Background/Objectives: MYH9 gene variants cause MYH9-related disease (MYH9-RD), which is also known as Epstein syndrome, Fechtner syndrome, May-Hegglin anomaly, and Sebastian syndrome. MYH9-RD is characterized by sensorineural hearing loss, macrothrombocytopenia, thrombocytopenia, hematuria/proteinuria, glomerulonephritis, cataracts purpura, and mucosal bleeding. In addition, the MYH9 gene is also known to be causative of autosomal dominant non-syndromic hearing loss (DFNA17). MYH9-RD is a relatively rare disorder, and the detailed clinical features and mutational spectra remain unclear. Methods: In this study, we performed next-generation sequencing analysis for 15,684 hearing loss patients and identified MYH9-associated hearing loss patients. Detailed clinical information was collected for these patients and summarized. Results: In this study, we identified 24 patients from 18 families with MYH9-associated hearing loss. We clarified the details of hearing deterioration observed in patients based on collected serial audiogram data. Some cases showed rapid hearing deterioration that worsened by about 50 dB within 5 years. Hearing loss is more likely to progress in patients with myosin head domain variants than in patients with myosin tail domain variants, but hearing loss in each set of patients finally deteriorates to bilateral profound hearing loss. Conclusions: In this study, we were able to clarify the detailed characteristics of MYH9-RD- and DFNA17-related hearing loss in a relatively large number of patients, particularly in some cases that showed rapid and asymmetrical hearing deterioration progressing to bilateral profound hearing loss. Our data will be useful for providing more appropriate treatment and follow-up for MYH9-associated hearing loss.

BACKGROUND:Hearing loss is a significant global health concern, with genetic factors accounting for up to 60% of congenital or prelingual onset deafness. Cochlear implantation is widely used as an effective treatment for patients with severe-to-profound hearing loss; however, the genetic background in Moroccan cochlear implant patients remains unclear. AIMS/OBJECTIVES:This study investigates the genetic background of congenital or pre-lingual onset severe-to-profound sensorineural hearing loss in pediatric patients who received cochlear implantation. MATERIAL AND METHODS:In this study, we enrolled 88 patients who underwent cochlear implantation and genetic diagnosis using next-generation sequencing with a panel covering 158 previously reported causative genes. RESULTS:We identified the genetic cause in 58 of the 88 patients, with a genetic diagnostic rate of 65.9%. We identified 28 genes associated with Moroccan pediatric cochlear implant patients. The most prevalent genetic cause identified in this study was the GJB2 gene (12.5%), followed by MYO7A (6.8%) and CDH23 (4.5%). CONCLUSIONS AND SIGNIFICANCE:The study highlights the importance of genetic screening in pediatric cochlear implant patients and underscores the potential of gene therapy for treating genetic hearing loss.

Background/Objectives: MYO7A is known to be the genetic cause of Usher syndrome type 1, as well as autosomal dominant and autosomal recessive non-syndromic hearing loss. In general, autosomal dominant MYO7A-associated hearing loss shows progressive high-frequency, sloping hearing loss. However, several variants are associated with low-frequency hearing loss. MYO7A-associated low-frequency hearing loss is relatively rare, and the clinical details remain unclear. Methods: A total of 18,475 Japanese patients with hearing loss were recruited. Targeted massively parallel sequencing of 158 deafness-related genes was performed, and individuals with variants related to MYO7A-associated low-frequency hearing loss were identified. Results: Among 18,475 hearing loss patients, we identified 60 patients from 44 unrelated families carrying five variants (p.[Asn140Lys; Glu1835Gln], p.Leu479Pro, p.Leu656Val, p.Gly660Arg, and p.Arg668His) for MYO7A-associated low-frequency hearing loss. Patients identified in this study initially showed postlingual-onset mild-to-moderate low-frequency hearing loss; however, high-frequency hearing also deteriorated after the fourth decade, eventually leading to moderate-to-severe flat-type hearing loss. In addition, we performed haplotype analysis for the recurrent variant c.1436T>C:p.Leu479Pro identified in this study and found that this variant is a founder mutation in the Japanese population. Conclusions: In this study, we were able to clarify the specific features of MYO7A-related low-frequency hearing loss in a significant number of patients. In particular, we clarified the details of hearing deterioration at each frequency. Our findings will be useful for providing more appropriate treatment and follow-up for MYO7A-associated low-frequency hearing loss.

