NPM1 gene mutation in Egyptian patients with cytogenetically normal acute myeloid leukemia.

Nucleophosmin1 (NPM1) protein encoded from the NPM1 gene is a ubiquitously expressed nucleolar phoshoprotein which shuttles continuously between the nucleus and cytoplasm. NPM1 protein plays an important role in cell proliferation and apoptosis. NPM1 gene mutations at exon 12 represent the hallmark of a large sub-group of cytogenetically normal acute myeloid leukemia (CN-AML) patients worldwide. Genomic DNA from 53 CN-AML patients were amplified by PCR and followed by fragment analysis of post-PCR products using GeneMapper software for detection of NPM1 mutations. NPM1 exon 12 mutations were found are 15/53 CN-AML patients (28.3%) including 3 of M1, 3 of M2, 5 of M4, 3 of M5, and 1 of M6 FAB subtypes. The NPM1 mutation was significantly associated with lower relapse rate (p < 0.05). The complete remission (CR) rate was significantly higher in the patients with high NPM1 mutation load (> 50%) than low NPM1 mutation load (< 50%) (87.5% vs. 28.6%; p = 0.02). The aim of this study was to evaluate the NPM1 gene exon 12 mutation in Egyptian patients with CN-AML and its relation to clinical characteristics and patient outcome and survival.