中文摘要：

目的探讨G蛋白β3亚单位（G—protein β polypeptide-3，GNβ3）基因与抑郁症的关系；并以负性生活事件和童年期创伤性事件作为环境因素，进一步阐明GNβ3基因-环境交互作用与抑郁症的关联，以了解抑郁症可能的发病机制。方法分别提取中国北方地区500名汉族抑郁患者和500名汉族健康对照组基因DNA，采用单碱基延伸SNP分型技术（Snapshot）检测GNβ3基因rs5443位点的基因型和等位基因频率。采用χ^2检验比较病例对照两组间基因型、等位基因的频率分布差异，应用Logistic回归分析基因-环境交互作用与抑郁症的关系。结果GNβ3 rs5443的基因型C／C、C／T、T／T和等位基因C、T在病例组与对照组间分布差异具有统计学意义（χ^2=20．249，P〈0．01；χ^2=4．803，P〈0．05）；其中病例组与健康对照组的CC基因型分别为102例、158例，CT基因型分别为280例、217例，TT基因型分别为118例＼125例；C等位基因型分别为484例、533例，T等位基因型分别为516例、467例。Logistic回归分析结果显示，GNβ3 rs5443与负性生活事件之间存在交互作用（P〈0．05），遭受负性生活事件并携带rs5443T＋基因型的个体罹患抑郁症的风险增加（OR=1．957）。结论GNβ3 rs5443位点可能是抑郁症的易感基因，GNβ3 rs5443位点与负性生活事件之间存在交互作用。

英文摘要：

Objective To explore the association between GNβ3 gene and depression,and to investigate the interaction of gene-environment（ negative life events and childhood trauma） and potential possible pathogenesis of depression. Methods The sample of peripheral blood was collected from Chinese Northern patients（ n= 500） and controls（ n= 500）. Snapshot technique was used to detect the genotype frequency and allele frequency of GNβ3 rs5443 polymorphism in cases and controls. The genotype and allele frequencies were analyzed by Chi-square test,the interactions of gene-environment were analyzed by Logistic regression. Results GNβ3 rs5443 genotype and allele frequencies were observed between patients and controls （ χ^2 = 20.249, P〈0.01 ;χ^2 = 4.803, P〈0.05）. There were genotype CC 102 and 158, genotype CT 280 and 217, genotype Tr 118 and 125; allele C 484 and 533, allele T 516 and 467 between patients and controls, respectively. Logistic regression analysis showed that the interaction between rs5443 T＋ and negative life events was associated with depression （P〈0.05, OR= 1.957）. In addition, individual carrying rs5443T＋ genotypes and negative life events could increase risk of depression. Conclusion GNβ3 rs5443 is a possible susceptibility gene of depression. The interaction between rs5443 and negative life events is associated with depression.