Background/Objectives: The OPA1 gene encodes a dynamin-related GTPase essential for mitochondrial fusion. Variants in OPA1 are a major cause of autosomal dominant optic atrophy (DOA). A subset of DOA patients exhibits hearing loss, often manifesting as auditory neuropathy spectrum disorder (ANSD). In this study, we aimed to describe the frequency of OPA1-related hearing loss in a large cohort of patients with hearing loss and to explore the genotype-phenotype correlations and appropriate interventions. Methods: A total of 18,475 Japanese patients with hearing loss were recruited. Targeted massively parallel sequencing of 158 deafness-related genes was performed, and individuals with OPA1 variants were identified. Clinical data, including age of onset, audiological findings, and systemic features, were retrospectively reviewed. Results: Ten individuals from eight independent families carrying OPA1 variants were identified. Three variants were classified as pathogenic or likely pathogenic, while five were variants of uncertain significance. Hearing loss was typically post-lingual in onset and progressive, with predominantly mild-to-moderate severity. Missense variants tended to be associated with DOA-plus phenotypes and ANSD. Five patients obtained only limited benefit from hearing aids, whereas one patient who received a cochlear implant achieved good speech perception. Conclusions: OPA1 is a rare causative gene for hearing loss and is frequently associated with the ANSD phenotype. Affected individuals exhibited phenotypic heterogeneity, which may reflect incomplete penetrance or the influence of mitochondrial DNA-related factors.

BACKGROUND:Branchio-oto-renal (BOR) syndrome is characterized by branchiogenic malformation, hearing loss, and renal anomalies, with EYA1, SIX1, and SIX5 known as the causative genes. As BOR syndrome presents with various clinical phenotypes, its characteristics and genotype-phenotype correlations remain unknown. AIMS/OBJECTIVES:In this study, we aimed to clarify the detailed hearing loss phenotypes and genotype-phenotype correlations of BOR syndrome. MATERIAL AND METHODS:In this study, we performed an etiological analysis of 169 BOR syndrome patients from 129 families. We also performed genetic testing for 78 probands. RESULTS:In all, 66.7% of BOR patients carried EYA1 variants, whereas 17.9% carried SIX1 variants. We also clarified the detailed clinical features including the prevalence of major and minor symptoms, asymmetrical hearing loss, type of hearing loss, severity of hearing loss and detailed clinical characteristics of auricular, external ear, and middle ear and inner ear anomalies. In terms of genotype-phenotype correlations, patients with SIX1 variants had no kidney anomalies and fewer middle ear anomalies. CONCLUSIONS AND SIGNIFICANCE:We clarified the detailed hearing loss phenotypes of BOR syndrome patients. Our study results will contribute to a better understanding and clinical management of BOR syndrome patients.

A 24-year-old female patient with a 4-year history of recurrent abdominal pain, diarrhea, periodic fever and elevated C-reactive protein was referred to our institution. Colonoscopy, esophago-gastro-duodenoscopy, capsule endoscopy and contrast-enhanced CT showed no significant findings. Because she and her mother had sensorineural hearing loss, a diagnosis of cryopyrin-associated periodic syndrome was suspected. Genetic testing of the patient and her mother revealed a candidate germline variant of NLRP3. The patient was commenced on subcutaneous 150 mg canakinumab, a fully human monoclonal antibody targeting IL-1β, at a dose of 150 mg every 8 weeks, which resulted in the persistence of sensorineural hearing loss but led to the complete disappearance of her abdominal symptoms and periodic fever.

