多环芳烃暴露及修复酶基因XPD多态性与新生儿出生体重的关系

Association between PAHs exposure, genetic polymorphisms of XPD 751 and newborn birth weight

目的探讨多环芳烃(PAHs)暴露与新生儿DNA修复酶基因XPD 751位点多态性对新生儿出生体重的影响。方法于2010年使用统一调查问卷调查太原市某医院的229对孕妇及新生儿,检测母亲静脉血清PAHs浓度,采用聚合酶链反应-限制性片段长度多态性(RFLP-PCR)方法检测XPD 751位点多态性。结果单因素、广义线性回归分析发现,未调整混杂因素前,DNA修复酶基因XPD Lys751Gln位点(野生型、杂合/纯合突变型)及母亲PAHs暴露对出生体重的影响均无统计学意义;对孕妇年龄、受教育程度、孕妇体质指数、家庭收入情况、被动吸烟、取暖方式、新生儿性别、孕周等校正后发现,母亲PAHs高暴露组(PAHs>3.17μg/L)的新生儿出生体重低于低暴露组(PAHs≤3.17μg/L),差异有统计学意义(P<0.01)。采用Univariate模型分析孕妇PAHs暴露水平和新生儿DNA修复酶基因XPD Lys751Gln位点(野生型、杂合/纯合突变型)多态性对新生儿出生体重的交互影响发现,母亲处于PAHs高暴露水平、新生儿携带XPD 751突变基因型组的出生体重低于PAHs低暴露野生型组(β=-78.88,P=0.042)。结论 PAHs暴露对新生儿出生体重的影响受其自身修复酶基因型的修饰,提示XPD基因突变可能导致出生体重降低,且存在环境与基因的交互作用。

Objective To investigate the association between PAHs exposure, genetic polymorphisms of XPD 751 and newborn birth weight. Methods This analysis was based on 229 infant-mother pairs in Taiyuan, serum PAHs concentrations in mothers were determined and the genotypes of XPD 751 polymorphism in newborns were detected by RFLP-PCR. Results After adjustment for major confounders including maternal age, education, maternal BMI, family income, passive smoking, heating form, infant gestational age and sex, PAHs high exposure was significantly associated with reduced birth weight. Moreover, in comparison of birth weights in four subgroups defined by PAHs concentration group （high/low） and newborn genotype of XPD 751 （AA, AC/CC）, it was found that infants in high PAHs exposure, infants carring the mutation genotype （AC/CC） had significantly birth weight reduction. Conclusion Newborn XPD polymorphism may play a modificative role in the association between PAHs exposure and birth weight, which indicates that there may be gene-environment interaction in this relationship.