The Analysis of FLT3 and NPM1 Gene Mutations in Chinese Patients with Acute Myeloid Leukemia.

To investigate the frequency of nucleophosmin(NPM1) gene mutations and FLT3 mutations in Chinese patients with acute myeloid leukemia (AML) and its correlation with clinical feature and prognosis.

123 first diagnosed AML patients were involved in our study. Polymerase chain reaction (PCR) combined with electrophoresis was directly used to detect FLT3-ITD mutations, PCR combined with EcoRV digestion was used to detect FLT3-TKD mutation, and PCR combined with directly sequencing was used to detect NPM1 mutations.

(1) In the 123 first diagnosed AML patients, 16 patients (13.0%) were found harboring FLT3-ITD mutation, 6 patients (4.9%) were FLT3-TKD positive, and one patient was found harboring co-existing FLT3-ITD and FLT3-TKD mutation. In addition, 24 patients (19.8%) were NPM1 positive, including 22 patients with A-type mutation, one patient with B-type mutation and one patient with D-type mutation. 5 patients were found harboring co-existing FLT3-ITD and NPM1 mutation. (2) FLT3-ITD and NPM1 mutations were identified as 17.5% (10/57) and 31.6% (18/57) individually in 57 AML patients with normal karyotype, which were significantly higher than patients with abnormal karyotype. All of patients with double mutation had normal karyotype. (3) White blood cell (WBC) count and leukemia cell of bone marrow in FLT3-ITD or FLT3-ITD+/NPM1+ patients were both higher than those patients with FLT3-ITD-/NPM1-. The CR rate of FLT3-ITD+/NPM1-, FLT3-ITD+/NPM1+, FLT3-ITD-/NPM1+, FLT3-ITD-/NPM1- were 50% (4/8), 20% (1/5), 87.5% (7/8), 79.5% (35/44) individually.

FLT3 gene and NPM1 gene mutations are common in AML patients, and early detection of FLT3 gene and NPM1 gene mutations will be beneficial for treatment and prognosis analysis of AML patients.

No relevant conflicts of interest to declare.