The etiology of idiopathic sudden sensorineural hearing loss (iSSNHL) remains unclear, and genome-wide genetic evidence is limited. We conducted a multicenter Japanese case-control genome-wide association study including 192 clinically defined iSSNHL cases and 15,302 controls aged ≥80 years without a history of hearing loss. After cross-platform SNP harmonization and imputation (Eagle/Minimac4), association testing was performed using dosage-based logistic regression in PLINK 2.0, adjusting for sex and principal components (PC1-PC10). Gene- and pathway-level analyses were conducted using MAGMA and the PANTHER overrepresentation test. Genomic inflation was modest (λ_GC = 1.04). Eight loci reached genome-wide significance (p < 5 × 10-8), led by FHIT, with additional loci near LHX2, TRMT1L, MEGF10, SPATS1, SAMD5, MYT1L, and ID4; 21 loci met the suggestive threshold (p < 1 × 10-6). MAGMA identified eight genes at FDR < 0.05 (FHIT, TRMT1L, MEGF10, RNF2, SWT1, VAMP1, TAPBPL, and C9orf3). These findings suggest that immune-inflammatory and cellular stress-homeostasis mechanisms may contribute to iSSNHL susceptibility and provide candidate loci for future replication and functional studies.

Approximately 200 genes have been identified as causative in hereditary hearing loss. Genetic testing is increasingly important, not only for accurate diagnosis but also for predicting audiometric profiles, prognoses, and potential syndromic features. Hereditary hearing loss can be syndromic or nonsyndromic, with nonsyndromic forms further classified by inheritance: autosomal-dominant or autosomal-recessive. In autosomal-dominant cases, three pathological mechanisms—haploinsufficiency, dominant-negative effects, and gain of function—are often implicated. Moreover, specific genes correlate with distinct audiometric patterns: WFS1 variants typically cause low-frequency hearing loss, whereas KCNQ4 and POU4F3 variants are linked to high-frequency loss. To investigate the underlying mechanisms of these frequency-dependent patterns, gene expression across cochlear turns was compared in mice, but interpretations of the results were limited because of inherent structural differences between rodent and primate cochleae. Therefore, the common marmoset (Callithrix jacchus), which offers closer anatomical and functional similarity to human cochleae, was utilized herein as an improved model. Using RNA sequencing (RNA-seq) across cochlear turns of common marmosets, the present study aimed to uncover gene expression and alternative splicing patterns that may explain tonotopic manifestations in hereditary hearing loss, including those caused by WFS1 variants, the present study being one such using common marmoset cochlear RNA-seq data, and these findings are highly valuable for genetic diagnosis and the development of gene therapies.

Background/Objectives: The OTOG gene is responsible for autosomal recessive non-syndromic sensorineural hearing loss and is assigned as DFNB18B. To date, 44 causative OTOG variants have been reported to cause non-syndromic hearing loss. However, the detailed clinical features for OTOG-associated hearing loss remain unclear. Methods: In this study, we analyzed 7065 patients with non-syndromic hearing loss (mean age 26.4 ± 22.9 years, 2988 male, 3855 female, and 222 without gender information) using massively parallel DNA sequencing for 158 target deafness genes. We identified the patients with biallelic OTOG variants and summarized the clinical characteristics. Results: Among the 7065 patients, we identified 14 possibly disease-causing OTOG variants in 26 probands, with 13 of the 14 variants regarded as novel. Patients with OTOG-associated hearing loss mostly showed congenital or childhood-onset hearing loss. They were considered to show non-progressive, mild-to-moderate hearing loss. There were no symptoms that accompanied the hearing loss in OTOG-associated hearing loss patients. Conclusions: We confirmed non-progressive, mild-to-moderate hearing loss as the clinical characteristics of OTOG-associated hearing loss. These findings will contribute to a better understanding of the clinical features of OTOG-associated HL and will be useful in clinical practice.

