新生儿呼吸窘迫综合征SP-A基因多态性的研究

目的：探讨新生儿呼吸窘迫综合征(respiratory distress syndrome，RDS)肺表面活性蛋白的基因表达特点已成为RDS发病机制的研究热点，目前国内尚无有关报道。该文旨在探讨中国早产儿SP-A基因型的表达特点，以及SP-A等位基因与RDS风险的相关性,从基因水平探讨RDS发病机制,以便更好的预防和治疗。方法：选择已确诊RDS的早产儿为实验组，因早产寄养的新生儿为对照组，取抗凝静脉血2 mL，采用SSCP方法检测SP-A基因6A2、6A3、1A0、1A1。结果：SP-A1等位基因6A2、6A3的分布频率在RDS组分别为0.50、0.056，在对照组分别为0.214、0.107；SP-A2等位基因1A0、1A1的分布频率在RDS组分别为0.722、0.667， 在对照组分别为0.679、0.821。两组比较SP-A1等位基因6A2在RDS组有过表达现象（P<0.05），而6A3有低表达倾向（P>0.05）；而SP-A2等位基因1A0、1A1的分布频率两组无显著差异（P>0.05）。在胎龄<32周的早产儿SP-A等位基因两组之间比较差异无显著性；而在>32周的早产儿，SP-A1等位基因6A2在RDS组有过表达现象（分布频率0.56，0.15，P<0.05）。男婴等位基因6A2在RDS组有过表达倾向（P>0.05）。结论：在该组正常早产儿人群中SP-A1等位基因6A2、6A3均为低频率分布，SP-A2等位基因1A0与1A1均为高频率分布，1A0、1A1的高表达为该组早产儿基因分布的特点；在 RDS患儿中，SP-A1等位基因6A2有高表达，提示6A2可能为RDS的易感基因。

Genetic polymorphism of surfactant protein A in neonatal respiratory distress syndrome

Objective To investigate the characteristics of gene expression of surfactant protein A in Chinese premature infants and the association between surfactant protein A and the risk of neonatal respiratory distress syndrome(RDS).Methods Vein-blood samples(2 mL)from 18 Chinese premature infants with RDS and 28 controls were assayed for SP-A genotypes 6A2,6A3,1A0 and 1A1 by SSCP.Results The frequency of allele distribution of SP-A1 allele 6A2 and 6A3 was 0.50 and 0.056 respectively in the RDS group and was 0.214 and 0.107 in the control group.Compared with the controls,SP-A1 allele 6A2 was over-represented in the RDS group(P<0.05).In contrast,SP-A1 allele 6A3 tended to be under-represented in the RDS group but there was no statistical difference when compared with the controls.The frequency of allele distribution of SP-A2 allele 1A0 and 1A1 was 0.722 and 0.667 respectively in the RDS group and was 0.679 and 0.821 respectively in the control group.There were no significant differences in the distribution frequency of SP-A2 allele 1A0 and 1A1 between the two groups.In the infants born at gestation >32 weeks,SP-A1 allele 6A2 was over-represented in the RDS group compared with the control group(frequency:0.56 vs 0.15;P<0.05).Conclusions The frequency of SP-A1 allele 6A2 and 6A3 was low,in contrast,the frequency of SP-A2 allele 1A0 and 1A1 was high in normal Chinese premature infants.SP-A1 allele 6A2 may be a susceptible gene for RDS.