A prospective study of genetic screening of 2 060 neonates by high-throughput sequencing / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases.@*METHODS@#A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA).@*RESULTS@#Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%).@*CONCLUSION@#Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.

Analysis of genotypes on 850 newborns with SLC26A4 single-allele mutation and the phenotypes of those with second variant / 中华耳鼻咽喉头颈外科杂志

Objective: To clarify the phenotypes of the newborns with SLC26A4 single-allele mutation in deafness genetic screening and second variant; to analyze the SLC26A4 genotype and hearing phenotype. Methods: 850 newborns born in Beijing from April 2015 to December 2019 were included and there were 468 males and 382 females. They received genetic deafness screening for 9 or 15 variants, with the result of SLC26A4 single-allele mutation. Firstly, three step deafness gene sequencing was adopted in this work, i.e., the first step was "SLC26A4 gene whole exons and splice sites" sequencing; the second step was "SLC26A4 gene promoter, FOXI1 gene and KCNJ10 gene whole exons" sequencing; and the third step was detection for "SLC26A4 gene copy number variation". Secondly, we collected the results of newborn hearing screening for all patients with the second mutation found in the three step test, and conducted audiological examinations, such as acoustic immittance, auditory brainstem response and auditory steady state response. Thirdly, for novel/VUS mutations, we searched the international deafness gene database or software, such as DVD, ClinVar and Mutation Taster, to predict the pathogenicity of mutations according to the ACMG guideline. Lastly, we analyzed the relationship between genotype and phenotype of newborns with SLC26A4 single allele mutation. Results: Among 850 cases, the median age of diagnosis was 4 months. In the first step, 850 cases were sequenced. A total of 32 cases (3.76%, 32/850) of a second variants were detected, including 18 cases (2.12%, 18/850) with identified pathogenic variants; 832 cases were sequenced and 8 cases of KCNJ10 gene missense variants were detected among the second step. No missense mutations in the FOXI1 gene and abnormal SLC26A4 gene promoter were detected; the third step sequencing results were all negative. Genotypes and hearing phenotypes included 18 cases combined with the second clear pathogenic variant, 16 cases (16/18) referred newborn hearing screening and 2 cases (2/18) passed in both ears; degree of hearing loss consisted of 18 profound ears (18/36), 13 severe ears (13/36) and 5 moderate ears (5/36); audiogram patterns comprised 17 high frequency drop ears (17/36), 14 flat ears (14/36), 3 undistinguished ears (3/36), and 2 U shaped ears (2/36); 11 cases underwent imaging examination, all of which were bilateral enlarged vestibular aqueduct. As for 22 cases of other genotypes, all passed neonatal hearing screening and the hearing diagnosis was normal, including 9 cases with VUS or possibly novel benign variants, 8 cases with KCNJ10 double gene heterozygous variants, and 5 cases with double heterozygous variants. Conclusions: The probability of individuals with SLC26A4 single-allele variant who merge with a second pathogenic variant is 2.12%, all of which are SNV, which can provide scientific basis for the genetic diagnosis and genetic counseling of SLC26A4 variants. Those who have merged with second pathogenic variant are all diagnosed with sensorineural hearing loss. Patients with KCNJ10 gene mutations do not manifest hearing loss during the infancy, suggesting the need for further follow-up.

Result of Sanger sequencing for newborn carriers of single heterozygous variants of GJB2 or SLC26A4 gene by genechip analysis / 中华医学遗传学杂志

OBJECTIVE@#To detect additional variants for newborn carriers of single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis in Changsha area, and explore the variation spectrum of deafness-related genes in this region.@*METHODS@#For 462 newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene, all exons of the genes were subjected to Sanger sequencing. The pathogenicity of the variants was analyzed by database and literature search.@*RESULTS@#For 305 newborns carrying a heterozygous GJB2 variant, 143 (46.49%) were found to carry additional variants, including 29 (9.51%) with c.109G>A likely pathogenic variant, and 1 (6.48%) with c.551G>A pathogenic variant. Among 153 newborns carrying single heterozygous variant of the SLC26A4 gene, 2 (1.31%) were found with a c.281C>T variant, and 1 (0.65%) with a c.1547_1548ins pathogenic variant. Among 4 newborns simultaneously carrying GJB2 and SLC26A4 variants, two were found to carry c.109G>A and c.844T>C variants (clinical significance unknown), respectively.@*CONCLUSION@#For newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis, the detection rate for other variants is quite high. Sanger sequencing can significantly improve the detection rate of high-risk newborns and enrich the variant spectrum of deafness genes.

