长治地区耳聋患者常见耳聋基因GJB2、GJB3和线粒体DNA 12S rRNA 1555A〉G相关性分析

目的通过对长治地区115例耳聋患者常见基因GJB2、GJB3和线粒体DIqA 12S rRNA 1555A〉G测序分析,研究该地区耳聋基因的突变情况及热点突变位点。方法收集长治地区特殊教育学校的115q,J耳聋患者的外周血样本,提取其DblA后对它的目的基因进行扩增并测序。结果115例耳聋患者中GJB2基因检测到81例发生突变,并发现了10个突变位点,其中C．7657T〉c是主要的多态位点,其携带率为22．6％（52／115）。另外,长治地区发现2例线粒体DNAl555A〉G位点突变,未检测出GJB3基因突变位点。结论通过对长治地区常见耳聋基因突变位点的研究,了解该地区的耳聋基因突变谱,为后续国内耳聋基因型分布提供数据支持,同时也为耳聋的早期诊断,治疗提供理论依据。     

The 342-kb deletion in GJB6 is not present in patients with non-syndromic hearing loss from Austria

Recently, a 342-kb deletion involving GJB6 was associated with autosomal-recessive non-syndromic hearing loss (NSHL) and in combination with a GJB2 mutation with digenic NSHL. This deletion was the second most common mutation causing prelingual NSHL in Spain, and was frequently observed in patients from France and Israel. We screened 393 patients with NSHL being negative or heterozygous for GJB2 mutations for this GJB6 deletion using a multiplex PCR. Most patients were of Austrian (84.2%), and the other patients were of Turkish, Serbian, and Bosnian origin. None of these patients was carrying the deletion in GJB6 indicating that the occurrence of this deletion is restricted to certain populations.     

大同地区耳聋基因GJB2和mtDNA1555突变分析

目的通过筛查大同地区87例耳聋患者常见基因GJB2和mtDNA1555的突变频率,研究该地区CJB2和mtD-NA1555基因突变情况及热点突变位点。方法采集大同地区87例耳聋患者外周血,对目的基因扩增并进行测序分析。结果所有患者中有58例GJB2基因检测到11个突变位点,与编码连接蛋白的非综合征耳聋突变数据库（http：／／davinci．crg．es／deafness／index．php？section=mut_db＆db=nonsynd）比对,9个位点已见报道,其中包括5个多肽位点c．79G〉A、c．341A〉G、c．608T〉C、c．368C〉A、c．765T〉C和4个致病住点c．235delc、c．109G〉A、c．176-c．191del16和c．299-c．300delAT,其中,c．79G〉A是主要突变方式,携带率为24．14％（42／174）。新发现两例未见报道的突变位点c．277A〉G和c．558G〉A;患者中只有1例检测到mtDNA1555A〉G位点突变。结论通过对大同地区GJB2基因和mtD-NA1555突变位点的研究,了解大同地区该基因突变谱,为后续国内耳聋基因型分布提供数据支持,同时也为耳聋的早期诊断,治疗提供理论依据。     

High prevalence of the IVS 1 + 1 G to A/GJB2 mutation among Czech hearing impaired patients with monoallelic mutation in the coding region of GJB2

Biallelic pathogenic GJB2 gene mutations cause pre-lingual genetic hearing loss in up to 50% of individuals with bilateral sensorineural hearing loss worldwide. Sequencing of the entire GJB2 gene-coding region in Czech patients with pre-lingual bilateral hearing loss revealed that 10.3% of Czech patients carry only one monoallelic pathogenic mutation in the coding region of the GJB2 gene, which is significantly more than the population frequency of 3.4%. The 309-kb GJB6 deletion, frequent in Spain and France, is very rare in the Czech population. In order to evaluate the impact of the IVS1 + 1 G to A splice site mutation in the non-coding part of the GJB2 gene among Czech patients, we tested all available patients with pre-lingual hearing loss with only one monoallelic mutation in the coding part of GJB2. By sequencing of the exon 1 region of the GJB2 gene and HphI restriction analysis in 20 Czech patients we identified nine patients carrying IVS1 + 1 G to A. Testing for this mutation explained deafness in 45% of Czech GJB2 monoallelic patients. This mutation represents now 4% of GJB2 pathogenic mutations in Czech patients and is the third most common GJB2 mutation found in our cohort of 242 unrelated Czech patients with prelingual hearing loss. A similar frequency may also be expected in other Central European or Slavic populations.     

