Connexin26 gene (<Emphasis Type="Italic">GJB2</Emphasis>): prevalence of mutations in the Chinese population

 The connexin26 gene (GJB2) has been shown to be responsible for DFNB1 and DFNA3 (Autosomal Recessive Hereditary Nonsyndromic Deafness Locus 1 and Autosomal Dominant Hereditary Nonsyndromic Deafness Locus 3). Two hundred ten independently ascertained Chinese probands with nonsyndromic hearing loss (NSHL) were evaluated for mutations in GJB2, including 43 probands from families with more than one sib with NSHL, likely indicating dominant inheritance, and sporadic cases of NSHL, compatible with recessive inheritance. Of the 210 probands, 43 (20%) were homozygous or heterozygous for mutations in GJB2. Four different mutations were identified: 35delG, 109G-A, 235delC, and 299–300delAT. It was confirmed that GJB2 mutations are an important cause of hearing loss in this population. Of these four mutations, 235delC was the most prevalent at 93%; yet the 35delG mutation, which is the most common GJB2 mutation in Caucasian subjects (Europeans and Americans), was found in low frequency in the present study. It appears from our limited data and reports from other East Asians that 235delC is the most prevalent GJB2 mutation in these populations. GJB2 mutations are consistent with ethnic predilections. Received: July 8, 2002 / Accepted: October 4, 2002     

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.     

Update of the Spectrum of GJB2 Mutations in 107 Patients with Nonsyndromic Hearing Loss in the Fujian Population of China

Mutations in the GJB2 gene, encoding connexin26, which is expressed in the inner ear, have been shown to be responsible for the majority of nonsyndromic hearing loss (NSHL) cases. To update and evaluate the spectrum and prevalence of GJB2 mutations in the Fujian population, we screened exon 2 (coding), exon 1, and flanking introns of GJB2 in 107 NSHL probands and 61 individuals with normal hearing. Twelve different variants were identified, including three pathogenic mutations (c.235delC, c.299_300delAT, and c.508insAACG), one hypomorphic allele (p.V37I), three polymorphic variants (p.V27I, p.E114G, and p.I230T), and five rare variants (p.N62N, p.F115C, p.T123N, p.G21E, and p.F142I). The p.G21E and p.F142I variants were potentially pathogenic as predicted by PolyPhen‐2, SIFT, and PROVEAN. The most common mutation was c.235delC with allele frequency 12.6% (27/214). The most common polymorphisms in the Fujian population were p.V27I and p.E114G, both detected at high frequency in probands and controls. The p.E114G variant was always in cis with p.V27I, and formed the haplotype, p.[V27I; E114G] in the Fujian population. Interestingly, only 17.76% (19/107) of NSHL probands had clearly defined pathogenic mutations in GJB2, indicating that the pathogenesis of NSHL in the Fujian population is heterogenous, and that further analysis of other NSHL genes is necessary.     

High prevalence of V37I genetic variant in the connexin-26 (GJB2) gene among non-syndromic hearing-impaired and control Thai individuals

Hearing loss is highly prevalent with a worldwide incidence of 1-2 per 1000 newborns. Several previous studies have demonstrated that mutations of connexin 26 (Cx26 or GJB2) are responsible for most cases of the recessive non-syndromic sensorineural hearing loss (NSSHL). Certain mutations have been described frequently among various populations, which include 35delG, 167delT, and 235delC. Recently, a missense mutation, V37I, was reported as a pathogenic change in East Asian affected individuals. To identify genetic variants associated with NSSHL in Thai population, we performed mutation analysis of Cx26 in 166 unrelated probands with NSSHL and 205 controls. We identified seven novel genetic variants in Cx26. We also identified a high prevalence of the V37I mutation among both affected probands (11.1%) and control subjects (8.5%), which suggests that the pathologic role of V37I may be modified by other genes. Our data support previous studies that show heterogeneity in the frequencies and types of mutations in Cx26 within populations and among ethnicities and that before clinical significance and causality can be attributed to a genetic variant, functional characterization is necessary.     

Sensorineural hearing loss and the incidence of Cx26 mutations in Austria

A clinical evaluation and Cx26 mutation analysis was performed in 92 consecutive patients with sensorineural hearing loss in order to delineate the spectrum of genetically caused hearing loss. Among patients of Austrian origin, 53% were classified with hereditary hearing loss. Cx26 mutations were found in 26% of NSHL patients (40% of familial vs 18% of sporadic cases). The mutation 35delG accounted for 52.8% of all presumed GJB2 disease alleles. The second most frequent mutation was L90P (16.7%) having been reported with a prevalence of 0.7-3.5% in other populations. Three novel mutations were found. The novel mutation, R143Q, was associated with dominant high-frequency hearing loss. Pseudodominant transmission of NSHL was seen in four families with Cx26 mutations. A mutation 35delG carrier rate of 0.9% was observed among 672 controls from West-Austria. Cx26 mutations were found associated with mild to profound, and with asymmetric hearing impairment.     

