目的 探讨SP-B外显子4（T131I）位点与内蒙古西部地区新生儿呼吸窘迫综合征（NRDS）易感性的关系。方 法 采用病例对照研究方法，选择于2009年9月－2016年2月住院诊断为NRDS的蒙古族早产儿86例作为病例组，选择 同期未发生NRDS的蒙古族早产儿86例作为对照组。应用聚合酶链反应-单链构象多态（PCR-SSCP）分析技术及基因测 序技术检测SP-B基因exon4区域上有无突变，以及T131I位点的基因型、等位基因分布。结果 在所有研究对象中，SP-B 基因exon4区域无突变发生，T131I位点基因型均可检出3种基因型，即CC、CT、TT，病例组所占比例分别为58.1%、 27.9%、14.0%，对照组分别为40.7%、43.0%、16.3%，两组基因型分布的差异无统计学意义（χ2=5.57， P=0.062）；病例 组C等位基因频率为80.2%，高于对照组（64.0%），差异有统计学意义（χ2=11.33， P ＜ 0.001）。 结论 SP-B基因外显子 4 （T131I）位点基因多态性可能是蒙古族NRDS易感基因之一。

 Objective To explore the relationship between the SP-B exon 4 (T131I) and susceptibility of neonatal respiratory distress syndrome (NRDS) in Western Inner Mongolia. Methods A case control study from September 2009 to February 2016 in the Affiliated Hospital of Inner Mongolia Medical University neonatal ward was performed. Eighty-six preterm infants of Mongol nationality suffered from NRDS were selected as the case group, while eighty-six preterms in the same period without NRDS were selected as the control group. Polymerase chain reaction were used to detect mutations in exon 4 of SP-B, genotype, and allelic distribution of T131I of exon 4, as well. Results  Newborns in western Inner Mongolia: ①No mutation was found in SP-B exon 4. ②The frequencies of genotype CC, CT and TT of T131I in the NRDS group were 58.1%、27.9% and 14.0%, respectively. Frequency of allele C were 80.2%, and frequency of allele T were 19.8%.  In the control group,?the frequencies of genotype CC, CT and TT were 40.7%、43.0% and 16.3%, respectively. Frequency of allele C were 64.0%, and frequency of allele T were 36.0%, there was significant difference in the frequencies of SP-B exon 4 T131I sites between these two groups (P < 0.05). Conclusion There was no mutation found in SP-B exon 4. Exon 4 (T131I) gene polymorphism of SP-B gene may be one of the susceptible locus of Mongolian infants in the western region of Inner Mongolia.