RARE DISEASE
Usher syndrome type 1
Usher syndrome type 1
Usher syndrome type 1
Synonyms: USH1
Synonyms: USH1
Synonyms: USH1
Drug discovery
2
drugs
With orphan designations
Overview
Usher Syndrome Type 1 (USH1) is an autosomal recessive disorder characterized by congenital profound sensorineural hearing loss, prepubertal-onset retinitis pigmentosa (RP), and vestibular areflexia. Balance issues delay motor milestones (e.g., walking after 18 months), while RP progresses from night blindness to legal blindness by mid-adulthood. Early cochlear implantation improves auditory outcomes, but no treatments prevent RP progression [1][3][6][10].
Categories: rare developmental anomalies during embryogenesis, rare genetic diseases, rare ophthalmic disorders, rare otorhinolaryngological diseases
Research Papers
141 drug discovery papers about Usher syndrome type 1, with 3 first-in-class and 2 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
141 drug discovery papers about Usher syndrome type 1, with 3 first-in-class and 2 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
gene therapies
2025-11-26 | Clinical Findings and Molecular Genetics of USH1C-Associated Usher Syndrome.
Expanding insight into the phenotypic spectrum, social burden of dual sensory impairment, and progression of USH1C-associated retinopathy is essential to inform prognosis and guide emerging therapies. To characterize some genetic variants, clinical features, natural history, and social outcomes of USH1C-associated retinopathy in a patient cohort. This was a retrospective case series including patients with molecularly confirmed UCH1C-associated retinopathy evaluated at a tertiary referral center from January 1989 to February 2024. Molecularly confirmed pathogenic variants in USH1C. Main outcomes included best-corrected visual acuity (BCVA) measured with the Snellen chart, retinal imaging features, genetic variants, and patient-reported social outcomes. Depression was documented by general practitioners using the Patient Health Questionnaire 9. Unemployment was self-reported at last follow-up. Retinitis pigmentosa diagnosis (RP) was diagnosed based on characteristic retinal findings and visual field loss. A total of 28 patients (mean [SD] age, 27.0 [12.2] years; range, 7-58 years; 15 female [53.6%]) were included in this analysis. Two novel pathogenic USH1C variants were identified; 18 patients were homozygous. Presenting symptoms included nyctalopia (24 of 26 patients [92.3%]) and peripheral vision difficulties (23 of 28 patients [82.1%]). Baseline BCVA (Snellen chart) in the better-seeing eye (n = 25) was 0.22 logMAR (20/32). Among 15 patients with follow-up of 5 years or more, baseline BCVA was 0.30 logMAR (20/40), declining to 0.59 logMAR (20/80). In Early Treatment Diabetic Retinopathy Study (ETDRS) equivalents (n = 15), decline averaged 0.53 letters per year (median, 0; range, 0-2). Four of 24 patients (16.7%) met World Health Organization criteria for severe sight impairment (20/200 or worse in the better-seeing eye). Depression was reported by 5 of 13 patients (38.5%) and unemployment by 7 of 23 patients (30.4%). Optical coherence tomography revealed cystoid macular edema in 5 of 21 patients at baseline, persisting in 2 patients at follow-up. Mean (SD) central subfield thickness was 260.6 (53.6) µm at baseline (n = 18) and 259.4 (44.5) µm at follow-up (n = 15). Patients with missense variants c.308G>A (p.Arg103His) and c.440A>G (p.His147Arg) showed retinitis pigmentosa sparing the superior retina. Results of this case series study suggest that USH1C-associated retinopathy was characterized by slow decline of visual acuity and modest ellipsoid zone loss over decades. Depression and unemployment were also observed, with implications for prognosis and counseling. Early onset and slow progression highlight its potential as a target for emerging therapies.
2025-10-08 | Identification of a variant in the USH1G gene in a family with Usher syndrome.
Usher syndrome is characterized by congenital sensorineural hearing loss, retinitis pigmentosa, and vestibular dysfunction. It is the most common cause of deafblindness worldwide. It is classified into three clinical types and twelve genetic subtypes. We report a case of a family affected by Usher syndrome due to a variant in the USH1G gene, coding for the SANS protein. The ocular and auditory tests were performed for clinical confirmation of the diagnosis. The molecular study consisted of a next-generation sequencing panel containing 14 genes associated with Usher syndrome: MYO7A, USHC1, CDH23, PCDH15, USHG1, CIB2, USH2A, ADGRV1, WHRN, CLRN1, HARS, PDZD7, CEP250, C2orf71. We present the case of a 13-year-old girl from a consanguineous Colombian family diagnosed with Usher syndrome type 1G. Clinical evaluations confirmed auditory, vestibular, and ocular alterations. Molecular analysis identified the homozygous p.Glu171Ter variant in the USH1G gene. We highlight the importance of an early diagnosis of Usher syndrome. Although the variant frequency in the USH1G gene is low, it should not be underestimated; the exact etiology must be identified in these families. We recommend establishing a panel with Colombianspecific variants to perform more accurate Usher syndrome diagnoses, and in the future, to guide the development of gene therapies.
2025-09-28 | Adeno-associated virus-based rescue of Myo7a expression restores hair-cell function and improves hearing thresholds in a USH1B mouse strain.
Mutations in MYO7A, the gene encoding the unconventional myosin 7a, cause hereditary deafness in mice and humans. In the cochlea, MYO7A is present in the sensory hair cells from embryonic stages of development, and plays a critical role in the development and maintenance of the mechanosensitive hair bundles composed of actin-rich stereocilia. Shaker-1 mutant mice (Myo7aSh1/Sh1), the murine model of Usher 1B syndrome, exhibit a progressive loss of the stereocilia, subsequent degeneration of the sensory epithelium and ultimately profound deafness. In addition to the hair bundle defects, we found that the shaker-1 mutation prevented both inner hair cells (IHCs) and outer hair cells (OHCs) from acquiring their fully mature basolateral current profile. Delivering exogenous Myo7a to newborn Myo7aSh1/Sh1 mice using dual-adeno-associated virus 8 (AAV8)-Myo7a or dual-AAV9-PhP.eB-Myo7a, which primarily target IHCs, led to a substantial rescue of their hair bundle structure. The rescued bundles regained their ability to generate mechanoelectrical transducer (MET) currents in response to fluid jet displacement. Although the average MET current was smaller than in control IHCs, the normal resting open probability of the MET channel was fully restored. The IHCs of the treated cochlea also regained a mature basolateral membrane current profile. Functionally, rescue of the IHC structure and function, but not that of OHCs, leads to an average improvement of 20-30 dB in hearing thresholds across most frequencies. These results support dual AAV-induced gene replacement therapy as an effective strategy to recover hair-cell function in Myo7aSh1/Sh1 mice. KEY POINTS: Shaker-1 mutant mice (Myo7aSh1/Sh1), which carry a mutation in the unconventional myosin MYO7A and are the murine model of Usher 1B syndrome, become profoundly deaf at 1 month of age or soon after. In the mammalian cochlea, MYO7A is expressed in the hair cells, including within their actin-rich stereociliary bundles. We show that hair cells of Myo7aSh1/Sh1 mice progressively lose their transducing stereocilia and mechanoelectrical transduction, and fail to acquire their fully mature basolateral current profile. Delivering exogenous Myo7a to newborn Myo7aSh1/Sh1 mice using dual-adeno-associated virus (AAVs) led to a substantial rescue of the bundle structure and function of inner hair cells, including mechanoelectrical transduction. This functional rescue led to a 20-30 dB improvement in hearing thresholds across most frequencies. These results support dual AAV-induced gene replacement therapy as an effective strategy to recover the hair-cell function in Myo7aSh1/Sh1 mice.
2025-07-14 | Pediatric Usher Syndrome Type 2A with Coexisting Rheumatic Heart Disease and Upper Gastro-Intestinal Bleed: A Case Report.
Usher syndrome is a rare autosomal recessive disorder characterized by progressive sensorineural hearing loss and retinitis pigmentosa, typically present from birth and later symptoms, including loss of night vision and peripheral vision slowly progressing to blindness. The condition exhibits clinical and genetic diversity and currently lacks the definitive treatment. This report presents a case of a ten-year-old female diagnosed with Usher syndrome type IIA via whole exome sequencing. The delayed onset of visual symptoms often leads to a misdiagnosis to isolated deafness in early years. The early identification allows for better prognosis through surveillance and intervention in hearing and visual impairments. If usher patients can receive a timely diagnosis, genetic molecular therapies may help preserve the photoreceptors, subsequently development of blindness could be delayed or possibly be prevented.
