Objective:To analyze genetic factors and phenotype characteristics in pediatric population with slight-to-moderate sensorineural hearing loss. Methods:Children with slight-to-moderate sensorineural hearing loss of and their parents, enrolled from the Chinese Deafness Genome Project, were studied. Hearing levels were assessed using pure tone audiometry, behavioral audiometry, auditory steady state response（ASSR）, auditory brainstem response（ABR） thresholds, and deformed partial otoacoustic emission（DPOAE）. Classification of hearing loss is according to the 2022 American College of Medical Genetics and Genomics（ACMG） Clinical Practice Guidelines for Hearing Loss. Whole exome sequencing（WES） and deafness gene Panel testing were performed on peripheral venous blood from probands and validations were performed on their parents by Sanger sequencing. Results:All 134 patients had childhood onset, exhibiting bilateral symmetrical slight-to-moderate sensorineural hearing loss, as indicated by audiological examinations. Of the 134 patients, 29（21.6%） had a family history of hearing loss, and the rest were sporadic patients. Genetic causative genes were identified in 66（49.3%） patients. A total of 11 causative genes were detected, of which GJB2 was causative in 34 cases（51.5%）, STRC in 10 cases（15.1%）, MPZL2 gene in six cases（9.1%）, and USH2A in five cases（7.6%）.The most common gene detected in slight-to-moderate hearing loss was GJB2, with c. 109G>A homozygous mutation found in 16 cases（47.1%） and c. 109G>A compound heterozygous mutation in 9 cases（26.5%）. Conclusion:This study provides a crucial genetic theory reference for early screening and detection of mild to moderate hearing loss in children, highlighting the predominance of recessive inheritance and the significance of gene like GJB2, STRC, MPZL2, USH2A.
Humans ; Child ; Connexins/genetics* ; Connexin 26/genetics* ; Hearing Loss, Sensorineural/diagnosis* ; Mutation ; Usher Syndromes ; Hearing Loss, Bilateral ; Audiometry, Pure-Tone ; Intercellular Signaling Peptides and Proteins

Objective:To elucidate the correlation between the GJB2 gene and auditory neuropathy, aiming to provide valuable insights for genetic counseling of affected individuals and their families. Methods:The general information, audiological data（including pure tone audiometry, distorted otoacoustic emission, auditory brainstem response, electrocochlography）, imaging data and genetic test data of 117 auditory neuropathy patients, and the patients with GJB2 gene mutation were screened out for the correlation analysis of auditory neuropathy. Results:Total of 16 patients were found to have GJB2 gene mutations, all of which were pathogenic or likely pathogenic.was Among them, one patient had compound heterozygous variants GJB2[c. 427C>T][c. 358_360del], exhibiting total deafness. One was GJB2[c. 299_300delAT][c. 35_36insG]compound heterozygous variants, the audiological findings were severe hearing loss.The remaining 14 patients with GJB2 gene variants exhibited typical auditory neuropathy. Conclusion:In this study, the relationship between GJB2 gene and auditory neuropathy was preliminarily analyzed,and explained the possible pathogenic mechanism of GJB2 gene variants that may be related to auditory neuropathy.
Humans ; Connexins/genetics* ; Connexin 26/genetics* ; Hearing Loss, Central/genetics* ; Deafness/genetics* ; Mutation

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.
Child ; Infant, Newborn ; Humans ; Female ; Prospective Studies ; Connexins/genetics* ; Connexin 26/genetics* ; Glucosephosphate Dehydrogenase Deficiency ; Mutation ; Sulfate Transporters/genetics* ; DNA Mutational Analysis ; Genetic Testing/methods* ; Deafness/genetics* ; Neonatal Screening/methods* ; Hearing Loss, Sensorineural/genetics* ; High-Throughput Nucleotide Sequencing ; Solute Carrier Family 22 Member 5/genetics*

OBJECTIVE: To analyze the clinical significance of combined newborn hearing and deafness gene screening in Yuncheng area of Shanxi Province. METHODS: Results of audiological examinations, including transient evoked otoacoustic emission and automatic discriminative auditory brainstem evoked potentials, for 6 723 newborns born in Yuncheng area from January 1, 2021 to December 31, 2021, were retrospectively analyzed. Those who failed one of the tests were considered to have failed the examination. A deafness-related gene testing kit was used to detect 15 hot spot variants of common deafness-associated genes in China including GJB2, SLC26A4, GJB3, and mtDNA12S rRNA. Neonates who had passed the audiological examinations and those who had not were compared using a chi-square test. RESULTS: Among the 6 723 neonates, 363 (5.40%) were found to carry variants. These have included 166 cases (2.47%) with GJB2 gene variants, 136 cases (2.03%) with SLC26A4 gene variants, 26 cases (0.39%) with mitochondrial 12S rRNA gene variants, and 33 cases (0.49%) with GJB3 gene variants. Among the 6 723 neonates, 267 had failed initial hearing screening, among which 244 had accepted a re-examination, for which 14 cases (5.73%) had failed again. This has yielded an approximate prevalence of hearing disorder of 0.21% (14/6 723). Among 230 newborns who had passed the re-examination, 10 (4.34%) were found to have carried a variant. By contrast, 4 out of the 14 neonates (28.57%) who had failed the re-examination had carried a variant, and there was a significant difference between the two groups (P < 0.05). CONCLUSION Genetic screening can provide an effective supplement to newborn hearing screening, and the combined screening can provide a best model for the prevention of hearing loss, which can enable early detection of deafness risks, targeted prevention measures, and genetic counseling to provide accurate prognosis for the newborns.
Infant, Newborn ; Humans ; Connexins/genetics* ; Retrospective Studies ; Deafness/genetics* ; Connexin 26/genetics* ; Neonatal Screening/methods* ; Mutation ; Genetic Testing/methods* ; China/epidemiology* ; Hearing ; DNA Mutational Analysis

