SMAD5基因在中国耳聋患者中的突变筛查研究

Mutation screening of Smad5 gene in patients with hearing loss in China

目的探讨SMAD5基因与中国耳聋人群的相关性。方法采集听力诊断中心143名耳聋患者的外周静脉血,提取基因组DNA。选取听力正常的对照组149人。应用Primer3在线引物设计软件在SMAD5基因的编码区及其毗邻的内含子区域设计6对引物进行PCR(Polymerasechainreaction)扩增反应。PCR产物直接测序,测序结果应用DNAStar软件进行序列比对分析。统计处理应用STATA8.0软件。结果143名耳聋患者中含有8种听力损失表型,其中感音神经性聋及先天性聋患者达到32名。PCR扩增SMAD5基因,在内含子中发现5种SNP,进行基于群体资料的关联分析,结果显示这5种SNP与致病基因不存在显著关联。结论在本研究选择的各种耳聋表型患者中未发现SMAD5基因与其关联,说明SMAD5在本组研究中尚未显示其与耳聋相关的直接证据,但不能完全排除其在人类听觉基因调控网络中的作用(如与耳聋疾病位点处在连锁平衡状态或不与耳聋疾病位点连锁)。

Objective To investigate the possible association between the SMAD5 gene and the patients with different phenotypes of hearing loss. Methods 143 patients from a hearing diagnosis center were recruited. The vein blood of the patients who provided an informed consent was collected and DNA was extracted. 149 controls with normal hearing also enrolled in the study. Six primers for amplifying the SMAD5 coding region including the neighbouring introns Using polymerase chain reaction （PCR） were designed with the Primer3 online software. PCR products were directly sequenced and aligned using DNAStar software. STATA 8.0 software was used for population-based association analysis of the single nucleotide polymorphisms （SNPs） within the gene. Results Eight phenotypes of hearing loss in the 143 patients were characterized and 32 patients were found having sensorineural hearing loss or congenital hearing loss. Five SNPs were identified in the introns of gene SMADS. Population-based association analysis was performed between cases and controls in terms of the SNPs＇ allele distributions. In the study, the SNP-phenotype. association was not found between the SMAD5 gene and several hearing loss phenotypes. Conclusion Based on the dataset collected from this study, although five SNPs were present in the hearing loss patients, their association with the SMAD5 genetic variants was not statistically significant （P 〉 0.05）. The finding implied that the SMAD5 gene might not be the direct causative gene for deafness, yet these data might not able to exclude its putative role（s） in the gene network of auditory system （e.g. due to linkage equilibrium between the gene and the disease locus or not linked at all）