SNP敏感性分子开关对神经性耳聋GJB3中C→T突变点的识别  

Discrimination of C→T Point Mutation in GJB3 Senorineural Deafness by SNP-operated on/off Switch

作　　者：彭翠英[1] 张佳[2] 郭紫芬[2] 陈琳玲[2] 廖端芳[2] 

机构地区：[1]南华大学生物教研室,湖南衡阳421001 [2]南华大学药物药理研究所

出　　处：《南华大学学报（医学版）》2003年第2期132-134,共3页Journal of Nanhua University(Medical Edition)

基　　金：国家自然科学基金资助 ( 3 0 1710 84);国家"973"项目部分资助 (G2 0 0 0 0 5 690 5 )

摘　　要：目的　利用硫化修饰的碱基特异性引物与高保真DNA聚合酶所构成的对SNP敏感的“开 关”系统识别神经性耳聋GJB3中C→T突变点。方法　以非耳聋志愿者染色体DNA为模板 ,采用配对及三末端不配对的 3′硫化修饰引物 ,使用不同保真度DNA聚合酶进行引物延伸反应。结果　该方法仅能使野生型基因相关的引物得以延伸 ,而耳聋基因相关引物则不能延伸。结论　本方法可在单碱基水平对遗传病相关基因进行特异性检测 。Objective To apply the 'on/off' switch of 3′ exonuclease in single base discrimination of C to T point mutation in GJB3 sensorineural deafness gene. Methods Two-directional primer extension was performed using polymerases with and without 3′ exonuclease activity. The 3′ phosphorothioate-modified allele- specific primers were evaluated in their effects on primer-extension with genomic DNA harboring wild type allele only. Results Amplified by exo + polymerase, primers targeting wild type allele were extended while no products were generated from primers targeting point-mutated deafness-related allele. As a control, exo - polymerase yielded products from both types of primers. Conclusion These data suggest that the 'off-switch' mediated by exo + polymerase is more reliable as compared to exo - polymerase in SNP assay and the novel 'on/off' switch has enormous application in the diagnosis of monogenic diseases.

关 键 词：神经性耳聋 高保真DNA聚合酶 GJB3 C→T突变点 SNP 单碱基突变 单基因遗传病 

分 类 号：R764.431[医药卫生—耳鼻咽喉科]