2025-05-29 | Usher syndrome 1C (autosomal recessive, severe) / USH1 protein network component harmonin (USH1C) : Machine learning discoveries of 2nd order synergy in Meningiomas
Background : USH1C encodes harmonin, a protein that in humans, that is expressed in sensory cells of the inner ear and retina. Mutations at the USH1C locus are known to cause Usher syndrome type 1c and nonsyndromic sensorineural deafness. It is not known whether USH1C plays any role in memnigiomas, however Patel et al. [1] record upregulation of USH1C in meningiomas. Meningiomas are the most common intracra- nial primary neoplasm in adults. Patel et al. [1] analyzed 160 tumors from all 3 World Health Organization (WHO) grades (I through III) using clinical, gene expression, and sequencing data and using unsupervised clustering analysis identified 3 molecular types (A, B, and C) that reliably predicted recurrence. Further, these groups did not directly correlate with the WHO grading system, which classifies more than half of the tumors in the most aggressive molecular type as benign. Issue : Increasing evidence point to the fact that meningioma classification and grading, that is based on histopathology does not always accurately predict tumor aggressiveness and recur- rence behaviour and knowledge of the underlying biology of the treatment resistant meningiomas and the impact of genetic alterations in these tumors, is lacking. At the current stage more genomic studies are required to unravel the role of other genes and their interations with other genetic factors. Resolution : In a recently published work Sinha [2], a frame work of a search engine was developed which can rank combinations of factors (genes/proteins) in a signaling pathway. Adapting this search engine to the Meningioma dataset, i present here 2nd order combinations of USH1C, some of which have been known to exist via wet lab experiments, but many are yet to be tested. The reveals combinations might help oncologists/biologists test possible hypotheses that might be the causing factors in meningioma. Further, in my limited grasp, if proven true, the combinations revealed by the search engine might pave way for development of gene based therapies aimed at resolving pathological issues related to meningiomas.
proteins
2025-04-03 | Tonotopic Specialization of MYO7A Isoforms in Auditory Hair Cells
1. Mutations in Myo7a cause Usher syndrome type 1B and non-syndromic deafness, but the precise function of MYO7A in sensory hair cells remains unclear. We identify and characterize a novel isoform, MYO7A-N, expressed in auditory hair cells alongside the canonical MYO7A-C. Isoform-specific knock-in mice reveal that inner hair cells primarily express MYO7A-C, while outer hair cells express both isoforms in opposing tonotopic gradients. Both localize to the upper tip-link insertion site, consistent with a role in the tip link for mechanotransduction. Loss of MYO7A-N leads to outer hair cell degeneration and progressive hearing loss. Cryo-EM structures reveal isoform-specific differences at actomyosin interfaces, correlating with distinct ATPase activities. These findings reveal an unexpected layer of molecular diversity within the mechanotransduction machinery. We propose that MYO7A isoform specialization enables fine-tuning of tip-link tension, thus hearing sensitivity, and contributes to the frequency-resolving power of the cochlea.
2023-04-20 | Three-Dimensional Structure of Inner Ear Hair Cell Ribbon Synapses in a Zebrafish Model of Usher Syndrome Type 1B.
Our understanding of inner ear hair cell ultrastructure has heretofore relied upon two-dimensional imaging; however, serial block-face scanning electron microscopy (SBFSEM) changes this paradigm allowing for three-dimensional evaluation. We compared inner ear hair cells of the apical cristae in myo7aa-/- null zebrafish, a model of human Usher Syndrome type 1B, to hair cells in wild-type zebrafish by SBFSEM to investigate possible ribbon synapse ultrastructural differences. Previously, it has been shown that compared to wild type, myo7aa-/- zebrafish neuromast hair cells have fewer ribbon synapses yet similar ribbon areas. We expect the recapitulation of these results within the inner ear apical crista hair cells furthering the knowledge of three-dimensional ribbon synapse structure while resolving the feasibility of therapeutically targeting myo7aa-/- mutant ribbons. In this report, we evaluated ribbon synapse number, volume, surface area, and sphericity. Localization of ribbons and their distance from the nearest innervation were also evaluated. We determined that myo7aa-/- mutant ribbon synapses are smaller in volume and surface area; however, all other measurements were not significantly different from wild-type zebrafish. Because the ribbon synapses are nearly indistinguishable between the myo7aa-/- mutant and wild type, it suggests that the ribbons are structurally receptive, supporting that therapeutic intervention may be feasible.
2015-09-29 | Structure and Regulation of the Movement of Human Myosin VIIA.
Human myosin VIIA (HM7A) is responsible for human Usher syndrome type 1B, which causes hearing and visual loss in humans. Here we studied the regulation of HM7A. The actin-activated ATPase activity of full-length HM7A (HM7AFull) was lower than that of tail-truncated HM7A (HM7AΔTail). Deletion of the C-terminal 40 amino acids and mutation of the basic residues in this region (R2176A or K2179A) abolished the inhibition. Electron microscopy revealed that HM7AFull is a monomer in which the tail domain bends back toward the head-neck domain to form a compact structure. This compact structure is extended at high ionic strength or in the presence of Ca(2+). Although myosin VIIA has five isoleucine-glutamine (IQ) motifs, the neck length seems to be shorter than the expected length of five bound calmodulins. Supporting this observation, the IQ domain bound only three calmodulins in Ca(2+), and the first IQ motif failed to bind calmodulin in EGTA. These results suggest that the unique IQ domain of HM7A is important for the tail-neck interaction and, therefore, regulation. Cellular studies revealed that dimer formation of HM7A is critical for its translocation to filopodial tips and that the tail domain (HM7ATail) markedly reduced the filopodial tip localization of the HM7AΔTail dimer, suggesting that the tail-inhibition mechanism is operating in vivo. The translocation of the HM7AFull dimer was significantly less than that of the HM7AΔTail dimer, and R2176A/R2179A mutation rescued the filopodial tip translocation. These results suggest that HM7A can transport its cargo molecules, such as USH1 proteins, upon release of the tail-dependent inhibition.
2015-01-19 | A genomic region encompassing a newly identified exon provides enhancing activity sufficient for normal myo7aa expression in zebrafish sensory hair cells
MYO7A is an unconventional myosin involved in the structural organization of hair bundles at the apex of sensory hair cells (SHCs) where it serves mechanotransduction in the process of hearing and balance. Mutations of MYO7A are responsible for abnormal shaping of hair bundles, resulting in human deafness and murine deafness/circling behavior. Myo7aa, expressed in SHCs of the inner ear and lateral line of zebrafish, causes circling behavior and abnormal hair cell function when deficient in mariner mutant. This work identifies a new hair cell-specific enhancer, highly conserved between species, located within Intron 2-3 of zebrafish myosin 7a (myo7aa) gene. This enhancer is contained within a 761-bp DNA fragment that encompasses a newly identified Exon of myo7aa and whose activity does not depend on orientation. Compensation of mariner mutation by expression of mCherry-Myo7aa fusion protein under the control of this 761-bp DNA fragment results in recovery of balance, normal hair bundle shape and restored hair cell function. Two smaller adjacent fragments (344-bp and 431-bp), extracted from the 761-bp fragment, both show hair cell-specific enhancing activity, with apparently reduced intensity and coverage. These data should help understand the role of Myo7aa in sensory hair cell differentiation and function. They provide tools to decipher how myo7aa gene is expressed and regulated in SHCs by allowing the identification of potential transcription factors involved in this process. The discovered enhancer could represent a new target for the identification of deafness-causing mutations affecting human MYO7A.
2014-01-28 | Harmonin enhances voltage-dependent facilitation of Cav1.3 channels and synchronous exocytosis in mouse inner hair cells.
