gjb2 mutation spectrum in inner mongolia and its comparison with other asian populations

Mutations in the GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the mutation spectrum and prevalence of mutations vary among different ethnic groups. Every year, 30,000 babies are born with congenital hearing impairment in China. In order to provide appro-pilate genetic testing and counseling to the family, we investigated the molecular etiology of nonsyndromic deafness in 135 unrelated school children attending Chifeng Municipal Special Education School in Inner Mongolia, China. The coding exon of the GJB2 gene was PCR amplified and sequenced. In addition, the 12S rRNA gene and tRNAser UCN of mitochondrial genome were screened for mutations responsible for hearing impairment. Sixty four GJB2 mu-tant alleles, including 60 confirmed pathogenic alleles and 4 unclassified variants, were identified in 31.1% (42/135) of the subjects. Twenty two subjects carried two pathogenic mutations and 20 subjects carried one mutant allele, in-cluding one subject with one autosomal dominant mutation. The 235delC was the most common mutation account-ing for 65.6%(42/64) GJB2 mutant alleles. When compared to other Asian populations, our subject cohort had high-er frequency of 235delC mutation than the Japanese population. The GJB2 mutant alleles account for 23.7% (64/270) of all chromosomes responsible for nonsyndromic heating impairment. Testing of the 4 most prevalent deleterious frame shift mutations(235delC, 299_300delAT, 176191_del16, and 560_605ins46) in this cohort detect-ed 90% of all GJB2 mutant alleles. These results demonstrate that effective genetic testing of the GJB2 gene for pa-tients and families with nonsyndromic hearing impairment is possible in the Chinese population. Since the most common 309kb GJB6 deletion is not detected and only one 1555 A>G mutation in mitochondrial DNA is detected in our patients, investigation of mutations in other nuclear genes and/or environmental factors responsible for non-syndromic heating impairment in the Chinese population is necessary.     

河北涿州、高碑店市特教学校非综合征性聋分子病因学分析——GJB2 235delC突变、SLC26A4 IVS7-2A＞G突变和线粒体DNA12SrRNA A1555G突变筛查报告

目的 对河北涿州、高碑店地区重度耳聋患者进行分子流行病学调查，了解耳聋的常见分子病因。方法 对河北涿州、高碑店市特殊教育学校64名耳聋学生进行遗传性耳聋问卷调查、全面的体格检查、耳鼻咽喉专科检查以及听力学评估（包括纯音测听和声导抗）。对64名非综合征型感音神经性耳聋患者分别进行GJB2基因235delC突变、线粒体DNA 12SrRNA基因A1555G点突变的限制性内切酶分析。应用直接测序法检测SLC26A4基因IVS7—2A〉G突变。结果7例（10．93％）携带GJB2基因235delC纯合突变；9例（14．06％）携带GJB2基因235delC杂合突变；6例（9．37％）携带SLC26A4基因ⅣS7—2A〉G纯合突变，12例（18．75％）携带SLC26A4基因IVS7—2A〉G杂合突变：未发现携带线粒体DNA 12SrRNA基因A1555G点突变者。结论 河北涿州、高碑店地区非综合征型耳聋患者存在较高的GJB2基因235delC和SLC26A4基因ⅣS7—2A〉G突变发生率，而线粒体DNA 12SrRNA基因A1555G突变发生率低于全国平均水平。聋病分子流行病学调查提示河北涿州、高碑店地区20.3％的非综合征型耳聋患者在分子水平能够明确诊断．另有32．81％的患者有遗传倾向。进行准确的耳聋早期诊断、遗传咨询、及时干预和治疗在这一地区的聋哑人群中非常重要。     

