{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T15:38:56Z","timestamp":1774453136243,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T00:00:00Z","timestamp":1774396800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Audiology Research"],"abstract":"<jats:p>Purpose: Hearing loss (HL) is a prevalent condition significantly impairing quality of life, with genetic mutations accounting for a substantial proportion of congenital cases, notably those involving the GJB2 gene encoding connexin 26. This study aims to analyze the current knowledge, feasibility, and challenges of gene therapy targeting GJB2-related HL, emphasizing both embryonic and postnatal interventions. Methods: A comprehensive scoping review was conducted across electronic databases up to October 2025, including studies focusing on GJB2-associated HL, gene therapy approaches, and the timing of interventions. Data extraction encompassed mutation types, animal models, delivery strategies, outcomes, and ethical considerations. Results: The results indicated over 467 GJB2 variants which could impair cochlear ion homeostasis and development. Animal models, mainly murine, demonstrated early-onset degeneration with limited recovery following delayed gene therapy, while early postnatal intervention showed greater efficacy. Viral vectors like AAV have been employed for targeted gene delivery via cochlear injections, achieving partial restoration of connexin expression and cochlear function, yet they have faced limitations including transduction efficiency, immune responses, and long-term stability. Challenges in translating these findings to humans have been compounded by anatomical, immunological, ethical, and safety issues, particularly regarding embryonic gene therapy and germline modifications. Ethical frameworks can vary internationally, highlighting the necessity for careful regulation. Conclusions: While promising advances in gene therapy for GJB2-related HL have been achieved in preclinical studies, significant scientific, technical, and ethical barriers must be addressed before clinical application, especially during embryogenesis. A multidisciplinary, cautious approach is essential to realize the potential of gene therapy in restoring natural hearing while safeguarding individual and societal interests.<\/jats:p>","DOI":"10.3390\/audiolres16020049","type":"journal-article","created":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T13:57:34Z","timestamp":1774447054000},"page":"49","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Exploring Embryonic and Postnatal Gene Therapy Approaches for GJB2-Related Deafness: A Scoping Review"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-7112-0282","authenticated-orcid":false,"given":"Valeria","family":"Caragli","sequence":"first","affiliation":[{"name":"Otorhinolaryngology-Head and Neck Surgery, Audiology Program, University of Modena and Reggio Emilia, 41125 Modena, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alessandro","family":"Martini","sequence":"additional","affiliation":[{"name":"Padova University Research Center \u201cInternational Auditory Processing Project in Venice (I-APPROVE)\u201d, Department of Neurosciences, University of Padua, 35128 Padua, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,25]]},"reference":[{"key":"ref_1","unstructured":"(2025, July 10). Available online: https:\/\/www.who.int\/teams\/noncommunicable-diseases\/sensory-functions-disability-and-rehabilitation\/highlighting-priorities-for-ear-and-hearing-care."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e185193","DOI":"10.1172\/jci.insight.185193","article-title":"AAV-mediated base editing restores cochlear gap junction in GJB2 dominant-negative mutation-associated syndromic hearing loss model","volume":"10","author":"Ukaji","year":"2025","journal-title":"JCI Insight"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1038\/387080a0","article-title":"Connexin 26 mutations in hereditary non-syndromic sensorineural deafness","volume":"387","author":"Kelsell","year":"1997","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Caragli, V., Di Pasquale Fiasca, V.M., Genovese, E., and Martini, A. (2025). Kolliker\u2019s Organ and Its Functional Role in the Development of Corti\u2019s Organ and Auditory Systems. Audiol. Res., 15.","DOI":"10.3390\/audiolres15040075"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1106","DOI":"10.1016\/S0960-9822(02)00904-1","article-title":"Targeted