Cav1.3 channels mediate Ca(2+) influx that triggers exocytosis of glutamate at cochlear inner hair cell (IHC) synapses. Harmonin is a PDZ-domain-containing protein that interacts with the C-terminus of the Cav1.3 α1 subunit (α11.3) and controls cell surface Cav1.3 levels by promoting ubiquitin-dependent proteosomal degradation. However, PDZ-domain-containing proteins have diverse functions and regulate other Cav1.3 properties, which could collectively influence presynaptic transmitter release. Here, we report that harmonin binding to the α11.3 distal C-terminus (dCT) enhances voltage-dependent facilitation (VDF) of Cav1.3 currents both in transfected HEK293T cells and in mouse inner hair cells. In HEK293T cells, this effect of harmonin was greater for Cav1.3 channels containing the auxiliary Cav β1 than with the β2 auxiliary subunit. Cav1.3 channels lacking the α11.3 dCT were insensitive to harmonin modulation. Moreover, the 'deaf-circler' dfcr mutant form of harmonin, which does not interact with the α11.3 dCT, did not promote VDF. In mature IHCs from mice expressing the dfcr harmonin mutant, Cav1.3 VDF was less than in control IHCs. This difference was not observed between control and dfcr IHCs prior to hearing onset. Membrane capacitance recordings from dfcr IHCs revealed a role for harmonin in synchronous exocytosis and in increasing the efficiency of Ca(2+) influx for triggering exocytosis. Collectively, our results indicate a multifaceted presynaptic role of harmonin in IHCs in regulating Cav1.3 Ca(2+) channels and exocytosis.
small molecules
2026-02-12 | Myosin 7a is required for maintaining the transducing stereocilia and for force transmission to the MET channel during cochlear hair cell development
Abstract Shaker‐1 mice carry a spontaneous missense mutation in Myo7a ( Myo7a Sh1 ) that interferes with the motor function of MYO7A. Mutation in the orthologous gene in humans causes syndromic (Usher 1B) or non‐syndromic forms of deafness. In hair cells, MYO7A is expressed throughout the stereocilia, where it has been implicated in tip‐link tensioning required for gating the mechanoelectrical transducer (MET) channel and setting its resting open probability ( P o ). The Myo7a Sh1 mutation progressively dysregulated the height of shorter stereocilia rows from the end of the first postnatal week onwards, associated with reduced MET current amplitude and hearing loss. Noise exposure exacerbated stereocilia dysfunction in Myo7a Sh1/Sh1 mice. Following the onset of maturation, hair cells from Myo7a Sh1/Sh1 mice showed normal resting P o and calcium sensitivity of the MET channel. In immature Myo7a Sh1/Sh1 hair cells, the resting P o was very small or absent in comparison to control cells, but it was restored by changing the membrane lipid bilayer fluidity or thickness by depleting cholesterol or PIP 2 . Bundle stiffness in immature IHCs was not affected by the absence of functional MYO7A but decreased after their onset of maturation in both genotypes. Expression of a subset of genes was affected similarly in immature Myo7a Sh1/Sh1 mice and in adult Myo7a conditional knockout mice, indicating a common response pathway in Myo7a ‐deficient mice. This study reveals that MET channel gating might differ depending on hair cell developmental stage, and MYO7A is likely to influence, albeit indirectly, force transmission via the lipid bilayer to the MET channel and maintenance of the shorter rows of transducing stereocilia. image Key points Shaker‐1 mice carry a spontaneous missense mutation in the shaker‐1 gene ( Myo7a Sh1 ) that interferes with the motor function of MYO7A, a protein expressed in hair‐cell stereocilia. The absence of functional MYO7A ( Myo7a Sh1/Sh1 mice) caused a progressive dysregulation in the height of the shortest two rows of stereocilia and the consequent loss of mechanoelectrical transduction (MET) current. Although immature hair cells from Myo7a Sh1/Sh1 mice exhibited a markedly reduced resting open probability of their MET channels, this was restored upon maturation or following depletion of cholesterol or PIP 2 from the lipid bilayer. Hair‐bundle stiffness was affected in immature inner hair cells from Myo7a Sh1/Sh1 mice, suggesting that MYO7A is not required for establishing the resting tension of the tip links gating the MET channels. We conclude that MYO7A is crucial for the structural integrity of the MET complex and transport of key proteins required to transfer forces efficiently from the lipid bilayer to the MET channel.
2025-06-03 | Lost in communication: How Müller glia cells fail to maintain retinal integrity in USH1C retinal organoids
Abstract Usher syndrome type 1, caused by pathogenic variants in the USH1C gene, leads to congenital deafness and progressive retinal degeneration resulting in vision loss. While auditory deficits can be compensated by cochlea implants and hearing aids, no treatment exists to prevent retinal degeneration. Here, we generated retinal organoids from induced pluripotent stem cells of two USH1C patients to elucidate the cellular and molecular mechanisms driving ocular pathogenesis. Single-cell RNA sequencing of both healthy and USH1C retinal organoids identified differential expression of genes related to phototransduction in photoreceptors, as well as alterations in cell adhesion and canonical Wnt signaling in Müller glia cells. Analysis of intercellular communication revealed an overall reduced signaling efficiency, particularly affecting Müller glia-mediated retinal adhesion processes. Morphological characterization of organoids confirmed transcriptome changes by showing degeneration of the outer limiting membrane and loss of adherens junction architecture. Moreover, photoreceptors revealed increased susceptibility to morphological and functional changes related to phototransduction. These results demonstrate that disruption of Müller glia signaling contributes to a loss of retinal integrity, providing novel insights into USH1C pathogenesis and offering targets for therapeutic interventions.
2025-02-11 | Identification of Unexpected Pathomechanisms Underlying the Human Usher Syndrome.
Human Usher syndrome (USH) is the most common form of hereditary deaf-blindness, characterized by inner ear defects and late-onset vision loss. USH is a complex genetic disorder, clinically and genetically heterogeneous. To date, there is no treatment for the ocular phenotype of any USH subtype, as the underlying pathomechanisms of the disease in the eye are far from being understood. We aim to elucidate the function of USH proteins to gain insight into the pathomechanisms leading to the retinal phenotype in USH. Here, we focus on the USH1 proteins SANS (USH1G) and harmonin (USH1C), and the USH2C protein ADGRV1. Results from affinity capture approaches revealed putative interacting proteins to these USH proteins, indicative of diverse various unexpected molecular pathways and modules. Functional studies in both cellular and animal models confirmed the roles of SANS in the pre-mRNA splicing of other retinal genes, especially USH genes and harmonin as a suppressor of the canonical Wnt signaling. Additionally, ADGRV1 showed characteristics of a metabotropic mechanoreceptor regulating cell adhesions, Ca2+ homeostasis of the cell, and autophagy. The dysfunction of these pathways and processes may contribute to the development of USH and are novel potential targets for future therapies.
2024-07-15 | Zebrafish myo7aa affects congenital hearing by regulating Rho-GTPase signaling
Introduction myo7aa , the homolog of the human Usher 1B syndrome pathogenic gene, myo7A , plays an important role in stereociliary development and maintenance, therefore, is critical for hearing and balance. However, the molecular mechanisms that myo7aa regulate hearing and balance still need to be studied. Methods In this study, we generated two independent zebrafish myo7aa knockout lines using CRISPR/Cas9 technology. To investigate the effects of myo7aa on hearing, YO-PRO-1 staining and startle response assay were used. To gain insight into the specific molecular mechanisms by which myo7aa affects hearing, transcriptome sequencing and bioinformatics analysis were employed. Results Our study showed that hair cells of myo7aa -/- zebrafish can not take up YO-PRO-1 fluorescent dye and are insensitive to acoustic stimulation in myo7aa -/- zebrafish compared to wild type. Genes related to the Rho GTPase signaling pathway, such as arhgap33, dab2ip, and arghef40, are significantly down-regulated in myo7aa -/- zebrafish embryos at 3 dpf. GTP and ATP compensation can partially rescue the hair cell defects in myo7aa knockout zebrafish. Discussion Our findings suggest that zebrafish myo7aa affects congenital hearing by regulating Rho GTPase signaling, and loss of myo7aa leads to abnormal Rho GTPase signaling and impairs hair cell function. myo7aa , myo7A , arhgap33, dab2ip, arghef40 and myo7aa -/- fonts in the abstract are italicized. -/- is a superscript format.
2023-12-30 | Hexafluoro slows retinal degeneration and improves visual function in zebrafish models of Usher syndrome 1F
ABSTRACT Usher syndrome is the leading genetic cause of deafblindness, affecting hundreds of thousands of people worldwide. The deafness can be addressed with hearing aids or cochlear implants, but there is currently no treatment for the vision loss, which is due to progressive degeneration of retinal photoreceptors. Studies in animal models of Usher syndrome have shown that photoreceptor degeneration is exacerbated by exposure to bright light, and other studies have shown that light-induced photostress reduces mitochondrial function. We previously synthesized hexafluoro and showed that it is a potent Sirt3 activator that promotes mitochondrial respiration. Here we examined the efficacy of hexafluoro as a potential therapeutic for treatment of vison loss in a zebrafish model of Usher syndrome type 1F, which exhibits early and severe vision defects along with vestibular dysfunction as seen in Usher type 1 pathology. We find that hexafluoro improves visual function, reduces photoreceptor degeneration, and protects the retina against exposure to bright light in this USH1F model.
oligonucleotides
2026-04-28 | Expanding the options for therapeutic exon skipping as a future treatment for USH2A -associated disease by 3D structural modeling of newly formed hybrid domains
ABSTRACT Usher syndrome, the leading cause of hereditary deaf-blindness affecting approximately 1 in 15,000 individuals worldwide, is currently still untreatable. Antisense oligonucleotide-based exon skipping has shown significant therapeutic promise for USH2A -associated retinal dysfunction. Selection of (combinations of) exons suitable for therapeutic exon skipping within the fibronectin type 3 (FN3) domain-encoding region of USH2A currently requires that skipped exons exactly align with complete protein domains. However, only few exon combinations meet this criterion, which significantly restricts the therapeutic potential of this strategy. Our study addresses this limitation by incorporating AlphaFold2 structural modelling into the exon skipping target selection pipeline. Following this adjusted framework, we can predict exon skipping combinations that allow remaining domain fragments to form structurally viable hybrid domains. As a proof-of-concept, we examined and confirmed the functionality of usherinΔexon54-58 that contains a hybrid FN3 domain, using zebrafish as a model. This highligts the potential of the newly developed paradigm for identifying exon skipping targets with potential therapeutic relevance. Our results emphasize the value of structural modeling in identifying new therapeutic exon skipping targets, aiming to improve precision, efficiency, applicability, and cost-effectiveness in the development of genetic therapies for hereditary diseases such as Usher syndrome.