荧光PCR法在非综合征型遗传性耳聋基因诊断中的应用研究

摘要：目的分析GJB2、SLC26A4和mtDNA12SrRNA基因热点突变在非综合征型遗传性耳聋人群中的突变谱和突变频率。方法采用荧光PCR法,针对本院收集的126例非综合征型耳聋患者进行中国人群常见的3个耳聋致病基因GJB2、SLC26A4和mtDNA 12SrRNA的10个热点突变的筛查,分析总结突变数据。阳性结果进一步采用直接测序法进行验证。结果应用荧光PCR技术在126例非综合征型耳聋（non syndromic hearing loss, NSHL）患者中检测出携带基因突变的患者31例,阳性率为24.6％（31/126）,其中GJB2双等位基因突变、SLC26A4双等位基因突变和12SrRNA的均质突变分别占该人群分子病因的6.35%（8/126）、2.33%（3/126）和3.17%（4/126）。此外,IVS7-2A>G单等位基因突变的检出率高达11.11%（14/126）。GJB2 c.235delC和SLC26A4 IVS7-2A>G是本研究中最为常见的热点突变。进一步采用直接测序法验证阳性位点,其结果与荧光PCR法一致。结论GJB2双等位基因突变是本研究人群最为常见的分子致病因素,其次为SLC26A4双等位基因突变和12SrRNA的均质突变。GJB2 c.235delC和SLC26A4 IVS7-2A>G是本研究中最为常见的热点突变。     

徐州地区354例耳聋患者GJB2及SLC26A4基因突变筛查分析

目的 从分子遗传学水平探讨徐州市重度及极重度感音神经性聋患者的病因学特点.方法 采集徐州市特殊教育学校共354例重度或极重度感音神经性聋患者的血样,提取DNA,利用SNPscan技术对其GJB2和SLC26A4基因突变进行检测,分析基因突变检出率及突变形式.结果 354例患者中共165例(46.61%,165/354)检出GJB2或SLC26A4基因致病突变,其中108例(30.51%,108/354)检出GJB2基因突变,50例(14.12%,50/354)为复合杂合突变,58例(16.38%,58/354)为纯合突变,其中235delC基因纯合突变54例;57例(16.10%,57/354)检出SLC26A4基因突变,其中复合杂合突变37例(10.45%,37)354,纯合突变20例(5.65%,20/354),均为919-2A>G纯合突变.结论 GJB2及SLC26A4基因为徐州地区重度或极重度感音神经性聋人群中的常见致病基因,235delC为GJB2基因突变主要形式,919-2A>G为SLC26A4基因突变主要形式.     

青海省回、藏、土、蒙古族非综合征型聋患者致聋基因SNPscan法检测分析

目的：调查 GJB2、SLC26A4和mtDNA12SrRNA基因突变在青海省回、藏、土、蒙古族非综合征型聋患者中的突变谱和突变频率。方法采集青海省回族（123例）、藏族（44例）、土族（34例）及蒙古族（10例）共211例非综合征型聋患者及180例正常人（对照组,其中回族100例,藏族40例,土族30例,蒙古族10例）的外周静脉血,提取基因组DNA,应用SNPscan法检测GJB2基因2个外显子36个突变位点、SLC26A4基因21个外显子77个突变位点和mtDNAA1555G及mtDNAC1494T突变。结果211例耳聋患者中,5例土族和1例蒙古族患者携带mtDNAA1555G均质性突变;回族、藏族、土族和蒙古族患者 GJB2基因突变检出率分别为11．38％、4．55％、5．88％和10％,各民族间差异无统计学意义（均为P＞0．05）。土族和蒙古族耳聋患者GJB2基因最常见的突变形式为c．235delC,等位基因频率分别为2．94％和5％;回族耳聋患者最常见的突变形式为 c．299300delAT,等位基因频率为4．47％。回族、藏族和土族患者SLC26A4基因突变检出率分别为6．5％、4．55％和2．94％,三个民族间差异无统计学意义（均为P＞0．05）;回族耳聋患者SLC26A4主要突变为c．919－2A＞G,等位基因频率为2．44％;藏族耳聋患者SLC26A4的主要突变为c．1226G＞A,等位基因频率为2．27％。正常对照组除了回族中有1例携带GJB2基因c．235delC杂合突变,1例携带SLC26A4基因c．919－2A＞G中等位基因突变,其余三个民族均未检测出GJB2、SLC26A4基因突变。结论青海省回、藏、土及蒙古族非综合征型聋患者中10．9％（23／211）是由GJB2、SLC26A4和mtDNA A1555G基因突变导致,GJB2和SLC26A4基因突变在该地区4个少数民族非综合征型聋患者中的致病具有民族特异性。     

