常染色体显性遗传性听神经病MPZ基因序列分析

Sequence analysis of MPZ gene in a family with dominantly inherited auditory neuropathy

目的:了解MPZ基因是否与1个常染色体显性遗传性听神经病中国家系的发病相关。方法:选择1个现存3代9人的常染色体显性遗传性听神经病家系为研究对象,用基因组DNA抽提试剂盒提取外周血DNA。首先,对所有家系成员DNA进行MPZ基因第3外显子的PCR扩增,扩增产物经纯化后直接测序;然后,采用相同方法对1名家系听神经病患者进行MPZ基因全部6个外显子的PCR扩增和测序分析。测序结果与标准序列对照进行突变检测。结果:所有研究对象的基因区域均扩增成功,序列分析在MPZ基因第3外显子上未检测到Thr124Met和Tyr145Ser 2个已知的突变,整个MPZ基因编码区也未见新的致聋突变。结论:该家系成员MPZ基因上未发现有意义的突变位点,提示新基因参与家系耳聋的发生。

Objective：To investigate whether the MPZ gene contributes to the non-syndromic hearing loss of a Chinese pedigree with dominantly inherited auditory neuropathy （AN）. Methods：Nine members in three generations of the family were selected for this study. Genomic DNA was isolated from the peripheral leukocytes of the patients using the Puregene DNA Isolation Kits. Firstly,the DNA fragment of the subjects was PCR amplified using oligonucleotides corresponding to exon 3 of the MPZ gene. Each fragment was purified and subsequently analyzed by direct sequencing in an Applied Biosystems 3730 automated DNA sequencer. The entire MPZ gene of one affected subject Ⅲ3 were then amplified with 6 overlapping fragments, and submitted for sequence analysis as described above. The resultant sequence data were compared with the standard sequence to identify deafness-associated mutations. Results：PCR amplifications were successfully conducted in all the subjects. We failed to detect the presence either mutations of Thr124Met and Tyr145Ser in the exon 3 that have been reported,or any other deafness-associated mutations in the whole MPZ gene,by sequence analysis. Conclusion：The MPZ gene seems not contribute to the pathogenesis of this Chinese AN family,which suggesting new gene （s） involvement.