迟发型常染色体显性遗传非综合征型感音神经性耳聋家系MYO7A基因新突变的鉴定  

Identification of a novel MYO7A gene mutation in a family with late-onset autosomal dominant nonsyndromic sensorineural hearing loss

作　　者：左杨瑾 文春秀[1] 何升[1] 覃再隆 阳奇[1] 易赏 陈碧艳[1] ZUO Yangjin;WEN Chunxiu;HE Sheng;QIN Zailong;YANG Qi;YI Shang(CHEN Biyan.Center Laboratory of Genetics and Metabolism,Maternity and Child Health Care of Guangxi Zhuang)

机构地区：[1]广西壮族自治区妇幼保健院遗传代谢中心实验室,广西出生缺陷临床医学研究中心,广西生殖健康与出生缺陷防治重点实验室,南宁530000

出　　处：《中国临床新医学》2025年第2期195-199,共5页CHINESE JOURNAL OF NEW CLINICAL MEDICINE

基　　金：广西卫生和计划生育委员会自筹经费科研课题(编号:Z2016702);广西生殖健康与出生缺陷防治重点实验室运行补助项目(编号:21-220-22)。

摘　　要：目的鉴定迟发型常染色体显性遗传非综合征型感音神经性耳聋家系MYO7A基因新突变。方法收集先证者及其家系成员的临床资料并绘制家系图,对先证者及其家系成员进行听力检查,对先证者进行基因组全外显子测序以定位目标耳聋基因及突变,对先证者及其家系成员的MYO7A基因进行Sanger测序验证。结果先证者16岁发病,被诊断为双侧重度感音神经性耳聋,其家系成员中共有18例语后进行性耳聋患者,呈常染色体显性遗传特征,发病年龄各不相同且存在家族世代间差异,Ⅳ代和Ⅴ代患者的发病年龄与Ⅲ代患者相比明显提早(P<0.05),呈现遗传早现趋势。先证者的双耳纯音听阈均值为83 dBHL(气导),骨导在各频段的最大强度均无响应,且在中高频段损失更为明显。全外显子测序定位了MYO7A基因第7号外显子c.689C>T杂合突变。经Sanger测序验证,先证者及其家系耳聋成员中均检出该突变。结论该文报道了MYO7A基因第7号外显子c.689C>T杂合突变导致的遗传性非综合征型耳聋,发现该突变在我国家系中独特的遗传早现现象。Objective To identify a novel MYO7A gene mutation in a family with late-onset autosomal dominant nonsyndromic sensorineural hearing loss.Methods The clinical data of a proband and her family members were collected and the family genogram were drawn.Hearing examination was performed on the proband and her family members.Genome whole-exome sequencing was performed on the proband to locate the targeted deafness gene and mutation,and MYO7A gene of the proband and her family members was verified by Sanger sequencing.Results The proband developed the disease at the age of 16 and was diagnosed with bilateral severe sensorineural hearing loss.There were 18 patients with post-lingual progressive hearing loss in the proband′s family members,characterized by autosomal dominant inheritance.The patients′age at onset varied among different individuals and differed between families and between generations.The onset age of patients with deafness in generationⅣand generationⅤwas significantly younger than that of patients with deafness in generationⅢ(P<0.05),showing a tendency of genetic early onset.The average pure-tone audiometric threshold in both ears of the proband was 83 dBHL(air conduction),and the maximum intensity of bone conduction in each frequency band showed no response,with more pronounced losses in the mid-to-high frequency ranges.A heterozygous mutation of c.689C>T in exon 7 of MYO7A gene was located by using whole-exome sequencing.Sanger sequencing confirmed that the mutation was detected in the proband and the deaf family members of the proband.Conclusion This paper reports a case of hereditary non-syndromic hearing loss caused by the heterozygous mutation of c.689C>T in exon 7 of MYO7A gene in a pedigree and discovers a unique genetic early onset phenomenon of this mutation in the family genogram in China.

关 键 词：常染色体显性遗传非综合征型耳聋 MYO7A 全外显子测序 DFNA11 感音神经性耳聋 耳聋基因诊断 

分 类 号：R764.43[医药卫生—耳鼻咽喉科]