AUNX1基因座位内的听神经病家系GRIA3基因突变分析

Analyzing GRIA3 Gene Mutations Located in AUNX1 Locus in a Chinese Pedigree with Auditory Neuropathy

目的在定位于AUNX1基因座位内的非综合征型听神经病家系中进行GRIA3基因突变检测,分析基因与该家系表型的关系。方法AUNX1家系共有43人,其中听神经病患者7人,听力正常36人。GRIA3基因共有16个外显子,针对GRIA3基因的全部编码序列(第2～16外显子)设计15对引物,进行PCR扩增,对扩增产物进行2%的琼脂糖凝胶电泳,检测其纯度、浓度,应用PCR产物直接测序法进行基因突变检测;使用DNAStar软件进行测序序列的对比分析,检测基因突变。结果在GRIA3基因第9外显子上检测到一个同义突变1200T>C(N400N),家系43人中5人检测了此位点,其中1人(听力正常男性)出现了这种变化。在距离第6个外显子前的第16个核苷酸的内含子(DNA第210 646位)中检测到T>C纯合和T/C杂合两种改变,家系43人中14人(均为听力正常)发生T>C纯合突变,10人(均为听力正常)发生T/C杂合突变。结论在AUNX1家系成员中检测到两个位点的三种碱基改变(1200T>C,210646T>C纯合或210646T/C杂合),没有引起氨基酸的改变,考虑GRIA3基因可能不是AUNX1听神经病家系的致病基因,需进一步研究探索。

Objective To analyze the mutations of GRIA3 gene for the purpose of identifying the causative gene located in AUNX1 locus in a Chinese pedigree with auditory neuropathy. Methods There were 43 members in this pedigree, among whom 7 were patients and 36 had normal hearing. The coding sequences of GRIA3 gene were amplified by polymerase chain reaction （PCR） with 15 pairs of primers, and PCR products bidireetional sequencing were performed and analyzed with DNAStar Software. Results Two point mutations were detected. The first mutant point was 1200T〉C （N400N）on exon 9 in 1 of 5 members with normal hearing. The second mutant point was the sixteenth base on an intron before exon 6（DNANo. 210646）, including T〉C and T/C mutations, which were found in 14 and 10 members with normal hearing. Conclusion We found two point mutations caused no amino acid changed, inconsistent with the clinic phenotype in the pedigree. GRIA3 gene isn＇t the responsible gene for this pedigree with auditory neuropathy.