Increased expression of pendrin in eosinophilic chronic rhinosinusitis with nasal polyps / Expressão aumentada de pendrina na rinossinusite crônica eosinofílica com pólipos

Abstract Introduction: Chronic rhinosinusitis with nasal polyps is a heterogeneous disease and appropriate diagnostic algorithms in individual cases are necessary for effective medical treatment. Objective: The purpose of this study was to clarify the relationship between the pendrin expression of nasal polyps and clinical and pathological characteristic features of eosinophilic chronic rhinosinusitis. Methods: A total of 68 patients were classified into eosinophilic chronic rhinosinusitis or non-eosinophilic chronic rhinosinusitis groups according to the degree of eosinophilic infiltration into the nasal polyps. Clinical, hematological, and immunohistochemical analyses were performed and statistically compared between both groups. Results: Thirty-eight were classified into eosinophilic chronic rhinosinusitis and 30 into non-eosinophilic chronic rhinosinusitis groups. There were no significant differences in age distribution, sex ratio, prevalence of asthma, or any other complications between the groups. The mean Lund-Mackay score and the number of serum eosinophils was significantly higher in the eosinophilic chronic rhinosinusitis than in the non-eosinophilic chronic rhinosinusitis groups. The pendrin expression was more frequently detected in the epithelial surface layer of nasal polyps in the eosinophilic chronic rhinosinusitis than in the non-eosinophilic chronic rhinosinusitis groups. In addition, mucin 5AC was more widely expressed in the eosinophilic chronic rhinosinusitis than in the non-eosinophilic chronic rhinosinusitis. Conclusion: Increased expression of pendrin and mucin 5AC in the nasal polyps would be associated with development of eosinophilic chronic rhinosinusitis. This finding could allow the development of a novel therapeutic agent targeted specifically to patients with eosinophilic chronic rhinosinusitis.

Resumo Introdução: A rinossinusite crônica com pólipos nasais é uma doença heterogênea e algoritmos diagnósticos apropriados em casos individuais são necessários para um tratamento médico eficaz. Objetivo: O objetivo deste estudo foi esclarecer a relação entre a expressão da pendrina de pólipos nasais e propriedades clínicas e patológicas características da rinossinusite crônica eosinofílica. Método: Um total de 68 pacientes foram classificados como tendo rinossinusite crônica eosinofílica ou rinossinusite crônica não eosinofílica de acordo com o grau de infiltração eosinofílica nos pólipos nasais. Análises clínicas, hematológicas e imunohistoquímicas foram realizadas e comparadas estatisticamente entre os dois grupos. Resultados: Entre os pacientes, 38 apresentavam rinossinusite crônica eosinofílica e constituíram o grupo 1; 30 tinham rinossinusite crônica não eosinofílica e constituíram o grupo 2. Não houve diferenças significantes na distribuição etária, razão entre os sexos, prevalência de asma ou qualquer outra complicação entre os grupos. O escore médio de Lund-Mackay e o número de eosinófilos séricos foram significantemente maiores no grupo com rinossinusite crônica eosinofílica do que no grupo com rinossinusite crônica não eosinofílica. A expressão da pendrina foi mais frequentemente detectada na camada epitelial superficial dos pólipos nasais na rinossinusite crônica eosinofílica do que no grupo com rinossinusite crônica não eosinofílica. Além disso, mucina 5AC foi mais amplamente expressa na rinossinusite crônica eosinofílica do que na rinossinusite crônica não eosinofílica. Conclusão: O aumento da expressão da pendrina e mucina 5AC nos pólipos nasais estaria associado ao desenvolvimento de rinossinusite crônica eosinofílica. Esse achado pode permitir o desenvolvimento de um novo agente terapêutico voltado especificamente para pacientes com rinossinusite crônica eosinofílica.