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.     

Frequencies of gap- and tight-junction mutations in Turkish families with autosomal-recessive non-syndromic hearing loss

Mutations in genes encoding gap- and tight-junction proteins have been shown to cause distinct forms of hearing loss. We have now determined the GJB2[connexin 26 (Cx26)] mutation spectrum in 60 index patients from mostly large Turkish families with autosomal-recessive inherited non-syndromic sensorineural hearing loss (NSSHL). GJB2 mutations were found in 31.7% of the families, and the GJB2-35delG mutation accounted for 73.6% of all GJB2 mutations. The carrier frequency of GJB2-35delG in the normal Turkish population was found to be 1.17% (five in 429). In addition to the described W24X, 233delC, 120delE and R127H mutations, we also identified a novel mutation, Q80R, in the GJB2 gene. Interestingly, the Q80R allele was inherited on the same haplotype as V27I and E114G polymorphisms. As little is known about the mutation frequencies of most other recently identified gap- and tight-junction genes as a cause for hearing loss, we further screened our patients for mutations in GJB3 (Cx31), GJA1 (Cx43), DeltaGJB6-D13S1830 (Cx30) and the gene encoding the tight-junction protein, claudin 14 (CLDN14). Several novel polymorphisms, but no disease-associated mutations, were identified in the CLND14 and GJA1 genes, and we were unable to detect the DeltaGJB6-D13S1830 deletion. A novel putative mutation, P223T, was found in the GJB3 gene in heterozygous form in a family with two affected children. Our data shows that the frequency of GJB2 mutations in Turkish patients with autosomal-recessive NSSHL and the carrier rate of the GJB2-35delG mutation in the Turkish population, is much lower than described for other Mediterranean countries. Furthermore, mutations in other gap- and tight-junction proteins are not a frequent cause of hearing loss in Turkey.     

一个遗传性非综合征型耳聋家系的突变分析

目的分析一个遗传性非综合征型耳聋家系的突变，并探讨缝隙连接蛋白beta2(gap junction protein beta 2，GJB2)基因235delC突变是否会加重线粒体A1555G突变导致的非综合征型耳聋症状。方法对一个母系遗传性非综合征型耳聋核心家系72个成员取外周血提取DNA，经聚合酶链反应扩增后，利用Alw26Ⅰ限制性内切酶酶切及直接测序验证，对其线粒体DNA突变进行研究；利用ApaⅠ限制性内切酶酶切及直接测序验证，筛查核心家系中GJB2基因235delC突变情况，并对GJB2基因235delC和线粒体A1555G突变的关系进行研究。结果在27名母系成员中均发现具有线粒体A1555G突变，呈母系遗传；具有耳聋表型的为21人(77．8％)，家族外显率高；所筛查的包括配偶在内的72名个体中，仅3例具有GJB2基因235delC杂合子突变，且均出现在母系成员中，但3例的耳聋表型却不同。结论线粒体A1555G突变是本家系耳聋遗传易感性的基础，在该家系中GJB2基因的235delC杂合子突变未加重线粒体A1555G突变导致的非综合征型耳聋。     

Molecular genetics of hearing impairment due to mutations in gap junction genes encoding beta connexins

Deafness is a complex disorder that involves a high number of genes and environmental factors. There has been enormous progress in non-syndromic deafness research during the last five years, with the identification of over 50 loci and 15 genes. Among these, three genes, GJB2, GJB3, and GJB6, encode for connexin proteins (Connexin26, Connexin31, and Connexin30, respectively). Another connexin (Connexin32, encoded by GJB1) is involved in X-linked peripheral neuropathy and hearing impairment. Mutations in these genes cause autosomal recessive (GJB2 and GJB3), autosomal dominant (GJB2, GJB3, and GJB6) or X-linked (GJB1) hearing impairment, both syndromic (GJB2, keratoderma; GJB3 erythrokeratodermia variabilis; and GJB1, peripheral neuropathy), and non-syndromic (GJB2, GJB3, and GJB6). Among these genes, mutations in GJB2 account for about 50% of all congenital cases of hearing impairment. Three mutations in GJB2 (35delG, 167delT, and 235delC) are particularly common in specific populations (Caucasoid, Jewish Ashkenazi, and Oriental, respectively), leading to carrier frequencies between one in 30 and one in 75. Over 50 mutations have been identified in the GJB2 gene, of which some missense changes (M34T, W44C, G59A, D66H, and R75W) have a negative dominant action in hearing impairment, with partial to full penetrance. Functional studies for some missense mutations in connexins 26, 30, and 32 have indicated abnormal gap junction conductivity. Expression patterns in mouse and rat cochlea indicate that Connexin26 and Connexin30 are expressed in the supportive cells of the cochlea, suggesting a potential role in endolymph potassium recycling. The high prevalence of mutations in GJB2 in some populations provides the tools for molecular diagnosis, carrier detection, and prenatal diagnosis of congenital hearing impairment.     