OBJECTIVE: To detect common pathogenic variants associated with congenital deafness among neonates from Huizhou and surrounding areas and discuss its implications. METHODS: Thirteen hot-spot mutations in four most common pathogenic genes were screened among 20 934 neonates from March 2017 to December 2019. RESULTS: In total 760 neonates were found to carry common pathogenic variants (3.63%). Sixty two neonates have carried homozygous/compound heterozygous variants or homoplasmy/heteroplasmy mutations of mtDNA (0.29%). Further analysis of five abnormal cases revealed that 3 of them have carried compound heterozygous mutations of GJB2 gene, and 2 were due to compound heterozygous variants of the CDH23 gene. CONCLUSION Genetic testing has a great clinical significance for the prevention and reduction of congenital hearing loss, but the scope needs to be updated and redefined by removing mutation sites with a very low rate, adding new significant sites, and improvement of the technical strategies.
Connexin 26 ; Connexins/genetics* ; DNA Mutational Analysis ; Deafness/genetics* ; Genetic Testing ; Hearing Loss/genetics* ; Humans ; Infant, Newborn ; Mutation ; Neonatal Screening

OBJECTIVEUsing simultaneous multi-gene mutation screening to investigate the new method molecular epidemiological basis of 225 patients with nonsyndromic hearing loss in Tianjin, and verifying the for simultaneous multi-gene mutation screening.

METHODSTwo hundred and twenty-five patients with severe non-syndromic deafness from Tianjin CDPF and Association of the Deaf were included in the study. The single nucleotide polymorphisms scan, (SNPscan) technique was used for screening the 115 spots mutations in three common deafness-related genes (GJB2, SLC26A4, mtDNA 12S rRNA) of patients with nonsyndromic hearing loss in Tianjin. We verified the results by Sanger sequencing.

RESULTSAmong the 225 patients, there were 111 cases of deafness caused by mutation (49.3%). Using this method, up to 50% of the patients in our study were identified to have hereditary HL caused by mutations in the three genes. 56 patients with the GJB2 mutations were detected (24.9%), including 30 cases of homozygous mutations (13.3%), 26 patients (11.6%) of compound heterozygous mutations, and 21 cases (9.33%) of single heterozygous mutations. 50 patients with the SLC26A4 mutations were detected (22.2%), including 22 cases of homozygous mutations(9.8%), 28 patients (12.4%) of compound heterozygous mutations, and 22 cases (9.8%) of single heterozygous mutations. mtDNA 12S rRNA A1555G mutation was detected in 5 patients (2.2%). mtDNA 12S rRNA 1494C>T mutation was not detected. We verified the results by Sanger sequencing. The accuracy of the sequencing results was 100%. The SNPscan cost eight hours and 160 yuan (each sample).

CONCLUSIONSApplying SNPscan technology can be accurate, rapid and cost-effective diagnostic screening in patients with hearing loss for etiology investigation. It is expected to become an effective means of large-scale genetic testing for hereditary deafness.

Connexin 26 ; Connexins ; genetics ; DNA Mutational Analysis ; methods ; DNA, Mitochondrial ; genetics ; Deafness ; genetics ; Genetic Testing ; methods ; Heterozygote ; Homozygote ; Humans ; Membrane Transport Proteins ; genetics ; Mutation ; Polymorphism, Single Nucleotide ; RNA, Ribosomal ; genetics

OBJECTIVETo screen for mutations of deafness-related genes among ethic Chinese women of child-bearing age.

METHODSIn 324 women, 9 mutational sites in 4 deafness-related genes (SLC26A4, GJB3, GJB2 and mtDNA 12s rRNA) were screened using a gene chip.

RESULTSTwenty women (6.17%) have carried mutations. These included 11 (3.40%) carrying a GJB2 gene mutation, 7 (2.16%) carrying a SLC26A4 gene mutation, 1 (0.31%) simultaneously carrying GJB3 and GJB2 gene mutations, and 1 (0.31%) carrying a mtDNA 12s rRNA gene mutation.

CONCLUSIONWomen of child-bearing age have a high rate for carrying mutations of common deafness-related genes, among which 235delC in GJB2 was most common. Prenatal screening of couples with normal hearing is an effective way to prevent birth of affected children.