2025-09-25 | AAV-mediated exon skipping therapy for Usher syndrome, type 2A.
Usher syndrome can cause loss of vision, hearing, and balance. There are four clinical subtypes, USH1-4, which are associated with mutations in genes important for structure, function, and survival of photoreceptor cells in the retina and sensory hair cells in the inner ear. Genetic mutations in the USH2A gene, which encodes usherin protein, are the most common cause of Usher syndrome worldwide, with c.2299delG (p.Glu767Serfs∗21) being the most frequent pathogenic variant. An investigational antisense oligonucleotide (ASO) for USH2A c.2299delG, QR-421a, designed to bypass the mutation, has already shown promise in phase 1/2 clinical trials. While recently developed chemistry provides longer ASO half-lives, repeated injection of ASOs may be required to provide long-term efficacy. To overcome this limitation, we screened novel USH2A exon 13 skippers and 20 AAV capsids with the goal of developing a vectorized ASO exon skipping strategy. Optimized vectors and skippers were evaluated in inner ear and retinal organoids derived from human stem cell lines bearing the USH2A c.2299delG mutation. The data revealed enhanced skipping of the pathogenic exon, offering an alternative strategy for treatment of USH2A patients using a single local injection which may prevent progression of vision and hearing loss.
2023-09-11 | Successful large gene augmentation of USH2A with non-viral episomal vectors.
USH2A mutations are a common cause of autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, for which there are currently no approved treatments. Gene augmentation is a valuable therapeutic strategy for treating many inherited retinal diseases; however, conventional adeno-associated virus (AAV) gene therapy cannot accommodate cDNAs exceeding 4.7 kb, such as the 15.6-kb-long USH2A coding sequence. In the present study, we adopted an alternative strategy to successfully generate scaffold/matrix attachment region (S/MAR) DNA plasmid vectors containing the full-length human USH2A coding sequence, a GFP reporter gene, and a ubiquitous promoter (CMV or CAG), reaching a size of approximately 23 kb. We assessed the vectors in transfected HEK293 cells and USH2A patient-derived dermal fibroblasts in addition to ush2au507 zebrafish microinjected with the vector at the one-cell stage. pS/MAR-USH2A vectors drove persistent transgene expression in patient fibroblasts with restoration of usherin. Twelve months of GFP expression was detected in the photoreceptor cells, with rescue of Usher 2 complex localization in the photoreceptors of ush2au507 zebrafish retinas injected with pS/MAR-USH2A. To our knowledge, this is the first reported vector that can be used to express full-length usherin with functional rescue. S/MAR DNA vectors have shown promise as a novel non-viral retinal gene therapy, warranting further translational development.
2023-03-30 | Natural Disease Course in Usher Syndrome Patients Harboring USH2A Variant p.Cys870* in Exon 13, Amenable to Exon Skipping Therapy.
The aim of the study was to determine the rate of retinal degeneration in patients with c.2610C>A (p.Cys870*) in USH2A exon 13, amenable to exon skipping therapy. There were nine patients from seven families, three of whom were male (two were homozygous). Seven patients had follow-up data (median of 11 years). Analysis included best corrected visual acuity (BCVA, decimal Snellen), visual field (Goldmann perimetry target II/4), fundus autofluorescence (FAF), optical coherence tomography (OCT), and microperimetry (MP). The median age at the onset of nyctalopia was 20 years (range, 8-35 years of age). At the first exam, at a median age of 42 years, the median BCVA was 0.5 (0.2-1.0), and the median visual field diameter was 23° (5°-114°). Imaging showed a hyperautofluorescent ring delineating preserved foveal photoreceptors in 78% (7/9) of patients, while 22% (2/9) had a hyperautofluorescent patch or atrophy, reflecting advanced disease. Survival analysis predicted that 50% of patients reach legal blindness based on a visual field diameter < 20° at the age of 52 (95% CI, 45-59) and legal blindness based on a BCVA ≤ 0. 1 (20/200) at the age of 55 (95% CI, 46-66). Visual field constriction occurred at the median rate of radial 1.5 deg/year, and hyperautofluorescent ring constriction occurred at the median rate of 34 μm/year. A non-null second allele was found in two patients: p.Thr4315Pro and p.Arg303His; the patient with p.Arg303His had a milder disease. The rates of progression will be useful in the design and execution of clinical trials.
2023-01-18 | Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction
A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.
other
2025-03-01 | Improvement of perceived cochlear implant sound quality through individualized psychoacoustic-based frequency fitting.
In recent years, there has been a trend toward more individualization in the fitting of cochlear implants (CI). Here, a new individualized approach to frequency band allocation was used. This approach is based on binaural perceptual pitch matching. The patient had congenital bilateral progressive sensorineural hearing loss due to Usher Syndrome. He had used hearing aids in both ears since the age of 4 years. In his mid-40s, he received a CI on his right ear and, ten months later, a second CI on the left ear. Adjustments to the frequency band allocations were made, guided by the binaural perceptual pitch matching of piano notes. For the first CI, pitch matching was performed using the contralateral ear as the reference, which had preserved low-frequency residual hearing (bimodal pitch matching). For the second CI, pitch matching was performed using the first implanted side as the reference (bilateral electrical pitch matching). The final frequency band allocation adjustments were always shifted toward lower frequencies relative to the default band allocations. The adjustments were larger in magnitude for the second CI compared to the first CI. Speech perception scores generally increased over the course of rehabilitation and were higher with the individualized fitting compared to the default fitting. The subjective sound quality was reportedly greatly improved with the individualized fitting. Individualized psychoacoustic frequency-based fitting can yield improvements in the perceived sound quality with a CI. However, this method requires significant residual hearing in at least one ear, and the patient must have relatively fine pitch discrimination abilities.
2024-07-11 | Long-Term Outcomes of Cochlear Implantation in Usher Syndrome.
Usher syndrome (USH), characterized by bilateral sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP), prompts increased reliance on hearing due to progressive visual deterioration. It can be categorized into three subtypes: USH type 1 (USH1), characterized by severe to profound congenital SNHL, childhood-onset RP, and vestibular areflexia; USH type 2 (USH2), presenting with moderate to severe progressive SNHL and RP onset in the second decade, with or without vestibular dysfunction; and USH type 3 (USH3), featuring variable progressive SNHL beginning in childhood, variable RP onset, and diverse vestibular function. Previous studies evaluating cochlear implant (CI) outcomes in individuals with USH used varying or short follow-up durations, while others did not evaluate outcomes for each subtype separately. This study evaluates long-term CI performance in subjects with USH, at both short-term and long-term, considering each subtype separately. This retrospective, observational cohort study identified 36 CI recipients (53 ears) who were categorized into four different groups: early-implanted USH1 (first CI at ≤7 years of age), late-implanted USH1 (first CI at ≥8 years of age), USH2 and USH3. Phoneme scores at 65 dB SPL with CI were evaluated at 1 year, ≥2 years (mid-term), and ≥5 years postimplantation (long-term). Each subtype was analyzed separately due to the significant variability in phenotype observed among the three subtypes. Early-implanted USH1-subjects (N = 23 ears) achieved excellent long-term phoneme scores (100% [interquartile ranges {IQR} = 95 to 100]), with younger age at implantation significantly correlating with better CI outcomes. Simultaneously implanted subjects had significantly better outcomes than sequentially implanted subjects ( p = 0.028). Late-implanted USH1 subjects (N = 3 ears) used CI solely for sound detection and showed a mean phoneme discrimination score of 12% (IQR = 0 to 12), while still expressing satisfaction with ambient sound detection. In the USH2 group (N = 23 ears), a long-term mean phoneme score of 85% (IQR = 81 to 95) was found. Better outcomes were associated with younger age at implantation and higher preimplantation speech perception scores. USH3-subjects (N = 7 ears) achieved a mean postimplantation phoneme score of 71% (IQR = 45 to 91). This study is currently one of the largest and most comprehensive studies evaluating CI outcomes in individuals with USH, demonstrating that overall, individuals with USH benefit from CI at both short- and long-term follow-up. Due to the considerable variability in phenotype observed among the three subtypes, each subtype was analyzed separately, resulting in smaller sample sizes. For USH1 subjects, optimal CI outcomes are expected with early simultaneous bilateral implantation. Late implantation in USH1 provides signaling function, but achieved speech recognition is insufficient for oral communication. In USH2 and USH3, favorable CI outcomes are expected, especially if individuals exhibit sufficient speech recognition with hearing aids and receive ample auditory stimulation preimplantation. Early implantation is recommended for USH2, given the progressive nature of hearing loss and concomitant severe visual impairment. In comparison with USH2, predicting outcomes in USH3 remains challenging due to the variability found. Counseling for USH2 and USH3 should highlight early implantation benefits and encourage hearing aid use.