Pyrosequencing for detection of mutations in the connexin 26 (GJB2) and mitochondrial 12S RNA (MTRNR1) genes associated with hereditary hearing loss

Hereditary hearing loss (HHL) is one of the most common congenital disorders and is highly heterogeneous. Mutations in the connexin 26 (CX26) gene (GJB2) account for about 20% of all cases of childhood deafness, and approach 50% in documented recessive cases of non-syndromic hearing loss. In addition, a single mitochondrial DNA mutation, mt1555A>G, in the 12S rRNA gene (MTRNR1), is associated with familial cases of progressive deafness. Effective screening of populations for HHL necessitates rapid assessment of several of these potential mutation sites. Pyrosequencing links a DNA synthesis protocol for determining sequence to an enzyme cascade that generates light whenever pyrophosphate is released during primer strand elongation. We assessed the ability of Pyrosequencing to detect common mutations causing HHL. Detection of the most common CX26 mutations in individuals of Caucasian (35delG), Ashkenazi (167delT), and Asian (235delC, V37I) descent was confirmed by Pyrosequencing. A total of 41 different mutations in the CX26 gene and the mitochondrial mt1555A>G mutation were confirmed. Genotyping of up to six different adjacent mutations was achieved, including simultaneous detection of 35delG and 167delT. Accurate and reproducible results were achieved taking advantage of assay flexibility and experimental conditions easily optimized for a high degree of standardization and cost-effectiveness. The standardized sample preparation steps, including target amplification by PCR and preparation of single-stranded template combined with automated sequence reaction and automated genotype scoring, positions this approach as a potentially high throughput platform for SNP/mutation genotyping in a clinical laboratory setting. .     

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.     

遗传性非综合征型耳聋患者GJB2基因编码序列分析

目的 对6个遗传性非综合征型耳聋家系成员的GJB2基因编码序列进行分析,寻找耳聋患者的致病基因突变,探讨GJB2基因突变致病的遗传模式.方法 提取患者及家系成员的外周血基因组DNA,扩增GJB2基因的编码序列,然后对扩增产物进行DNA测序,对出现重叠峰形的扩增产物进行TA克隆后再测序,确定基因突变是否存在于同一拷贝.结果 6个遗传性非综合征型耳聋家系中,4个家系是GJB2基因突变所致.患者的GJB2基因突变包括235delC、299-300delAT、79G→A+341A→G和109G→A.非致聋突变79G→A与341A→G组合具有致聋效应,109G→A和235delC的杂合突变可能也有致聋效应.结论 GJB2基因突变致聋具有明显异质性,非致聋突变并非完全不致聋,环境因素或其它基因可能参与GJB2基因突变所致耳聋.     

Clinical features of patients with GJB2 (connexin 26) mutations: severity of hearing loss is correlated with genotypes and protein expression patterns

Mutations in the GJB2 (connexin 26, Cx26) gene are the major cause of nonsyndromic hearing impairment in many populations. Genetic testing offers opportunities to determine the cause of deafness and predict the course of hearing, enabling the prognostication of language development. In the current study, we compared severity of hearing impairment in 60 patients associated with biallelic GJB2 mutations and assessed the correlation of genotypes and phenotypes. Within a spectrum of GJB2 mutations found in the Japanese population, the phenotype of the most prevalent mutation, 235delC, was found to show more severe hearing impairment than that of V37I, which is the second most frequent mutation. The results of the present study, taken together with phenotypes caused by other types of mutations, support the general rule that phenotypes caused by the truncating GJB2 mutations are more severe than those caused by missense mutations. The present in vitro study further confirmed that differences in phenotypes could be explained by the protein expression pattern.     

Newborn genetic screening for hearing impairment: a population-based longitudinal study

PurposeThe feasibility of genetic screening for deafness-causing mutations in newborns has been reported in several studies. The aim of this study was to investigate the long-term results in those who screened positive for deafness mutations; these results are crucial to determine the cost-effectiveness to justify population-wide genetic screening.MethodsWe performed simultaneous hearing screening and genetic screening targeting four common deafness mutations (p.V37I and c.235delC of GJB2, c.919-2A>G of SLC26A4, and the mitochondrial m.1555A>G) in 5173 newborns at a tertiary hospital between 2009 and 2015. Serial audiometric results up to 6 years old were then analyzed in children with conclusive genotypes.ResultsNewborn genetic screening identified 82 (1.6%) babies with conclusive genotypes, comprising 62 (1.2%) with GJB2 p.V37I/p.V37I, 16 (0.3%) with GJB2 p.V37I/c.235delC, and 4 (0.1%) with m.1555A>G. Of these, 46 (56.1%) passed hearing screening at birth. Long-term follow-up demonstrated progressive hearing loss in children with the GJB2 p.V37I/p.V37I and p.V37I/c.235delC genotypes; this hearing loss deteriorated by approximately 1 decibel hearing level (dBHL) per year.ConclusionsWe delineated the longitudinal auditory features of the highly prevalent GJB2 p.V37I mutation on a general population basis and confirmed the utility of newborn genetic screening in identifying infants with late-onset or progressive hearing impairment undetectable by newborn hearing screening.     

