Advances In Gene Therapy Research Articles

The complex pathophysiology and clinical management of epidermolysis bullosa: a comprehensive review

Epidermolysis bullosa (EB) represents a group of rare, genetically heterogeneous disorders characterized by the formation of blisters and erosions of the skin and mucous membranes in response to minor mechanical trauma. EB is classified into four major types-EB simplex, junctional EB, dystrophic EB, and Kindler syndrome, each associated with mutations in specific genes that encode structural proteins essential for skin integrity. The clinical spectrum of EB ranges from mild forms, presenting with localized skin involvement, to severe variants that lead to widespread blistering, mutilating scarring, and significant morbidity. The pathophysiology of EB is complex, involving disruptions in the adhesion between the dermis and epidermis, leading to compromised structural stability of the skin. Current therapeutic strategies focus on symptom management, including wound care, infection prevention, and pain control, as no definitive cure exists. Advances in gene therapy, stem cell therapy, and protein replacement therapy hold promise for future treatment paradigms. This review aims to elucidate the molecular underpinnings, clinical manifestations, and emerging therapeutic approaches for EB, providing a comprehensive overview for clinicians and researchers engaged in the management and study of this challenging condition.

Nutrition in phenylketonuria

Phenylketonuria (PKU) is a genetic metabolic disease resulting from a deficiency in the enzyme phenylalanine hydroxylase. This defect prevents the conversion of phenylalanine to tyrosine, and as a result, the level of phenylalanine in the body increases abnormally. The accumulation of this amino acid may cause brain damage and grows development in these patients.The primary approach to treating the disease involves dietary management that restricts protein and phenylalanine intake, often alongside Tetrahydrobiopterin (BH4) supplementation. Medical foods specifically formulated for these patients are utilized to supply the necessary energy, protein, and tyrosine. Other treatment options, including the use of large neutral amino acids (LNAAs) and the enzyme Phenylalanine ammonia lyase (PAL), can be utilized to manage symptoms in adult patients. Advancements in gene therapy aimed at correcting defective genes in patients may help restore phenylalanine metabolism, though further research in this area is necessary. Effective personal management of phenylketonuria necessitates enhanced knowledge and collaboration among healthcare professionals to achieve optimal treatment outcomes for patients. This article emphasis the nutritional management of individuals with phenylketonuria across various stages of their lives.

PCDH15 Dual-AAV Gene Therapy for Deafness and Blindness in Usher Syndrome Type 1F Models.

Usher syndrome type 1F (USH1F), resulting from mutations in the protocadherin-15 (PCDH15) gene, is characterized by congenital lack of hearing and balance, and progressive blindness in the form of retinitis pigmentosa. In this study, we explore an approach for USH1F gene therapy, exceeding the single AAV packaging limit by employing a dual adeno-associated virus (AAV) strategy to deliver the full-length PCDH15 coding sequence. We demonstrate the efficacy of this strategy in mouse USH1F models, effectively restoring hearing and balance in these mice. Importantly, our approach also proves successful in expressing PCDH15 protein in clinically relevant retinal models, including human retinal organoids and non-human primate retina, showing efficient targeting of photoreceptors and proper protein expression in the calyceal processes. This research represents a major step toward advancing gene therapy for USH1F and the multiple challenges of hearing, balance, and vision impairment.

A review on achromatopsia: Exploring genetic basis, diagnostic innovations, and therapeutic prospects

Achromatopsia (ACHM) is a rare inherited retinal disorder characterized by partial or complete color blindness, which impacts individuals' quality of life and daily functioning. This review delves into the genetic basis, diagnostic innovations, and therapeutic prospects associated with ACHM. The main objective is to comprehensively explore the current understanding of ACHM, including genetic mutations, diagnostic techniques, and management approaches, while also discussing potential therapeutic interventions. Achromatopsia primarily results from mutations in genes encoding cone photoreceptor proteins, such as GNAT2, ATF6, PDE6H, PDE6C, CNGA3, and CNGB3. Various diagnostic methods, including electroretinography (ERG) and optical coherence tomography (OCT), are pivotal in confirming ACHM diagnosis by assessing cone function and structural abnormalities in dysfunctional cone cells. This review also highlights gene therapy interventions aimed at restoring cone function, highlighting promising advancements in preclinical and clinical settings. Additionally, it discusses the clinical features of ACHM, such as reduced visual acuity, photophobia, and color vision impairment, emphasizing the need for tailored management strategies to increase patients' quality of life. This review underscores the complex genetic landscape of ACHM and the importance of accurate diagnosis through advanced diagnostic modalities such as ERG and OCT. While there is currently no cure for ACHM, management approaches focus on symptom alleviation and improving patients' daily functioning. Gene therapy has emerged as a promising avenue for potential treatment, with ongoing research aiming to address the underlying genetic defects and restore cone photoreceptor function. The findings of this review hold clinical relevance by providing insights into the pathogenesis, diagnosis, and management of ACHM, guiding healthcare professionals in delivering personalized care to affected individuals. Continued research and advancements in gene therapy offer hope for future therapeutic interventions, highlighting the importance of updating the latest developments in the field of ACHM.

