A Novel EYA1 Mutation Causing Alternative RNA Splicing in a Chinese Family With Branchio-Oto Syndrome: Implications for Molecular Diagnosis and Clinical Application.

OBJECTIVES: Branchio-oto syndrome (BOS) primarily manifests as hearing loss, preauricular pits, and branchial defects. EYA1 is the most common pathogenic gene, and splicing mutations account for a substantial proportion of cases. However, few studies have addressed the structural changes in the protein caused by splicing mutations and potential pathogenic factors, and several studies have shown that middle-ear surgery has limited effectiveness in improving hearing in these patients. BOS has also been relatively infrequently reported in the Chinese population. This study explored the genetic etiology in the family of a proband with BOS and provided clinical treatment to improve the patient's hearing. METHODS: We collected detailed clinical features and peripheral blood samples from the patients and unaffected individuals within the family. Pathogenic mutations were identified by whole-exome sequencing and cosegregation analysis and classified according to the American College of Medical Genetics and Genomics guidelines. Alternative splicing was verified through a minigene assay. The predicted three-dimensional protein structure and biochemical experiments were used to investigate the pathogenicity of the mutation. The proband underwent middle-ear surgery and was followed up at 1 month and 6 months postoperatively to monitor auditory improvement. RESULTS: A novel heterozygous EYA1 splicing variant (c.1050+4 A>C) was identified and classified as pathogenic (PVS1(RNA), PM2, PP1). Skipping of exon 11 of the EYA1 pre-mRNA was confirmed using a minigene assay. This mutation may impair EYA1-SIX1 interactions, as shown by an immunoprecipitation assay. The EYA1-Mut protein exhibited cellular mislocalization and decreased protein expression in cytological experiments. Middle-ear surgery significantly improved hearing loss caused by bone-conduction abnormalities in the proband. CONCLUSION: We reported a novel splicing variant of EYA1 in a Chinese family with BOS and revealed the potential molecular pathogenic mechanism. The significant hearing improvement observed in the proband after middle-ear surgery provides a reference for auditory rehabilitation in similar patients.

Current status of universal newborn hearing screening program at 26 institutions in China.

OBJECTIVES: The present study aimed to determine the status of a universal newborn hearing screening (UNHS) program being conducted in parts of China, by comparing differences in the program findings between 2016 and 2017, as well as across regions in China. METHODS: This study investigated a nationally representative sample of newborns from 26 provinces, autonomous regions, and municipalities in mainland China. A ''Newborn Hearing Screening Survey'' questionnaire was sent to 43 hearing screening institutions throughout China and the data were analyzed, with appropriate quality control throughout the study process. RESULTS: Twenty-six questionnaires, covering 55.88% (19/34) of the provincial administrative regions in China were appropriately completed. The overall sampling frame comprised 238,795 (year 2016) and 229,185 (year 2017) newborns, respectively. We found differences between two years, the initial screening coverage in 2017 (96.10%) was higher than that in 2016 (94.96%); the referral rate at initial screening in 2017 (9.21%) was lower than that in 2016 (10.26%); and the rescreening rate in 2017 (73.50%) was higher than that in 2016 (68.44%). We found differences across three regions, the rescreening rate were highest in West China, the referral rate at rescreening and the referral rate to diagnostic audiological assessment diagnosis were both highest, while the hearing-loss rate was lowest, in the East China in two years. Overall, 61.54% (n = 16) reported using otoacoustic emissions (OAEs), while 38.46% (n = 10) reported using OAEs in combination with automated auditory brainstem response (AABR) tests, for the initial screening. For rescreening, most sites (n = 19, 73.08%) reported using OAEs in combination with AABR, followed by OAEs only (n = 4, 15.38%) and AABR only (n = 3, 11.54%). Of the twenty-six institutions, 57.69% (n = 15) were equipped with a digital information management system for UNHS program, East China had the highest rate of it (81.82%, 9/11). CONCLUSIONS: This study indicated that implementation of a UNHS program had essentially been achieved in many regions of China under the guidance of technical specifications for newborn hearing screening. Compared with 2016, the overall quality of the UNHS program had improved in 2017 and that in East China was better than in the Midland and West China. However, national quality control of the UNHS program is still required to enhance the quality of the program and public education needs to be emphasized to improve the rescreening and reception rate.

Comparison of auditory steady-state response and click-evoked auditory brain response in infants with different types and degrees of hearing loss.

Background: Auditory steady-state response (ASSR) and click-evoked auditory brain response (c-ABR) have been used for hearing assessment for decades years, the correlation of the two methods and the effects of type and degree of hearing loss (HL) to the correlation in infants younger than 6 months of age are unclear.Objectives: To compare the correlation of ASSR and c-ABR and then to analyse the effects of type and degree of HL on the correlation in infants younger than 6 months of age.Material and methods: Retrospective study comparing ASSR thresholds at various frequencies with c-ABR thresholds. 182 ears from 96 infants were assessed and classified according to types and degrees of HL.Results: The correlation coefficients were: 0.823, 0.864, 0.891, 0.871, 0.908, 0.915 and 0.913 between ASSR thresholds at 0.5, 1, 2, 4, 2-4, 1-2-4, 0.5-1-2-4 kHz and c-ABR thresholds respectively. The correlation coefficients in the group of sensorineural HL (SHL) (r = 0.763-0.900) were higher than conductive HL (r = 0.309-0.619) across all frequencies. The coefficients of severe-profound SHL (r = 0.595-0.790) were higher than mild-moderate SHL (r = 0.434-0.687) across all frequencies.Conclusions and significance: ASSR was one valuable cross-check measure by providing frequency specific information in auditory assessment.