Background/Objectives: The OTOF gene is reported to be the causative gene for non-syndromic recessive sensorineural hearing loss and auditory neuropathy spectrum disorder. About 300 variants have been reported, but there have been no reports to date on copy gain variants. Methods: We identified a copy gain variant in the OTOF gene through short-read next-generation sequencing analysis from one patient with auditory neuropathy. We also performed long-read next-generation sequencing analysis using the Oxford Nanopore Technologies adaptive sampling procedure. Results: The four-year-old male carried a duplication of chr2: 26,477,852 to 26,483,106 (a 5254-base duplication including exon 14 to exon 18 of the OTOF gene NM_001287489) and a c.5385C>A single nucleotide variant. We also confirmed that these two variants were located in the trans configuration based on haplotype phasing results using the long-read next-generation sequencing data. Conclusions: This is the first report of an auditory neuropathy patient with a large duplication variant in the OTOF gene. The identified variants were novel, but based on the clinical phenotype of the patient, these variants seem to be the genetic cause of this patient’s phenotype. Oxford Nanopore Technologies adaptive sampling is a powerful tool for the analysis of structural variants (particularly for determining the breakpoint and direction) and haplotype phasing.

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.

Background/Objectives: Hearing loss is one of the most common sensorineural impairments, and approximately 60% of early-onset cases are due to genetic variations. The otogelin-like protein, encoded by the OTOGL gene, is a component of the acellular membranes of the inner ear, such as the tectorial membrane, and is thought to play an important role in cochlear amplification. OTOGL gene variants are a rare cause of hearing loss such as DFNB84B, a mild-to-moderate sensorineural hearing loss presenting in early childhood with autosomal recessive inheritance. In this study, we aim to enhance our comprehension of the phenotypes of hearing loss caused by OTOGL variants. Methods: A total of 7056 Japanese patients with hearing loss were recruited, and based on massively parallel DNA sequencing on 158 target genes, we selected patients with biallelic OTOGL variants. Results: Ten affected individuals with OTOGL gene variants were detected, the largest group of patients yet to be reported, and eight of the eleven variants were novel. Our results showed that variations in this gene led to mild-to-moderate non-progressive hearing loss, and the accompanying symptoms, mainly vestibular symptoms, were speculated to present in adulthood. Conclusions: Determination of the phenotypes of genes causative of hearing loss is expected to greatly benefit patients with hearing loss as it can assist in predicting outcomes and lead to appropriate intervention, which, in OTOGL-associated hearing loss cases, is based around the fact that the patients need not be concerned with deterioration in hearing, but require careful follow-up for vestibular symptoms.

Background/Objectives: MYO3A belongs to the unconventional myosin superfamily, and the myosin IIIa protein localizes on the tip of the stereocilia of vestibular and cochlear hair cells. Deficiencies in MYO3A have been reported to cause the deformation of hair cells into abnormally long stereocilia with an increase in spacing. MYO3A is a rare causative gene of autosomal recessive sensorineural hearing loss (DFNB30), with only 13 cases reported to date. In this study, we aimed to elucidate the phenotypes caused by MYO3A variations. Methods: Massively parallel DNA sequencing was performed on 15,684 Japanese hearing loss patients (mean age 27.5 ± 23.1 years old, 6574 male, 8612 female and 498 patients for whom information was unavailable), identifying nine candidate patients with MYO3A variants. Results: We identified eight causative MYO3A variants by massively parallel DNA sequencing, including six novel variants, and reported nine individuals possessing MYO3A gene variants, which is the largest group of non-related patients yet to be detected. Our findings confirmed that MYO3A variants cause progressive hearing loss, with its onset varying from birth to the second decade, eventually leading to severe-to-profound hearing loss. Conclusions: We clarified that patients with MYO3A gene variants present with late-onset, progressive hearing loss. Our findings have enabled us to predict the outcomes of hearing loss in patients with candidate MYO3A gene variants and to provide intervention in a timely manner.