广西地区222例感音神经性聋患者常见耳聋基因筛查结果分析

目的：分析广西地区222例感音神经性聋患者常见耳聋基因的突变特点,为临床防聋及治聋提供参考。方法采用晶芯.十五项遗传性聋基因检测试剂盒（微阵列芯片法）对广西地区222例感音神经性聋患者进行常见的4种耳聋基因的15个突变位点检测：GJB2（35del G、235delC、176del16、299del AT ）、SLC26A4（2168A＞G、IVS7－2A＞G、1174A＞T、1226G＞A、1229C＞T、1975G＞C、2027T＞A、IVS15＋5 G＞A）、线粒体DNA12SrRNA （1494C＞T、1555A＞G）和GJB3（538C＞T）,对未确诊的阳性结果进行基因全序列分析。结果222例患者中23例（10．36％,23／222）被检测出耳聋基因突变,其中,GJB2235delC 纯合突变3例（1．35％）,杂合突变8例（3．60％）,GJB235delG杂合突变2例（0．90％）,GJB2235delC／109A＞G 复合杂合突变2例（0．90％）;SLC26A4 IVS7－2 A＞G杂合突变2例（0．90％）,SLC26A41229C＞T纯合突变2例（0．90％）,IVS7－2A＞G／IVS11＋47T＞C／1548insC复合杂合突变2例（0．90％）;GJB3538C＞T 杂合突变1例（0．45％）;线粒体DNA12SrRNA 1555A＞G异质突变1例（0．45％）;1例（0．45％）同时携带GJB2235delC杂合突变及SLC26A41226G＞A杂合突变。结论本组广西地区感音神经性聋患者耳聋基因突变率低于全国水平,主要以 GJB2基因突变为主,其次是SLC26 A4基因突变。     

52例听力损失儿童及其父母耳聋基因芯片筛查结果分析

目的：对非综合征性先天性重度及以上感音神经性听力损失儿童及其父母进行耳聋相关基因检测,探讨耳聋基因芯片筛查在临床中应用的有效性和可行性。方法选择来自医院听力检测中心的47个听障儿童家庭,包括52例非综合征性先天性感音神经性听力损失患儿及其父母,应用遗传学耳聋基因芯片对47个家庭进行GJB2、GJB3、SLC26A4、线粒体12S rRNA4个常见耳聋基因9个检测位点的基因检测。结果146例受检者中,17个家庭的43例筛查结果阳性,其中16例听力损失患儿筛查阳性,筛查阳性率为30.8%。GJB2基因235delC位点纯合突变8例,GJB2基因235delC位点杂合突变20例,GJB2基因235delC位点和SLC26A4基因IVS7-2A〉G位点杂合突变1例,SLC26A4基因IVS7-2A〉G位点纯合突变2例,SLC26A4基因IVS7-2A〉G位点杂合突变10例,SLC26A4基因2168A〉G位点杂合突变2例。结论应用耳聋基因芯片检测技术能快速、高效地检测非综合征性耳聋患者的遗传性致病基因,适用于大规模群体耳聋基因的筛查,有助于临床医生从病因学角度辅助耳聋诊断,引入正确的康复干预措施,并为具有聋病易感基因的听力损失儿童家庭提供针对性的遗传咨询指导。     

