111 例未通过听力筛查新生儿常见耳聋基因突变位点分析

目的了解未通过听力筛查新生儿耳聋基因突变情况。方法随机选取听力筛查未通过、经听觉脑干诱发电位(ABR)测试为感音神经性耳聋患儿111例,收集足跟血血片,提取基因组DNA后,检测GJB2、SLC26A4和线粒体12 Sr RNA基因中的11个热点的突变,分析听力损失程度与突变的关联。结果 111例新生儿中,共检出携带耳聋基因突变24例(21.6%)。其中,GJB 2基因突变14例(12.6%),包括235 del C单杂合突变5例,235 del C和299_300 del AT复合杂合突变5例,以及235del C纯合突变、299_300del AT单杂合突变、176_191del16和235del C复合杂合突变、299_300del AT和508_511 dup AACG复合杂合突变各1例;SLC 26 A 4基因突变10例(9.0%),包括IVS 7-2 AG单杂合突变2例,1226 GA单杂合突变3例,2168 AG单杂合突变2例,IVS7-2AG和2168 AG复合杂合突变3例。本组耳聋患儿中未检出线粒体基因突变。结论未通过听力筛查新生儿中,超过1/5检测到聋基因突变,并以GJB2基因突变最常见,实施热点致聋基因检测可以提高耳聋的病因诊断率。

The analysis of common mutation in deafness-associated gene in 111 neonates who failed to pass newborn hearing screening

Objective To explore the genetic mutation in neonates who failed to pass hearing screening.Methods A total of 111 cases of neonates who failed to pass hearing screening and were conifrmed sensorineural deafness by auditory brainstem evoked potential (ABR) were randomly selected. The heel blood was collected and DNA was extracted.GJB2, SLC26A4, and 11 mutation hotspots in mitochondria gene12SrRNA were tested. The relationship between degree of hearing loss and gene mutation was analyzed.Results In 111 neonates, mutation in deafness gene were found in 24 cases (21.6%) . Among them 14 cases (12.6%) hadGJB2 gene mutation including 5 cases of 235delC single heterozygous mutation, 5 cases of 235delC, and 1 case each of 299_300delAT compound heterozygous mutation, 235delC homozygous mutation, 299_300delAT single heterozygous mutation, 176_191del16 and 235delC compound heterozygous mutation, and 299_300delAT and 508_511dupAACG compound heterozygous mutation respectively. Ten cases (9.0%) hadSLC26A4 gene mutation including 2 cases of IVS7-2A>G single heterozygous mutation, 3 cases of 1226G>A single heterozygous mutation, 2 cases of 2168A>G single heterozygous mutation, and 3 cases of IVS7-2A>G and 2168A>G compound heterozygous mutation. Mitochondrial gene mutations were not detected. Conclusions Deafness gene mutation is detected in more than 1/5 neonates who failed to pass newborn hearing screening. GJB2 gene mutation is the most commons. The implementation of hotspots deafness gene detection can improve the diagnostic rate of deafness.