遗传性传导性聋家系的遗传学特征分析

目的探讨遗传性传导性聋的家系遗传学特征。方法利用解放军总医院耳鼻咽喉研究所遗传资源网络所收集的遗传性聋家系资源,对发现的一个特殊的常染色体显性遗传的传导性听力损失伴上睑下垂大家系（028家系）,追踪调查了四代成员44人,对现存家系成员中具有遗传信息的19人进行了全身体检及听觉系统功能的检查,对2名传导性听力损失患者进行鼓室探查术。结果9名患者表现为先天性传导性听力损失伴双侧上睑下垂,1名患者表现为单纯上睑下垂,2名患者表现为单纯传导性聋。对2名典型传导性聋患者进行的鼓室探查术发现,其传导性听力损失源于中耳发育畸形（听骨链畸形与镫骨固定）。家系图谱分析显示该家系为常染色体显性遗传性聋家系。结论028家系是目前国内发现的第一个传导性聋表型大家系,进一步的基因定位与克隆研究将为遗传性传导性聋分子病理机制的研究创造条件。     

非综合征型X-连锁遗传性聋致病基因的研究进展

耳聋是最常见的遗传病之一。在我国，现有听力语言残疾者2057万，占全国现有各类残疾人总数(6000万)的34％，占全国人口的1．58％，在各类残疾性疾病中听力言语残疾性疾病高居首位。     

KCNQ4基因突变对常染色体显性遗传性聋家系的影响

目的 应用选基因法了解KCNQ4基因对中国耳聋家系的影响，检测其突变形式。方法 在一个6代相传的常染色体显性遗传性家系中，应用聚合酶链反应－单链构像多态性（polymerase chain reaction-single strand conformation polymorphism,PCR-SSCP)及克隆测序方法对KCNQ4基因的全部编码序列的PCR产物进行突变位点及多态序列检测。结果 在该家系中，对36位家系成员进行了KCNQ4基因的编码序列的检测，发现KCNQ4基因外显子2的分子多态现象，经测序分析证明这种多态是由于内含子中47个碱基复制数的差异所造成的。结论 本实验证明KCNQ4基因外显子2的编码区附近存在一个新的分子多态标记，这种分子多态表现出不同的基因型。通过对这些基因型与耳聋表型的相关分析发现，随着内含子复制数的增加，耳聋表现度明显增加。提示KCNQ4基因外显子2与外显子3之间内含子复制数的变化可能是这个家系出现耳聋的一种特征性分子标记。     

非综合征型聋的基因检测

先天性感音神经性聋50％是由遗传因素导致的,遗传因素中70％属于非综合征型先天性聋,引起非综合征型聋的热点基因有GJB2、SLC26A4、线粒体DNA和非热点基因GJB6、OTOF、跨膜丝氨酸蛋白酶等。通过对热点基因的产前诊断和新生儿早期检测可以实现遗传咨询、生育指导、聋儿早期防治和早期干预,减少听力残疾婴儿的降临。本文对引起非综合征型先天性聋的热点和非热点基因突变以及产前诊断的研究现状做一综述。     

一个迟发性非综合征型常染色体显性遗传性聋家系表型特征及致病基因初步探讨

目的分析一个迟发性遗传性聋大家系的临床表型,探讨该家系耳聋患者的致病基因。方法对一个湖南籍耳聋大家系成员进行详细的病史资料采集、体格检查、听力学检查,其中两名患者做了颞骨CT检查。绘制家系图。以先证者外周血基因组DNA为模板对候选致病基因进行涵盖全部编码序列聚合酶链反应(polymer-ase chain reaction,PCR)扩增,对扩增产物进行酶切纯化后用ABI 3730测序仪直接测序,用DNASTAR-Laser-gene SeqMan Pro软件对测序结果进行分析。结果系谱分析得知该家系是一个常染色体显性遗传性非综合征型聋家系。患者临床表现高度一致,均表现为在9～25岁时首先出现"嗡嗡样"耳鸣,然后自觉双耳听力下降,纯音测听显示早期为以高频听力下降为主的神经性聋,之后听力下降程度逐步加重并波及低频。对候选致病基因进行突变检测,未发现致病突变。结论该家系符合常染色体显性遗传的特征,其致病基因还有待于进一步探索。     