ablation of connexin26 in the inner ear epithelial gap junction network causes hearing impairment and cell death","volume":"12","author":"Ott","year":"2002","journal-title":"Curr. Biol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.bbrc.2009.05.023","article-title":"Targeted connexin26 ablation arrests postnatal development of the organ of Corti","volume":"385","author":"Wang","year":"2009","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1177\/0194599817697054","article-title":"Predictive Value of GJB2 Mutation Status for Hearing Outcomes of Pediatric Cochlear Implantation","volume":"157","author":"Abdurehim","year":"2017","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e2406510","DOI":"10.1002\/advs.202406510","article-title":"Viral-Mediated Connexin 26 Expression Combined with Dexamethasone Rescues Hearing in a Conditional Gjb2 Null Mice Model","volume":"12","author":"Wang","year":"2025","journal-title":"Adv. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"149326","DOI":"10.1016\/j.gene.2025.149326","article-title":"Mechanisms of congenital hearing loss caused by GJB2 gene mutations and current progress in gene therapy","volume":"946","author":"Ma","year":"2025","journal-title":"Gene"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2317","DOI":"10.1016\/S0140-6736(23)02874-X","article-title":"AAV1-hOTOF gene therapy for autosomal recessive deafness 9: A single-arm trial","volume":"403","author":"Lv","year":"2024","journal-title":"Lancet"},{"key":"ref_11","unstructured":"(2025, July 10). Available online: https:\/\/www.clinicaltrials.gov\/study\/NCT05788536?cond=Auditory%20Neuropathy&rank=8."},{"key":"ref_12","unstructured":"(2025, July 10). Available online: https:\/\/www.otofclinicaltrial.com\/ak-otof-101-study."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"546","DOI":"10.2174\/156652409788488775","article-title":"Function and expression pattern of nonsyndromic deafness genes","volume":"9","author":"Hilgert","year":"2009","journal-title":"Curr. Mol. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1337","DOI":"10.1073\/pnas.0606855104","article-title":"Restoration of connexin26 protein level in the cochlea completely rescues hearing in a mouse model of human connexin30-linked deafness","volume":"104","author":"Ahmad","year":"2007","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.heares.2013.11.009","article-title":"Connexin 26 null mice exhibit spiral ganglion degeneration that can be blocked by BDNF gene therapy","volume":"309","author":"Takada","year":"2014","journal-title":"Hear. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/j.omtm.2021.09.009","article-title":"GJB2 gene therapy and conditional deletion reveal developmental stage-dependent effects on inner ear structure and function","volume":"23","author":"Guo","year":"2021","journal-title":"Mol. Ther. Methods Clin. Dev."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3651","DOI":"10.1093\/hmg\/ddv109","article-title":"Perinatal Gjb2 gene transfer rescues hearing in a mouse model of hereditary deafness","volume":"24","author":"Iizuka","year":"2015","journal-title":"Hum. Mol. Genet."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.neures.2007.03.006","article-title":"Cochlear expression of a dominant-negative GJB2R75W construct delivered through the round window membrane in mice","volume":"58","author":"Maeda","year":"2007","journal-title":"Neurosci. Res."},{"key":"ref_19","first-page":"13","article-title":"Therapeutic regulation of gene expression in the inner ear using RNA interference","volume":"66","author":"Maeda","year":"2009","journal-title":"Adv. Otorhinolaryngol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/S0378-5955(00)00216-1","article-title":"A surgical approach appropriate for targeted cochlear gene therapy in the mouse","volume":"151","author":"Jero","year":"2001","journal-title":"Hear. Res."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhang, L., Wang, W., Kim, S.M., Wang, J., Zhou, B., Kong, W., Zheng, J., and Lin, X. (2022). Virally Mediated Connexin 26 Expression in Postnatal Scala Media Significantly and Transiently Preserves Hearing in Connexin 30 Null Mice. Front. Cell Dev. Biol., 10, Erratum in Front. Cell Dev. Biol.