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.     

Prevalence of Mutations in Deafness‐Causing Genes in Cochlear Implanted Patients with Profound Nonsyndromic Sensorineural Hearing Loss in Shandong Province,China

The mutations of GJB2, SLC26A4, and mtDNA12SrRNA are the most common inherited causes of nonsyndromic sensorineural hearing loss (NSHL) in China, yet previous genetic screenings were mainly carried on patients with moderate‐to‐profound impairment. We aimed to detect the mutation frequencies in NSHL population within a more specified range of severity. Patients with profound NSHL who had undergone cochlear implantation in the Shandong Provincial Hospital (Shandong, China) were recruited. The majority (n = 472) were between 0.7 and 6 years old, and the remaining (n = 63) were between 6 and 70 years old. In total, 115 mutation alleles of the three genes were screened with SNP scan assay. Of the patients, 19.44% (104/535) were found to have GJB2 mutations, and the most common allele was c.235delC, followed by c.299_300delAT and c.109G>A. SLC26A4 mutations were detected in 13.46% patients (72/535), and the most common allele was c.919‐2A>G (IVS7‐2A>G), followed by c.1174A>T and c.2168A>G. Seven patients (1.31%) carried mutations in mtDNA12SrRNA, with the alleles of m.1555A>G and m.1494C>T. We found the allele frequency of c.109G>A (GJB2) was relatively lower in the profound NSHL population in comparison to the moderate‐to‐profound ones, and the c.1174A>T (SLC26A4) relatively higher. It suggests those mutations may be connected with the degree of deafness, which needs more observations and analyses to support.     

2623例新生儿听力筛查和GJB2基因检测结果分析

目的探讨常规听力筛查的同时进行GJB2基因检测的可行性。方法采取知情同意、自愿选择的原则,对2623例新生儿出生后2-3天采集足跟血,利用飞行时间质谱技术对GJB2耳聋基因进行检测,包括5个热点突变位点235delC、299-300delAT、35delG、l76-191dell6、167delT突变,并采用GSI耳声发射仪（DPOAE）进行新生儿听力筛查。结果2623例新生儿中GJB2基因检测阳性率3．20％,其中听力初筛通过婴儿中基因阳性率2．50％,听力初筛未通过婴儿中基因阳性率5．21％,听力初筛未通过GJB2耳聋基因阳性率高于听力初筛通过婴儿,差异性显著（P〈0．01）。l例GJB2235del纯合突变经ABR检查确诊为双耳中重度听力损失。结论 将JB2基因筛查和常规听力筛查联合对早期发现新生儿语前听力损失或迟发的听力损失,及婚育指导具有重要意义。     

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.     

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.     

遗传性非综合征性常见耳聋基因诊断的研究

目的应用三种方法对非综合征性感音神经性耳聋患者及其家属进行分子病因学研究,以期获得一种快速、简便、有效的临床诊断方法。方法采用酶切法、芯片法和测序法对国内报道突变频率比较高的6个耳聋基因进行检测。结果 19例耳聋患者,酶切法共检出4例GJB2 235delC,1例mt 12S rRNA;; A;;1555G;其中8例患者及1例患者的父母基因芯片法检出1例mt 12S rRNA;; A;;1555G,3例GJB2 235delC,3例SLC26A;;4基因突变,3例9位点均正常。mt 12S rRNA;;A;;1555G和GJB2 235delC基因芯片检测结果与酶切相一致。10例基因芯片检测及GJB3测序分析均未检出GJB3 538C〉T突变及GJB3其他致病突变;GJB6基因序列未发现致病突变位点。mt 12S rRNA;; A;;1555G和GJB2 235delC位点测序分析结果与基因芯片和酶切结果相一致。SLC26A;;4基因突变IVS7-2A;;〉G和2168A;;〉G测序分析结果与基因芯片结果相符。随后对部分患者父母采用上述方法筛查,48例样品中,共检出15例携带致聋突变,检出率31.25%。结论酶切法、基因芯片法及测序法三者检查结果相符合。临床诊断因患者而异,综合三种检测技术,设计最佳筛查方式。