常染色体显性遗传非综合征性耳聋家系临床听力学特征分析及致病基因定位研究

目的 分析一个连续六代遗传的耳聋家系临床听力学特征及遗传特征,应用连锁分析的方法定位致聋基因.方法 通过家系调查,对一个高频感音神经性聋家系的资料进行了收集、整理及临床听力学和遗传学特征的分析.对家系成员进行调查并绘制系谱图.对调查的家系成员进行病史采集、体检、纯音测听和声导抗检查.结果 该耳聋家系遗传方式为常染色体显性遗传,耳聋患者表现为语后、迟发、渐进、以高频下降为主的听力损失,早期以高频听力损失为主,随着年龄增长逐渐累及全频听力,听力曲线由下降型变为平坦型.结论 该耳聋家系为常染色体显性遗传方式,表现为高频感音神经性耳聋,通过全基因组SNP扫描及连锁分析,初步定位于4号染色体190384723-190669832区域.     

一个常染色体显性遗传非综合征型聋家系分析

目的分析一个连续5代遗传的常染色体显性遗传性聋家系的临床听力学及遗传学特征。方法对一个常染色体显性遗传高频感音神经性聋家系成员进行全面体检及临床听力学检查,整理、分析家系资料,确定遗传规律,绘制遗传图谱并进行听力学特征分析。应用Sanger测序技术对该家系成员进行候选基因鉴定。结果该耳聋家系遗传方式为常染色体显性遗传,发病年龄各代间较稳定,在30-45岁之间。听力学表型为代代相传、迟发性、渐进性的中度至重度听力损失,患者早期以高频听力下降为主,随着年龄增长逐渐累及全频听力。应用Sanger测序技术进行候选基因鉴定,未发现致聋突变位点。结论该家系遗传学特征符合常染色体显性遗传方式,听力学具有早期高频听力下降并逐渐累及全频的特征,在候选基因中进行测序未发现致聋突变位点。因此希望通过对家系进一步的表型分析或者运用新一代测序技术,可以找到该家系的致聋基因。     

一个常染色体显性遗传性聋家系致病基因鉴定

目的分析常染色体显性遗传性聋家系的听力学及遗传学特征,利用高通量测序和连锁分析技术进行致病基因鉴定。方法采集一个常染色体显性遗传性非综合征型聋家系患者的临床资料,进行耳聋表型和遗传方式的判定并绘制家系图,提取家系成员外周血DNA,首先利用耳聋相关基因靶向测序,对家系先证者进行162个已知耳聋基因的筛查,然后采用全外显子组测序和连锁分析相结合的方法继续寻找致病基因,筛选出候选基因变异位点在家系中进行验证,以明确该家系致病原因。结果该耳聋家系来自河南省,编号为HBSY-012,现存三代共34人,14人诊断为感音神经性聋,为常染色体显性遗传模式,耳聋者发病年龄5~7岁,早期表现为高频听力下降,随年龄增长迅速发展为全频受累的重度或极重度感音神经性聋。对先证者进行已知162个耳聋基因筛查未发现致病突变,家系连锁分析将致病基因定位于第9号染色体q31.1-q31.3区间内(最大LOD值3.6076)。全外显子组测序数据分析显示在连锁分析定位的区间内未发现候选变异,在区间以外筛选出4个候选基因变异位点,候选变异为ANKMY2基因NM_020319c.822_826del、DDX49基因NM_019070c.341C>T、DEFB129基因NM_080831c.284G>T以及EVI5基因NM_005665c.2399C>T,并对4个候选基因变异位点进行家系验证,结果提示都不是该家系的致病突变。结论该常染色体显性遗传非综合征型聋家系连锁分析将致病基因定位于第9号染色体q31.1-q31.3区间内。耳聋相关基因靶向测序和全外显子组测序均未发现致病突变,考虑该家系致病原因可能为基因的非编码区域的突变或者罕见的CNV/SV所致。     

非综合征型遗传性聋研究现状及思考

研究表明,先天性聋群体中半数以上的患者是由遗传因素导致的,其中非综合征型聋约占70%,综合征型聋约占30%[1]。遗传性聋一般表现为中重度或重度感音神经性聋,为患者带来严重的交流障碍,也为家庭和国家带来了十分沉重的负担,所以遗传性聋一直是人们关注和研究的焦点。     