2006-04-28 | Audiologic Performance and Benefit of Cochlear Implantation in Usher Syndrome Type I
Abstract Objective: The objective of this retrospective study was to evaluate the benefit and performance of cochlear implantation in patients with Usher syndrome type 1 (USH1). Methods: Fourteen patients with a clinical diagnosis of USH1 were included. Mutation analysis of USH1 genes was performed in all of them. All patients filled in the G(C)BI questionnaire, which measures the benefit of implantation. In addition, equivalent hearing level scores (EHL) were calculated to measure performance. Correlations between the mentioned parameters were studied. Results: One or two pathogenic mutations were identified in seven of the 14 examined patients. Similar to previous studies, it was demonstrated that implantation at an earlier age results in better performance than implantation at higher age. Cochlear implantation performed within the first 2 decades of life was beneficial to 13 of 14 (93%) of the patients with USH1. Finally, the EHL score and the G(C)BI score showed a significant correlation; the benefit of implantation increases with a decreasing EHL score. Conclusions: Cochlear implantation in patients with USH1 improves the audiologic performance when patients are implanted at an earlier age and is beneficial according to the G(C)BI when performed within the first 2 decades of life.
gene therapies
2025-11-26 | Clinical Findings and Molecular Genetics of USH1C-Associated Usher Syndrome.
Expanding insight into the phenotypic spectrum, social burden of dual sensory impairment, and progression of USH1C-associated retinopathy is essential to inform prognosis and guide emerging therapies. To characterize some genetic variants, clinical features, natural history, and social outcomes of USH1C-associated retinopathy in a patient cohort. This was a retrospective case series including patients with molecularly confirmed UCH1C-associated retinopathy evaluated at a tertiary referral center from January 1989 to February 2024. Molecularly confirmed pathogenic variants in USH1C. Main outcomes included best-corrected visual acuity (BCVA) measured with the Snellen chart, retinal imaging features, genetic variants, and patient-reported social outcomes. Depression was documented by general practitioners using the Patient Health Questionnaire 9. Unemployment was self-reported at last follow-up. Retinitis pigmentosa diagnosis (RP) was diagnosed based on characteristic retinal findings and visual field loss. A total of 28 patients (mean [SD] age, 27.0 [12.2] years; range, 7-58 years; 15 female [53.6%]) were included in this analysis. Two novel pathogenic USH1C variants were identified; 18 patients were homozygous. Presenting symptoms included nyctalopia (24 of 26 patients [92.3%]) and peripheral vision difficulties (23 of 28 patients [82.1%]). Baseline BCVA (Snellen chart) in the better-seeing eye (n = 25) was 0.22 logMAR (20/32). Among 15 patients with follow-up of 5 years or more, baseline BCVA was 0.30 logMAR (20/40), declining to 0.59 logMAR (20/80). In Early Treatment Diabetic Retinopathy Study (ETDRS) equivalents (n = 15), decline averaged 0.53 letters per year (median, 0; range, 0-2). Four of 24 patients (16.7%) met World Health Organization criteria for severe sight impairment (20/200 or worse in the better-seeing eye). Depression was reported by 5 of 13 patients (38.5%) and unemployment by 7 of 23 patients (30.4%). Optical coherence tomography revealed cystoid macular edema in 5 of 21 patients at baseline, persisting in 2 patients at follow-up. Mean (SD) central subfield thickness was 260.6 (53.6) µm at baseline (n = 18) and 259.4 (44.5) µm at follow-up (n = 15). Patients with missense variants c.308G>A (p.Arg103His) and c.440A>G (p.His147Arg) showed retinitis pigmentosa sparing the superior retina. Results of this case series study suggest that USH1C-associated retinopathy was characterized by slow decline of visual acuity and modest ellipsoid zone loss over decades. Depression and unemployment were also observed, with implications for prognosis and counseling. Early onset and slow progression highlight its potential as a target for emerging therapies.
2025-10-08 | Identification of a variant in the USH1G gene in a family with Usher syndrome.
Usher syndrome is characterized by congenital sensorineural hearing loss, retinitis pigmentosa, and vestibular dysfunction. It is the most common cause of deafblindness worldwide. It is classified into three clinical types and twelve genetic subtypes. We report a case of a family affected by Usher syndrome due to a variant in the USH1G gene, coding for the SANS protein. The ocular and auditory tests were performed for clinical confirmation of the diagnosis. The molecular study consisted of a next-generation sequencing panel containing 14 genes associated with Usher syndrome: MYO7A, USHC1, CDH23, PCDH15, USHG1, CIB2, USH2A, ADGRV1, WHRN, CLRN1, HARS, PDZD7, CEP250, C2orf71. We present the case of a 13-year-old girl from a consanguineous Colombian family diagnosed with Usher syndrome type 1G. Clinical evaluations confirmed auditory, vestibular, and ocular alterations. Molecular analysis identified the homozygous p.Glu171Ter variant in the USH1G gene. We highlight the importance of an early diagnosis of Usher syndrome. Although the variant frequency in the USH1G gene is low, it should not be underestimated; the exact etiology must be identified in these families. We recommend establishing a panel with Colombianspecific variants to perform more accurate Usher syndrome diagnoses, and in the future, to guide the development of gene therapies.
2025-09-28 | Adeno-associated virus-based rescue of Myo7a expression restores hair-cell function and improves hearing thresholds in a USH1B mouse strain.
Mutations in MYO7A, the gene encoding the unconventional myosin 7a, cause hereditary deafness in mice and humans. In the cochlea, MYO7A is present in the sensory hair cells from embryonic stages of development, and plays a critical role in the development and maintenance of the mechanosensitive hair bundles composed of actin-rich stereocilia. Shaker-1 mutant mice (Myo7aSh1/Sh1), the murine model of Usher 1B syndrome, exhibit a progressive loss of the stereocilia, subsequent degeneration of the sensory epithelium and ultimately profound deafness. In addition to the hair bundle defects, we found that the shaker-1 mutation prevented both inner hair cells (IHCs) and outer hair cells (OHCs) from acquiring their fully mature basolateral current profile. Delivering exogenous Myo7a to newborn Myo7aSh1/Sh1 mice using dual-adeno-associated virus 8 (AAV8)-Myo7a or dual-AAV9-PhP.eB-Myo7a, which primarily target IHCs, led to a substantial rescue of their hair bundle structure. The rescued bundles regained their ability to generate mechanoelectrical transducer (MET) currents in response to fluid jet displacement. Although the average MET current was smaller than in control IHCs, the normal resting open probability of the MET channel was fully restored. The IHCs of the treated cochlea also regained a mature basolateral membrane current profile. Functionally, rescue of the IHC structure and function, but not that of OHCs, leads to an average improvement of 20-30 dB in hearing thresholds across most frequencies. These results support dual AAV-induced gene replacement therapy as an effective strategy to recover hair-cell function in Myo7aSh1/Sh1 mice. KEY POINTS: Shaker-1 mutant mice (Myo7aSh1/Sh1), which carry a mutation in the unconventional myosin MYO7A and are the murine model of Usher 1B syndrome, become profoundly deaf at 1 month of age or soon after. In the mammalian cochlea, MYO7A is expressed in the hair cells, including within their actin-rich stereociliary bundles. We show that hair cells of Myo7aSh1/Sh1 mice progressively lose their transducing stereocilia and mechanoelectrical transduction, and fail to acquire their fully mature basolateral current profile. Delivering exogenous Myo7a to newborn Myo7aSh1/Sh1 mice using dual-adeno-associated virus (AAVs) led to a substantial rescue of the bundle structure and function of inner hair cells, including mechanoelectrical transduction. This functional rescue led to a 20-30 dB improvement in hearing thresholds across most frequencies. These results support dual AAV-induced gene replacement therapy as an effective strategy to recover the hair-cell function in Myo7aSh1/Sh1 mice.
