邯郸市特教学校耳聋患者SLC26A4基因突变分析

目的对SLC26A4基因编码区突变进行分析,以明确非综合征型耳聋患者发病的分子学基础,为耳聋基因的筛查和产前诊断提供实验和理论依据。方法选取河北省邯郸市特教学校100例非综合征型耳聋患者的静脉血,用于SLC26A4基因的聚合酶链反应(PCR)扩增,应用直接测序法分别对SLC26A4基因20个外显子进行直接测序。结果①耳聋分型:根据世界卫生组织《障碍、残疾和残废的国际分类》(1980年)中听力损失分级标准进行评定,100例患者均被诊断为重度以上双侧耳聋且均为非综合征型耳聋。②PCR检测结果:以100例患者的DNA样本(SLC26A4基因20个外显子)进行PCR扩增,扩增产物片段大小与预期相符。③测序结果:被检测的100例非综合征型耳聋患者中,6例SLC26A4突变导致的内耳最常见的畸形前庭水管扩大(EVA),携带SLC26A4基因ⅣS7-2A>G纯合突变的6例(占6%),携带SLC26A4基因单杂合突变和复合杂合突变的14例(占14%)。结论河北省邯郸市特教学校耳聋患者存在较高的SLC26A4基因ⅣS7-2A>G纯合突变及携带SLC26A4基因单杂合突变和复合杂合突变,因此对SLC26A4基因突变进行早期筛查、早期诊断,可有效避免高危人群出现耳聋,提高人口素质。

Mutation Analysis of SLC26A4 Gene in Deaf Population from Special Educational School of Handan City

Objective To analyze mutations of coding sequence of SLC26A4 gene,to clarify the molecular basis of the onset of the non-syndromic hearing impairment(NSHI),and provide experimental and theoretical references for deafness gene detection and prenatal diagnosis.Methods Venous blood of 100 cases of(NSHI)patients from Special Educational School of Handan City were collected.The expression of SLC26A4 gene expression were detected by using polymerase chain reaction(PCR) methods.Direct sequencing was used to detect the sequence of 20 exons of SLC26A4 gene.Results ①Deafness categorization:according to the hearing loss classification standard of the world health organization(WHO) the International Classification of the Barrier,the Disabled and the Crippled(1980),100 cases were diagnosed as severe bilateral deafness and were all non-syndromic deafness.②PCR test results: DNA samples(SLC26A4 gene 20 explicit son) of the 100 cases PCR amplification product segment size matched with expectations.③Sequencing results:among the 100 cases,there were 6 cases of the inner ear SLC26A4 mutations resulted the most common deformity vestibular conduit expansion(enlarged vestibular agueduet,EVA),6(6%) carried homozygous SLC26A4 IVS7-2A>G mutation,and 14(14%)carried SLC26A4 single heterozygous genes mutations and composite heterozygous mutation.Conclusion Incidence of homozygous SLC26A4 IVS7-2A>G mutation,and SLC26A4 single heterozygous genes mutations and composite heterozygous mutation are high in Special Educational School of Handan City.Therefore,early screening and early diagnosis of SLC26A4 gene mutations can effectively avoid high-risk groups deafness and improve population quality.