线粒体突变与非综合征型遗传性聋

耳聋是耳鼻咽喉科的常见病，严重影响人们的健康和生活质量，其中相当一部分由遗传因素引起。关于遗传性聋的总发病率在我国还没有可靠的统计资料，在发达国家，60％的耳聋因遗传缺陷引起，发生率约为1／800—1／1000。遗传性聋是指因遗传因素造成的内耳畸形或内耳毛细胞功能失常所导致的先天或迟发的感音神经性聋。目前至少有一半的严重先天性聋和部分的后天无诱因的渐进性聋是由遗传因素所造成的。[第一段]     

Early onset and rapid progression of dominant nonsyndromic DFNA36 hearing loss.

OBJECTIVE: To characterize the auditory and vestibular phenotype of autosomal dominant nonsyndromic DFNA36 hearing loss. STUDY DESIGN: Clinical evaluation of individuals with DFNA36 hearing loss linked to the D572N mutation of transmembrane channel-like gene 1 (TMC1). Medical history interviews, physical examinations, and pure-tone air conduction audiometry were performed in the field. Audiology and radiology reports were available and retrospectively reviewed for a subset of subjects. SETTING: Primary, secondary, and tertiary referral centers (retrospectively reviewed studies); subjects' homes (prospective clinical evaluations). PATIENTS: Thirteen affected members of a North American Caucasian family segregating DFNA36 hearing loss. MAIN OUTCOME MEASURES: Pure-tone audiometric thresholds and their rates of progression. RESULTS: Subjects had bilateral, symmetric, sensorineural hearing loss with a postlingual onset in the first decade of life. High frequencies were initially affected, followed by rapid progression (5.9 dB/yr for the 0.5/1/2/4-kHz pure-tone average) to profound deafness across all frequencies by the second decade of life. Two individuals had excellent auditory-verbal communication after rehabilitation with cochlear implants placed over two decades after total deafening. CONCLUSIONS: DFNA36 has one of the earliest onsets and most rapid rates of progression among the autosomal dominant non-syndromic hearing loss phenotypes. These distinctive features should facilitate its clinical detection and the development of clinical-molecular genetic diagnostic algorithms for dominant nonsyndromic hearing loss.     

常染色体显性遗传无综合征耳聋家系致病基因的排除性定位研究

目的 :定位一个常染色体显性遗传无综合征耳聋家系的致病基因。方法 :采用已报道的 2 2个常染色体显性遗传性耳聋位点的筛选微卫星标记物对该家系进行连锁分析。结果 :各位点连锁分析所得的LOD值均小于 1,显示该家系致聋基因与这 2 2个位点均不连锁。结论 :该家系的耳聋发病很可能由一新基因所致。     

The phenotype of DFNA13/COL11A2: nonsyndromic autosomal dominant mid-frequency and high-frequency sensorineural hearing impairment

OBJECTIVE: To study nonsyndromic progressive sensorineural hearing impairment in patients with a COL11A2 mutation (DFNA13) in a Dutch kindred. STUDY DESIGN: Survey. SETTING: Department of otorhinolaryngology of a university hospital. PATIENTS: Twenty-one living members of a Dutch family (150 relatives in 5 generations; 49 were studied) with autosomal dominant nonsyndromic sensorineural hearing impairment showed linkage to the DFNA13 locus. Mutation analysis revealed a missense mutation in the COL11A2 gene. METHODS: History was taken, hearing threshold levels were measured in all affected persons, and penetrance was evaluated. Longitudinal analysis (using linear regression analysis of threshold-on-age data) was possible in only 1 case. Cross-sectional analysis comprised the comparison of threshold levels between different generations of the family. Also, hearing thresholds were corrected for median presbyacusis to find out whether the hearing impairment characteristic of this trait is stationary or progressive. Vestibular functions were evaluated with electronystagmography, by use of rotatory and caloric tests. RESULTS: Most of the affected persons dated their first hearing impairment symptoms to the second to third decade of life. A possibly reduced penetrance was found. Anamnestically, 4 affected persons had hearing impairment symptoms from early childhood onward. Longitudinal analysis in the proband (IV26) revealed the exceptional combination of congenital offset and substantial early progression. Most of the threshold levels differed significantly between the frequencies within each age group and, at the high frequencies (2-8 kHz), between the two age groups covered by generations IV and III (ages 30-38 years and 58-74 years, respectively); the latter could be attributed to presbyacusis. Various caloric abnormalities, including areflexia, were found in about half (8/17) of the tested subjects with sensorineural hearing impairment. CONCLUSIONS: Correction for age, hearing impairment-presumably present and stationary from an early age onward-showed the worst or second-worst threshold usually at 1, 2, and 6 kHz (3540 dB) or 8 kHz (50 dB), whereas the best or second-best threshold was found at 0.25 to 0.5 and 4 kHz (25 dB). Presbyacusis, presumably from the fourth decade of life onward, caused a change of the typically shaped audiogram described as midfrequency hearing impairment with additional high-frequency impairment.     