GJB3在携带GJB2单等位基因突变的中国耳聋人群中的突变分析

目的 在GJB2病理性单等位基因突变携带者中进行GJB3基因编码区序列分析,探讨GJB2与GJB3双基因模式遗传致聋的可能性.方法 对从全国24个省市自治区3323例重度-极重度感音神经性耳聋患者中筛查出的108例携带GJB2病理性单等位基因突变的耳聋患者进行GJB3基因编码区全序列测序,分析测得序列,对所发现突变或变异编码氨基酸的物种进化保守性进行分析,结合听力正常对照人群中GJB3基因编码区测序结果,对考虑为携带GJB3突变及GJB2病理性单等位基因突变的耳聋患者进行家系分析.结果 108例携带GJB2病理性单等位基因突变的耳聋患者中共检测到7种GJB3基因变异类型,其中错义突变3种,静止变异4种.5例携带GJB3基因的错义变异(V84I,A194T,N166S),结合对照组检测结果,V84I为中国人群GJB3基因的多态改变,GJB3基因N166S和A194T可能为导致常染色体隐性非综合征性耳聋的的病理性突变.结论 GJB3与GJB2可能以双基因模式遗传导致耳聋,其致病机制还待进一步阐明.     

甘肃省375例非综合征型聋患者聋病易感基因突变检测分析

目的 通过对甘肃省部分非综合征型聋患者进行聋病易感基因筛查,从分子水平了解其遗传病因及特点.方法 采集甘肃省375例非综合征型聋患者的外周静脉血5~10 ml,提取基因组DNA,运用SNPscan技术检测GJB2基因2个外显子36个突变位点、SLC26A4基因21个外显子77个突变位点和mtDNA12SrRNA A1555G及C1494T突变.结果 375例非综合征型聋患者中,23例携带mtDNA12SrRNA A1555G均质性突变(6.13%, 23/375),2例携带mtDNA12SrRNA C1494T均质性突变(0.53%, 2/375);检出GJB2基因突变致聋者42例(11.20%, 42/375),其中纯合突变31例(8.27%, 31/375)、复合杂合突变11例(2.93%, 11/375),GJB2基因单杂合突变携带者25例(6.67%,25/375),c.235delC为最常见的突变类型,等位基因频率为8.80%(66/750);检出SLC26A4基因突变致聋者29例(7.73%, 29/375),其中纯合突变17例(4.53%, 17/375)、复合杂合突变12例(3.20%, 12/375),SLC26A4基因单杂合突变携带者14例(3.73%,14/375),c.919-2A>G和c.2168A>G为其最主要的突变类型,等位基因频率分别为5.20%(39/750)和2.0%(15/750).结论 甘肃省部分非综合征型聋患者mt DNA12SrRNA A1555G突变检出率明显高于全国水平(2.83%,57/2016),而GJB2、SLC26A4基因突变检出率与全国水平相近;三个常见聋病易感基因筛查可为25.60%的本组耳聋患者提供明确的分子病因学诊断.     

中国西北地区线粒体DNA12SrRNAA1555G和GJB2基因突变

目的研究mtDNA 12SrRNA A1555G突变和GJB2突变在西北地区非综合征型感音神经性聋患者中的流行情况,探讨GJB2基因与mtDNA A1555G点突变的关系。方法收集本地区221例非综合征感音神经性聋患者的基因组DNA,多聚酶链反应扩增线粒体DNA和GJB2基因目的片断,Alw26Ⅰ限制性内切酶检测A1555G点突变,对酶切阳性病例和全部的GJB2基因的PCR产物进行DNA测序。结果21例患者检出mtDNA 12SrRNA A1555G突变;发现GJB2基因11种序列改变,有44例患者检出GJB2致病突变,235delC占携带致病突变患者的54．54％：在21例A1555G突变患者中,11例为GJB2基因多态改变,9例未检出GJB2基因序列改变,1例为109G→A（V371）突变。结论mDNA 12SrRNA A1555G在这一地区人群中有较高的发生频率．235delC是本地区GJB2基因突变的主要形式,GJB2基因突变不是mtDNA A1555G突变致聋的主要修饰因素。     

GJB2, SLC26A4 and mitochondrial DNA A1555G mutations in prelingual deafness in Northern Chinese subjects

