线粒体DNA 12SrRNA A1555G突变在中国西北地区的流行病学研究

目的 调查中国西北地区非综合征感音神经性耳聋患者群体中线粒体DNA 12SrRNA A1555G突变的流行情况．评估开展这一突变检测的临床价值。方法 收集中国西北地区共612例感音神经性聋患者外周静脉血，从白细胞中提取DNA，多聚酶链反应（PCR）扩增线粒体DNA目的片断，Alw26I限制性内切酶检测A1555G点突变，而后对阳性病例的PCR产物进行DNA测序验证。结果 在612例感音神经性聋患者中，共发现56例A1555G突变患者：其中217例为药物性耳聋患者，有47例为A1555G点突变阳性；在其余395例非药物性耳聋患者中，检出9例A1555G突变。结论 中国西北地区的药物性耳聋较为常见，A1555G突变在本地区感音神经性耳聋人群中有较高的检出率（9．15％），在该地区开展线粒体DNA12SrRNAA1555G突变检测有重要意义。

Molecular epidemiology of mitochondrial DNA A1555G mutation in Northwest China

Objective To explore the incidence of the mitochondrial 12S ribosomal RNA A1555G mutation in Northwest Chinese populations with nonsyndromic sensorineural hearing loss,and to estimate the clinical value of this molecular diagnosis. Methods Blood samples were obtained from 612 patients with nonsyndromic sensorineural hearing loss in Northwest China. Genomic DNA was extracted from isolated leukocytes. The mitochondrial DNA fragments were amplified by polymerase chain reaction. MtDNA 12SrRNA A1555G mutation was detected using Alw26I restriction endonuclease digestion,followed by direct sequencing to identify the A1555G mutation. Results Forty-seven individuals from 217 patients with aminoglycoside antibiotic-induced deafness(AAID) had homoplasmic mtDNA 12SrRNA A1555G mutation,furthermore,this mutation was found in 9 individuals from other 395 patients without a history of aminoglycoside antibiotic use. Conclusion The aminoglycoside antibiotic-induced deafness is one of the main types of deafness in this region; also,there is a high prevalence of the mtDNA A1555G mutation in this region. Thus screening for mtDNA 12SrRNA A1555G mutation is useful to molecular diagnosis for AAID .