大连地区108例非综合征性耳聋者及亲属耳聋基因测序结果分析

摘要

To investigate the deafness gene mutation in patients with nonsyndromic hearing impairment and their first-degree family relatives in Dalian. Methods A total of 108 subjects (98 new borns with nonsyndromic hearing impairment and 10 family relatives) were recruited. Pure tone audiometry, acoustic immittance audiometry and brainstem evoked poten-tials were tested. Peripheral blood samples were obtained, from which genomic DNA was extracted for PCR processing. Two mutation sites of mtDNA 12SrRNA genes and all the exons in four most common deafness pathologic gene were examined with the Ion torrent semiconductor sequencing method, including GJB2, GJB3, GJB6 and SLC26A4. Results Forty-five of the 108 participants (41.7%) and thirty-eight of the 98 patients(38.8%)showed pathologic gene mutation sites, involving 3 deafness gene and 23 mutation sites. We discovered a rare splice site mutation of SLC26A4 IVS15-2A>T gene. In 38 cases, 34 showed singgle gene mutation and 4 showeed double gene mutations. GJB2 mutations were seen in 27 cases (64.3%,27/42), SLC26A4 mutation were seen in 12 cases(28.6%,12/42)and GJB3 mutation were seen in 3 cases(7.1%,3/42). No case appeared GJB6、12s rRNA mutation. 33 cases who failed Universal Newborn Hearing Screening showed moderate to severe hearing loss by auditory brainstem response(ABR) test. Pathologic gene mutation was detected in 15 of them(45.5%,15/33).We detected 62 sporadic cases with bilateral neurosensory deaness ,20 of them appeared pathologic gene mutation (32.3%,20/62). Conclu-sion Pathologic gene mutation was detected in over 1/3 of the 98 nonsyndromichearingimpairment patients in Dalian. GJB2 mutation is the most common one. Genetic screening for these hot-spot mutations is the pivotal step for the diagnosis to high risk children who have passed Universal Newborn Hearing Screening and bilateral nuerosensory deafness cases.%目的：了解大连地区非综合征性耳聋者及直系亲属耳聋基因突变情况。方法收集大连地区非综合征型耳聋患者及部分直系亲属共108例（患者98例，亲属10人），行纯音测听、声导抗测听及脑干诱发电位等听功能检查,采集末梢血用Ion torrent半导体测序方法，检测GJB2、GJB3、GJB6和SLC26A4基因的全外显子和线粒体12S rRNA基因的2个突变位点。结果病理性基因突变在108例受检者中检出率为41.7%（45/108）,98例患者中检出率为38.8%（38/98），涉及3个基因23个突变位点，发现1例非常罕见的SLC26A4 IVS15-2A>T剪接位点杂合突变。38例患者中34例（89.5%，34/38）为单基因突变，其中13例为复合杂合突变、6例为纯合突变；另外4例（10.5%，4/38）有两个基因同时发生突变。38例患者的42例次基因突变中，27例次(64.3%,27/42）为GJB2基因突变，12例次（28.6%，12/42）为SLC26A4基因突变，3例次（7.1%，3/42）为GJB3基因突变，没有检测到GJB6、12S rRNA基因突变；听力筛查不通过、经ABR测试为中重度感音神经性耳聋患儿33例，15例（45.5%，15/33）检测到病理性基因突变；成人散发性双耳感音神经性耳聋患者62例，病理性基因突变检出20例（32.3%，20/62）。结论大连地区98例非综合征性耳聋者，超过1/3检测到病理性耳聋基因突变，并以GJB2基因突变最常见。听力筛查通过的高危儿童及原因不明的双侧感音神经性耳聋者，实施热点致聋基因测序可以提高耳聋的病因诊断率。