Use of a multiplex PCR/sequencing strategy to detect both connexin 30 (GJB6) 342 kb deletion and connexin 26 (GJB2) mutations in cases of childhood deafness

Hearing loss is a common congenital disorder that is frequently associated with mutations in the Cx26 gene (GJB2). Three recent reports that found a large deletion in another DFNB1 gene, Cx30 (GJB6), suggest that this defect may cause nonsyndromic recessive hearing loss through either a homozygous deletion of Cx30, or digenic inheritance of a Cx30 deletion and a Cx26 mutation in trans. We designed a simple diagnostic strategy with multiplex PCR followed by direct sequencing to allow for the simultaneous detection of Cx26 mutations and Cx30 deletions, and evaluated its effectiveness as a clinical genetic test by examining 200 DNA samples. In the 108 samples from deaf subjects, two digenic mutations were identified in Cx26 and Cx30 (E47X/342 kb deletion and 167delT/342 kb deletion); 69 had only Cx26 mutations (29 biallelic, 40 singleton), including two novel frameshift mutations 511-512insAACG and 358-360delAG; and 37 had no detectable mutation in either Cx26 or Cx30. Our deletion mapping suggested that the proximal breakpoint of all reported Cx30 large deletions are between the nucleotide 444 and 627 at the Cx30 coding region within a maximal interval of 78 or 184 bp. This simultaneous examination of Cx26 and Cx30 is a practical and efficient diagnostic approach for patients with nonsyndromic congenital deafness.     

A multicenter study of the frequency and distribution of GJB2 and GJB6 mutations in a large North American cohort.

PURPOSE: The aim of the study was to determine the actual GJB2 and GJB6 mutation frequencies in North America after several years of generalized testing for autosomal recessive nonsyndromic sensorineural hearing loss to help guide diagnostic testing algorithms, especially in light of molecular diagnostic follow-up to universal newborn hearing screening. METHODS: Mutation types, frequencies, ethnic distributions, and genotype-phenotype correlations for GJB2 and GJB6 were assessed in a very large North American cohort. RESULTS: GJB2 variants were identified in 1796 (24.3%) of the 7401 individuals examined, with 399 (5.4%) homozygous and 429 (5.8%) compound heterozygous. GJB6 deletion testing was performed in 12.0% (888/7401) of all cases. The >300-kb deletion was identified in only nine individuals (1.0%), all of whom were compound heterozygous for mutations in GJB2 and GJB6. Among a total of 139 GJB2 variants identified, 53 (38.1%) were previously unreported, presumably representing novel pathogenic or benign variants. CONCLUSIONS: The frequency and distribution of sequence changes in GJB2 and GJB6 in North America differ from those previously reported, suggesting a considerable role for loci other than GJB2 and GJB6 in the etiology of autosomal recessive nonsyndromic sensorineural hearing loss, with minimal prevalence of the GJB6 deletion.     

吕梁地区遗传性耳聋GJB2基因和mtDNA1555位点的突变筛查

目的通过对吕梁地区96例耳聋患者的GJB2基因和mtDNA1555位点突变筛查,了解该地区的基因突变情况及热点突变位点。方法采用聚合酶链式反应（PCR）扩增96例标本的GJB2基因和mtDNA1555位点所在区段,产物酶切、测序分析。结果96例标本共计检出10个GJB2基因突变位点,与编码连接蛋白的非综合征耳聋突变数据库（http：／／davinci．crg．es／deafness／index．php？seccion=mut_db＆db=nonsynd）比对,8个位点已见报道,其中包括4个多肽位点c．79G〉A、C．341A〉G、c．608T〉C、C．457G〉A和4个致病位点C．235delC、e．109G〉A、c．176-C．191dell6和C．299-c．300delAT,其中,c．235delC是主要突变方式,携带率为6．25％（12／192）;2个位点（c．IVS1—35G〉T和c．88A〉G）属首次报道。酶切发现1例患者携带mt．1555纯合突变,后经测序发现还携带有mt．1438A〉G突变位点。结论吕梁地区耳聋患者以GJB2C．235delC为主要致病位点,本次研究结果为吕梁地区的耳聋预防奠定了基础,同时为今后临床医师诊断、治疗及遗传咨询提供了参考。     

