中文摘要：

目的了解早期B细胞因子1（EBF1）基因异常在急性B淋巴细胞白血病（B-ALL）患儿中的发生情况,并进一步分析EBF1基因异常与B-ALL患儿预后的相关性。方法应用多重连接探针扩增（MLPA）技术检测2008年4月至2013年4月中国医学科学院北京协和医学院血液病医院血液学研究所儿童血液病诊疗中心初诊的B-ALL195例患儿EBF1基因异常情况。根据有无EBF1基因缺失将所有B-ALL患儿分为EBF1缺失组和非EBF1缺失组。结果 195例中15例（7.7%）发生EBF1缺失。两组初诊各项临床特征差异无统计学意义（P〉0.05）。Kaplan-Meier法分析显示EBF1缺失组无病生存率（DFS）及无事件生存率（EFS）明显低于非EBF1缺失组[（59.5±14.8）%vs.（85.5±3.2）%;（55.6±14.3）%vs.（84.2±2.9）%;P均〈0.05]。但两组总生存率（OS）差异无统计学意义[（86.7±8.8）%vs.（91.9±2.1）%,P〉0.05]。Cox法分析显示在排除多项影响因素后,EBF1缺失仍为影响患儿DFS及EFS的不利因素（P〈0.05）。结论部分B-ALL患儿初诊时伴EBF1基因缺失,EBF1缺失为B-ALL患儿DFS及EFS的独立危险因素。

英文摘要：

Objective To identify EBF1 gene copy number abnormalities in pediatric B-ALL patients and to further investigate its value in the pathogenesis and prognosis. Methods A total of 195 children with B-ALL whose bone marrows could be extracted enough DNA for the detection were selected retrospectively. All the patients were diagnosed and systematically treated according to CCLG-2008 in Department of Pediatrics,Institute of Hematology and Blood Diseases Hospital,CAMS and PUMC from April 2008 to April 2013. The 195 cases were divided into two groups according to the results of EBF1 gene copy number abnormalities by MLPA：the group with EBF1 deletion and the group without EBF1 deletion. Results Fifteen（7.7%）out of 195 B-ALL patients had EBF1 deletion. There were no differences between the two groups in clinical characteristics at diagnosis（all P〈0.05）. Patients with EBF1 deletions had a lower 4-year disease-free survival（DFS）[（59.5±14.8）% vs.（85.5±3.2）%,P=0.020]and event-free survival（EFS）[（55.6±14.3）%vs.（84.2±2.9）%,P=0.017]compared to those without. The overall survival rate had no statistical difference betweenthe two group[（86.7 ± 8.8）% vs.（91.9 ± 2.1）%,P〈0.05]. Excluding many influencing factors,Cox analysis showed that EBF1 deletion still affected the patients＇ DFS and EFS（P〈0.05）. Conclusion Some of pediatric B-cell precursor ALL can be detected EBF1 deletion;And EBF1 deletion is an independent poor prognosis factor to the patients＇ DFS and EFS.