Adult ; Connexin 26 ; Connexins ; genetics ; Deafness ; genetics ; Female ; Humans ; Mutation

OBJECTIVETo evaluate the efficacy of combined newborn hearing screening and deafness-related mutation screening.

METHODSEleven thousand and forty-six newborn babies were screened with otoacoustic emission, automatic auditory brainstem response and genetic testing using a standard protocol. Common mutations of three deafness-related genes have included GJB2 (c.235delC, c.299-300delAT), mtDNA 12srRNA (c.1494C>T, c.1555A>G) and SLC26A4 (c.2168A>G, c.IVS7-2A>G).

RESULTSThe detection rate for hearing loss in the first-step screening was 0.81% (90/11,046). 513 individuals were found to carry one or two mutant alleles, which gave a carrier rate of 4.64% (513/11,046). Five hundred and eighty-four newborns were positive for hearing screening and genetic screening. Among these, 19 have failed both tests, 71 have failed hearing screening, and 494 have failed genetic screening. The combined hearing and genetic screening has given a positive rate of 5.29%.

CONCLUSIONNeither hearing screening nor genetic screening is sufficient to identify individuals susceptible to auditory disorders. Combined used of these methods can improve the rate of detection.

Asian Continental Ancestry Group ; genetics ; China ; Connexin 26 ; Connexins ; genetics ; DNA Mutational Analysis ; DNA, Mitochondrial ; chemistry ; genetics ; Deafness ; diagnosis ; ethnology ; genetics ; Gene Frequency ; Genetic Predisposition to Disease ; ethnology ; genetics ; Genetic Testing ; methods ; Genotype ; Hearing ; genetics ; Hearing Tests ; Humans ; Infant, Newborn ; Membrane Transport Proteins ; genetics ; Mutation ; Neonatal Screening ; methods ; Polymerase Chain Reaction ; RNA, Ribosomal ; genetics ; Reproducibility of Results ; Sensitivity and Specificity

OBJECTIVETo determine the carrier rate for common mutations causing deafness among pregnant women in order to prevent births of deaf children.

METHODSFor 893 pregnant women, 2 mL peripheral venous blood was taken and DNA was extracted. A deafness DNA microarray screening was applied to such samples, and DNA sequencing was applied to husbands of women with positive screening results.

RESULTSA total of 40 carriers were detected, with the overall mutation rate being 4.48%. Among such carriers, GJB2 235delC was the most common heterozygous mutation (18 cases) and the mutation rate was 2.02%. GJB2 299A-T heterozygous mutation was detected in 7 cases with a mutation rate of 0.78%. IVS7-2A to G heterozygous mutation was detected in 9 cases with a mutation rate of 1.02%. There were 2 cases carrying GJB3 heterozygous mutation and 2 cases of mitochondrial 12S rRNA heterozygous mutation, with a mutation rate of 0.22%. IVS7-2A>G with GJB3 538C>T double heterozygous mutation was detected in 1 case, and IVS7-2A>G with GJB2 299A-T double heterozygous mutation was detected in another case, with the mutation rate of each being 0.11%. DNA sequencing has failed to find presence of mutations in the same gene in the husbands. The results of neonatal hearing follow-up were all normal.

CONCLUSIONApplications of the deaf genes screening in pregnant women may play prove to be valuable for the early detection for neonatal deafness.

Adult ; Connexin 26 ; Connexins ; genetics ; Deafness ; diagnosis ; embryology ; genetics ; prevention & control ; Female ; Genetic Testing ; Humans ; Mutation ; Pregnancy ; Pregnancy Complications ; diagnosis ; genetics ; Prenatal Diagnosis ; RNA, Ribosomal ; genetics ; Young Adult

OBJECTIVETo screen for common mutations of deafness-related genes in order to determine the carrier rate, types of mutation, and their relevance to hearing loss.

METHODSFor 4 deafness-related genes GJB2, GJB3, 12S rRNA and SLC26A4, 20 common mutations were screened among 2725 newborns from Shaoxing, Zhejiang by matrix-assisted laser desorption ionization-time of flight-mass spectrometry.

RESULTSAmong the 2725 newborns,149 (5.47%) were diagnosed with mutations, which included 84 (3.08%) with GJB2 mutations, 13 (0.48%) with GJB3 mutations, 49 (1.80%) with SLC26A4 mutations and 3 (0.11%) with 12S rRNA mutations. Fourteen mutational hotspots were identified. The most common mutations have included GJB2 c.235delC (65 cases), SLC26A4 IVS7-2A>G (34 cases), GJB2 c.299_300delAT (13 cases), GJB3 c.538C>T (7 cases), GJB2 c.176_191del16 (6 cases) and GJB3 c.547G>A (6 cases).

CONCLUSIONThe detecting rate for deafness-related gene mutations has been relatively high. To broaden the screening spectrum may improve such rate. Besides GJB2, 12S rRNA, SLC26A4, GJB3 also features a high mutation rate in the region.

Asian Continental Ancestry Group ; genetics ; China ; Connexin 26 ; Connexins ; genetics ; Deafness ; genetics ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Membrane Transport Proteins ; genetics ; Mutation ; Neonatal Screening ; RNA, Ribosomal ; genetics