A novel quantitative assessment of minimal residual disease in patients with acute myeloid leukemia carrying NPM1 (nucleophosmin) exon 12 mutations

Abstract

Acute myeloid leukemia (AML) is a heterogeneous group of diseases affecting hematopoietic stem cells. In recent years, several novel molecular abnormalities have been identified in patients with AML, particularly in cases with normal karyotype. Among these, mutations of the nucleophosmin gene (NPM1) have been established as currently the most common abnormality in AML, found about half of all AML patients with normal karyotype. For the detection of NPM1 mutations on the molecular level, several different assays have been described, including direct sequencing, fragment analysis or high resolution melt analysis or high-performance liquid chromatography. NPM1 mutations might be also suitable as target structure for minimal residual disease monitoring. Here, we describe a novel quantitative assessment based on allelic discrimination assays and real-time PCR with mutation-specific minor groove binding (MGB) probes. This method offers an alternative to the standard routine laboratory evaluation and representing an efficient approach to the specific detection of NPM1 mutations without any false positivities caused by amplification on the wild-type alleles.