2025-07-14 | Pediatric Usher Syndrome Type 2A with Coexisting Rheumatic Heart Disease and Upper Gastro-Intestinal Bleed: A Case Report.
Usher syndrome is a rare autosomal recessive disorder characterized by progressive sensorineural hearing loss and retinitis pigmentosa, typically present from birth and later symptoms, including loss of night vision and peripheral vision slowly progressing to blindness. The condition exhibits clinical and genetic diversity and currently lacks the definitive treatment. This report presents a case of a ten-year-old female diagnosed with Usher syndrome type IIA via whole exome sequencing. The delayed onset of visual symptoms often leads to a misdiagnosis to isolated deafness in early years. The early identification allows for better prognosis through surveillance and intervention in hearing and visual impairments. If usher patients can receive a timely diagnosis, genetic molecular therapies may help preserve the photoreceptors, subsequently development of blindness could be delayed or possibly be prevented.
2025-05-29 | Usher syndrome 1C (autosomal recessive, severe) / USH1 protein network component harmonin (USH1C) : Machine learning discoveries of 2nd order synergy in Meningiomas
Background : USH1C encodes harmonin, a protein that in humans, that is expressed in sensory cells of the inner ear and retina. Mutations at the USH1C locus are known to cause Usher syndrome type 1c and nonsyndromic sensorineural deafness. It is not known whether USH1C plays any role in memnigiomas, however Patel et al. [1] record upregulation of USH1C in meningiomas. Meningiomas are the most common intracra- nial primary neoplasm in adults. Patel et al. [1] analyzed 160 tumors from all 3 World Health Organization (WHO) grades (I through III) using clinical, gene expression, and sequencing data and using unsupervised clustering analysis identified 3 molecular types (A, B, and C) that reliably predicted recurrence. Further, these groups did not directly correlate with the WHO grading system, which classifies more than half of the tumors in the most aggressive molecular type as benign. Issue : Increasing evidence point to the fact that meningioma classification and grading, that is based on histopathology does not always accurately predict tumor aggressiveness and recur- rence behaviour and knowledge of the underlying biology of the treatment resistant meningiomas and the impact of genetic alterations in these tumors, is lacking. At the current stage more genomic studies are required to unravel the role of other genes and their interations with other genetic factors. Resolution : In a recently published work Sinha [2], a frame work of a search engine was developed which can rank combinations of factors (genes/proteins) in a signaling pathway. Adapting this search engine to the Meningioma dataset, i present here 2nd order combinations of USH1C, some of which have been known to exist via wet lab experiments, but many are yet to be tested. The reveals combinations might help oncologists/biologists test possible hypotheses that might be the causing factors in meningioma. Further, in my limited grasp, if proven true, the combinations revealed by the search engine might pave way for development of gene based therapies aimed at resolving pathological issues related to meningiomas.
proteins
2025-04-03 | Tonotopic Specialization of MYO7A Isoforms in Auditory Hair Cells
1. Mutations in Myo7a cause Usher syndrome type 1B and non-syndromic deafness, but the precise function of MYO7A in sensory hair cells remains unclear. We identify and characterize a novel isoform, MYO7A-N, expressed in auditory hair cells alongside the canonical MYO7A-C. Isoform-specific knock-in mice reveal that inner hair cells primarily express MYO7A-C, while outer hair cells express both isoforms in opposing tonotopic gradients. Both localize to the upper tip-link insertion site, consistent with a role in the tip link for mechanotransduction. Loss of MYO7A-N leads to outer hair cell degeneration and progressive hearing loss. Cryo-EM structures reveal isoform-specific differences at actomyosin interfaces, correlating with distinct ATPase activities. These findings reveal an unexpected layer of molecular diversity within the mechanotransduction machinery. We propose that MYO7A isoform specialization enables fine-tuning of tip-link tension, thus hearing sensitivity, and contributes to the frequency-resolving power of the cochlea.
2023-04-20 | Three-Dimensional Structure of Inner Ear Hair Cell Ribbon Synapses in a Zebrafish Model of Usher Syndrome Type 1B.
Our understanding of inner ear hair cell ultrastructure has heretofore relied upon two-dimensional imaging; however, serial block-face scanning electron microscopy (SBFSEM) changes this paradigm allowing for three-dimensional evaluation. We compared inner ear hair cells of the apical cristae in myo7aa-/- null zebrafish, a model of human Usher Syndrome type 1B, to hair cells in wild-type zebrafish by SBFSEM to investigate possible ribbon synapse ultrastructural differences. Previously, it has been shown that compared to wild type, myo7aa-/- zebrafish neuromast hair cells have fewer ribbon synapses yet similar ribbon areas. We expect the recapitulation of these results within the inner ear apical crista hair cells furthering the knowledge of three-dimensional ribbon synapse structure while resolving the feasibility of therapeutically targeting myo7aa-/- mutant ribbons. In this report, we evaluated ribbon synapse number, volume, surface area, and sphericity. Localization of ribbons and their distance from the nearest innervation were also evaluated. We determined that myo7aa-/- mutant ribbon synapses are smaller in volume and surface area; however, all other measurements were not significantly different from wild-type zebrafish. Because the ribbon synapses are nearly indistinguishable between the myo7aa-/- mutant and wild type, it suggests that the ribbons are structurally receptive, supporting that therapeutic intervention may be feasible.
2015-09-29 | Structure and Regulation of the Movement of Human Myosin VIIA.
Human myosin VIIA (HM7A) is responsible for human Usher syndrome type 1B, which causes hearing and visual loss in humans. Here we studied the regulation of HM7A. The actin-activated ATPase activity of full-length HM7A (HM7AFull) was lower than that of tail-truncated HM7A (HM7AΔTail). Deletion of the C-terminal 40 amino acids and mutation of the basic residues in this region (R2176A or K2179A) abolished the inhibition. Electron microscopy revealed that HM7AFull is a monomer in which the tail domain bends back toward the head-neck domain to form a compact structure. This compact structure is extended at high ionic strength or in the presence of Ca(2+). Although myosin VIIA has five isoleucine-glutamine (IQ) motifs, the neck length seems to be shorter than the expected length of five bound calmodulins. Supporting this observation, the IQ domain bound only three calmodulins in Ca(2+), and the first IQ motif failed to bind calmodulin in EGTA. These results suggest that the unique IQ domain of HM7A is important for the tail-neck interaction and, therefore, regulation. Cellular studies revealed that dimer formation of HM7A is critical for its translocation to filopodial tips and that the tail domain (HM7ATail) markedly reduced the filopodial tip localization of the HM7AΔTail dimer, suggesting that the tail-inhibition mechanism is operating in vivo. The translocation of the HM7AFull dimer was significantly less than that of the HM7AΔTail dimer, and R2176A/R2179A mutation rescued the filopodial tip translocation. These results suggest that HM7A can transport its cargo molecules, such as USH1 proteins, upon release of the tail-dependent inhibition.
2015-01-19 | A genomic region encompassing a newly identified exon provides enhancing activity sufficient for normal myo7aa expression in zebrafish sensory hair cells
MYO7A is an unconventional myosin involved in the structural organization of hair bundles at the apex of sensory hair cells (SHCs) where it serves mechanotransduction in the process of hearing and balance. Mutations of MYO7A are responsible for abnormal shaping of hair bundles, resulting in human deafness and murine deafness/circling behavior. Myo7aa, expressed in SHCs of the inner ear and lateral line of zebrafish, causes circling behavior and abnormal hair cell function when deficient in mariner mutant. This work identifies a new hair cell-specific enhancer, highly conserved between species, located within Intron 2-3 of zebrafish myosin 7a (myo7aa) gene. This enhancer is contained within a 761-bp DNA fragment that encompasses a newly identified Exon of myo7aa and whose activity does not depend on orientation. Compensation of mariner mutation by expression of mCherry-Myo7aa fusion protein under the control of this 761-bp DNA fragment results in recovery of balance, normal hair bundle shape and restored hair cell function. Two smaller adjacent fragments (344-bp and 431-bp), extracted from the 761-bp fragment, both show hair cell-specific enhancing activity, with apparently reduced intensity and coverage. These data should help understand the role of Myo7aa in sensory hair cell differentiation and function. They provide tools to decipher how myo7aa gene is expressed and regulated in SHCs by allowing the identification of potential transcription factors involved in this process. The discovered enhancer could represent a new target for the identification of deafness-causing mutations affecting human MYO7A.
2014-01-28 | Harmonin enhances voltage-dependent facilitation of Cav1.3 channels and synchronous exocytosis in mouse inner hair cells.