Mutations in GJB2, GJB6, and mitochondrial DNA are rare in African American and Caribbean Hispanic individuals with hearing impairment

Autosomal recessive nonsyndromic sensorineural hearing impairment (ARNSHI) comprises 80% of familial hearing loss cases. Approximately half result from mutations in the connexin 26 (Cx26) gene, GJB2, in Caucasian populations. Heterozygous mutations in GJB2 occasionally co-occur with a deletion of part of GJB6 (connexin 30; Cx30). It is estimated that approximately 1% of deafness is maternally inherited, due to mutations in mitochondrial DNA (mtDNA). Few studies have focused on the frequency of mutations in connexins or mtDNA in African American (AA) and Caribbean Hispanic (CH) admixture populations. In this study, we performed bidirectional sequencing of the GJB2 gene and polymerase chain reaction (PCR) screening for the common GJB6 deletion, as well as PCR/RFLP analysis for three mutations in mtDNA (A1555G, A3243G, A7445G), in 109 predominantly simplex AA and CH individuals. Variations found were a 101T > C (M34T; 1/101 cases), 109G > A (V37I; 1/101), 35delG (mutation; 4/101, (3/4) of non-AA/CH ethnicity), 167delT (mutation; 1/101), 139G > T (mutation; E47X; 1/101 homozygote, consanguineous), -15C > T (1/101), 79G > A (V27I; 9/101), 380G > A (R127H; 4/101; Guyana, India, Pakistan ethnicity), 670A > C (Indeterminate; K224Q; 1/101), 503A > G (novel; K168R; 3/101) and 684C > A (novel; 1/101). All but one of the AA and CH patients had monoallelic variations. There were no hemizygous GJB6 deletions in those with monoallelic GJB2 variations. We also did not identify any patients with the three mutations in mtDNA. Bidirectional sequencing of the GJB2 gene was performed in 187 AA and Hispanic healthy individuals. Our results reveal that GJB2 mutations, GJB6 deletions, and mtDNA mutations may not be significant in these minority admixture populations.     

Exploring the clinical and epidemiological complexity of GJB2-linked deafness

GJB2 mutation analysis was performed in 179 unrelated subjects with sporadic or familial hearing loss (HL). Among 57 families, 18 showed a vertical transmission of HL, the disease being present in two or three generations. Besides 155 nonsyndromic cases, 24 patients presenting with extra-auditory clinical signs were included in the molecular study. GJB2 mutation analysis was also performed in 19 subjects with an anamnestic history of perinatal risks factors for acquired HL. The 35delG mutation accounted for 22.1% of analyzed chromosomes in sporadic cases and 39.4% in familial cases; 35delG prevalence reached 41% in autosomal recessive and 44.4% in pseudodominant pedigrees. Two novel GJB2 mutations were identified in compound heterozygosity with 35delG allele (D159V, 284ins/dup[CACGT]). Two 35delG homozygous subjects were identified among HL cases classified as environmental in origin. Four patients 35delG heterozygous (35delG/V95M, 35delG/L90P, 35delG/167delT, and 35delG/?) and two homozygous presented with extra-auditory clinical signs involving different organs (skin, vascular system, hemopoietic lineages, and thyroid). In a high proportion of 35delG heterozygous HL patients (52%), no second GJB2 mutation was detected. The reported data highlight the complexity of the genetic epidemiology of GJB2-linked deafness, further enlarging the spectrum of situations in which GJB2 mutation analysis should be performed. The presence of extra-auditory signs in a significant portion of GJB2-mutated patients suggests the possibility that GJB2 loss of function could contribute to clinical phenotypes presenting in association with deafness. This hypothesis deserves further investigation. The failure to identify a presumed partnering GJB2 mutation in a high proportion of deaf patients remains a challenging problem to be clarified.     