\u00a02022, 10, 969989. https:\/\/doi.org\/10.3389\/fcell.2022.969989.","DOI":"10.3389\/fcell.2022.900416"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"100285","DOI":"10.1016\/j.mocell.2025.100285","article-title":"Recent preclinical and clinical advances in gene therapy for hereditary hearing loss","volume":"48","author":"Jang","year":"2025","journal-title":"Mol. Cells"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"6567","DOI":"10.1038\/s41598-017-06759-y","article-title":"In vivo genetic manipulation of inner ear connexin expression by bovine adeno-associated viral vectors","volume":"7","author":"Crispino","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1452","DOI":"10.1097\/00007890-200405150-00023","article-title":"Transplanted human amniotic epithelial cells express connexin 26 and Na-K-adenosine triphosphatase in the inner ear","volume":"77","author":"Yuge","year":"2004","journal-title":"Transplantation"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"101229","DOI":"10.1016\/j.omtm.2024.101229","article-title":"Embryo and fetal gene editing: Technical challenges and progress toward clinical applications","volume":"32","author":"Mattar","year":"2024","journal-title":"Mol. Ther. Methods Clin. Dev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3006","DOI":"10.1016\/j.ymthe.2025.03.029","article-title":"Combined AAV-mediated specific Gjb2 expression restores hearing in DFNB1 mouse models","volume":"33","author":"Sun","year":"2025","journal-title":"Mol. Ther. J. Am. Soc. Gene Ther."},{"key":"ref_27","unstructured":"(2025, July 10). Progress and Challenges With Gene Therapy in Hereditary Hearing Loss. Available online: https:\/\/www.ajmc.com\/view\/progress-and-challenges-with-gene-therapy-in-hereditary-hearing-loss."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.ydbio.2018.10.008","article-title":"Mosaicism in CRISPR\/Cas9-mediated genome editing","volume":"445","author":"Mehravar","year":"2019","journal-title":"Dev. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Schleidgen, S., Dederer, H.G., Sgodda, S., Cravcisin, S., L\u00fcneburg, L., Cantz, T., and Heinemann, T. (2020). Human germline editing in the era of CRISPR-Cas: Risk and uncertainty, inter-generational responsibility, therapeutic legitimacy. BMC Med. Ethics, 21.","DOI":"10.1186\/s12910-020-00487-1"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"lsaa080","DOI":"10.1093\/jlb\/lsaa080","article-title":"Framing and legitimating EU legal regulation of human gene-editing technologies: Key facets and functions of an imaginary","volume":"8","author":"Mahalatchimy","year":"2021","journal-title":"J. Law Biosci."},{"key":"ref_31","unstructured":"HFEA (Human Fertilisation and Embryology Authority) (2025, July 10). Regulations on Embryo Research and Gene Editing in the UK, Available online: https:\/\/www.hfea.gov.uk."},{"key":"ref_32","first-page":"461","article-title":"Ethical implications of human embryo editing in China","volume":"45","author":"Li","year":"2019","journal-title":"J. Med. Ethics"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1080\/20502877.2019.1606151","article-title":"The Wisdom of Germline Editing: An Ethical Analysis of the Use of CRISPR-Cas9 to Edit Human Embryos","volume":"25","author":"Gumer","year":"2019","journal-title":"New Bioeth."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"18770","DOI":"10.1073\/pnas.0800793105","article-title":"ATP release through connexin hemichannels and gap junction transfer of second messengers propagate Ca2+ signals across the inner ear","volume":"105","author":"Anselmi","year":"2008","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1007\/s10730-024-09538-1","article-title":"The Ethics of Human Embryo Editing via CRISPR-Cas9 Technology: A Systematic Review of Ethical Arguments, Reasons, and Concerns","volume":"37","author":"Wiley","year":"2025","journal-title":"HEC Forum"},{"key":"ref_36","unstructured":"(2025, July 10). Available online: https:\/\/www.europarl.europa.eu\/RegData\/etudes\/STUD\/2022\/729506\/EPRS_STU(2022)729506_EN.pdf."}],"container-title":["Audiology Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2039-4349\/16\/2\/49\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T14:39:41Z","timestamp":1774449581000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2039-4349\/16\/2\/49"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,25]]},"references-count":36,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["audiolres16020049"],"URL":"https:\/\/doi.org\/10.3390\/audiolres16020049","relation":{},"ISSN":["2039-4349"],"issn-type":[{"value":"2039-4349","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,25]]}}}