Cav1.3 channels mediate Ca(2+) influx that triggers exocytosis of glutamate at cochlear inner hair cell (IHC) synapses. Harmonin is a PDZ-domain-containing protein that interacts with the C-terminus of the Cav1.3 α1 subunit (α11.3) and controls cell surface Cav1.3 levels by promoting ubiquitin-dependent proteosomal degradation. However, PDZ-domain-containing proteins have diverse functions and regulate other Cav1.3 properties, which could collectively influence presynaptic transmitter release. Here, we report that harmonin binding to the α11.3 distal C-terminus (dCT) enhances voltage-dependent facilitation (VDF) of Cav1.3 currents both in transfected HEK293T cells and in mouse inner hair cells. In HEK293T cells, this effect of harmonin was greater for Cav1.3 channels containing the auxiliary Cav β1 than with the β2 auxiliary subunit. Cav1.3 channels lacking the α11.3 dCT were insensitive to harmonin modulation. Moreover, the 'deaf-circler' dfcr mutant form of harmonin, which does not interact with the α11.3 dCT, did not promote VDF. In mature IHCs from mice expressing the dfcr harmonin mutant, Cav1.3 VDF was less than in control IHCs. This difference was not observed between control and dfcr IHCs prior to hearing onset. Membrane capacitance recordings from dfcr IHCs revealed a role for harmonin in synchronous exocytosis and in increasing the efficiency of Ca(2+) influx for triggering exocytosis. Collectively, our results indicate a multifaceted presynaptic role of harmonin in IHCs in regulating Cav1.3 Ca(2+) channels and exocytosis.
small molecules
2026-02-12 | Myosin 7a is required for maintaining the transducing stereocilia and for force transmission to the MET channel during cochlear hair cell development
Abstract Shaker‐1 mice carry a spontaneous missense mutation in Myo7a ( Myo7a Sh1 ) that interferes with the motor function of MYO7A. Mutation in the orthologous gene in humans causes syndromic (Usher 1B) or non‐syndromic forms of deafness. In hair cells, MYO7A is expressed throughout the stereocilia, where it has been implicated in tip‐link tensioning required for gating the mechanoelectrical transducer (MET) channel and setting its resting open probability ( P o ). The Myo7a Sh1 mutation progressively dysregulated the height of shorter stereocilia rows from the end of the first postnatal week onwards, associated with reduced MET current amplitude and hearing loss. Noise exposure exacerbated stereocilia dysfunction in Myo7a Sh1/Sh1 mice. Following the onset of maturation, hair cells from Myo7a Sh1/Sh1 mice showed normal resting P o and calcium sensitivity of the MET channel. In immature Myo7a Sh1/Sh1 hair cells, the resting P o was very small or absent in comparison to control cells, but it was restored by changing the membrane lipid bilayer fluidity or thickness by depleting cholesterol or PIP 2 . Bundle stiffness in immature IHCs was not affected by the absence of functional MYO7A but decreased after their onset of maturation in both genotypes. Expression of a subset of genes was affected similarly in immature Myo7a Sh1/Sh1 mice and in adult Myo7a conditional knockout mice, indicating a common response pathway in Myo7a ‐deficient mice. This study reveals that MET channel gating might differ depending on hair cell developmental stage, and MYO7A is likely to influence, albeit indirectly, force transmission via the lipid bilayer to the MET channel and maintenance of the shorter rows of transducing stereocilia. image Key points Shaker‐1 mice carry a spontaneous missense mutation in the shaker‐1 gene ( Myo7a Sh1 ) that interferes with the motor function of MYO7A, a protein expressed in hair‐cell stereocilia. The absence of functional MYO7A ( Myo7a Sh1/Sh1 mice) caused a progressive dysregulation in the height of the shortest two rows of stereocilia and the consequent loss of mechanoelectrical transduction (MET) current. Although immature hair cells from Myo7a Sh1/Sh1 mice exhibited a markedly reduced resting open probability of their MET channels, this was restored upon maturation or following depletion of cholesterol or PIP 2 from the lipid bilayer. Hair‐bundle stiffness was affected in immature inner hair cells from Myo7a Sh1/Sh1 mice, suggesting that MYO7A is not required for establishing the resting tension of the tip links gating the MET channels. We conclude that MYO7A is crucial for the structural integrity of the MET complex and transport of key proteins required to transfer forces efficiently from the lipid bilayer to the MET channel.
2025-06-03 | Lost in communication: How Müller glia cells fail to maintain retinal integrity in USH1C retinal organoids
Abstract Usher syndrome type 1, caused by pathogenic variants in the USH1C gene, leads to congenital deafness and progressive retinal degeneration resulting in vision loss. While auditory deficits can be compensated by cochlea implants and hearing aids, no treatment exists to prevent retinal degeneration. Here, we generated retinal organoids from induced pluripotent stem cells of two USH1C patients to elucidate the cellular and molecular mechanisms driving ocular pathogenesis. Single-cell RNA sequencing of both healthy and USH1C retinal organoids identified differential expression of genes related to phototransduction in photoreceptors, as well as alterations in cell adhesion and canonical Wnt signaling in Müller glia cells. Analysis of intercellular communication revealed an overall reduced signaling efficiency, particularly affecting Müller glia-mediated retinal adhesion processes. Morphological characterization of organoids confirmed transcriptome changes by showing degeneration of the outer limiting membrane and loss of adherens junction architecture. Moreover, photoreceptors revealed increased susceptibility to morphological and functional changes related to phototransduction. These results demonstrate that disruption of Müller glia signaling contributes to a loss of retinal integrity, providing novel insights into USH1C pathogenesis and offering targets for therapeutic interventions.
2025-02-11 | Identification of Unexpected Pathomechanisms Underlying the Human Usher Syndrome.
Human Usher syndrome (USH) is the most common form of hereditary deaf-blindness, characterized by inner ear defects and late-onset vision loss. USH is a complex genetic disorder, clinically and genetically heterogeneous. To date, there is no treatment for the ocular phenotype of any USH subtype, as the underlying pathomechanisms of the disease in the eye are far from being understood. We aim to elucidate the function of USH proteins to gain insight into the pathomechanisms leading to the retinal phenotype in USH. Here, we focus on the USH1 proteins SANS (USH1G) and harmonin (USH1C), and the USH2C protein ADGRV1. Results from affinity capture approaches revealed putative interacting proteins to these USH proteins, indicative of diverse various unexpected molecular pathways and modules. Functional studies in both cellular and animal models confirmed the roles of SANS in the pre-mRNA splicing of other retinal genes, especially USH genes and harmonin as a suppressor of the canonical Wnt signaling. Additionally, ADGRV1 showed characteristics of a metabotropic mechanoreceptor regulating cell adhesions, Ca2+ homeostasis of the cell, and autophagy. The dysfunction of these pathways and processes may contribute to the development of USH and are novel potential targets for future therapies.
2024-07-15 | Zebrafish myo7aa affects congenital hearing by regulating Rho-GTPase signaling
Introduction myo7aa , the homolog of the human Usher 1B syndrome pathogenic gene, myo7A , plays an important role in stereociliary development and maintenance, therefore, is critical for hearing and balance. However, the molecular mechanisms that myo7aa regulate hearing and balance still need to be studied. Methods In this study, we generated two independent zebrafish myo7aa knockout lines using CRISPR/Cas9 technology. To investigate the effects of myo7aa on hearing, YO-PRO-1 staining and startle response assay were used. To gain insight into the specific molecular mechanisms by which myo7aa affects hearing, transcriptome sequencing and bioinformatics analysis were employed. Results Our study showed that hair cells of myo7aa -/- zebrafish can not take up YO-PRO-1 fluorescent dye and are insensitive to acoustic stimulation in myo7aa -/- zebrafish compared to wild type. Genes related to the Rho GTPase signaling pathway, such as arhgap33, dab2ip, and arghef40, are significantly down-regulated in myo7aa -/- zebrafish embryos at 3 dpf. GTP and ATP compensation can partially rescue the hair cell defects in myo7aa knockout zebrafish. Discussion Our findings suggest that zebrafish myo7aa affects congenital hearing by regulating Rho GTPase signaling, and loss of myo7aa leads to abnormal Rho GTPase signaling and impairs hair cell function. myo7aa , myo7A , arhgap33, dab2ip, arghef40 and myo7aa -/- fonts in the abstract are italicized. -/- is a superscript format.
