散发感音神经性聋患者中GJB2基因突变检测的临床意义

目的探讨散发感音神经性聋患者中GJB2基因突变检测的临床指导意义.方法运用聚合酶链反应对解放军总医院听力诊断中心收集的242例散发感音神经性聋患者(135例语前聋患者,107例语后聋患者)的GJB2基因编码区进行扩增,扩增产物纯化后直接测序分析.结果 135例语前聋患者中GJB2基因致病突变的复合杂合和纯合个体有26例,占语前聋个体的19.26%;107例语后聋患者中未发现复合杂合和纯合致病突变,仅发现3例235delC杂合突变携带者、1例176del16杂合突变携带者.结论语前聋者GJB2基因致病突变阳性率明显高于语后聋患者,语前聋患者常规进行GJB2基因检测可从基因水平明确诊断,并为耳聋患者提供重要遗传信息.

The clincal significance of screening the mutations of GJB2 gene in sporadic patients with sensorineural hearing loss

OBJECTIVE The purpose of this study is to explore the clinical significance of screening the mutations of GJB2 gene in sporadic patients with sensorineural hearing loss. METHODS Subjects recruited were 242 patients with sensorineural hearing loss including 135 prelingual deafness patients and 107 postlingual deafness patients, which were collected by Chinese PLA hearing diagnosis centre. Genomic DNA was extracted from whole blood of patients, and the coding region of GJB2 gene was amplified by PCR. The amplicons of GJB2 gene were purified and directly sequenced by two directions. Sequencing results were analyzed by DANstar software. RESULTS There were 26 patients with homozygous and compound heterozygous pathogenic mutations of GJB2 gene in 135 prelingual deafness patients (19.26 %) . In contrast, homozygous and compound heterozygous pathogenic mutations of GJB2 gene were not found in 107 postlingual deafness patients with sensorineural hearing loss, only three patients were heterozygous carriers of 235delC of GJB2 gene, and one patient was heterozygous carriers of 176del16. CONCLUSION This study shows that frequencies of known pathogenic alleles of GJB2 gene are significantly higher in prelingual deafness than postlingual deafness. Routine detection of mutations in GJB2 gene is necessary, which not only give certain diagnosis from molecular level but also offer genetic information to the deafness.