儿童特发性间质性肺疾病与肺表面活性物质-B基因多态性的相关性研究

Correlation of polymorphism of surfactant protein-B gene in children with idiopathic interstitial lung disease

目的探讨肺表面活性物质（surfactant protein，SP）-B外显子4（T131I）位点的基因多态性与儿童特发性间质性肺疾病的相关性。方法收集2013年10月至2016年9月在深圳市儿童医院和广西医科大学附属第一医院住院诊断为特发性间质性肺疾病的患儿共67例为病例组，选择同期与特发性间质性肺疾病无关的因呼吸道感染在深圳市儿童医院住院的102例患儿为对照组，采用SP—B全外显子和侧翼区高通量测序法对所有病例采集的标本进行检测，分析外显子4（T131I）位点的基因型和等位基因分布。结果病例组和对照组SP—B基因外显子4（T131I）位点的基因型均可检出3种，CC、CT及TT型，病例组所占比例分别为67．16％、25．37％、7．46％，对照组分别为56．86％、35．29％、7．84％，两组基因型分布的差异无统计学意义（Х^2=1．981，P=0．371）；病例组C等位基因频率为79．85％，对照组为74．51％，差异无统计学意义（Х^2=1．288，P：0．256）。对照组SP-B基因外显子4（T131I）位点的基因突变频率为43．14％（44／102），与人类基因组千人人群数据库基因突变频率平均值52．00％比较，差异无统计学意义（P〉0．05）；与欧洲千人人群数据库基因突变频率53．88％、南亚千人人群数据库基因突变频率45．50％和美洲整体人群数据库基因突变频率41．93％比较，差异无统计学意义（P〉0．05），而与东亚千人人群数据库基因突变频率26．39％和非洲千人人群数据库基因突变频率80．18％比较，差异有统计学意义（P〈0．05）。结论SP—B基因外显子4（T131I）位点的基因多态性与儿童特发性间质性肺疾病易感性不存在相关性，外显子4（T131I）位点的基因突变频率与种族人群和地域具有一定的差异性。

Objective To investigate the distribution of surfactant protein-B （SP-B） gene single nucleotide polymorphisms and to clarify the correlation between SP-B gene polymorphisms and idiopathic interstitial lung disease （ILD） in children. Methods Sixty-seven children with idiopathic ILD （case group） and 102 children without idiopathic ILD（ control group）were selected from October 2013 to September 2016 in Shenzhen Children＇s Hospital and the First Affiliated Hospital of Guangxi Medical University. Total exons and flanking region of SP-B were detected by high-throughput sequencing, genotype and allele distribution of exon 4（T131I）were analyzed. Results SP-B exon 4（T131I） genotypes could check out three genotypes： namely CC,CT and TT. The frequencies of genotype CC,CT and TT of exon 4（T131I） in the case group were 67.16%, 25.37%, 7.46%, and in the control group were 56. 86%, 35.29%, 7.84%, respectively. There was no significant difference in genotype distribution between the two groups（Х^2 = 1. 981 ,P = 0. 371 ）. Frequency of allele C was 79. 85 % in the case group and 74. 51% in the control group, no significant difference showed between the two groups（Х^2 = 1. 288 ,P = 0. 256）. In the control group, the mutation frequency of SP-B exon 4（T131I） was 43.14% （44/102） ,compared to the frequency of mutations in the population data in the thousands of human genome programs was 52. 00% ,in European was 53.88% ,in South Asia was 45.50% ,and in American was 41.93% （P 〉0. 05） ;but the frequency of gene mutations was 26. 39% in East Asia and 80. 18% in Africa, there were significant differences compared to the control group （ P 〈 0.05 ）. Conclusion The genetic polymorphism of SP-B exon 4 （ T131 I） is not correlated with the susceptibility of idiopathic ILD in children. The mutation frequency of SP-B exon 4（T131I） is related to the race and the region.