Application of next generation sequencing for the diagnosis of congenital hearing loss / 中华医学遗传学杂志

OBJECTIVE@#To identify genetic mutations among patients with hearing loss but without common GJB2, SLC26A4, 12 SrRNA mutations.@*METHODS@#Thirty-three patients were subjected to next-generation sequencing (NGS). Suspected mutations were verified by Sanger sequencing.@*RESULTS@#Four patients were found to harbor previously known pathogenic variations, and four were found to carry suspicious pathogenic variations, which yielded a detection rate of 24.2%.@*CONCLUSION@#NGS can improve the detection rate for mutations underlying congenital hearing loss and improve the efficiency and accuracy of the diagnosis.

Analysis of GJB2, SLC26A4, GJB3 and 12S rRNA gene mutations among patients with nonsyndromic hearing loss from eastern Shandong / 中华医学遗传学杂志

OBJECTIVE@#To explore the characteristics of mutations of four common pathogenic genes (GJB2, SLC26A4, GJB3 and 12S rRNA) among patients with nonsyndromic hearing loss (NSHL) from eastern Shandong.@*METHODS@#Peripheral blood samples of 420 NSHL patients were collected, and a hereditary-deafness-gene microarray was used to detect GJB2 c.235delC, c.299-300delAT, c.35delG and c.176del16 mutations, GJB3 c.538C>T mutation, SLC26A4 c.2168A>G and c.IVS7-2A>G mutations, and 12S rRNA c.1555A>C and c.1494C>T mutations. For patients carrying single heterozygous mutations, the coding regions of the above genes were analyzed with Sanger sequencing.@*RESULTS@#The results of the microarray assay and Sanger sequencing showed that 84 patients (20.00%) carried GJB2 mutations, with c.235delC (16.43%) and c.299-300delAT (7.86%) being most common. Seventy-five patients (17.86%) carried SLC26A4 mutations, for which c.IVS7-2A>G accounted for 15.71%. In addition, 5.95% of patients carried 12S rRNA mutations. Only one patient was found to carried GJB3 mutation (c.538C>T).@*CONCLUSION@#Common pathogenic mutations for NSHL in eastern Shandong included GJB2 c.235delC and SLC26A4 c.IVS7-2A>G. Of note, 5.95% of patients were due to 12S rRNA m.1555A>G mutation, which gave a frequency greater than other regions of China.

Mutational analysis of 117 patients with non-syndromic hearing loss / 中华医学遗传学杂志

OBJECTIVE@#To determine the frequencies of deafness gene mutations among patients with non-syndromic hearing loss (NSHL) from northern Jiangsu province.@*METHODS@#A total of 117 patients with NSHL were enrolled. The coding region of GJB2 gene, IVS7-2A>G and 2168A>G mutations of SLC26A4 gene, and 1555A>G and 1494C>T mutations of mitochondrial DNA 12S rRNA were subjected to Sanger sequencing. Patients in whom no mutation was detected were further tested by targeted gene capture and high-throughput sequencing.@*RESULTS@#Among the 117 patients, 86 (73.50%) were found to carry mutations. GJB2 gene mutations were found in 61 patients (52.14%), including 22 (18.80%) with homozygous mutations and 39 (33.33%) with heterozygous mutations. SLC26A4 gene mutations were found in 19 patients (16.24%), including 4 (3.42%) with homozygous mutations and 15 with heterozygous mutations (14.53%). Mitochondrial 12S rRNA gene mutation was found in 6 patients (5.13%). Targeted gene capture and high-throughput sequencing of 8 patients identified 4 further cases, including 1 with RDX gene 129_130del and 76_79del compound heterozygous mutations, 1 with OTOF gene 1274G>C homozygous mutation, 1 with SLC26A4 gene 919-2A>G and IVS16-6G>A compound heterozygous mutation, and 1 with SLC26A4 gene 919-2A>G and A1673T compound heterozygous mutation.@*CONCLUSION@#The frequency of mutation among patients with NSHL from north Jiangsu was 73.50%, and GJB2 gene was most commonly mutated.

