[Analysis of NPM1 gene mutations in acute myeloid leukemia].

OBJECTIVE

To evaluate the prevalence of nucleophosmin (NPM1) gene exon 12 mutations in adults with acute myeloid leukemia (AML) and its clinical characteristics.

METHODS

Genomic DNAs from 101 AML adults were screened by PCR and sequencing or capillary electrophoresis (CE) for NPMI mutations.

RESULTS

NPM1 exon 12 mutations were present in 31.7% of the overall cohort, including 1/1 (100%) of M0, 9/17(52.9%) of M1 , 7/25 (28.0%) of M2, 0/23(0%) of M3, 2/7 (28.6%) of M4 and 13/25 (52.0% ) of M5. NPM1 gene mutations were more prevalent in patients with normal karyotype (27/59, 45.8%) compared with that in those with karyotypic abnormalities (5/42, 11.9% ) (P < 0.001). NPM1 mutant cases were significantly associated with old age (P < 0.05), high peripheral white cell count (P < 0.05) and low expression of CD34 (P < 0.05) and CD17 (P<0.05). Sequence analysis of these NPM1 mutant cases revealed 5 known mutations (type A, B, D, N(M), and P(M)) and 1 novel variant (named as type S).

CONCLUSIONS

NPM1 exon 12 mutations occur with a considerable percentage in AML patients with normal karyotype, M1/M5 subtype and older age, and are associated with higher peripheral white cell count and lower expression of CD34 and CD117.