Phenotype of DFNA11: a nonsyndromic hearing loss caused by a myosin VIIA mutation

OBJECTIVES/HYPOTHESIS: To characterize the audiovestibular phenotype of DFNA11, an autosomal dominant nonsyndromic hearing impairment caused by a mutation in the myosin VIIA gene (MYO7A), including whether DFNA11-affected subjects have retinal degeneration as is characteristic of Usher syndrome type 1B, caused by different MYO7A mutations. STUDY DESIGN: Retrospective study of audiovestibular and ophthalmological data in a Japanese family linked to DFNA11. METHODS: Otoscopic examination and pure-tone audiometry were performed in all participants in the family. Selected subjects underwent additional examinations including speech discrimination scoring, acoustic reflex measurements, Békésy audiometry, evoked and distortion-product otoacoustic emissions, auditory brainstem responses, and bithermal caloric testing; visual acuity, ocular tonometry, slit-lamp examination, ophthalmoscopy, and electroretinography; and computed tomography of the temporal bone. RESULTS: Most affected individuals had moderate cochlear hearing loss beginning in the second decade and progressing at all frequencies. Variable degrees of asymptomatic vestibular dysfunction were present. Computed tomography showed normal inner and middle ear structures. No evidence suggested retinitis pigmentosa. CONCLUSIONS: The phenotype of DFNA11 is postlingual, nonsyndromic sensorineural hearing loss with gradual progression. Showing moderate hearing loss with asymptomatic variable vestibular dysfunction and no retinal degeneration, the DFNA11 phenotype is mildest among phenotypes caused by MYO7A mutations.     

一个常染色体显性遗传非综合征性聋家系分析

目的:分析一个连续5代遗传的常染色体显性高频听力损失家系的听力学及遗传学特征。方法:通过对家系成员进行全面体检及临床听力学检测,整理、分析家系资料,确定遗传规律,绘制遗传图谱并进行听力学特征分析。应用Affymetrix 5.0SNP芯片对该家系参与连锁分析的32例成员进行全基因组扫描及连锁分析,行致病基因的染色体定位。结果:该耳聋家系(命名为SX-G087)成员共计91例。其先证者为感音神经性聋,无全身其他系统异常。耳聋遗传方式为常染色体显性遗传,发病年龄各代间较稳定,为20～35岁。听力表型为代代相传、迟发性、渐进性的中度至重度听力损失,以高频下降为主,部分患者随着年龄增长逐渐累及全频听力,听力曲线由下降型变为平坦型。应用芯片进行全基因组扫描,1～22号染色体未发现有显著连锁的区段。结论:该家系遗传学特征符合常染色体显性遗传方式,表现为早期高频听力下降并逐渐累积全频的特征,全基因组扫描未发现有显著连锁的区段。因此希望通过对该家系进一步的表型分析或者运用新一代测序技术,可以找到该家系高频感音神经性聋的致病基因。     

