摘要目的：探讨细胞色素氧化酶 P4501 A1（CYP1A1）编码区单核苷酸多态性（SNP）在急性白血病患儿和对照组儿童中的等位基因频率和各基因型分布特征，及其与中国汉族急性淋巴细胞白血病（ALL）和急性髓细胞白血病（AML）患儿发病风险的关系。方法选择2007年1月至2014年1月在遵义医学院深圳市儿童医院血液科住院的初治急性白血病患儿121例为病例组，男76例，女45例，平均年龄4．42岁。其中 ALL 患儿（ALL 组）101例，男65例，女36例，平均年龄4．38岁；AML 患儿（AML 组）20例，男11例，女9例，平均年龄4．66岁。对照组为同期健康体检儿童或单纯上呼吸道感染患儿，共116例，男74例，女42例，平均年龄3．93岁。用反转录-PCR-变性梯度凝胶电泳（DGGE）结合 DNA 测序技术对病例组和对照组儿童的 CYP1A1编码区开放阅读框进行筛查。结果在中国汉族儿童 CYP1A1开放阅读框仅筛查到1个 SNP，即 A4889G。在病例组、ALL 组、AML 组和对照组中 CYP1A1 A4889G 等位基因频率分别为31．4％、32．2％、27．5％和38．8％。CYP1A1 A4889G AG 和 AG ＋GG 基因型可降低 AML 发病风险（OR ＝0．31，95％CI：0．11～0．87，P ＝0．02；OR ＝0．35，95％CI：0．14～0．93，P ＝0．03），且主要降低男性儿童的 AML 易感性（OR ＝0．12，95％CI：0．03～0．60，P ＝0．01；OR ＝0．16，95％CI：0．04～0．65，P ＝0．01），而各基因型与 ALL 易感性则无关（P ＞0．05）；全部标本的 CYP1A1 A4889G 等位基因频率及各基因型分布和美国、印度、朝鲜、巴西和伊朗人群的差异均有统计学意义（P均＜0．05）。结论CYP1A1 A4889G 与 ALL 发生风险可能无关，但可能是 AML 遗传易感因素，特别能降低男性儿童的 AML 患病风险；且该位点多态性分布具有种族差异性。

abstractsObjective To investigate the single nucleotide polymorphism(SNP)in the coding region in cyto-chrome P4501 A1 (CYP1A1)gene and to evaluate the contributions of SNPs to acute lymphocytic leukemia(ALL)and acute myeloid leukemia(AML)susceptibility in children.Methods One hundred and twenty -one(male 76,female 45)children with acute leukemia were selected from Department of Hematology in Shenzhen Children′s Hospital,Zuyi Medical College between January 2007 and January 201 4 as the case study group,and the average age was 4.42 years old.Case study group included 1 01 (male 65,female 36,average age 4.38 years old)ALL children (ALL group)and 20(male 1 1 ,female 9,average age 4.66 years old)AML children(AML group).A total of 1 1 6(male 74,female 42) children with respiratory tract infections on health examination during the same period were selected as the control group and the average age was 3.93 years old.SNPs in the coding region in CYP1A1 gene were detected by reverse transcrip-tional(RT)-PCR -denaturing gradient gel elelctrphoresis(DGGE)combined with direct sequencing in the case study group and the control group.Results Only one SNP,A4889G,was screened in the open reading frame (ORF)of CYP1A1 gene in Chinese Han children and the G allele frequency of CYP1A1 gene in the case group,ALL group,AML group and the control group were 31 .4%,32.2%,27.5% and 38.8%.The CYP1A1 A4889G AG and AG +GG geno-type were linked with decreased risk of AML(OR =0.31 ,95%CI:0.1 1 -0.87,P =0.02;OR =0.35,95%CI:0.1 4 -0.93,P =0.03)especially in boys with AML(OR =0.1 2,95%CI:0.03 -0.60,P =0.01 ;OR =0.1 6,95%CI:0.04 -0.65,P =0.01 ),but the CYP1A1 A4889G polymorphism was not associated with the risk of ALL(P >0.05). The CYP1A1 A4889G allele frequency and the distribution of genotypes were significantly different from those reported in America,India,Korea,Brazil and Iran(all P <0.05).Conclusions CYP1A1 A4889G polymorphism may be not as-sociated with susceptibility to ALL,but may decrease the risk of childhood AML especially in boys with AML.In addi-tion,it may exhibit an ethnic difference.