非综合征性耳聋患儿家庭耳聋易感基因突变检测分析

Detection and analysis of susceptibility genes for family deafness in children with non syndromic hearing loss

目的研究广东惠州地区耳聋家庭中与耳聋相关的GJB2、GJB3、SLC26A4和线粒体DNA(mtDNA)的基因型分布和发病特征,为耳聋基因筛查提供科学的参考数据。方法 2017年3-7月,收集37个耳聋患儿家庭外周血样本99例。行听力测试并采用聚合酶链反应联合寡核苷酸探针导流杂交法检测,检测范围包括GJB2、GJB3、SLC26A4和mtDNA的4个基因13个突变位点。结果 99例样本中50例未通过听力测试,不通过率为50.51%(50/99)。在37个耳聋家庭中,检出携带耳聋基因家庭有11个,检出35例阳性样本,检出率为35.35%(35/99)。共检出10种突变类型,主要包括GJB2基因突变16例,SLC26A4基因突变19例。其中双等位基因突变(纯合突变+复合杂合突变)9例,检出率为9.09%(9/99);26例仅检测到1个等位基因突变,检出率为26.26%(26/99)。6个耳聋家庭夫妻为同种类型耳聋基因突变携带者,且4个妈妈处于早孕期,行产前诊断。结论 SLC26A4基因突变是导致本研究患儿耳聋最常见的原因,其次是GJB2基因突变。对遗传性耳聋易感基因的准确快速诊断有利于早发现早治疗,从而改善患者的生存质量。

Objective To investigate the genotype distribution and clinical feature of GJB2,GJB3,SLC26A4 and mitochondria DNA(mtDNA)related to deafness in deaf families in Huizhou City,Guangdong province,so as to provide scientific data for deafness genes screening.Methods From March to July 2017,99 peripheral blood samples from 37 deaf families were collected.Hearing tests were performed and polymerase chain reaction and oligonucleotide probe guided hybridization were used to detect 13 mutations in 4 genes including GJB2,GJB3,SLC26A4 and mtDNA.Results Of the 99 samples,50 samples did not pass the hearing test,and the rate of failure was 50.51%(50/99).Of the 37 deaf families,11 were found to carry deaf genes,and 35 were positive,the detection rate was 35.35%(35/99).A total of 10 mutations were detected,including 16 mutations in the GJB2 gene and 19 mutations in the SLC26A4 gene.Among them,9 cases had double allele mutation(homozygous mutation+compound heterozygous mutation),the detection rate was 9.09%(9/99),26 cases had only one allele mutation,the detection rate was 26.26%(26/99).6 deaf couples were carriers of the same type of deaf gene mutation,and 4 mothers were in early pregnancy for prenatal diagnosis.Conclusion Mutation of SLC26A4 gene is the most common cause of deafness in this study,followed by GJB2 gene mutation.Accurate and rapid diagnosis of hereditary deafness susceptibility genes is conducive to early detection and treatment,thus improving the quality of life of patients.