中文摘要：

目的：探讨发育相关基因Pax-9多态性与低出生体重儿之间是否存在关联。方法：选取60例低出生体重儿和70例正常儿做对照，采用聚合酶链反应一限制性片段长度多态性（PER—RFLP）方法检测Pax-9基因的3个多态性位点（rs2073244、rs2073247、rs4904210）并比较各自的基因型和等位基因的分布频率。结果：Pax-9基因的rs2073247和rs4904210位点基因型总体分布差异有统计学意义（X2=14．53和16．66，P〈0．05），而rs2073244位点的基因型总体分布差异没有统计学意义（X2=5．74，P〉0．05）。其中rs2073244位点AG基因型、rs2073247位点TT基因型和rs4904210位点CC基因型在低出生体重组的分布明显高于正常新生儿组（P〈0．05），而rs2073244位点AA基因型、rs2073247位点TC基因型和rs4904210位点CG基因型在正常新生儿组的分布明显高于低出生体重组（P〈0．05）。结沦：Pax-9基因rs2073247、rs4904210和rs2073244位点基因型不同程度的影响了低出生体重儿的发生率。

英文摘要：

Objective： To explore the correlation between Pax -9 genetic polymorphism and low birth weight infants. Methods： 60 low birth weight infants and 70 normal birth weight infants were selected, the three gene locus （rs2073244, rs2073247, rs4904210） of Pax - 9 gene were detected by polymerase chain reaction - restriction fragment length polymorphism （ PCR - RFLP）, and the genotypes and dis- tribution frequency of alleles were compared. Results ： There was significant difference in the total distribution frequency of Pax - 9 gene in rs2073247 situs and rs4904210 situs （X2 = 14. 53 and 16. 66, P 〈 0. 05）, but there was no difference in rs2073244 situs （X2 = 5.74, P 〉 O. 05） . The distribution frequencies of AG genotype in rs2073244 situs, TT genotype in rs2073247 situs and CC genotype in rs4904210 situs in low birth weight infants group were significantly higher those in normal birth weight infants group （ P 〈 0. 05 ）, while the distribution frequencies of AA genotype in rs2073244 situs, TC genotype in rs2073247 situs and CG genotype in rs4904210 situs reversed （P 〈 0.05） . Conclusion： The distribution frequencies of rs2073247 situs, rs4904210 situs and rs2073244 situs in Pax -9 gene affect the incidence of low birth weight infants.