目的 通过研究急性白血病（AL）患儿还原型辅酶Ⅱ（NADPH）氧化酶亚基RAC2基因的遗传多态性，探讨其与柔红霉素引起心肌损伤的关系。方法 选取42例接受正规化疗的AL患儿（AL组）和25名健康儿童（正常对照组），采集所有儿童的外周静脉血并抽提DNA，采用PCR技术扩增RAC2基因单核苷酸多态性（SNP）位点的上、下游片段，基因测序法检测rs13058338位点的RAC2基因遗传多态性，比较各组间RAC2基因遗传多态性的分布频率。结果 67名被研究者出现RAC2基因遗传多态性的总体阳性率为19.4%，AL组和正常对照组的分布频率基本一致（P=0.531）。AL组中，氨基未端脑利钠肽（NT-proBNP）（>125 pg/mL）升高组和NT-proBNP（0~125 pg/mL）正常组的RAC2基因遗传多态性频率分别为25.9%（7/27）和0（0/15），差异有统计学意义（P=0.035）；柔红霉素累积剂量为60~120 mg/m2组和>120 mg/m2组的分布频率分别为20.0%（5/25）和11.8%（2/17），差异无统计学意义（P=0.681）。NT-proBNP升高组中，7例出现AT等位基因患儿的NT-proBNP水平为（276.08±158.60）pg/mL，20例TT等位基因患儿的NT-proBNP水平为（289.64±209.47）pg/mL，差异无统计学意义（P>0.05）。结论 RAC2基因遗传多态性具有个体差异；RAC2基因遗传多态性可能是柔红霉素导致心脏毒性的原因之一。

Objective To investigate the RAC2 genetic polymorphisms of reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase in children with acute leukemia (AL), and explore the relationship between RAC2 genetic polymorphisms and daunorubicin-induced cardiotoxicity. Methods Forty-two children diagnosed as AL with conventional chemotherapy (AL group) and 25 healthy children (normal control group) were enrolled. Peripheral venous blood was obtained, and DNA was extracted. Upstream and downstream fragments of RAC2 genetic polymorphism sites were amplified by PCR, RAC2 genetic polymorphisms of rs13058338 site were detected by gene sequencing, and the distribution frequencies of RAC2 genetic polymorphisms were compared among groups. Results The total positive rate of RAC2 genetic polymorphisms was 19.4%, and there was no significant difference in distribution frequencies between AL group and normal control group (P=0.531). In AL group, there were significant differences in frequencies of RAC2 genetic polymorphisms between high level N-terminal brain natriuretic peptide (NT-proBNP)(>125 pg/mL) group (25.9%, 7/27) and normal level NT-proBNP (0-125 pg/mL) group(0, 0/15) (P=0.035), while there was no significant difference in distribution frequencies between daunomycin accumulated dose 60-120 mg/m2 group (20.0%, 5/25) and daunomycin accumulated dose >120 mg/m2 group (11.8%, 2/17)(P=0.681). In high level NT-proBNP group, there was no significant difference in NT-proBNP levels between 7 children with AT allele and 20 children with TT allele [(276.08±158.60) pg/mL vs (289.64±209.47) pg/mL, P>0.05]. Conclusion There are individual differences in RAC2 genetic polymorphisms; RAC2 genetic polymorphisms may contribute to daunorubicin-induced cardiotoxicity.