常染色体显性遗传非综合征型耳聋家系听力学及遗传学特征分析

目的分析一个连续5代遗传的耳聋大家系的临床听力学特征及遗传规律。方法通过家系调查,对家系成员进行全身系统检查及临床听力学检测,分析遗传规律,绘制遗传图谱并进行听力学特征分析。结果此耳聋家系成员共计35人。其先证者为感音神经性聋,无全身其他系统异常。耳聋遗传方式为常染色体显性遗传,发病年龄各代间较稳定,为15～30岁。听力表型为代代相传、迟发性、渐进性的中度至重度听力损失,听力损失初以高频下降为主,随着年龄增长逐渐累及全频听力,听力曲线由下降型变为平坦型。结论该家系遗传学特征分析符合非综合征型常染色体显性遗传方式,该研究为进一步致病基因的定位与克隆奠定了基础。     

Identification of a novel mutation in the myosin VIIA motor domain in a family with autosomal dominant hearing loss (DFNA11)

We ascertained a large Italian family with an autosomal dominant form of non-syndromic sensorineural hearing loss with vestibular involvement. A genome-wide scan found linkage to locus DFNA11. Sequencing of the MYO7A gene in the linked region identified a new missense mutation resulting in an Ala230Val change in the motor domain of the myosin VIIA. Myosin VIIA has already been implicated in several forms of deafness, but this is the third mutation causing a dominant form of deafness, located in the myosin VIIA motor domain in a region never involved in hearing loss until now. A modelled protein structure of myosin VII motor domain provides evidence for a significant functional effect of this missense mutation.     

常染色体显性遗传性聋家系的临床表型及候选致病基因分析

目的探讨线粒体DNA 961delT/insC（n）突变与氨基甙类药物性耳聋的相关性。方法对一个耳聋家系11个成员采集氨基甙类抗生素用药史、进行听力学检查、表型分析,采集外周静脉血样本,从白细胞中提取DNA,用聚合酶链反应扩增线粒体DNA（mtDNA）全序列,对扩增片段进行DNA测序,对发现的基因突变与耳聋表型进行分离分析。结果参与研究的所有9例母系成员均检出mtDNA 961delT/insC（n）突变。有明确氨基甙类抗生素用药史的4例中只有2例耳聋患者,其中1例为用药之前出现的先天性聋,另1例为用药后38年出现的轻度耳聋。突变不与耳聋共分离。结论本研究不支持mtDNA 961delT/insC（n）突变是该家系耳聋的致病突变,mtDNA 961位点附近可能是一个多变异的区域,mtDNA 961delT/insC（n）可能是一个与氨基甙类药物性耳聋不明确相关的多态。     

Connexin 26 mutations in nonsyndromic autosomal recessive hearing loss: speech and hearing rehabilitation

OBJECTIVE: Hearing loss is the most common form of sensory impairment, with approximately one infant/1000 born with profound congenital deafness. A pre-lingual bilateral sensorineural hearing impairment poses a substantial problem as it negatively impacts on the subject's ability to conduct a normal social life. The aim of the study was to observe, in a group of children affected by pre-lingual non-syndromic autosomal recessive hearing impairment: (1) the role of the possible mutation of connexin 26 in the pathogenesis of the hearing loss; (2) the audiological and clinical aspects of the hearing impairment; (3) therapy to be adopted for the different patients. METHODS: The study was carried out on 39 patients, 16 males and 23 females, aged between six and 17 years (mean 12 years), affected by non syndromic congenital deafness, presumably hereditary, referred to the out-patients audiology clinic for children of the Department of Otolaryngology of the Federico II University of Naples. RESULTS: Our study conducted on 39 children with pre-lingual bilateral sensorineural autosomal recessive deafness showed as follows: (I) from a molecular perspective: an incidence of 41% in the cases studied of mutations in the encoding of the connexin 26 gene; a prevalence in our case study of the 35delG mutation (69%). (II) The characteristics of the hearing impairments in the children studied were homogeneous, regardless of the presence or absence of a connexin 26 mutation: the hearing impairment was pre-lingual bilateral sensorineural, the impairment often involved mainly the high frequencies, but, especially in the severe forms an involvement of all the frequencies was not rare; the hearing impairments were symmetrical and non progressive in time. (III) The results of the application of prosthesis and thereafter rehabilitative language therapy are generally satisfactory but correlated of course to the severity of the hearing loss. CONCLUSION: In conclusion, we hope that further developments in the research on genetic hearing impairments will promptly result in advances in clinical practice.