Establishment of a congenital chloride diarrhea-associated SLC26A3 c.392C>G (p.P131R) polymorphism-expressing cell model and a preliminary analysis of its mechanism of action / 中国当代儿科杂志

OBJECTIVE@#To establish a congenital chloride diarrhea (CCD)-associated SLC26A3 c.392C>G (p.P131R) polymorphism-expressing cell model, and to investigate its biological function.@*METHODS@#The sequence of the SLC26A3 gene in GenBank was used to design the upstream and downstream single-guide RNA (sgRNA) that could specifically recognize the 392 locus of the SLC26A3 gene, and the sgRNA was mixed with the pSpCas9-puro vector after enzyme digestion to construct an eukaryotic recombinant expression plasmid (pSpCas9-SLC26A3). Caco-2 cells were transfected with the recombinant plasmid and synthesized single-stranded DNA oligonucleotides (ssODNs), and Taqman genotyping assay and Sanger sequencing were used to identify the expression of SLC26A3 c.392C>G (p.P131R) in Caco-2 cells. Wild-type Caco-2 cells were selected as normal control group and the Caco-2 cells with successful expression of SLC26A3 c.392C>G (p.P131R) was selected as P131R group. Both groups were treated with 100 ng/mL tumor necrosis factor-α (TNF-α), and then the normal control group was named as TNF-α group, and the P131R group was named as TNF-α+P131R group. Electric cell-substrate impedance sensing (ECIS) assay was used to evaluate the change in the monolayer barrier function of intestinal epithelial cells in the above four groups, and Western blot was used to measure the change in the expression of SLC26A3 protein in the normal control group and the P131R group.@*RESULTS@#The eukaryotic recombinant expression plasmid (pSpCas9-SLC26A3) was successfully constructed. Both Taqman genotyping assay and Sanger sequencing confirmed the successful establishment of the Caco-2 cell model of SLC26A3 c.392C>G (p.P131R) expression. ECIS assay showed that compared with the normal control group, the P131R group had a significant increase in the monolayer permeability of intestinal epithelial cells (PG (p.P131R) can reduce the expression of SLC26A3 protein, increase the monolayer permeability of intestinal epithelial cells, and thus lead to diarrhea.

Mutation screening of the SLC26A4 gene in a cohort of 192 Chinese patients with congenital hypothyroidism

ABSTRACT Objective Pendred syndrome (PS) is an autosomal recessive disorder characterised by sensorineural hearing loss and thyroid dyshormonogenesis. It is caused by biallelic mutations in the SLC26A4 gene encoding for pendrin. Hypothyroidism in PS can be present from birth and therefore diagnosed by neonatal screening. The aim of this study was to examine the SLC26A4 mutation spectrum and prevalence among congenital hypothyroidism (CH) patients in the Guangxi Zhuang Autonomous Region of China and to establish how frequently PS causes hearing impairment in our patients with CH. Subjects and methods Blood samples were collected from 192 CH patients in Guangxi Zhuang Autonomous Region, China, and genomic DNA was extracted from peripheral blood leukocytes. All exons of the SLC26A4 gene together with their exon-intron boundaries were screened by next-generation sequencing. Patients with SLC26A4 mutations underwent a complete audiological evaluation including otoscopic examination, audiometry and morphological evaluation of the inner ear. Results Next generation sequencing analysis of SLC26A4 in 192 CH patients revealed five different heterozygous variations in eight individuals (8/192, 4%). The prevalence of SLC26A4 mutations was 4% among studied Chinese CH. Three of the eight were diagnosed as enlargement of the vestibular aqueduct (EVA), no PS were found in our 192 CH patients. The mutations included one novel missense variant p.P469S, as well as four known missense variants, namely p.V233L, p.M147I, p.V609G and p.D661E. Of the eight patients identified with SLC26A4 variations in our study, seven patients showed normal size/location of thyroid gland, and one patients showed a decreased size one. Conclusions The prevalence of SLC26A4 pathogenic variants was 4% among studied Chinese patients with CH. Our study expanded the SLC26A4 mutation spectrum, provided the best estimation of SLC26A4 mutation rate for Chinese CH patients and indicated the rarity of PS as a cause of CH.