CONCLUSION: This genetic epidemiological study demonstrated that 26.65% of the prelingual deafness in Northern Chinese patients can be detected at younger ages by genetic testing of three common hearing loss genes (GJB2, SLC26A4 and mtDNA A1555G), and thus, early intervention measures could be undertaken to help them in language acquisition. OBJECTIVES: The GJB2, SLC26A4 and mtDNA A1555G mutations are the prevalent causes of prelingual deafness worldwide. Numerous studies have revealed that the forms and frequencies of the mutations in the three genes are largely dependent on the ethnic or geographic origins. Hence, this study aimed to characterize the mutation profiles of the three genes in prelingual deafness in Northern Chinese patients. SUBECTS AND METHODS: An investigation of 514 patients with prelingual deafness and 117 controls with normal hearing was conducted. Bidirectional sequencing (or enzyme digestion) was applied to identify sequence variations. RESULTS: This study revealed that 26.65% patients had two mutated alleles (homozygote or compound heterozygote) of GJB2 (9.14%) or SLC26A4 (8.95%) and/or an mtDNA A1555G (8.56%) mutation. In detail, 19.26% patients carried GJB2 mutations including 10.12% single mutant carriers. 235delC was the most common type, making up 69.18% of all mutants for GJB2. The mutant carrier rate for SLC26A4 was 15.2%, including 6.23% single mutant carriers. The two most common types (IVS7-2A > G and H723R) accounted for 51.61% and 33.06% mutations, respectively. Forty-five patients had mtDNA A1555G, giving a frequency of 8.75%. In the control group with normal hearing, 2.56%, 1.71% and 0% of the subjects carried a single mutant for GJB2, SLC26A4 and mtDNA A1555G, respectively.     

GJB2 gene mutations in newborns with non-syndromic hearing impairment in Northern China

Mutations in GJB2 account for the majority of recessive forms of prelingual hearing loss. However, in most previous studies it was not possible to distinguish between congenital (present at birth) and non-congenital prelingual hearing loss. In the present study, the frequency of GJB2 alleles in 20 newborns with bilateral severe-to-profound non-syndromic hearing impairment (NSHI) who were found at birth through newborn hearing screening and clinical examination is reported. PCR was used to amplify the coding region of GJB2 gene followed by sequencing analyses. Fifty volunteers with normal hearing were included as controls. Results showed that three cases were 235delC/235delC homozygotes; one was 235delC/605ins46 compound heterozygotes, 605ins46 mutation was a novel mutation reported in the Chinese population; another was 235delC/299-300delAT compound heterozygotes. 25% (5/20) of the deafness in newborns studied was caused by GJB2 gene mutations. The frequency of 235delC allele carrier in patients and in control group was 22.5% and 1%, respectively. One case was identified as being a 235delC heterozygote without other mutations detected. Besides, multiple polymorphisms such as V27I, V37I, E114G, T123N were also detected. In conclusion, GJB2 analysis is an important test that identifies a major cause of newborns with bilateral severe-to-profound NSHI screened by universal newborn hearing screening in Northern China. The most common pathologic mutation of GJB2 in studied cases was 235delC. Molecular analysis and genetic counseling will be extremely important for congenital deafness present at birth.     

