Detection of NPM1 exon 12 mutations and FLT3 - internal tandem duplications by high resolution melting analysis in normal karyotype acute myeloid leukemia.
BACKGROUND
Molecular characterisation of normal karyotype acute myeloid leukemia (NK-AML) allows prognostic stratification and potentially can alter treatment choices and pathways. Approximately 45-60% of patients with NK-AML carry NPM1 gene mutations and are associated with a favourable clinical outcome when FLT3-internal tandem duplications (ITD) are absent. High resolution melting (HRM) is a novel screening method that enables rapid identification of mutation positive DNA samples.


RESULTS
We developed HRM assays to detect NPM1 mutations and FLT3-ITD and tested diagnostic samples from 44 NK-AML patients. Eight were NPM1 mutation positive only, 4 were both NPM1 mutation and FLT3-ITD positive and 4 were FLT3-ITD positive only. A novel point mutation Y572C (c.1715A>G) in exon 14 of FLT3 was also detected. In the group with de novo NK-AML, 40% (12/29) were NPM1 mutation positive whereas NPM1 mutations were observed in 20% (3/15) of secondary NK-AML cases. Sequencing was performed and demonstrated 100% concordance with the HRM results.


CONCLUSIONS
HRM is a rapid and efficient method of screening NK-AML samples for both novel and known NPM1 and FLT3 mutations. NPM1 mutations can be observed in both primary and secondary NK-AML cases.
Tan
Angela Y C
AY
Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, Australia. angela.tan@petermac.org
Westerman
David A
DA
Carney
Dennis A
DA
Seymour
John F
JF
Juneja
Surender
S
Dobrovic
Alexander
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020440:Gene Duplication; D005820:Genetic Testing / Q000191:economics / Q000379:methods*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D000090243:Nucleophosmin; D013997:Time Factors; D055815:Young Adult; D051941:fms-Like Tyrosine Kinase 3 / Q000235:genetics*
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3