新的基因复合杂合模式导致的综合征型耳聋家系研究  

Study on syndromic deafness caused by novel pattern of compound heterozygous variants in the CDH23 gene

作　　者：陈蓓[1] 张森 田永安 刘欢飞 柳丹华 薛夏 李瑞君 胡欣欣 关景元 汤文学 许红恩[2,5] Chen Bei;Zhang Sen;Tian Yongan;Liu Huanfei;Liu Danhua;Xue Xia;Li Ruijun;Hu Xinxin;Guan Jingyuan;Tang Wenxue;Xu Hongen(Department of Otology,the First Affiliated Hospital of Zhengzhou University,Zhengzhou 450052,China;Precision Medicine Center,Academy of Medical Science,Zhengzhou University,Zhengzhou 450052,China;Beijing Genomics Institute College,Zhengzhou University,Zhengzhou 450052,China;Henan Institute of Medical and Pharmaceutical Sciences,Zhengzhou 450052,China;Application Center for Precision Medicine Research,the Second Affiliated Hospital of Zhengzhou University,Zhengzhou 450052,China)

机构地区：[1]郑州大学第一附属医院耳科,450052 [2]郑州大学医学科学院精准医学中心,450052 [3]郑州大学华大基因学院,450052 [4]河南省医药科学研究院,郑州450052 [5]郑州大学第二附属医院精准医学研究应用中心,450052

出　　处：《中华耳鼻咽喉头颈外科杂志》2020年第9期822-829,共8页Chinese Journal of Otorhinolaryngology Head and Neck Surgery

基　　金：2018年河南省医学科技攻关计划项目(SBGJ2018043);郑州市协同创新重大专项(郑州大学)(18XTZX12004)。

摘　　要：目的采用高通量测序技术,对一个综合征型耳聋家系的致病基因及突变进行探究。方法2018年6月至2020年7月,郑州大学第一附属医院耳科联合郑州大学相关机构对该家系进行了研究。该家系来自河南省濮阳市,2代4人,详细询问病史及家族史,绘制家系图。先证者及其妹患有先天性耳聋,其父母表型正常。对该家系进行临床表型分析,包括影像学、听力检查(包括纯音测听、声导抗、脑干诱发电位、耳声发射)、前庭功能检查及眼科检查(包括视力、视野、眼底检查、视觉诱发电位及视网膜电图)。靶向捕获129个耳聋相关基因的编码区域,采用高通量测序方法检测,并进行生物信息学分析,筛选疑似致病突变,使用Sanger测序和minigene试验进行验证。结果该家系共2代4人,其中第二代2人(即2例患儿)均患有双耳重度感音神经性聋,伴有双眼视力下降、夜盲症、周边视野敏感度下降及部分视野缺损,前庭功能正常。2例患儿均携带CDH23(NM022124.5)、c.6049G>A(p.Gly2017Ser)、c.9856C>G(p.His3286Asp)及c.8699A>G(p.Asp2900Gly),其中c.6049G>A及c.9856C>G遗传自表型正常的父亲,c.8699A>G遗传自表型正常的母亲。错义突变c.9856C>G及c.8699A>G在gnomAD数据库中未收录。错义突变c.6049G>A位于第46号外显子的最后一个碱基位置,生物信息学软件预测其可能影响剪切,minigene试验表明,该突变位点会造成第46号外显子的跳跃,导致其所表达的蛋白功能异常。通过文献检索,并根据美国医学遗传学与基因组学学会遗传突变分类标准与指南,将c.6049G>A及c.8699A>G归类为致病/可能致病突变,c.9856C>G归类为临床意义未明突变。结论该病例是由CDH23剪切变异与错义变异复合杂合导致的Usher综合征1D型(USH1D),CDH23的这种复合杂合形式会导致USH1D。Objective:To explore the pathogenic variants of a family with syndromic deafness by high-throughput sequencing.Methods:The family was from Puyang City,Henan Province,and had four members,including two with syndromic deafness.The proband and his sister had congenital deafness,and their parents had normal phenotypes.The clinical phenotype of the family was characterized using clinical examinations and pedigree analysis.The clinical examinations included imaging examination,audiometry(pure tone audiometry,acoustic immittance,brainstem auditory evoked potential,and otoacoustic emission),vestibular function test,and ophthalmic examination(visual acuity test,visual field test,fundus examination,visual evoked potential,and electroretinogram).Target exome sequencing of 129 known deafness genes and bioinformatics analysis were used to screen suspected pathogenic variants.Sanger sequencing and minigene assay were used to verify and functionally investigate the mutation detected,respectively.According to the standards and guidelines for interpreting genetic variants proposed by the American College of Medical Genetics and Genomics,the variants c.6049G>A and c.8699A>G were classified as pathogenic/likely pathogenic,and the variant c.9856C>G was classified as variants of uncertain significance.Results:The probands and his sister had severe sensorineural hearing loss with decreased binocular vision,night blindness,decreased peripheral visual field sensitivity and partial visual field defect,and normal vestibular function.Both of them had three CDH23 mutations,including CDH23(NM_022124.5)c.6049G>A(p.Gly2017Ser),c.9856C>G(p.His3286Asp),and c.8699A>G(p.Asp2900Gly),The first two were inherited from the father,and the last one was from the mother.The missense variants c.9856C>G and c.8699A>G were not included in the gnomad database.The missense mutation c.6049G>A was located in the last position of exon 46 and was predicted to affect splicing by bioinformatics software.The minigene experiment showed that the mutation cause exon ski

关 键 词：聋 基因 USHER综合征 CDH23 DFNB12 

分 类 号：R764.43[医药卫生—耳鼻咽喉科]