湖南地区汉族非综合征型耳聋相关基因检测及热点突变分析

目的研究湖南地区汉族非综合征型耳聋（NSHL）患者中GJB2、SLC26A4基因的突变频率和突变热点,了解线粒体DNA（mtDNA）12SrRNA A1555G突变的频率。方法收集湖南地区汉族NSHL患者共139例,抽取外周静脉血并提取DNA;分别采用直接测序、变性高效液相色谱法（denaturing high performance liquid chromatography,DHPLC）和聚合酶联-限制性片段变态（polymerase chain reaction restriction fragment length polymorphism,PCR RFLP）技术对患者进行GJB2、SLC26A4基因和mtDNA 12SrRNA A1555G突变的检测;对SLC26A4基因突变者进行回访并行高分辨颞骨CT检查。结果61例（43.9%）NSHL患者至少携带一种常见耳聋相关基因突变,GJB2、SLC26A4和线粒体DNA 12SrRNA A1555G突变的检出率分别为23%、18.7%和3.6%;共发现6种GJB2和13种SLC26A4基因已报道致病性突变,235delC和IVS7-2A〉G分别是GJB2和SLC26A4基因最常见的突变类型,分别占这两个基因突变等位基因的87.5%和46.5%;与SLC26A4基因突变有关的EVAS的发生率为14.4%,低于该地区GJB2基因相关性耳聋的发生率17.3%。结论湖南地区汉族NSHL中43.9%的患者携带常见耳聋基因突变,反映湖南地区遗传性耳聋高发的现象。GJB2基因突变是该地区NSHL最常见的原因,其次为SLC26A4基因。235delC、IVS7-2A〉G和A1555G突变分别是GJB2、SLC26A4和线粒体DNA基因的热点突变,占所有突变的71.2%。通过筛查,为其中35.3%的患者明确了分子病因。为该地区进一步开展遗传咨询、基因诊断和产前诊断提供了重要的依据,并为临床用药提供指导。     

粤西部分地区耳聋患者耳聋基因检测结果分析

目的通过对常见致聋基因的筛查,初步了解粤西肇庆市和云浮市地区耳聋患者耳聋基因突变情况及特点。方法在相关人员知情同意的情况下,对肇庆市和云浮市地区92例非综合征型耳聋患者进行外周静脉血采集,提取基因组DNA,应用PCR-反向点杂交技术(PCR-RDB法)对4个常见耳聋基因的16个热点突变位点进行检测,同时对GJB2基因的全外显子和线粒体12S rRNA基因进行Sanger测序。结果92例受检者中,33例为GJB2基因基因变异,其中携带致病突变有18例(包括纯合,复合杂合或杂合致病突变),突变频率为19.57%(18/92),其中c.109G>A和c.235delC等位基因频率分别为9.78%(18/184)和3.26%(6/184),共占检出的GJB2基因致病等位基因数的66.67%(24/36),因此c.109G>A和c.235delC是该地区GJB2基因上的两个热点突变;检出9例SLC26A4基因突变(包括纯合,复合杂合或杂合致病突变),突变频率为9.78%(9/92),主要为c.919-2A>G;线粒体DNA(mitochondria DNA,mtDNA 12S rRNA),未检出m.1555A>G点突变或m.1494C>T,但检出2例罕见的致聋的突变m.1027A>G和m.1452T>C。另外,检出1例m.1236C>T,截止到2018年9月未见文献报道。GJB3基因未检出突变。结论GJB2基因突变是引起粤西肇庆市和云浮地区耳聋学生听力障碍的主要原因,其中,c.109G>A和c.235delC为GJB2基因最主要的突变位点,而c.919-2A>G则是SLC26A4基因最常见的突变位点。对该地区听力障碍患者进行了四个热点耳聋基因检测,让30.43%(28/92)患者明确了其分子病因,同时给其提供了详细的遗传咨询服务,这将有利于本地区的耳聋防治。     

湖南郴州非综合征型聋患者GJB2、SLC26A4和线粒体DNA12SrRNA基因突变分析

目的探讨湖南郴州非综合征型聋患者的分子病因特点。方法采取湖南郴州154名非综合征型聋患者的外周血,提取DNA,采用基因芯片筛查GJB2、SLC26A4和线粒体DNA12SrRNA基因的热点突变,基因芯片法未确诊的样本则采用DNA测序法进一步检测。结果两种方法共在34例(22.08%,34/154)患者中检出7种GJB2基因突变,其中235delC(13.63%,21/154)发生率最高,其次是299delAT(9.09%,14/154);在8例伴有大前庭水管的患者中检测出7种SLC26A4基因突变,包括一种新突变Q696X;3例患者被检出线粒体DNA12SrRNA基因突变。结论湖南郴州非综合征型聋患者中GJB2、SLC26A4和线粒体DNA12SrRNA基因突变的发生率与中国大部分地区相似,Q696X为新发现的SLC26A4基因突变。     

