急性髓系白血病中异柠檬酸脱氢酶基因突变的研究

Isocitrate Dehydrogenase Gene Mutations in Acute Myeloid Luekemia

本研究探讨急性髓系白血病(acute myeloid leukemia,AML)患者中异柠檬酸脱氢酶基因(IDH1、IDH2基因)点突变及其临床意义。选取90例初发AML患者,以基因组DNA为模板,分别扩增IDH1、IDH2基因的4号外显子,PCR产物通过直接测序法检测IDH突变情况。结果表明,有IDH1基因突变的患者为4例,有IDH2基因突变的患者为7例,突变率分别为4.4%、7.8%,无患者同时存在有2种突变,总突变率为12.2%。在有突变的患者中正常核型所占比例为72.7%,明显高于核型异常患者。存在突变的患者的缓解率为72.7%,较无突变患者高,但两者无统计学差异。有IDH基因突变的患者在缓解后突变消失,而复发后在同样位点再次出现突变。结论:IDH基因突变主要见于正常核型的患者中,尤其是合并NPM1基因突变患者,并与复发相关。IDH基因突变可能成为AML尤其是正常核型AML治疗和预后的指标。

The purpose of this study was to identify point mutation of the isocitrate dehydrogenase gene （IDH1 and IDH2） in patients with acute myeloid leukemia （AML） and its clinical significance. 90 de novo AML patients were selected for this study, the genomic DNA was served as template, the exon4 of 1DH1 and IDH2 were amplified respectively. The IDH mutation was detected by using directly soguencing method for PCR product. The results indicated that among 90 de novo AML patients,4 patients （4.4%） showed the IDH1 gene mutation positive, and 7（7.8% ） patients showed IDH2 gene mutation positive. None was found harboring both mutations, the overall rate of mutation positive of them was 12.2%. In the AML patients with IDH gene mutation positive, the rate of normal karyotype was 72.7%, which was significantly higher than that in abnormality karyotype. The CR rate in mutation positive patients was 72.7%, which seemed as if higher than that in mutation negative patients, but without statistical significance. The mutation disappeared when the patients gained CR, and reappeared in same loci after relapse occurred. It is concluded that the IDH gene point mutation appears in normal karyotype patients, especially in patients combined with NPM1 gene mutation. The IDH gene mutation may be an important target for therapy and evaluating clinical prognosis of patients with normal karyotype.