Cationic Carbosilane Dendrimers for Apmnkq2 Aptamer Transfection in Breast Cancer: An Alternative to Traditional Transfectants.

Transfection efficiency is a critical parameter in gene therapy and molecular biology, representing the success rate at which nucleic acids are introduced and expressed in target cells. The combination of aptamers with nanotechnology-based delivery systems has demonstrated remarkable improvements in the transfection efficiency of therapeutic agents and holds significant potential for advancing gene therapy and the development of targeted treatments for various diseases, including cancer. In this work, cationic carbosilane dendritic systems are presented as an alternative to commercial transfection agents, demonstrating an increase in transfection efficiency when used for the internalization of apMNKQ2, an aptamer selected against a target in cancer. Their potential therapeutic use has been evaluated in breast cancer cell lines, MDA-MB-468 and MDA-MB-231, studying the cytotoxicity of the nanoconjugate, the internalization process, and its effect on cellular migration processes.

Therapeutic Options for Crigler–Najjar Syndrome: A Scoping Review

Crigler–Najjar Syndrome (CNS) is a rare genetic disorder caused by mutations in the UGT1A1 gene, leading to impaired bilirubin conjugation and severe unconjugated hyperbilirubinemia. CNS presents in the following forms: CNS type 1 (CNS1), the more severe form with the complete absence of UGT1A1 activity, and CNS type 2 (CNS2), with partial enzyme activity. This narrative review aims to provide a detailed overview of CNS, highlighting its clinical significance and the need for new, more effective treatments. By summarizing current knowledge and discussing future treatments, this article seeks to encourage further research and advancements that can improve outcomes for CNS patients. The literature analysis showed that CNS1 requires aggressive management, including phototherapy and plasmapheresis, but liver transplantation (LT) remains the only definitive cure. The timing of LT is critical, as it must be performed before the onset of irreversible brain damage (kernicterus), making early intervention essential. However, LT poses risks such as graft rejection and lifelong immunosuppression. CNS2 is milder, with patients responding well to phenobarbital and having a lower risk of kernicterus. Recent advancements in gene therapy and autologous hepatocyte transplantation offer promising alternatives to LT. Gene therapy using adeno-associated virus (AAV) vectors has shown potential in preclinical studies, though challenges remain in pediatric applications due to liver growth and pre-existing immunity. Autologous hepatocyte transplantation avoids the risk of rejection but requires further research. These emerging therapies provide hope for more effective and less invasive treatment options, aiming to improve the quality of life for CNS patients and reduce reliance on lifelong interventions.

Recent advances and current status of gene therapy for epilepsy.

Epilepsy is a common neurological disorder with complex pathogenic mechanisms, and refractory epilepsy often lacks effective treatments. Gene therapy is a promising therapeutic option, with various preclinical experiments achieving positive results, some of which have progressed to clinical studies. This narrative review was conducted by searching for papers published in PubMed/MEDLINE with the following single and/or combination keywords: epilepsy, children, neurodevelopmental disorders, genetics, gene therapy, vectors, transgenes, receptors, ion channels, micro RNAs (miRNAs), clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas)9 (CRISPR/Cas9), expression regulation, optogenetics, chemical genetics, mitochondrial epilepsy, challenges, ethics, and disease models. Currently, gene therapy research in epilepsy primarily focuses on symptoms attenuationmediated by viral vectors such as adeno-associated virus and other types. Advances in gene therapy technologies, such as CRISPR/Cas9, have provided a new direction for epilepsy treatment. However, the clinical application still faces several challenges, including issues related to vectors, models, expression controllability, and ethical considerations. Here, we summarize the relevant research and clinical advances in gene therapy for epilepsy and outline the challenges facing its clinical application. In addition to the shortcomings inherent in gene therapy components, the reconfiguration of excitatory and inhibitory properties in epilepsy treatment is a delicate process. On-demand, cell-autonomous treatments and multidisciplinary collaborations may be crucial in addressing these issues. Understanding gene therapy for epilepsy will help clinicians gain a clearer perception of the research progress and challenges, guiding the design of future clinical protocols and research decisions.