Analysis common gene mutation spots of 127 non-syndromic deafness natients in Guangxi Drovince / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the mutation characteristics of common deafness gene from 127 non-syndromic hearing loss patients in Guangxi province.@*METHOD@#Deafness-related gene mutations detection kit was used to detect 15 mutation sites in four deafness-associated genes, and a total of 127 hearing impaired patients were tested. The samples that could not be diagnosed with DNA microarray were subjected to PCR and sequenced to detect other mutations.@*RESULT@#Among the 127 patients with non-syndromic deafness, the total mutation rate is 8.66% (11/127), including GJB2 235delC homozygous in 3 cases (2.36%), 235delC single heterozygous mutation in 2 cases (1.57%), GJB2 235delC and 109 A > G mutations in 2 cases (1.57%); SLC26A4 1229C > T homozygous in 1 case (0.79%), IVS7-2A > G, IVS11 + 47T > C and 15448insC mutaion in 2 cases (1.57%); mitochondrial 12S rRNA gene mutations were not detected. The result indicates that GJB2 and SLC26A4 were the main genes in this study, and the mutation rate is significantly lower than the national average level. Three new mutations (SLC26A4 IVS11 + 47T > C,1548insC and GJB2 109A > G) were found. There may be rare mutations among sites or genes associated with deafness in Guangxi.

Analysis of deafness-related gene mutations in 100 non-syndromic hearing loss patients in Henan province / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To preliminarily determine the gene mutation frequency and the hotspots in Henan province, we analysed the deafness-related gene mutation in patients with non-syndromic hearing loss (NSHL).@*METHOD@#Genomic DNA samples of 100 patients with NSHL in Henan province were extracted from peripheral blood after clinical history inquiry and clinical examination, Four common deafness genes GJB2, SLC26A4, mitochondrial 12SrRNA, and GJB3 were detected by Sanger sequencing method,and then data analysis were conducted.@*RESULT@#Among 100 patients with NSHL. the gene mutation frequency was 44%. In these patients, 29 cases had GJB2 mutations, 13 cases had SLC26A4 gene mutations, and 3 cases had mitochondrial 12SrRNA mutations.@*CONCLUSION@#Among the patients with NSHL in Henan province, the most frequent mutation causing hereditary deafness was mutation in GJB2, followed by SLC26A4,and it will provide a theoretical basis to determine the etiology of deafness in Henan Province.

Clinical analysis of Mondini dysplasia with cerebrospinal fluid leakage and preliminary genetic research of it / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To summarize and analyze the clinical characteristics of Mondini dysplasia with cerebrospinal fluid leakage, as well as preliminarily investigate the genetic mechanism of the disease.@*METHOD@#The clinical data of 2 patients diagnosed as Mondini dysplasia with cerebrospinal fluid leakage treated in our hospital were analyzed. Blood samples of these two patients were obtained to extract DNA. We screened DNA samples for gene SLC26A4 mutations by using polymerase chain reaction and direct sequencing. The sequencing results were analyzed in DNASTAR software.@*RESULT@#Both patients came to our hospital because of recurrent meningitis, and the fistula were both located in vestibular window. Patients were cured one-time after surgical closure of the leakages with temporalis + temporalis fascia + temporalis through the mastoid approach. No pathogenic mutations of gene SLC26A4 with exome sequencing were found.@*CONCLUSION@#Mondini dysplasia with cerebrospinal fluid leakage should be considered in patients with recurrent meningitis and hearing disorder. Temporal bone HRCT is helpful to the diagnosis. Surgical closure is an effective therapeutic method and may prevent recurrent meningitis. The molecular mechanism of simple Mondini dysplasia needs further study.