Background/Objectives: During and after electric–acoustic stimulation (EAS) surgery (as well as regular cochlear implant surgery), the oral and/or intravenous administration of steroids is recommended to prevent acute inflammatory reactions and subsequent fibrosis. However, the effect does not last long. Therefore, with the hope of providing a sustained effect, a new dexamethasone (DEX)-eluting electrode (FLEX28 DEX) has recently been developed. Methods: A case study was performed at Shinshu University in February 2024 in which a DEX-eluting electrode array was utilized for a patient presenting with high-frequency hearing loss with a defined etiology (hearing loss due to a mitochondrial m.1555A > G variant). Results: Residual hearing was well preserved after EAS surgery, and post-operative impedance field telemetry was maintained at a very low level in contrast with a historical/retrospective control group (FLEX28 electrodes without DEX); therefore, it is expected that post-operative fibrosis will be minimized. Further, it was shown that the DEX-eluting electrode can also be applied to EAS. Conclusions: The DEX-eluting electrode was useful in maintaining post-operative impedance at a very low level, indicating that post-operative fibrosis could be minimized even after EAS surgery.

The stereocilin (STRC) gene is a significant contributor to mild-to-moderate sensorineural hearing loss (SNHL), particularly in cases of biallelic STRC deletions and copy number alterations. Although pathogenic single nucleotide variants (SNVs) or small insertion-deletions (indels) have been investigated across the coding region of STRC, the pseudogene STRCP1, which shares 98% homology with the STRC gene, makes interpreting sequence data from this region challenging. To detect missing SNVs, targeted long-read sequencing was conducted using the nanopore MinION platform coupled with long-range polymerase chain reaction (PCR) enrichment on individuals exhibiting heterozygous STRC deletions and associated phenotypes. Sequencing results were obtained from 149 DNA samples. The median number of reads and depth of coverage were 4,088 and 2,780, respectively. The average read length of 20.76 kbp corresponded to that of a long-range PCR product, indicating precise analysis using MinION. Forty-three individuals carrying SNVs or small indels and 27 variants were identified. Thirteen were previously reported as hearing loss-causing variants and 14 were novel variants. Long-read sequencing technology enables precise detection of pathogenic variants in complex genomic regions, such as STRC, where conventional methods face challenges owing to pseudogene interference. Therefore, this approach is a valuable complement to conventional methods for resolving unresolved SNHL. This study demonstrates the utility of targeted long-read sequencing as a complementary method to short-read NGS for resolving complex regions such as STRC. The combination with long-range PCR enabled precise enrichment and improved resolution in SNV detection.

We determined the relative expression levels of the receptors TrkA, TrkB, TrkC, and p75NTR and ligands BDNF, NT-3, NGF, and NT-4 with RNAseq analysis on fetal human inner ear samples, located TrkB and TrkC proteins, and quantified BDNF with in situ hybridization on histological sections between gestational weeks (GW) 9 to 19. Spiral ganglion neurons (SGNs) and satellite glia appear to be the main source of BDNF and synthesis peaks twice at GW10 and GW15–GW17. Tonotopical gradients of BDNF revert between GW8 and GW15 and follow a maturation and innervation density gradient in SGNs. NT-3/TrkC follows the same time course of expression as BDNF/TrkB. Immunostaining reveals that TrkB signaling may act mainly through satellite glia, Schwann cells, and supporting cells of Kölliker’s organ, while TrkC signaling targets SGNs and pillar cells in humans. The NT-4 expression is upregulated when BDNF/NT-3 is downregulated, suggesting a balancing effect for sustained TrkB activation during fetal development. The mission of neurotrophins expects nerve fiber guidance, innervation, maturation, and trophic effects. The data shall serve to provide a better understanding of neurotrophic regulation and action in human development and to assess the transferability of neurotrophic regenerative therapy from animal models.