Prospects for gene therapy in polycystic kidney disease.

We aim to provide an updated perspective on the recent advancements in gene therapy for polycystic kidney disease (PKD), a genetic disorder with significant morbidity. Given the rapid evolution of gene therapy technologies and their potential for treating inherited diseases, this review explores the therapeutic prospects and challenges in applying these technologies to PKD. Significant progress has been made in understanding the genetic underpinnings of PKD, making it a prime candidate for gene therapy. Re-expression of the PKD genes, treatment with the C-terminal tail of polycystin 1 protein and antagomir therapy against miR-17 have shown promise in reducing cyst formation and preserving kidney function. The rapid development of gene-editing tools, antisense oligonucleotide-based strategies, programmable RNA, and advanced gene delivery systems has opened new possibilities for PKD treatment. However, challenges such as off-target effects, delivery efficiency, and long-term safety remain significant barriers to clinical application. Current research highlights the transformative potential of gene therapy for PKD. Ongoing studies are crucial to overcoming existing challenges and translating these findings into clinical practice. We highlight the need for multidisciplinary efforts to optimize gene-editing technologies and ensure their safety and efficacy in treating PKD.

Bridged Ethylene Polyethylene Oxide Surfaces to Improve Packing Materials for Widepore Size Exclusion Chromatography.

Here, we describe the preparation of bridged ethylene polyethylene oxide (BE-PEO) surface-modified silica packing materials for size exclusion chromatography. BE-PEO surface-modified silica was hydrolyzed and subsequent 1H nuclear magnetic resonance analysis of hydrolysis products confirmed the successful formation of BE-PEO bonded surface. Silica particles exhibiting 3µm diameters and 1000 Å nominal pore diameters were selected as a base material for this work out of the critical need to improve analytical capabilities for the testing of cell and gene therapy drug products. Accelerated high pH aging study revealed significant enhancement in column stability. Multi-angle light scattering noise measurements showed inordinately lower baseline noise. Moreover, we evaluated the chromatographic performance of BE-PEO silica-packed columns through separations of a protein test mixture, DNA ladder, monoclonal antibody-based therapeutics, and adeno-associated viruses. BE-PEO silica columns demonstrated high resolution, high recovery separations that were confirmed to be reproducible and capable of extended column lifetimes and exhibited low ionic and hydrophobic secondary interactions. In summary, BE-PEO silica particles have yielded a new level of performance, improved base stability, and inherently lower baseline noise. These novel widepore particles will facilitate more sensitive size-based detection and characterization of large biologics in the form of advanced gene therapy products.

Cromosome X-linked pigmentary retinosis

To report a clinical case of X-linked Retinitis pigmentosa, highlighting the importance of complementary studies and genetic testing, to the patient and his family, to identify the underlying mutation. A 10-year-old boy was brought to the clinic for refractive changes and difficulty seeing at night (nyctalopia). As a relevant family history, the maternal grandmother had Retinitis pigmentosa and the mother had high myopia (14.0 D). On ophthalmologic examination she had 4/10 corrected vision in both eyes, with moderate to severe myopia. Fundus examination showed diffuse mottled pigmentary changes with multiple yellowish-white dots distributed throughout the midperiphery, with arteriolar attenuation and mild bilateral optic nerve pallor. Autofluorescence showed a hyperautofluorescent ring around the macula and more peripheral hypoautofluorescence. On optical coherence tomography the ellipsoid zone is preserved centrally and these outer layers are thinned towards the periphery. The flash electroretinogram showed a dysfunction of both cones and rods that is not absolute. Regarding the genetic study, a variant in hemizygosis has been identified in the RPGR gene, being this result compatible with X-linked retinitis pigmentosa. In conclusion, it is of high relevance that those patients in whom we suspect a cone and rod dystrophy are extensively studied by a complete ophthalmologic examination, complementary studies, electrophysiologic and fundamentally genetic studies to identify the underlying mutation, since the advent of gene therapy could provide them with a better quality of life.