GJB2, SLC26A4, and mitochondrial DNA12S rRNA hot-spots in 156 subjects with non-syndromic hearing loss in Tengzhou,China

Conclusion: In this cohort of 156 non-syndromic hearing-impaired subjects of Tengzhou area, the most common deafness-associated genes GJB2, SLC26A4 and mtDNA 12S rRNA were investigated by SNPscan efficiently. GJB2 c.235delC and SLC26A4 c.IVS7-2A?>?G were the most common mutation sites. Objectives: Until now, there is no systematic gentic analysis in patients with non-syndromic hearing loss for Tengzhou area, so we evaluated the molecular etiology to investigate the hot-sports. Methods: Peripheral blood samples were obtained from 156 patients with severe-to-profound non-syndromic deafness in Tengzhou. The SNP scan assay technique was performed for a rapid multiplex genetic screening to detect the 115 mutations of the most common three genes. All results were statistically analyzed with SPSS software. Results: Among the 156 analyzed patients, 60 patients were demonstrated with deafness genes, accounting for 38.46% (60/156), including GJB2 (22.44%, 35/156), SLC26A4 (13.66%, 22/156), and mtDNA 12S rRNA (2.56%, 4/156). In this study, we confirmed 23 deafness-causing mutations and 27 different allelic combinations including GJB2 (eight variants, 11 allelic combinations), SLC26A4 (13 variants, 16 allelic combinations) and mtDNA 12S rRNA (two variants). The occurrence rates of these deafness-causing mutations GJB2 c.235delC and SLC26A4 c.IVS7-2A?>?G were significantly higher than other mutation sites (p?相似文献   

南京地区耳聋患者常见耳聋基因突变的分析

目的 通过对南京地区重度-极重度感音神经性聋患者进行常见耳聋基因检测,分析该类患者常见致聋基因和各位点发生频率,阐明该地区耳聋的遗传病因学。 方法 首先对患者进行病史采集、体格检查、高分辨颞骨CT以及临床听力学检查,然后采集128例患者的外周静脉血2~4 mL,对其标本进行4种常见基因21个突变位点的检测。 结果 128例患者中,39例(30.47%,39/128)检测到基因突变,其中携带双基因杂合突变1例、携带基因纯合突变14例。30例(23.44%,30/128)患者携带GJB2基因突变,其中 18例(14.06%,18/128)为纯合或复合杂合突变。235delC位点突变检出率为20.31%(26/128),299_300delAT位点突变检出率为4.69%(6/128),176_191del位点突变检出率为3.91%(5/128)。10例(7.81%,10/128)患儿携带SLC26A4基因突变,其中携带纯合和复合杂合突变4 例(3.13%,4/128)。IVS7-2 A>G突变检出率为7.03%。患者未检出线粒体12SrRNA基因和GJB3基因突变。患者中高分辨颞骨CT提示前庭导水管扩大者11例,其中检测出SLC26A4基因纯合或杂合突变10例,二者的吻合率为90.91%(10/11)。 结论 南京地区重度-极重度感音神经性聋患者中,GJB2基因为最主要的致聋基因,其最常见的突变位点是235delC,其次为SLC26A4基因,最常见的突变位点是IVS7-2 A>G。研究发现SLC26A4基因突变在大前庭水管综合征患者中检出率极高,筛查SLC26A4基因热点突变有助于大前庭水管综合征的诊断,但仍需结合高分辨颞骨CT检查,避免患者漏诊。     

非综合征型感音神经性聋儿GJB2基因突变分析

目的 对散发聋病患儿进行GJB2基因突变检测,探究其在遗传性聋临床工作中的意义.方法 收集门诊139例散发非综合征型感音神经性聋患儿及150例听力正常个体的外周血DNA样本共289例,采用聚合酶链反应分析方法扩增GJB2基因片断进行序列分析.结果 139例病患组中发现GJB2基因突变31例,占22.30%.其中235d...     

