Detection of NPM1 exon 12 mutations and FLT3 – internal tandem duplications by high resolution melting analysis in normal karyotype acute myeloid leukemia

Angela YC Tan¹ , David A Westerman¹^,2^,3 , Dennis A Carney² , John F Seymour² , Surender Juneja⁴ and Alexander Dobrovic¹^,3

¹Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, Australia

²Department of Haematology and Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia

³Department of Pathology, University of Melbourne, Parkville, Australia

⁴Royal Melbourne Hospital, Parkville, Australia

author email corresponding author email

Journal of Hematology & Oncology 2008, 1:10doi:10.1186/1756-8722-1-10


Published:	29 July 2008

Abstract

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.

Conclusion

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.