目的：研究DEK-NUP214融合基因阳性的小儿急性髓系白血病（AML）的临床特点、治疗方案和预后。方法：回顾性分析了2015年5月至2022年2月在中国医学科学院血液病医院小儿血液病中心入院的7例DEK-NUP214融合基因阳性AML患儿的临床资料、遗传和分子结果、治疗过程及生存状况。结果：在同期诊断的683例小儿AML中，DEK-NUP214融合基因阳性AML占1.02％（7/683），其中有4名男性和3名女性。发病年龄为8.2（7.5，9.5）岁。骨髓中的爆发百分比为0.275（0.225，0.480），FAB分类为M5的患者有6例。除了一例骨髓形态未知外，所有病例均观察到病理造血。三例携带FLT3-ITD突变，四例携带NRAS突变，两例携带KRAS突变。诊断后，4例接受IAE诱导方案（依达拉奉、阿糖胞苷和依托泊苷），1例接受MAE诱导方案（米托蒽醌、阿糖胞苷和依托泊苷），1例接受DAH诱导方案（多柔比星、阿糖胞苷和同滑石碱），1例接受DAE诱导方案（多柔比星、阿糖胞苷和依托泊苷）。在一次诱导治疗后，3例患者达到完全缓解。4例未达到完全缓解的患者接受了CAG（阿克拉霉素、阿糖胞苷和粒细胞集落刺激因子）、IAH（依达拉奉、阿糖胞苷和同滑石碱）、CAG联合氯达葆甙和HAG（同滑石碱、阿糖胞苷和粒细胞集落刺激因子）联合氯达葆甙再诱导治疗，全部4例患者达到完全缓解。除一例完全缓解后失访外，6名患者在1-2次密集巩固治疗后接受了造血干细胞移植（HSCT）。诊断至HSCT的时间为143（121，174）天。HSCT前，一例患者为流式细胞学极微量残留病阳性，3例患者为DEK-NUP214融合基因阳性。三例接受单倍体供者、两例接受无关脐血供者和一例接受配型同胞供者。随访时间为20.4（12.9，53.1）个月，总生存率和无事件生存率均为100%。结论：DEK-NUP214融合基因阳性的小儿AML是一种独特而罕见的亚型，常在相对较年长的儿童中诊断。该病特点为骨髓中的爆发百分比低、病理造血显著以及FLT3-ITD和RAS基因突变率高。化疗仅缓解率低和复发率极高表明其高恶性和预后差。第一次完全缓解后早期接受HSCT可以改善其预后。

Objective: To investigate the clinical features, treatment regime, and outcome of pediatric acute myeloid leukemia (AML) with DEK-NUP214 fusion gene. Methods: The clinical data, genetic and molecular results, treatment process and survival status of 7 cases of DEK-NUP214 fusion gene positive AML children admitted to the Pediatric Blood Diseases Center of Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from May 2015 to February 2022 were analyzed retrospectively. Results: DEK-NUP214 fusion gene positive AML accounted for 1.02% (7/683) of pediatric AML diagnosed in the same period, with 4 males and 3 females. The age of disease onset was 8.2 (7.5, 9.5) years. The blast percentage in bone marrow was 0.275 (0.225, 0.480), and 6 cases were M5 by FAB classification. Pathological hematopoiesis was observed in all cases except for one whose bone marrow morphology was unknown. Three cases carried FLT3-ITD mutations, 4 cases carried NRAS mutations, and 2 cases carried KRAS mutations. After diagnosis, 4 cases received IAE induction regimen (idarubicin, cytarabine and etoposide), 1 case received MAE induction regimen (mitoxantrone, cytarabine and etoposide), 1 case received DAH induction regimen (daunorubicin, cytarabine and homoharringtonine) and 1 case received DAE induction regimen (daunorubicin, cytarabine and etoposide). Complete remission was achieved in 3 cases after one course of induction. Four cases who did not achieved complete remission received CAG (aclarubicin, cytarabine and granulocyte colony-stimulating factor), IAH (idarubicin, cytarabine and homoharringtonine), CAG combined with cladribine, and HAG (homoharringtonine, cytarabine and granulocyte colony-stimulating factor) combined with cladribine reinduction therapy, respectively, all 4 cases reached complete remission. Six patients received hematopoietic stem cell transplantation (HSCT) after 1-2 sessions of intensive consolidation treatment, except that one case was lost to follow-up after complete remission. The time from diagnosis to HSCT was 143 (121, 174) days. Before HSCT, one case was positive for flow cytometry minimal residual disease and 3 cases were positive for DEK-NUP214 fusion gene. Three cases accepted haploid donors, 2 cases accepted unrelated cord blood donors, and 1 case accepted matched sibling donor. The follow-up time was 20.4 (12.9, 53.1) months, the overall survival and event free survival rates were all 100%. Conclusions: Pediatric AML with DEK-NUP214 fusion gene is a unique and rare subtype, often diagnosed in relatively older children. The disease is characterized with a low blast percentage in bone marrow, significant pathological hematopoiesis and a high mutation rate in FLT3-ITD and RAS genes. Low remission rate by chemotherapy only and very high recurrence rate indicate its high malignancy and poor prognosis. Early HSCT after the first complete remission can improve its prognosis.