Mutations of Cx26 gene (GJB2) for prelingual deafness in Taiwan

Mutations in the Cx26 (GJB2) gene have been shown to be responsible for a major part of autosomal recessive non-syndromic inherited prelingual deafness. We have sequenced the coding region of GJB2 gene from 169 Taiwanese patients with prelingual deafness and 100 unrelated normal individuals. In the deaf patients, three mutations were found: two novel mutations, 551G-->A, and 299-300delAT, and one previously described mutation, 235delC. Four previously reported polymorphisms, 79G-->A, 109G-->A, 341A-->G, and 608T-->C, were also found in both deaf patients and normal individuals and one new possible polymorphism, 558G-->A, which was only found in a patient. Interestingly, we did not find the 35delG allele, which is commonly found in the Caucasian population, either in the patients or in normal individuals we examined. Our data also showed 235delC to be the most common type of mutation found in Cx26 mutants (approximately 57%). Therefore, based on our findings, we have developed a simple molecular test for the 235delC mutation and it should be of considerable help to those families to understand the cause of their children having the prelingual deafness.     

Double Heterozygosity with Mutations Involving both the GJB2 and GJB6 Genes is a Possible, but very Rare, Cause of Congenital Deafness in the Czech Population

Mutations in the GJB2 gene are the most common cause of prelingual, autosomal recessive, sensorineural hearing loss worldwide. Nevertheless, 10% to 50% of patients with prelingual nonsyndromic deafness only carry one mutation in the GJB2 gene. Recently a large 342 kb deletion named Δ(GJB6‐D13S1830) involving the GJB6 gene was reported in Spanish and French deafness patients, either in a homozygous state or in combination with a monoallelic GJB2 mutation. No data have been reported about the frequency of this mutation in central Europe. Thirteen Czech patients with prelingual nonsyndromic sensorineural deafness carrying only one pathogenic mutation in the GJB2 gene were tested for the presence of the Δ(GJB6‐D13S1830) mutation. One patient with a GJB2 mutation (313del14) also carried the Δ(GJB6‐D13S1830). This is the first reported Czech case, and probably also the first central European case, of prelingual deafness due to mutations involving both the GJB2 and GJB6 genes. In addition, the Δ(GJB6‐D13S1830) was not detected in 600 control chromosomes from Czech individuals with normal hearing. We show that in the Czech Republic the Δ(GJB6‐D13S1830) is not the second most common causal factor in deafness patients heterozygous for a single GJB2 mutation, and that Δ(GJB6‐D13S1830) is very rare in central Europe compared to reports from Spain, France and Israel.     

GJB2: the spectrum of deafness-causing allele variants and their phenotype

Genetic testing was completed on 1,294 persons with deafness referred to the Molecular Otolaryngology Research Laboratories to establish a diagnosis of DFNB1. Exon 2 of GJB2 was screened for coding sequence allele variants by denaturing high-performance liquid chromatography (DHPLC) complemented by bidirectional sequencing. If two deafness-causing mutations of GJB2 (encoding Connexin 26) were identified, further screening was not performed. If only a single deafness-causing mutation was identified, we screened for the g.1777179_2085947del (hereafter called del(GJB6-D13S1830); GenBank NT_024524.13) and mutations in the noncoding region of GJB2. Phenotype-genotype correlations were evaluated by categorizing mutations as either protein truncating or nontruncating. A total of 205 persons carried two GJB2 exon 2 mutations and were diagnosed as having DFNB1; 100 persons carried only a single deafness-causing allele variant of exon 2. A total of 37 of these persons were c.35delG carriers, and 51 carried other allele variants of GJB2. Persons diagnosed with DFNB1 segregating two truncating/nonsense mutations had a more severe phenotype than persons carrying two missense mutations, with mean hearing impairments being 88 and 37%, respectively (P < 0.05). The number of deaf c.35delG carriers was greater than expected when compared to the c.35delG carrier frequency in normal-hearing controls (P < 0.05), suggesting the existence of at least one other mutation outside the GJB2 coding region that does not complement GJB2 deafness-causing allele variants.     

Prevalent connexin 26 gene (GJB2) mutations in Japanese

The gene responsible for DNFB1 and DFNA3, connexin 26 (GJB2), was recently identified and more than 20 disease causing mutations have been reported so far. This paper presents mutation analysis for GJB2 in Japanese non-syndromic hearing loss patients compatible with recessive inheritance. It was confirmed that GJB2 mutations are an important cause of hearing loss in this population, with three mutations, 235delC, Y136X, and R143W, especially frequent. Of these three mutations, 235delC was most prevalent at 73%. Surprisingly, the 35delG mutation, which is the most common GJB2 mutation in white subjects, was not found in the present study. Our data indicated that specific combinations of GJB2 mutation exist in different populations.     