Metabolic gene therapy in a canine with pulmonary hypertension secondary to degenerative mitral valve disease.

Myxomatous mitral valve disease (MMVD) stands out as the most prevalent acquired canine heart disease. Its occurrence can reach up to 40% in small breed dogs and escalates in geriatric canine populations. MMVD leads to thickening and incomplete coaptation of valve leaflets during systole, resulting in secondary mitral valve regurgitation. Serious complications may arise concurrently with the worsening of mitral valve regurgitation, including left-and right-sided congestive heart failure, and pulmonary hypertension (PH). Ultimately, the PH progression might contribute to the patient's demise or to the owner's decision of euthanasia. Most currently available FDA-approved therapies for PH are costly and aim to address the imbalance between vasoconstriction and vasodilation to restore endothelial cell function. However, none of these medications impact the molecular dysfunction of cells or impede the advancement of pulmonary vascular and right ventricular remodeling. Recent evidence has showcased successful gene therapy approaches in laboratory animal models of PH. In this manuscript, we summarize the latest advancements in gene therapy for the treatment of PH in animals. The manuscript incorporates original data showcasing sample presentations, along with non-invasive hemodynamic assessments. Our findings demonstrate that the use of metabolic gene therapy, combining synthetic adeno-associated virus with acid ceramidase, has the potential to significantly reduce the need for drug treatment and improve spontaneously occurring PH in dogs.

Advancing Gene Therapy education for rare diseases: a comprehensive e-learning module for healthcare professionals

Advancing Gene Therapy education for rare diseases: a comprehensive e-learning module for healthcare professionals

Cryoprotectant optimization for enhanced stability and transfection efficiency of pDNA-loaded ionizable lipid nanoparticles

Advances in gene therapy, exemplified by mRNA vaccines against COVID-19, highlight the importance of lipid nanoparticles (LNPs) for nucleic acid delivery despite challenging storage conditions. Substituting mRNA with pDNA in LNPs may enhance stability and efficacy, yet maintaining LNP stability poses challenges, particularly during freeze-drying. Cryoprotectants offer potential to mitigate destabilization, improving LNP properties and in vivo performance. Here, we evaluated the effects of different concentrations of various cryoprotectants on the freeze-drying process of pDNA-loaded LNPs, assessing their physicochemical characteristics and transfection efficiency. Stability was examined under various storage conditions, confirming biological efficacy post-storage. Our results highlight the role of cryoprotectants in optimizing freeze-drying for the extended shelf life of nucleic acid-loaded LNPs. Trehalose emerged as an efficient cryoprotectant, maintaining LNP stability after the freeze-drying process for up to 2 years, with diameters and transfection efficiency comparable to fresh formulations. These findings demonstrate the optimized concentration of cryoprotectants to sustain LNP stability despite freeze-drying and prolonged storage, providing valuable insights for nucleic acid-based therapies.

Reporter Mice for Gene Editing: A Key Tool for Advancing Gene Therapy of Rare Diseases.

Most rare diseases are caused by mutations and can have devastating consequences. Precise gene editing by CRISPR/Cas is an exciting possibility for helping these patients, if no irreversible developmental defects have occurred. To optimize gene editing therapy, reporter mice for gene editing have been generated which, by expression of reporter genes, indicate the efficiency of precise and imprecise gene editing. These mice are important tools for testing and comparing novel gene editing methodologies. This review provides a comprehensive overview of reporter mice for gene editing which all have been used for monitoring CRISPR/Cas-mediated gene editing involving DNA double-strand breaks (DSBs). Furthermore, we discuss how reporter mice can be used for quickly checking genetic alterations by base editing (BE) or prime editing (PE).

The Conundrum of Mechanics Versus Genetics in Congenital Hydrocephalus and Its Implications for Fetal Therapy Approaches: A Scoping Review.

