimal residual disease (MRD) status prior to allogeneic hematopoietic stem cell transplant has been shown to be a good predictor of outcome.
Because of the design of this assay, a very small number of NPM1 alterations at diagnosis may not be detected by the more targeted quantitative polymerase chain reaction component.
1. Heath EM, Chan SM, Minden MD, Murphy T, Shlush LI, Schimmer AD. Biological and clinical consequences of NPM1 mutations in AML. Leukemia. 2017;31(4):798-807
2. Falini B, Sciabolacci S, Falini L, Brunetti L, Martelli MP. Diagnostic and therapeutic pitfalls in NPM1-mutated AML: notes from the field. Leukemia. 2021;35(11):3113-3126
3. Hindley A, Catherwood MA, McMullin MF, Mills KI. Significance of NPM1 Gene Mutations in AML. Int J Mol Sci. 2021;22(18):10040
4. Khoury JD, Solary E, Abla O, et al. The 5th edition of the World Health Organization classification of haematolymphoid tumours: myeloid and histiocytic/dendritic neoplasms. Leukemia. 2022;36(7):1703-1719
The assay is performed using an automated platform, GeneXpert (Cepheid). Bone marrow sample is processed, added to an individual sample cartridge, and loaded onto the GeneXpert machine. It quantifies mutant nucleophosmin (NPM1) mRNA transcript types A, B, and D in exon 12 and reports the percent ratio of mutant NPM1 to ABL1 endogenous control mRNA transcript.(Unpublished Mayo method)
Monday through Friday
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.
81310
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
NPMFM | NPM1 Mutation Analysis, BM | 75034-9 |
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.
|
---|---|---|
620655 | Final Diagnosis: | 59465-5 |
620707 | Signing Pathologist | 19139-5 |