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Background/Objectives: A heterozygous mutation in the WFS1 gene is responsible for autosomal dominant non-syndromic hearing loss (DFNA6/14/38) and Wolfram-like syndrome, which is characterized by bilateral sensorineural hearing loss with optic atrophy and/or diabetes mellitus. However, detailed clinical features for the patients with the heterozygous p.A684V variant remain unknown. Methods: We report the clinical details of 14 cases with a heterozygous p.A684V variant in the WFS1 gene identified from target resequencing analysis of 63 previously reported deafness genes by next-generation sequencing of 15,684 hearing loss patients (mean age 27.5 ± 23.1 years old, 6574 male, 8612 female and 498 for whom information was unavailable). Results: Among the 14 patients from 13 families with the p.A684V variant, nine were sporadic cases. In addition, we confirmed de novo occurrence of this variant in seven families. This result strongly supports the notion that this variant was located on a mutational hotspot. When comparing previously reported cases of autosomal dominant WFS1 gene-associated hearing loss, most of the patients in this study showed severe-to-profound bilateral sensorineural hearing loss (genotype–phenotype correlation). Two patients had optic atrophy, while the others did not have any other complications. Conclusions: The identified heterozygous p.A684V variant appears to be a hotspot mutation and likely to cause severe-to-profound hearing loss in early childhood. Cochlear implantation is considered favorable in cases of hearing impairment due to this variant. [ABSTRACT FROM AUTHOR]

Trisomy 18 is a common chromosomal aberration syndrome, characterized by variable clinical manifestations, including cardiovascular, pulmonary, genitourinary, and musculoskeletal findings, leading to a shorter survival and severe developmental delay in survivors. However, recently, intensive therapeutic intervention has allowed for prolonging survival. In terms of otological complications, only a limited number of relevant reports have been published. To demonstrate the characteristic of hearing loss (HL) in children with Trisomy 18, we retrospectively evaluated 22 patients (44 ears) by comprehensive auditory evaluation with the auditory steady‐state response (ASSR) test and temporal bone computed tomography (CT). ASSR revealed that 20 patients (91%) had bilateral moderate to profound HL, more frequent and severe than that in Trisomy 21; among 42 ears having HL, 12 ears (29%) had conductive HL, and 26 ears (62%) had mixed HL. CT scans of 38 ears revealed that 34 ears (89%) had an external and middle ear malformation. Hearing aids (HA) were fitted in 17 patients (air and bone‐conduction HAs). The threshold hearing with HA was improved in all of them. Accurate otological evaluation using ASSR and CT and intervention by HAs could be a feasible choice for children with Trisomy 18. [ABSTRACT FROM AUTHOR]

Cochlear implants (CIs) were noncompatible with magnetic resonance imaging (MRI) initially; however, recently, implants have become available that are compatible with MRI without the need for magnet removal or bandage fixation. The images produced by MRI scans are sometimes deteriorated by artifacts and are not clinically useful. In this study, we discussed the size differences of such artifacts with respect to the imaging modality and sequences with their clinical validity. We performed a head MRI, using a head bandage and without magnet removal in five patients who underwent cochlear implantation at our department and analyzed the MRI findings. Without magnet removal, diffusion-weighted images and T2 star-weighted images had larger artifacts and less useful images. T1-weighted images, T2-weighted images (T2WIs), T2-weighted fluid-attenuated inversion recovery (T2-FLAIR) images, and heavy T2WIs could evaluate the unimplanted side and middle of the head but had limited applicability on the CI side. The characteristic features of MRI scan images vary with the method used as well as with the sequence, suggesting that the choice of MRI is largely determined on the basis of clinical feasibility and the requirement. Accordingly, we need to judge well in advance of imaging whether the images would be clinically relevant. [ABSTRACT FROM AUTHOR]

To achieve better speech performance following cochlear implantation (CI), measuring the patient's cochlear duct length (CDL) and determining the appropriate length of the CI array are important. To investigate the CDL in CI patients after using the OTOPLAN software preoperatively and compare the results of angular insertion depth (AID) estimation by OTOPLAN and postoperative radiography. The study included 105 Japanese CI patients with normal cochleae. We measured the CDL using OTOPLAN and the position of the tip channel of the electrode for each selected electrode array, and estimated the AID using the software. The mean CDL was 35.1 ± 1.6 mm. Preoperatively, the mean estimated AID was 580.3 ± 57.8°. Postoperative radiography revealed a mean AID of 583.0 ± 56.7°, demonstrating a strong linear correlation between the two measurements (R2 = 0.635). Our findings revealed that CDL varies widely, which is consistent with previous studies. To achieve better speech perception, surgeons should select the appropriate length of CI electrode array based on the individual's CDL. Preoperative measurement of each CDL by OTOPLAN, which is clinically feasible and comparable to postoperative evaluation, can be used to ensure selection of the appropriate electrode array length. [ABSTRACT FROM AUTHOR]

Background: The primary pathological alterations of Pendred syndrome are endolymphatic pH acidification and luminal enlargement of the inner ear. However, the molecular contributions of specific cell types remain poorly characterized. Therefore, we aimed to identify pH regulators in pendrin-expressing cells that may contribute to the homeostasis of endolymph pH and define the cellular pathogenic mechanisms that contribute to the dysregulation of cochlear endolymph pH in Slc26a4−/− mice. Methods: We used single-cell RNA sequencing to identify both Slc26a4-expressing cells and Kcnj10-expressing cells in wild-type (WT, Slc26a4+/+) and Slc26a4−/− mice. Bioinformatic analysis of expression data confirmed marker genes defining the different cell types of the stria vascularis. In addition, specific findings were confirmed at the protein level by immunofluorescence. Results: We found that spindle cells, which express pendrin, contain extrinsic cellular components, a factor that enables cell-to-cell communication. In addition, the gene expression profile informed the pH of the spindle cells. Compared to WT, the transcriptional profiles in Slc26a4−/− mice showed downregulation of extracellular exosome-related genes in spindle cells. Immunofluorescence studies in spindle cells of Slc26a4−/− mice validated the increased expression of the exosome-related protein, annexin A1, and the clathrin-mediated endocytosis-related protein, adaptor protein 2. Conclusion: Overall, cell isolation of stria vascularis from WT and Slc26a4−/− samples combined with cell type-specific transcriptomic analyses revealed pH-dependent alternations in spindle cells and intermediate cells, inspiring further studies into the dysfunctional role of stria vascularis cells in SLC26A4-related hearing loss. [ABSTRACT FROM AUTHOR]

Usher syndrome (USH) typically leads to deaf-blindness, requiring the provision of extensive education and rehabilitation services. Therefore, investigating the prevalence is crucial to requests for proper government support for USH patients. The aim was to perform a nationwide epidemiologic survey of USH in Japan to estimate the prevalence of USH and reveal the relative frequency and characteristics of the three USH subtypes. To estimate the number of USH patients visiting hospitals over a 1-year period, 1,628 hospitals were randomly selected from all Departments of Otorhinolaryngology and Ophthalmology in Japan. Subsequently, we collected data regarding the clinical characteristics of each patient treated and the results of genetic testing, if performed. We found that the prevalence of USH was at least 0.4 per 100,000 population. The frequency of clinical subtypes and causal genes for USH were consistent with previous reports. Also, we demonstrated the feasibility of genetic counseling for USH patients based on the results of genetic testing. USH is a rare disease, but requires social support due to the severity of symptoms. To minimize these issues, understanding the clinical characteristics and performing comprehensive genetic testing could allow early and accurate diagnosis as well as medical intervention. [ABSTRACT FROM AUTHOR]