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Sakuma N, Nishio SY, Goto SI, Honkura Y, Oda K, Takeda H, Kobayashi M, Kumakawa K, Iwasaki S, Takahashi M, Ito T, Arai Y, Isono Y, Obara N, Matsunobu T, Okubo K, Usami SI. Detailed Clinical Features of PTPRQ-Associated Hearing Loss Identified in a Large Japanese Hearing Loss Cohort. Genes (Basel) 2024; 15:489. [PMID: 38674423 PMCID: PMC11050587 DOI: 10.3390/genes15040489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
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.
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Affiliation(s)
- Naoko Sakuma
- Department of Otorhinolaryngology, Head and Neck Surgery, Nippon Medical School, Tokyo 113-8603, Japan; (N.S.); (T.M.); (K.O.)
| | - Shin-ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1, Asahi, Matsumoto City 390-8621, Japan;
| | - Shin-ichi Goto
- Department of Otorhinolaryngology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8560, Japan;
| | - Yohei Honkura
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai 980-8575, Japan;
| | - Kiyoshi Oda
- Department of Otolaryngology, Tohoku Rosai Hospital, Sendai 981-8563, Japan;
| | - Hidehiko Takeda
- Department of Otorhinolaryngology, Toranomon Hospital, Tokyo 105-8470, Japan; (H.T.); (M.K.)
| | - Marina Kobayashi
- Department of Otorhinolaryngology, Toranomon Hospital, Tokyo 105-8470, Japan; (H.T.); (M.K.)
| | - Kozo Kumakawa
- Department of Otolaryngology, Kamio Memorial Hospital, Tokyo 101-0063, Japan;
- Akasaka Toranomon Clinic, Tokyo 107-0052, Japan
| | - Satoshi Iwasaki
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo 108-8329, Japan; (S.I.); (M.T.)
| | - Masahiro Takahashi
- Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo 108-8329, Japan; (S.I.); (M.T.)
| | - Taku Ito
- Department of Otorhinolaryngology, Tokyo Medical and Dental University, Tokyo 113-8510, Japan;
| | - Yasuhiro Arai
- Department of Otorhinolaryngology-Head and Neck Surgery, Yokohama City University School of Medicine, Yokohama 236-0004, Japan;
| | - Yasuhiro Isono
- Department of Otolaryngology, Yokohama City University Medical Center, Yokohama 232-0024, Japan;
| | - Natsuko Obara
- Department of Otolaryngology, Gifu University Graduate School of Medicine, Gifu City 501-1194, Japan;
| | - Takeshi Matsunobu
- Department of Otorhinolaryngology, Head and Neck Surgery, Nippon Medical School, Tokyo 113-8603, Japan; (N.S.); (T.M.); (K.O.)
| | - Kimihiro Okubo
- Department of Otorhinolaryngology, Head and Neck Surgery, Nippon Medical School, Tokyo 113-8603, Japan; (N.S.); (T.M.); (K.O.)
| | - Shin-ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1, Asahi, Matsumoto City 390-8621, Japan;
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Hartmann AM, Nothwang HG. NKCC1 and KCC2: Structural insights into phospho-regulation. Front Mol Neurosci 2022; 15:964488. [PMID: 35935337 PMCID: PMC9355526 DOI: 10.3389/fnmol.2022.964488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory neurotransmission plays a fundamental role in the central nervous system, with about 30–50% of synaptic connections being inhibitory. The action of both inhibitory neurotransmitter, gamma-aminobutyric-acid (GABA) and glycine, mainly relies on the intracellular Cl– concentration in neurons. This is set by the interplay of the cation chloride cotransporters NKCC1 (Na+, K+, Cl– cotransporter), a main Cl– uptake transporter, and KCC2 (K+, Cl– cotransporter), the principle Cl– extruder in neurons. Accordingly, their dysfunction is associated with severe neurological, psychiatric, and neurodegenerative disorders. This has triggered great interest in understanding their regulation, with a strong focus on phosphorylation. Recent structural data by cryogenic electron microscopy provide the unique possibility to gain insight into the action of these phosphorylations. Interestingly, in KCC2, six out of ten (60%) known regulatory phospho-sites reside within a region of 134 amino acid residues (12% of the total residues) between helices α8 and α9 that lacks fixed or ordered three-dimensional structures. It thus represents a so-called intrinsically disordered region. Two further phospho-sites, Tyr903 and Thr906, are also located in a disordered region between the ß8 strand and the α8 helix. We make the case that especially the disordered region between helices α8 and α9 acts as a platform to integrate different signaling pathways and simultaneously constitute a flexible, highly dynamic linker that can survey a wide variety of distinct conformations. As each conformation can have distinct binding affinities and specificity properties, this enables regulation of [Cl–]i and thus the ionic driving force in a history-dependent way. This region might thus act as a molecular processor underlying the well described phenomenon of ionic plasticity that has been ascribed to inhibitory neurotransmission. Finally, it might explain the stunning long-range effects of mutations on phospho-sites in KCC2.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- *Correspondence: Anna-Maria Hartmann,
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Jin Y, Liu XZ, Xie L, Xie W, Chen S, Sun Y. Targeted Next-Generation Sequencing Identified Novel Compound Heterozygous Variants in the PTPRQ Gene Causing Autosomal Recessive Hearing Loss in a Chinese Family. Front Genet 2022; 13:884522. [PMID: 35899188 PMCID: PMC9310072 DOI: 10.3389/fgene.2022.884522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 05/26/2022] [Indexed: 11/28/2022] Open
Abstract
Hearing loss is among the most common congenital sensory impairments. Genetic causes account for more than 50% of the cases of congenital hearing loss. The PTPRQ gene, encoding protein tyrosine phosphatase receptor Q, plays an important role in maintaining the stereocilia structure and function of hair cells. Mutations in the PTPRQ gene have been reported to cause hereditary sensorineural hearing loss. By using next-generation sequencing and Sanger sequencing, we identified a novel compound heterozygous mutation (c.997 G > A and c.6603-3 T > G) of the PTPRQ gene in a Chinese consanguineous family. This is the first report linking these two mutations to recessive hereditary sensorineural hearing loss. These findings contribute to the understanding of the relationship between genotype and hearing phenotype of PTPRQ-related hearing loss, which may be helpful to clinical management and genetic counseling.
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Affiliation(s)
- Yuan Jin
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Zhou Liu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Le Xie
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wen Xie
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sen Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Tongji Medical College, Institute of Otorhinolaryngology, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Yu Sun,
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