Spectrum and frequencies of mutations in the GJB2 (Cx26) gene among 156 Czech patients with pre-lingual deafness

Mutations in the gene gap junction beta 2 (GJB2), the gene for the connexin 26, are the most common cause of pre-lingual deafness worldwide. The mutation 35delG within GJB2 is prevalent in Europe. To date, there are no data about GJB2 mutation spectrum and frequencies from the Czech population. We investigated and report here the spectrum and frequencies of mutations in the GJB2 gene among 156 unrelated, congenital deafness Czech patients. Allele-specific polymerase chain reaction, together with fluorescent fragment analysis, were used for the detection of the 35delG mutation. The entire coding region of the GJB2 was directly sequenced in all patients who were not homozygous for the 35delG. No pathogenic mutation was detected in 51.9% of patients. At least one pathogenic mutation was found in 48.1% of patients, and both pathogenic mutations were detected in 37.8% of patients. Single mutations in a heterozygous state were detected in 10.3% of patients. The mutation 35delG accounts for 82.8% of detected disease mutations, Trp24stop accounts for 9.7% of pathogenic alleles and was found in patients with gypsy heritage. Mutation 313del14 accounts for 3.7% of pathogenic alleles. The frequency of 35delG heterozygotes in the Czech Republic is 1 : 29.6. Testing for only the three most common mutations would detect over 96% of all pathogenic alleles in the Czech Republic.     

Novel mutations in the connexin 26 gene (GJB2) responsible for childhood deafness in the Japanese population

Mutations in the connexin 26 gene (GJB2), which encodes a gap-junction protein and is expressed in the inner ear, have been shown to be responsible for a major part of nonsyndromic hereditary prelingual (early-childhood) deafness in Caucasians. We have sequenced the GJB2 gene in 39 Japanese patients with prelingual deafness (group 1), 39 Japanese patients with postlingual progressive sensorineural hearing loss (group 2), and 63 Japanese individuals with normal hearing (group 3). Three novel mutations were identified in group 1: a single nucleotide deletion (235delC), a 16-bp deletion (176-191 del (16)), and a nonsense mutation (Y136X) in five unrelated patients. The 235delC mutation was most frequently observed, accounting for seven alleles in 10 mutant alleles. Screening of 203 unrelated normal individuals for the three mutations indicated that the carrier frequency of the 235delC mutation was 2/203 in the Japanese population. No mutation was found in group-2 patients. We also identified two novel polymorphisms (E114G and I203T) as well as two previously reported polymorphisms (V27I andV37I). Genotyping with these four polymorphisms allowed normal Japanese alleles to be classified into seven haplotypes. All 235delC mutant alleles identified in four patients resided only on haplotype type 1. These findings indicate that GJB2 mutations are also responsible for prelingual deafness in Japan.     

湖州地区聋哑学校68名聋哑学生耳聋易感基因突变分析研究

目的研究4个耳聋易感基因GJB2、GJB3、SLC26A4、线粒体12SrRNA在湖州市聋哑学校68名聋哑学生中的突变类型分布情况。方法应用飞行时间质谱技术,对68名聋哑学生进行GJB2、GJB3、SLC26A4、线粒体12SrRNA 4个耳聋易感基因检测,检测位点包含以上基因的20个热点突变。结果68名聋哑学生中共检出耳聋基因突变27例,阳性率39.71％,其中GJB2基因突变19例,占70.37％;GJB3基因突变l例,占3.7％;SLC26A4基因突变5例,占18.52％;线粒体12SrRNA基因突变2例,占7.41％。结论在湖州市聋哑学校中,GJB2是最常见的耳聋突变基因,235delC是GJB2基因最常见的突变位点。     

The prevalence of the 235delC GJB2 mutation in a Chinese deaf population.