Knowledge and attitude of mothers regarding infant hearing loss in Changsha, Hunan province, China.

OBJECTIVE: The objective of this study was to explore the knowledge and attitude among mothers of newborns regarding infant hearing loss (HL) in Changsha, Hunan province, China. DESIGN: A questionnaire including 18 items was given to mothers. STUDY SAMPLE: A total of 115 mothers participated in the study. RESULTS: Seven risk factors for hearing loss were identified correctly by above 60% of respondents and the top three were prolonged noise (88.7%), high fever (82.6%) and ear discharge (82.6%). Poor knowledge was demonstrated on risk factors jaundice (20.0%), measles (22.6%), convulsion (33.0%) and traditional Chinese medicine (39.1%). Maternal knowledge scores in identification and intervention (2.68 ± 0.31) was slightly higher than the score in risk factors (2.47 ± 0.34). Ninety-nine per cent of the mothers expressed the willingness to test baby's hearing soon after birth and concern about hearing. CONCLUSIONS: Mothers were concerned about baby's hearing and the attitude was positive. However, the correct recognition rate towards some risk factors for HL was low. Action needs to be taken to raise awareness about ear and hearing care, prevent HL caused by preventable causes and prompt early identification, early diagnosis and intervention of HL.

[Screening and identification interaction proteins of connexin 30].

OBJECTIVE: To explore interaction proteins affect functions of connexin 30 (Cx30) by screening and identification interaction proteins of Cx30. METHODS: The fusion expression vecto of CX30-C-terminal functional domain-pGEX-4T-2-GST was constructed, and then, fusion protein and GST were purified. They were incubated with the proteins of the foetus brain tissue disruption to pull down interaction proteins. The interaction proteins were separated by SDS-PAGE. Differential straps were cut to enzymolysis to prepare for mass chromatographic analysis, and then to index and screen interaction proteins in NCBInr database. The interaction proteins were identified by immunolocalization. RESULTS: The four interaction proteins of Cx30 were screened in the foetus brain tissue, as follow, Keratin 16, Camk2b, Tubulin beta-3 and alpha-tubulin. Cx30 was proved to coexist with Keratin 16 and Tubulin beta-3. CONCLUSIONS: Keratin 16, Camk2b, Tubulin beta-3 and alpha-tubulin are the interaction proteins of Cx30. The interaction proteins affect the assembly, intracellular transport, and channel switch of Cx30.

[The prenatal diagnosis and early intervention of nonsyndromic hearing loss of connexin26 gene].

OBJECTIVE: To detect the mutations of gene connexin26 in the pedigrees of nonsyndromic hearing loss, and to make prenatal diagnosis and carry out early intervention to the pedigrees with mutations of gene con nexin26. METHOD: The connexin26 gene of probands in 100 nonsyndromic hearing loss pedigrees was inspected by polymerase chain reaction, single strand conformational polymorphism and direct sequencing to detect the gene mutations. To the pregnant women in pedigrees with confirmed nosogenetic mutations of connexin26 gene, the prenatal diagnosis to the fetus by cordocentesis was made and the early intervention was carried out. RESULT: The homozygous deletion C at position 233-235 of connexin26 cDNA was proved to be a nosogenetic mutation, and G79A, G109A, A341G, G442A, G506A and T608C were proved to be polymorphisms. In the prenatal diagnosis for the second pregnancy of a woman in a pedigree with the homozygous deletion C at position 233-235 of connexin26 cDNA, the same mutation in the fetus' connexin26 gene was found and she was advised to end the pregnancy. CONCLUSION: The homozygous deletion C at position 233-235 of connexin26 cDNA will induce autosomal recessive nonsyndromic hereditary hearing loss and the heterogeneous mutation will not cause hearing loss. The prenatal diagnosis and early intervention can prevent the birth of deaf children. This is the first time in our country to make prenatal diagnosis and proceed early intervention to the fetus of hereditary hearing loss.

[Mutation analysis of gene CX31.1 in the hereditary hearing loss pedigrees].

OBJECTIVE: To make clear of the relation between CX31.1 and hereditary hearing loss by the mutation detect of gene CX31.1 in nonsyndromic hearing loss pedigrees. METHOD: Thirty-seven pedigrees of autosomal recessive inheritance hereditary hearing loss and twenty-four pedigrees of autosomal dominant inheritance hereditary hearing loss were collected from decades provinces of China. By using polymerase chain reaction and direct sequence, we screened the members of this pedigrees for the mutations of gene CX31.1. RESULT: One polymorphism and one synonymous mutation of gene CX31.1 and two absent pieces in the introns of CX31.1 were found. CONCLUSION: Though we have not found mutations of CX31.1 which can induce corresponding hereditary deafness of the pedigrees inspected before, we don't think we can deny gene CX31.1 is a nosogenesis gene of hereditary hearing loss, and what we can do is to collect enough pedigrees to continue our research.