DNA microarray screening analysis in children with profound hearing impairment in Hubei province / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate characteristics of molecular etiology of children with profound sensorineural hearing loss in Hubei province, and to provide reference for deafness treatment and genetic counseling.@*METHOD@#Three hundred and six children with profound sensorineural hearing loss in Hubei province were enrolled, their genomic DNA were extracted from peripheral blood and a deafness gene test chip was used to screen nine hot spot mutation in the GJB2, GJB3, SLC26A4, and mitochondria 12SrRNA gene. All patients with SLC26A4 gene mutation were given temporal bone CT scan.@*RESULT@#One hundred and thirty-two (43.14%) out of 306 children were found carrying at least one pathogenic gene mutation. The mutation rates of GJB2, SLC26A4 and mitochondria DNA 12SrRNA gene were 29.41% (90/306), 13.72% (42/306) and 0.65% (2/306), respectively. None out of 306 children was detected GJB3 gene mutation. Thirty-six patients carrying SLC26A4 gene mutation were detected enlarged vestibular aqueduct by CT scan.@*CONCLUSION@#Mutations of GJB2 and SLC26A4 gene are two major pathogenic gene for genetic hearing loss in children. 235delC mutation is the main mutation type, followed by IVS7-2A> G mutation type. The screening of SLC26A4 gene common mutations contribute to the diagnosis of enlarged vestibular aqueduct syndrome.

Analysis the relationship between SLC26A4 mutation and current diagnosis of inner ear malformation in children with sensorineural hearing loss / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#Explore the relationship between the pathogenic mutations of SLC26A4 gene and inner ear malformation, and analyze the feasibility of genetic testing to help current diagnosis in part of children with sensorineural hearing loss.@*METHOD@#2094 cases of children were detected by SLC26A4 with the method of DNA sequence. CT phenotypes of those children were classified according to the method proposed by Sennaroglu. We analyzed the relationship between the pathogenic mutations of gene and the CT phenotypes.@*RESULT@#(1) 685 cases of inner ear malformations were found in 2094 cases of children with sensorineural hearing loss by CT examination (371 cases of cochlea malformation were consisted of the follow types of malformation. Michel deformity was 6 cases, cochlea aplasia was 8 cases, common cavity deformity was 12 cases, incomplete partition type I was 27 cases, cochlea hypoplasia was 30 cases and Mondini malformation was 288 cases); Vestibular aqueduct was 265 cases; Vestibular/semicircular canal/internal auditory canal were 49 cases, normal was 1409 cases. (2) The DNA sequence results revealed that 465 cases carried pathogenic mutations (Bi-allelic mutations) of SLC26A4 gene, among which 135 cases were homozygous, 330 cases were compound heterozygous. (3) Pathogenic mutations of SLC26A4 gene detected 100% (465/465) in the group related to vestibular aqueduct malformation.@*CONCLUSION@#The results suggest that pathogenic mutation of SLC26A4 gene is closely related to the CT phenotype of vestibular aqueduct malformation. Detecting of pathogenic mutations for hearing loss is binging the possibility to identify children with inner malformations at an early stage. As a consequence, it will improve the current diagnosis and therapeutical option.

The clinical application of gene chips combined with CT examination in the diagnosis of large vestibular aqueduct syndrome patients / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the feasibility and superiority of the gene chip method and temporal bone CT in diagnosis of large vestibular aqueduct syndrome.@*METHOD@#One hundred and eighty-eight cases of deaf students in Guangzhou were selected,the microarray detection of the SLC26A4 gene locus was performed,and the 26 cases of students with detected SLC26A4 gene mutations received temporal bone CT imaging.@*RESULT@#Among the detected 26 cases of patients with hearing loss, IVS7-2A>G homozygous mutation was found in 7 cases, 17 cases were heterozygous mutation, 2168A>G heterozygous mutation presented in three cases, including one case of IVS7-2A>G and 2168A>G compound heterozygous mutations. Temporal bone CT findings of 25 cases among the 26 patients showed bilateral large vestibular aqueduct,among which 9 cases exhibited bilateral cochlear malformations, and 1 case was normal.@*CONCLUSION@#Among the different SLC26A4 gene mutations, IVS7-2A>G point mutation rates the highest, followed by 2168A>G. Most of the CT examination prompted the expansion of the vestibular aqueduct. Deafness gene chip hotspot detection of SLC26A4 gene mutations can diagnose such patients before CT examination,which can be used for screening people with high risk of deafness prenatal screening. The early detection and early diagnosis can guide proper precautionary measures in advance to prevent the occurrence of prelingual deafness.