新疆地区941例新生儿聋病基因GJB2、SLC26A4、线粒体DNA 12S rRNA筛查分析

目的通过对新生儿进行聋病易感基因和听力筛查,探讨聋病易感基因筛查应用于新生儿筛查的必要性,为制订防聋治聋策略提供依据。方法以941例新生儿作为研究对象,所有新生儿出生时采脐带血,采用限制性内切酶酶切结合直接测序的方法对3种国人常见耳聋易感基因（线粒体DNA 12S rRNA、GJB2、SLC26A4）突变热点进行筛查,运用SPSS 13.0软件对结果进行统计分析。结果3种基因热点突变的总携带率为2.02%（19/941）,GJB2基因235delC杂合突变9例（0.96%）,SLC26A4基因IVS7-2A〉G杂合突变9例（0.96%）,线粒体DNA 12S rRNA A1555G突变3例（0.32%）,其中2例为复合突变（235delC杂合突变/IVS7-2A〉G杂合突变、1555A〉G均质突变/235delC杂合突变）。GJB2基因235delC杂合突变在维吾尔族和汉族新生儿中的携带率分别为0.36％（1/276）、1.19％（7/586）;SLC26A4基因IVS7-2A〉G杂合突变在维吾尔族和汉族新生儿中的携带率分别为0.36％（1/276）、1.37％（8/586）;线粒体DNA 12S rRNA 1555A〉G突变在维吾尔族和汉族新生儿中的携带率分别为0.72％（2/276）、0％。在维吾尔族和汉族新生儿中,以上三基因突变携带率不同,但没有统计学差异。结论聋病易感基因筛查应用于维、汉族新生儿筛查必要且可行。     

Common molecular etiology of nonsyndromic hearing loss in 484 patients of 3 ethnicities in northwest China

Conclusions: In the study population in northwest China, a total of 33.06% of deaf patients have inherited hearing impairment caused by GJB2, SLC26A4, and mtDNA 1555A>G mutations. The mutation frequencies of GJB2, SLC26A4, and mtDNA 1555A>G genes were 16.12%, 10.54%, and 6.4%, respectively, in our study cohort. Thus, screening is conventionally performed for GJB2, SLC26A4, and mtDNA 1555A>G in these populations. Objective: This study aimed to investigate the mutations of GJB2, mitochondrial DNA 12S rRNA1555A>G, and SLC26A4 genes in Han Chinese, Hui people, and Tibetan ethnicities in patients with nonsyndromic hearing loss (NSHL) in northwest China. Methods: A total of 484 unrelated subjects with hearing loss who attended special education schools in northwest China were enrolled in this study. Three prominent deafness-related genes, GJB2, SLC26A4, and mtDNA 1555A>G, were screened for mutations in our study cohort. Results: The mutation frequencies of GJB2, SLC26A4, and mtDNA 1555A>G genes were 16.12%, 10.54%, and 6.4%, respectively. The prevalence of GJB2 mutations was 17.52%, 15.35%, and 11.43% in Han Chinese, Hui people, and Tibetan participants, respectively. c.235delC was the most prevalent mutation, accounting for 65.71% of all GJB2 mutant alleles. The prevalence of SLC26A4 mutations was 12.39%, 8.84%, and 8.57% in Han Chinese, Hui people, and Tibetan participants, respectively. The c.919-2 A>G mutation was the most common form, accounting for 60.47% of all SLC26A4 mutant alleles. The prevalence of the homoplasmic mtDNA 1555A>G mutation was 8.97%, 3.72%, and 5.71% in Han Chinese, Hui people, and Tibetan participants, respectively, which represents a statistically significant difference between the Han Chinese and Hui people (χ² = 5.118, p < 0.05).