PURPOSE: Mutations in the GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment in populations studied to date. However, the prevalence of mutations varies among different ethnic groups. In most areas of China, genetic testing for nonsyndromic hearing impairment is currently not available because of the lack of information regarding the molecular cause of nonsyndromic hearing impairment. The purpose of this study is to determine the prevalence of a common GJB2 mutation, 235delC, in Chinese deaf children. METHODS: We collected DNA specimens from 3004 patients with nonsyndromic hearing impairment from 26 regions of China; 368 Han Chinese and 98 Uigur controls, and screened for the 235delC mutation. The coding exon of the GJB2 gene was polymerase chain reaction amplified, followed by restriction enzyme digestion with ApaI and analysis by agarose gel. RESULTS: Overall, 488 patients (16.3%) were determined to carry at least one 235delC mutant allele, with 233 (7.8%) homozygotes and 255 (8.5%) heterozygotes. Therefore, within the subpopulations examined, the frequency varies from 0% to 14.7% for 235delC homozygotes and from 1.7% to 16.1% for heterozygotes. On the basis of this survey of the patient cohort as stated, Chinese patients with nonsyndromic hearing impairment appear to have a relatively higher 235delC frequency than that of other Asian populations. CONCLUSION: These results demonstrate that an easy and fast genetic testing method for this well-known GJB2 gene mutation can be made available for at least 2 million Chinese patients and family members with nonsyndromic hearing impairment. By screening for the common GJB2 235delC mutation, the molecular cause in as high as 15% of patients with nonsyndromic hearing impairment in certain regions of China can be identified. In addition, patients who are negative for the 235delC mutation would be candidates for further mutational analysis of GJB2 or other deafness-related genes.     

Molecular study in Brazilian cochlear implant recipients

The most common form of non-syndromic autosomal recessive deafness (NSRD) is caused by mutations in the GJB2 gene. Recently, a deletion truncating the GJB6 gene, called del(GJB6-D13S1,830) has also been described normally accompanying mutations in another allele of the GJB2 gene. Among all the mutations described to date, 35delG in the GJB2 gene is the most common. Preliminary data suggest that pathologic changes due to GJB2 mutations do not affect the spiral ganglion cells, which are the site of stimulation of the cochlear implant. Besides, the survival of the spiral ganglion cells is believed to be an important determinant of the outcome after surgery. Therefore, we have studied 49 non-syndromic deaf patients with unknown etiologies in order to determine the prevalence of GJB2 and GJB6 gene mutations in patients undergoing cochlear implantation surgery. Also, the molecular studies were performed using polymerase chain reaction amplification and direct sequencing. As a result, we found 19 individuals with GJB2 mutation including one new mutation (K168R), one patient homozygous for the del(GJB6-D13S1,830). These results establish that genetic screening can provide an etiologic diagnosis, and may help with prognosis after cochlear implantation, as has been hypothesized in previous studies.     

耳聋患者及正常人GJB2基因的突变筛查

目的 检测常染色体隐性遗传耳聋患者GJB2基因突变情况,并分析其与临床表型的关系.方法 收集42例耳聋患者的临床资料,对患者进行纯音电测听检查、声阻抗检测、脑干听觉诱发电位检查;应用聚合酶链反应和直接测序法,对患者和9例患者的父母以及105名正常对照进行GJB2基因检测.结果 两例患者具有235delC纯合性突变,其中1例系感音神经性耳聋,另1例系混合性耳聋;1对混合性耳聋的双生子患者同时携带176de116bp杂合性突变.109G→A、79G→A和341A→G的纯合及杂合突变在患者及正常对照中均有出现.结论 235delC纯合性突变为致病突变,该突变可出现在混合性耳聋中;双生子患者的176de116bp杂合性突变考虑为宫内受到外界环境影响所致,或者由其它基因突变所致.109G→A、79G→A和341A→G考虑为是该基因的多态性,其临床意义仍需进一步探索.     

阳泉地区非综合征性耳聋患者常见耳聋基因突变的分析

目的通过对阳泉市盲聋哑学校69例耳聋患者进行GJB2、PDS及线粒体DNA基因热点突变筛查,分析该地区耳聋的突变分布及分子病因。方法收集山西省阳泉市69例耳聋患者,对所有患者线粒体DNAA1555G／C1494T、GJB2基因、PDS基因第7、8和19外显子进行扩增及测序。结果69例非综合征性耳聋患者共有60例检测到基因突变,突变率为86．96％（60／69）。57例患者检出GJB2基因突变,检出率达82．61％（57／69）,其中C．235delC突变率为10．14％;3例患者有PDS基因突变,分别为c．2168A〉G l例,IVS7-2G〉A 2例;未检测到线粒体DNAA1555G／C1494T突变。结论山西省阳泉市常见耳聋基因突变以GJB2基因突变率较高,为耳聋的诊断与治疗提供依据。