Clinical characteristics of NPM1 gene mutation in acute myelogenous leukemia

Objective To analyze nucleophosmin ( NPM1) gene exon12 mutations in patients with acute myeloid leukemia( AML) ,we explored the clinical characters of AML patients with NPM1 mutation. Methods Genomic DNAs from 98 acute leukemia and myelodysplastic syndrome ( MDS) patients were extracted,including 78 AML,10 ALL and 10 MDS. Genomic DNAs from all patients were amplified by multi-PCR for NPM1 exon 12 and FLT3 exon14,15,then screened gene mutations of NPM1 and FLT3 by PCR-capillary electrophoresis simultaneously. Results NPM1 gene mutations were present in 26. 9% of the overall 78 AML patients. There were no NPM1 gene mutation in 10 ALL and 10 MDS patients. NPM1 gene mutations were more prevelant in patients with normal karyotype-AML ( NK-AML) ( 19 /52,36. 5% ) compared with that in those with abnormal karyotype AML( 2 /26,7. 7% ) ( P 0. 05). NPM1 mutations were more frequently seen in M2 and M5 patients. NPM1 mutation cases were significantly associated with older age 53( 18-77) vs. 43( 17-73) ,P 0. 05,and high peripheral white cell counts 42. 0( 16. 3-102. 0) × 109 /L vs. 14. 0 ( 3. 4-67. 2) × 109 /L,P 0. 05. FLT3-ITD mutation was more frequent inNPM1 mutant than wild cases ( 57. 1% vs. 22. 8% ,P 0. 05). 8/9 NPM1 + /FLT3-ITD -,3/12 NPM1 + / FLT3-ITD + ,16/33 NPM1 -/FLT3-ITD and 2/13 NPM1 -/FLT3-ITD + patients gained CR1. Compared with the other groups,NPM1 + /FLT3-ITD -patients owed higher CR1 ( P 0. 05). Conclusions NPM1 gene mutations were the prevelant mutations in patients with AML,especially in those with NK-AML. The clinical characters of AML with NPM1 mutations were significantly associated with older age,high peripheral WBC,subtype M2,M5,high incidence of FLT3-ITD mutations and high CR1.