RESUMO
INTRODUCTION: Gene mutations play an important role in acute myeloid leukemia (AML) pathogenesis. Several genes have been identified in AML, such as FLT3, KIT, NPM1, and JAK2. This study investigated the frequency of novel mutations in IDH1 (amino acid R132) and IDH2 (R140 and R172) and analyzed their impact on disease biology and interaction with other mutations in Chinese patients with de novo AML. METHODS: A total of 195 patients were screened for mutations in the IDH1, IDH2, JAK2 V617F, NPM1, FLT3, and KIT genes, using polymerase chain reaction (PCR)-based and direct sequencing assays. RESULTS: IDH mutations occurred at a considerable frequency of 15.89% in Chinese AML cases; IDH2 R140Q was the most frequent genetic alteration and was associated with older age, normal karyotype, and French-American-British classification M2 at diagnosis. There was a strong association of IDH2 mutation with NPM1 mutations and a trend with FLT3-internal-tandem duplication. CONCLUSION: IDH mutations may be a novel genetic marker in cytogenetically normal AML and may cooperate in leukemogenesis.
Assuntos
Predisposição Genética para Doença/genética , Isocitrato Desidrogenase/genética , Leucemia Mieloide Aguda/genética , Mutação , Proteínas Nucleares/genética , Adolescente , Adulto , Idoso , Substituição de Aminoácidos , Povo Asiático/genética , Sequência de Bases , China , Aberrações Cromossômicas , Análise Mutacional de DNA , Frequência do Gene , Genótipo , Humanos , Janus Quinase 2/genética , Leucemia Mieloide Aguda/etnologia , Pessoa de Meia-Idade , Nucleofosmina , Proteínas Proto-Oncogênicas c-kit/genética , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
The Janus kinase 2 (JAK2) V617F mutation has considerably helped understanding of the molecular pathogenesis of chronic myeloproliferative disorders (MPD), hence this study investigated for the first time the mutational status and relative quantitation of JAK2 V617F mRNA in Chinese patients with chronic MPD. The study cohort comprised 123 chronic MPD patients (35 with polycythaemia vera [PV], 85 with essential thrombocythaemia [ET], three with idiopathic myelofibrosis [IMF]). Blood samples examined by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and capillary electrophoresis showed that the prevalence of the JAK2 V617F mutation was 100%, 62.4% and 66.7% in PV, ET and IMF patients, respectively. The proportion of JAK2 V617F mutated mRNA was 89.5% in homozygotes and 57.9% in heterozygotes; 18 PV heterozygous patients showed significantly higher mutated JAK2 mRNA levels than 36 heterozygous ET patients. Six of 93 patients exhibited abnormal karyotypes, but specific chromosomal abnormality was not found. The combination of ARMS-PCR and capillary electrophoresis enables quantitative assay of JAK2 V617F mutation, which helps in chronic MPD diagnosis and estimation of minimal residual disease.