Investigation of SLC26A4 mutations associated with inner ear malformations / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the molecular pathogenesis of SLC26A4 mutations associated with inner ear malformations including large vestibular aqueduct syndrome (LVAS), Mondini dysplasia and inner ear malformations but not accompanied with LVAS.@*METHOD@#DNA sample and clinical material were obtained from 14 sporadic LVAS probands, six Mondini dysplasia probands and seven inner ear malformations excluding IVAS probands. SLC26A4 gene mutation was analyzed by direct sequencing for its 20 coding exons. GJB2 gene and also mt12SrRNA were analyzed by direct sequencing.@*RESULT@#In 14 cases of LVAS, two mutations were detected in 12 patients (85.7%, either homozygous or compound heterozygous mutations), and one mutation was found in two patients (14.3%). In six cases of Mondini dysplasia, two mutations were detected in all of patients (100%). No mutation could be found in the seven cases of other inner ear abnormalities not accompanied with LVAS. No pathogenic mutation was detected in all of these 27 probands in GJB2 gene and mt12SrRNA 1555/1494T.@*CONCLUSION@#We have shown that LVAS and Mondini dysplasia closely correlate with SLC26A4 gene. No mutation was detected in seven probands of inner ear malformations not accompanied with LVAS. We should study the molecular pathogenesis of this disease in depth.

Genetic testing and mutation analysis for the cochlear implantation children and their normal auditory phenotype parents / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the characteristics and significant of mutations of GJB2 gene, SLC26A4 gene and mitochondrial 12S rRNA in deaf children who received cochlear implantation (CI) in Yunnan and to provide the data for diagnoses and research of recovery in C1 children.@*METHOD@#Genomic DNA was extracted from the peripheral blood samples collected from 46 children and their parents (110 cases). All the children received the CI. Their parents had normal auditory phenotype. PCR was performed and the products were sequenced by automated DNA sequencer to detect the hot spots of mutations.@*RESULT@#The detection rates of GJB2 235delC (13.0%) and 109G>A (24.0%) mutations were significantly higher than other mutations. SLC26A was the secondary major mutation (13.0%). We found out that no patient carried the mitochondrial 12S rRNA mutations. Leukoencephalopathy, hyperbilirubinemia and hypoxic-ischemic injure were disclosed in 7 patients (15.2%). The rate of mutations in parents was 36.0% (23/64). There had no difference between Han and other racial minorities (P>0.05).@*CONCLUSION@#The CI recipients in Yunnan with a high frequency of 235 delC and 109 G>A mutation, IVS7-2A>G (6.5%) is also a common mutation related hearing loss; aminoglycoside antibiotics may not be the main reason which induced congenital deaf in CI children; environment facts was suggested to contribute another important cause. The hot-spots gene screening for the C1 children could offer an accurate genetic counseling for early diagnosis and treatment, it also provide evidences for the clinical analysis between mutations and curative effect.