Recent advances in gene therapy, particularly for single-gene disorders (SGDs), have led to significant progress in developing innovative precision medicine approaches that hold promise for treating conditions such as primary hydrocephalus (CH), which is characterized by increased cerebrospinal fluid (CSF) volumes and cerebral ventricular dilation as a result of impaired brain development, often due to genetic causes. CH is a significant contributor to childhood morbidity and mortality and a driver of healthcare costs. In many cases, prenatal ultrasound can readily identify ventriculomegaly as early as 14-20weeks of gestation, with severe cases showing poor neurodevelopmental outcomes. Postnatal surgical approaches, such as ventriculoperitoneal shunts, do not address the underlying genetic causes, have high complication rates, and result in a marginal improvement of neurocognitive deficits. Prenatal somatic cell gene therapy (PSCGT) promises a novel approach to conditions such as CH by targeting genetic mutations in utero, potentially improving long-term outcomes. To better understand the pathophysiology, genetic basis, and molecular pathomechanisms of CH, we conducted a scoping review of the literature that identified over 160 published genes linked to CH. Mutations in L1CAM, TRIM71, MPDZ, and CCDC88C play a critical role in neural stem cell development, subventricular zone architecture, and the maintenance of the neural stem cell niche, driving the development of CH. Early prenatal interventions targeting these genes could curb the development of the expected CH phenotype, improve neurodevelopmental outcomes, and possibly limit the need for surgical approaches. However, further research is needed to establish robust genotype-phenotype correlations and develop safe and effective PSCGT strategies for CH.

Advances in gene therapy for inborn errors of immunity

Inborn errors of immunity (IEI) are a diverse group of disorders caused by defects in immune system structure or function, involving both innate and adaptive immunity. The 2022 update of the IEI classification includes 485 distinct disorders, categorized into ten major disease groups. With the rapid development of molecular biology, the specific pathogenesis of many IEI has been revealed, making gene therapy possible in preclinical and clinical research of this type of disease. This article reviews the advancements in gene therapy for IEI, aiming to increase awareness and understanding of these disorders.

Timing of SMN replacement therapies in mouse models of spinal muscular atrophy: a systematic review and meta-analysis.

Mutations in the Survival of Motor Neuron 1 gene lead to a loss of survival motor neuron protein in patients with spinal muscular atrophy. Revolutionary advances in gene therapy have led to survival motor neuron-replacement therapies that significantly prolong life expectancy and improve neuromuscular function. However, accumulating evidence suggests that the timing of survival motor neuron-replacement therapies is a critical determinant of success. We performed a systematic review and meta-analysis of all pre-clinical studies testing survival motor neuron replacement therapies in mouse models of spinal muscular atrophy to assess the impact of timing of delivery on therapeutic effectiveness. We incorporated four databases in this pre-registered study (PROSPERO 2020 CRD42020200180): EMBASE, PubMed, Scopus and Web of Science. Inclusion criteria were; primary research article, a measure of survival analysis, use of survival motor neuron mouse model and evaluation of survival motor neuron-targeting therapy. Exclusion criteria included; use of therapies not known to directly target survival motor neuron, genetic manipulations and/or lack of appropriate controls. We screened papers using the SyRF platform. The main outcome we assessed was survival in treated groups compared to untreated groups. We performed meta-analysis of survival using median survival ratio and the random effects model and measured heterogeneity using the I 2 statistic. Subgroup analyses were performed to assess treatment efficacy based on timing of intervention (embryonic delivery, day of birth, postnatal day 2 and postnatal day 3 or later) and treatment type. If detailed in the studies, body weight compared to untreated spinal muscular atrophy models and motor neuron number were included as secondary outcomes for meta-analysis. 3469 studies were initially identified, with 78 ultimately included. Survival motor neuron-replacement therapies significantly affected survival in favour of treatment by a factor of 1.20 (95% CI 1.10-1.30, P < 0.001) with high heterogeneity (I 2 = 95%). Timing of treatment was a significant source of heterogeneity (P < 0.01), with earlier treatment having a greater impact on survival. When stratified by type of treatment, earlier treatment continued to have the strongest effect with viral vector replacement therapy and antisense oligonucleotide therapy. Secondary outcome measures of body weight and spinal motor neuron counts were also positively associated with early treatment. Earlier delivery of survival motor neuron replacement therapies is therefore a key determinant of treatment efficacy in spinal muscular atrophy.