BackgroundIn cases of congenital sensorineural hearing loss, testing for genetic etiologies and congenital cytomegalovirus (cCMV) infection have become common practice.Aims/ObjectivesThe purpose of this study is to determine which specific testing methodologies should be used and when.Material and methodsWe surveyed 20 practicing otolaryngologists across eighteen institutions in thirteen countries about their approach to cCMV, GJB2, and wider genetic testing.ResultsWe found 90% of respondents employ all three tests, either in routine or special cases. cCMV testing is widely used, with 95% of respondents incorporating it into their clinical practice. GJB2 testing was employed by 90%. In cases with negative GJB2 test results, a majority of respondents proceeded to wider genetic screening. Test reimbursement was also examined for each test. For cCMV testing, 63.1% reported reimbursement, 68.4% reported reimbursement for GJB2 variant testing and 52.6% reported reimbursement for wider genetic screening.Conclusions and significanceA common approach is to perform cCMV and GJB2 testing as the first tests, followed by wider genetic testing. This study offers insight into the prevalence, methodologies, and reimbursement status of these testing methodologies across multiple hearing centers and countries. Current consensus and future directions are described based on the current survey. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) (cCMV) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) 13 (sic)(sic)(sic)/(sic)(sic)18(sic)(sic)(sic)(sic)20(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)cCMV,GJB2(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic) 90% (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).cCMV(sic)(sic)(sic)(sic)(sic)(sic)(sic), 95% (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).90% (sic)(sic)(sic)(sic)(sic) GJB2 (sic)(sic).(sic) GJB2 (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic) cCMV (sic)(sic), 63.1% (sic)(sic)(sic)(sic)(sic)(sic)(sic), 68.4% (sic)(sic)(sic)(sic)(sic) GJB2 (sic)(sic)(sic)(sic)(sic)(sic)(sic), 52.6% (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) cCMV (sic) GJB2 (sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)/(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

To investigate the association between hereditary hearing loss and vestibular function, we compared vestibular function and symptoms among patients with GJB2, SLC26A4, and CDH23 variants. Thirty-nine patients with sensory neural hearing loss (11 males and 28 females) with biallelic pathogenic variants in either GJB2, SLC26A4, or CDH23 were included in this study (13 GJB2, 15 SLC26A4, and 11 CDH23). The patients were examined using caloric testing and cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP). We also compared vestibular function and symptoms between patients with these gene variants and 78 normal-hearing ears without vestibular symptoms as controls. The frequency of semicircular canal hypofunction in caloric testing was higher in patients with SLC26A4 variants (47%) than in those with GJB2 (0%) and CDH23 variants (27%). According to the cVEMP results, 69% of patients with GJB2 variants had saccular hypofunction, a significantly higher proportion than in those carrying other variants (SLC26A4, 20%; CDH23, 18%). In oVEMP, which reflects utricular function, no difference was observed in the frequency of hypofunction among the three genes (GJB2, 15%; SLC26A4, 40%; and CDH23, 36%). Hence, discernable trends indicate vestibular dysfunction associated with each gene.

The PTPRQ gene has been identified as one of the genes responsible for non-syndromic sensorineural hearing loss (SNHL), and assigned as DFNA73 and DFNB84. To date, about 30 causative PTPRQ variants have been reported to cause SNHL. However, the detailed clinical features of PTPRQ-associated hearing loss (HL) remain unclear. In this study, 15,684 patients with SNHL were enrolled and genetic analysis was performed using massively parallel DNA sequencing (MPS) for 63 target deafness genes. We identified 17 possibly disease-causing PTPRQ variants in 13 Japanese patients, with 15 of the 17 variants regarded as novel. The majority of variants identified in this study were loss of function. Patients with PTPRQ-associated HL mostly showed congenital or childhood onset. Their hearing levels at high frequency deteriorated earlier than that at low frequency. The severity of HL progressed from moderate to severe or profound HL. Five patients with profound or severe HL received cochlear implantation, and the postoperative sound field threshold levels and discrimination scores were favorable. These findings will contribute to a greater understanding of the clinical features of PTPRQ-associated HL and may be relevant in clinical practice.