Molecular etiology analysis among students with profound hearing loss in a special education school in Yangzhou / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study molecular epidemiological basis of non-syndromic hearing loss in Yangzhou area.@*METHOD@#The selected objects were 90 severe non-syndrome deafness students in special education schools in Yangzhou city, Jiangsu province. The deafness gene chip diagnostic kit was used for screening the nine hot spots mutations in four common deafness-related genes in Medical Testing Center of Northern Jiangsu People's Hospital. These nine hot spots gene mutations included GJB2 (35 delG, 176 del16, 235 delC and 299 delAT) GJB3 (538C > T), SLC26A4 (IVS7-2A > G, 2168A > G) and mtDNA 12S rRNA (A > G,1494C > T) mutation detection by line.@*RESULT@#In 90 patients, 64 patients were found to carry deafness mutations by using gene chip diagnostic kit (the rate of mutation was 71.7%) GJB2 gene mutation in 40 cases (44.4%)which included 235 delC homozygous in 20 (22.2%) cases, 235 delC single heterozygous mutation in 4 cases (4.4%)and 235 delC and 299 delAT compound heterozygous mutations in 2 case (2.2%) separately. 299 delAT single heterozygous mutation in 2 case (2.2%), 299 delAT simple mutation in 2 case (2.2%). 176 del16 heterozygous mutations in 2 case, 176 del16 homozygous mutation in 2 case (2.2%). 176 del16 heterozygous mutations, and 235 del C heterozygous mutation in 6 cases (6.7%). SLC26A4 gene mutations in 22 cases (24.4%),which included IVS7-2A > G homozygous in 2 (2.22%) cases, IVS7-2A > G and 2168A > G compound heterozygous mutations in 2 cases (2.2%), IVS7-2A > G single heterozygous mutation in 18 cases (20.2%), and mtDNA 12S rRNA A > G mutation in 2 cases (2.2%), GJB3 mutations were not detected.@*CONCLUSION@#The deafness gene diagnostic techniques is worth applying for screening and diagnosis.

A literature review of epidemiological studies on mutation hot spots of Chinese population with non-syndromic hearing loss / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To identify the regional mutation hot spots characteristics, and then to establish a regional genetic screening programs.@*METHOD@#Molecular epidemiological literatures about Chinese deafness gene GJB2, SLC26A4, mitochondrial DNA mutations from 2006 to the first half of 2011 were retrieved in Wanfang and Pubmed literature database. The primary data of these studies including the number of samples, demographic characteristics, mutation frequencies and so on,were analyzed statically.@*RESULT@#Of 46 papers, 42 were included in this study. The patients all had non-syndromic sensorineural hearing loss and lived in 20 regions of China. A total of 18094 were counted and the average mutation frequencies were approximately 42.0%. The mutation frequencies of 235 delC were 16.34%, 299-300 delAT were 4.75% in GJB2 gene and IVS7-2A > G were 12.60%, 2168A > G were 2.32% in SLC26A4 gene and the mutation frequencies of 1555A > G, 1494C > T in mtDNA were 5.21%, 1.11% respectively. The statistical discrepancy was significant among mutation frequencies in different regions by chi2-test (P < 0.05).@*CONCLUSION@#Molecular epidemiological statistics show that the 6 locus are the mutation hot spots in Chinese people with non-syndromic hearing loss and can be used for genetic screening according to the specific regional mutation characteristics.

Analysis of positive rate of common genetic mutations in 1448 cases with different hearing phenotype / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To analyze the positive rate of common genetic mutations in Chinese non-syndromic sensorineural hearing loss groups with different hearing phenotype.@*METHOD@#One thousand four hundred and forty-eight subjects with hearing test results received at least one of three genetic testings including: mutations in coding region of GJB2 and SLC26A4 with sequencing analysis and mitochondrial DNA C1494T/A1555G with microarray detection. Of 1448 subjects, 1333 have bilateral sensorineural hearing loss, 65 have unilateral hearing loss and 50 have normal hearing threshold even though they have high frequency hearing loss or family history. The informed consent of each subject was achieved.@*RESULT@#Mutation positive rate of GJB2, SLC26A4 and mtDNA C1494T/ A1555G of 1448 subjects were 19.23%, 27.55%, 0.1% and 1.72% respectively. The positive rate of GJB2 and SLC26A4 mutations in bilateral hearing loss group (20.22%, 29.17%) was statistically significantly higher than unilateral group (0, 0) (P < 0.01). In bilateral hearing loss group, the positive rate of GJB2 mutations was highest in the profound group (24.67%), and then severe (22.33%), moderate (14.33%) and mild group (6.58%) (P < 0.01). The positive rate of SLC26A4 mutations was highest in the severe group (48.67%), and then profound (28.42%), moderate (21.16%) and mild (8.93%) (P < 0.01).@*CONCLUSION@#The positive rate of GJB2 and SLC26A4 mutations is high in the groups with bilateral profound and severe sensorineural hearing loss, whose genetic testing should be put emphasis on. However, the genetic testing should be performed in patients with mild to moderate hearing impairment as well if necessary.