Glutathione hybrid poly (beta-amino ester)-plasmid nanoparticles for enhancing gene delivery and biosafety

IntroductionCRISPR/Cas9 gene editing technology has significantly advanced gene therapy, with gene vectors being one of the key factors for its success. Poly (beta-amino ester) (PBAE), a distinguished non-viral cationic gene vector, is known to elevate intracellular reactive oxygen species (ROS) levels, which may cause cytotoxicity and, consequently, impact gene transfection efficacy (T.E.). ObjectivesTo develop a simple but efficient strategy to improve the gene delivery ability and biosafety of PBAE both in vivo and in vitro. MethodsWe used glutathione (GSH), a clinically utilized drug with capability to modulating intracellular ROS level, to prepare a hybrid system with PBAE-plasmid nanoparticles (NPs). This system was characterized by flow cytometry, RNA-seq, Polymerase Chain Reaction (PCR) and Sanger sequencing in vitro, and its safety and efficacy in vivo was evaluated by imaging, PCR, Sanger sequencing and histology analysis. ResultsThe particle size of GSH-PBAE-plasmid NPs were 168.31 nm with a ζ-potential of 15.21 mV. An enhancement in T.E. and gene editing efficiency, ranging from 10 % to 100 %, was observed compared to GSH-free PBAE-plasmid NPs in various cell lines. In vitro results proved that GSH-PBAE-plasmid NPs reduced intracellular ROS levels by 25 %–40 %, decreased the total number of upregulated/downregulated genes from 4,952 to 789, and significantly avoided the disturbance in gene expression related to cellular oxidative stress-response and cell growth regulation signaling pathway compared to PBAE-plasmid NPs. They also demonstrated lower impact on the cell cycle, slighter hemolysis, and higher cell viability after gene transfection. Furthermore, GSH hybrid PBAE-plasmid NPs exhibited superior safety and improved tumor suppression ability in an Epstein–Barr virus (EBV)-infected murine tumor model, via targeting cleavage the EBV related oncogene by delivering CRISPR/Cas9 gene editing system and down-regulating the expression levels. This simple but effective strategy is expected to promote clinical applications of non-viral vector gene delivery.

Transforming Cell-Drug Interaction through Granular Hydrogel-Mediated Delivery of Polyplex Nanoparticles for Enhanced Safety and Extended Efficacy in Gene Therapy.

The utilization of hydrogels for DNA/cationic polymer polyplex nanoparticle (polyplex) delivery has significantly advanced gene therapy in tissue regeneration and cancer treatment. However, persistent challenges related to the efficacy and safety of encapsulated polyplexes, stemming from issues such as aggregation, degradation, or difficulties in controlled release during or postintegration with hydrogel scaffolds, necessitate further exploration. Here, we introduce an injectable gene therapy gel achieved by incorporating concentrated polyplexes onto densely packed hydrogel microparticles (HMPs). Polyplexes, when uniformly adhered to the gene therapy gel through reversible electrostatic interactions, can detach from the HMP surface in a controlled manner, contrasting with free polyplexes, and thereby reducing dose-dependent toxicity during transfection. Additionally, the integration of RGD cell adhesion peptides enhances the scaffolding characteristics of the gel, facilitating cell adhesion, migration, and further minimizing toxicity during gene drug administration. Notably, despite the overall transfection efficiency showing average performance, utilizing confocal microscopy to meticulously observe and analyze the cellular states infiltrating into various depths of the gene therapy gel resulted in the groundbreaking discovery of significantly enhanced local transfection efficiency, with primary cell transfection approaching 80%. This phenomenon could be potentially attributed to the granular hydrogel-mediated delivery of polyplex nanoparticles, which revolutionizes the spatial and temporal distribution and thus the "encounter" mode between polyplexes and cells. Moreover, the gene therapy gel's intrinsic injectability and self-healing properties offer ease of administration, making it a highly promising candidate as a novel gene transfection gel dressing with significant potential across various fields, including regenerative medicine and innovative living materials.

Gene therapy advancements for the treatment of acquired and hereditary hearing loss

Greater understanding of the molecular intricacies of acquired and hereditary hearing loss has spurred considerable advances in inner ear gene therapy. While approaches like cochlear amplification and cochlear implantation offer varying degrees of efficacy in restoring hearing function, there is an absence of FDA-approved pharmacotherapies targeting the underlying causes of hearing loss. Recent preclinical investigations have demonstrated promising outcomes in murine and non-human primate models, demonstrating efficient transduction and hearing recovery for both acquired and hereditary forms of hearing loss. This review provides a comprehensive analysis of the latest developments in gene therapy for hearing loss. Specifically, we focus on conditions characterized by sensory epithelium and spiral ganglion neuron dysfunction, encompassing both hereditary and acquired etiologies. We discuss recent preclinical advancements in cell-type-specific transduction strategies and highlight key findings from clinical trials exploring gene therapy interventions for hearing loss. Additionally, we address current limitations and offer insights into future directions for advancing gene therapy as a viable treatment option for individuals with hearing loss.