2023-12-30 | Hexafluoro slows retinal degeneration and improves visual function in zebrafish models of Usher syndrome 1F
ABSTRACT Usher syndrome is the leading genetic cause of deafblindness, affecting hundreds of thousands of people worldwide. The deafness can be addressed with hearing aids or cochlear implants, but there is currently no treatment for the vision loss, which is due to progressive degeneration of retinal photoreceptors. Studies in animal models of Usher syndrome have shown that photoreceptor degeneration is exacerbated by exposure to bright light, and other studies have shown that light-induced photostress reduces mitochondrial function. We previously synthesized hexafluoro and showed that it is a potent Sirt3 activator that promotes mitochondrial respiration. Here we examined the efficacy of hexafluoro as a potential therapeutic for treatment of vison loss in a zebrafish model of Usher syndrome type 1F, which exhibits early and severe vision defects along with vestibular dysfunction as seen in Usher type 1 pathology. We find that hexafluoro improves visual function, reduces photoreceptor degeneration, and protects the retina against exposure to bright light in this USH1F model.
oligonucleotides
2026-04-28 | Expanding the options for therapeutic exon skipping as a future treatment for USH2A -associated disease by 3D structural modeling of newly formed hybrid domains
ABSTRACT Usher syndrome, the leading cause of hereditary deaf-blindness affecting approximately 1 in 15,000 individuals worldwide, is currently still untreatable. Antisense oligonucleotide-based exon skipping has shown significant therapeutic promise for USH2A -associated retinal dysfunction. Selection of (combinations of) exons suitable for therapeutic exon skipping within the fibronectin type 3 (FN3) domain-encoding region of USH2A currently requires that skipped exons exactly align with complete protein domains. However, only few exon combinations meet this criterion, which significantly restricts the therapeutic potential of this strategy. Our study addresses this limitation by incorporating AlphaFold2 structural modelling into the exon skipping target selection pipeline. Following this adjusted framework, we can predict exon skipping combinations that allow remaining domain fragments to form structurally viable hybrid domains. As a proof-of-concept, we examined and confirmed the functionality of usherinΔexon54-58 that contains a hybrid FN3 domain, using zebrafish as a model. This highligts the potential of the newly developed paradigm for identifying exon skipping targets with potential therapeutic relevance. Our results emphasize the value of structural modeling in identifying new therapeutic exon skipping targets, aiming to improve precision, efficiency, applicability, and cost-effectiveness in the development of genetic therapies for hereditary diseases such as Usher syndrome.
2025-09-25 | AAV-mediated exon skipping therapy for Usher syndrome, type 2A.
Usher syndrome can cause loss of vision, hearing, and balance. There are four clinical subtypes, USH1-4, which are associated with mutations in genes important for structure, function, and survival of photoreceptor cells in the retina and sensory hair cells in the inner ear. Genetic mutations in the USH2A gene, which encodes usherin protein, are the most common cause of Usher syndrome worldwide, with c.2299delG (p.Glu767Serfs∗21) being the most frequent pathogenic variant. An investigational antisense oligonucleotide (ASO) for USH2A c.2299delG, QR-421a, designed to bypass the mutation, has already shown promise in phase 1/2 clinical trials. While recently developed chemistry provides longer ASO half-lives, repeated injection of ASOs may be required to provide long-term efficacy. To overcome this limitation, we screened novel USH2A exon 13 skippers and 20 AAV capsids with the goal of developing a vectorized ASO exon skipping strategy. Optimized vectors and skippers were evaluated in inner ear and retinal organoids derived from human stem cell lines bearing the USH2A c.2299delG mutation. The data revealed enhanced skipping of the pathogenic exon, offering an alternative strategy for treatment of USH2A patients using a single local injection which may prevent progression of vision and hearing loss.
2023-09-11 | Successful large gene augmentation of USH2A with non-viral episomal vectors.
USH2A mutations are a common cause of autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, for which there are currently no approved treatments. Gene augmentation is a valuable therapeutic strategy for treating many inherited retinal diseases; however, conventional adeno-associated virus (AAV) gene therapy cannot accommodate cDNAs exceeding 4.7 kb, such as the 15.6-kb-long USH2A coding sequence. In the present study, we adopted an alternative strategy to successfully generate scaffold/matrix attachment region (S/MAR) DNA plasmid vectors containing the full-length human USH2A coding sequence, a GFP reporter gene, and a ubiquitous promoter (CMV or CAG), reaching a size of approximately 23 kb. We assessed the vectors in transfected HEK293 cells and USH2A patient-derived dermal fibroblasts in addition to ush2au507 zebrafish microinjected with the vector at the one-cell stage. pS/MAR-USH2A vectors drove persistent transgene expression in patient fibroblasts with restoration of usherin. Twelve months of GFP expression was detected in the photoreceptor cells, with rescue of Usher 2 complex localization in the photoreceptors of ush2au507 zebrafish retinas injected with pS/MAR-USH2A. To our knowledge, this is the first reported vector that can be used to express full-length usherin with functional rescue. S/MAR DNA vectors have shown promise as a novel non-viral retinal gene therapy, warranting further translational development.
2023-03-30 | Natural Disease Course in Usher Syndrome Patients Harboring USH2A Variant p.Cys870* in Exon 13, Amenable to Exon Skipping Therapy.
The aim of the study was to determine the rate of retinal degeneration in patients with c.2610C>A (p.Cys870*) in USH2A exon 13, amenable to exon skipping therapy. There were nine patients from seven families, three of whom were male (two were homozygous). Seven patients had follow-up data (median of 11 years). Analysis included best corrected visual acuity (BCVA, decimal Snellen), visual field (Goldmann perimetry target II/4), fundus autofluorescence (FAF), optical coherence tomography (OCT), and microperimetry (MP). The median age at the onset of nyctalopia was 20 years (range, 8-35 years of age). At the first exam, at a median age of 42 years, the median BCVA was 0.5 (0.2-1.0), and the median visual field diameter was 23° (5°-114°). Imaging showed a hyperautofluorescent ring delineating preserved foveal photoreceptors in 78% (7/9) of patients, while 22% (2/9) had a hyperautofluorescent patch or atrophy, reflecting advanced disease. Survival analysis predicted that 50% of patients reach legal blindness based on a visual field diameter < 20° at the age of 52 (95% CI, 45-59) and legal blindness based on a BCVA ≤ 0. 1 (20/200) at the age of 55 (95% CI, 46-66). Visual field constriction occurred at the median rate of radial 1.5 deg/year, and hyperautofluorescent ring constriction occurred at the median rate of 34 μm/year. A non-null second allele was found in two patients: p.Thr4315Pro and p.Arg303His; the patient with p.Arg303His had a milder disease. The rates of progression will be useful in the design and execution of clinical trials.
2023-01-18 | Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction
A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.
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2025-03-01 | Improvement of perceived cochlear implant sound quality through individualized psychoacoustic-based frequency fitting.
In recent years, there has been a trend toward more individualization in the fitting of cochlear implants (CI). Here, a new individualized approach to frequency band allocation was used. This approach is based on binaural perceptual pitch matching. The patient had congenital bilateral progressive sensorineural hearing loss due to Usher Syndrome. He had used hearing aids in both ears since the age of 4 years. In his mid-40s, he received a CI on his right ear and, ten months later, a second CI on the left ear. Adjustments to the frequency band allocations were made, guided by the binaural perceptual pitch matching of piano notes. For the first CI, pitch matching was performed using the contralateral ear as the reference, which had preserved low-frequency residual hearing (bimodal pitch matching). For the second CI, pitch matching was performed using the first implanted side as the reference (bilateral electrical pitch matching). The final frequency band allocation adjustments were always shifted toward lower frequencies relative to the default band allocations. The adjustments were larger in magnitude for the second CI compared to the first CI. Speech perception scores generally increased over the course of rehabilitation and were higher with the individualized fitting compared to the default fitting. The subjective sound quality was reportedly greatly improved with the individualized fitting. Individualized psychoacoustic frequency-based fitting can yield improvements in the perceived sound quality with a CI. However, this method requires significant residual hearing in at least one ear, and the patient must have relatively fine pitch discrimination abilities.
2024-07-11 | Long-Term Outcomes of Cochlear Implantation in Usher Syndrome.
Usher syndrome (USH), characterized by bilateral sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP), prompts increased reliance on hearing due to progressive visual deterioration. It can be categorized into three subtypes: USH type 1 (USH1), characterized by severe to profound congenital SNHL, childhood-onset RP, and vestibular areflexia; USH type 2 (USH2), presenting with moderate to severe progressive SNHL and RP onset in the second decade, with or without vestibular dysfunction; and USH type 3 (USH3), featuring variable progressive SNHL beginning in childhood, variable RP onset, and diverse vestibular function. Previous studies evaluating cochlear implant (CI) outcomes in individuals with USH used varying or short follow-up durations, while others did not evaluate outcomes for each subtype separately. This study evaluates long-term CI performance in subjects with USH, at both short-term and long-term, considering each subtype separately. This retrospective, observational cohort study identified 36 CI recipients (53 ears) who were categorized into four different groups: early-implanted USH1 (first CI at ≤7 years of age), late-implanted USH1 (first CI at ≥8 years of age), USH2 and USH3. Phoneme scores at 65 dB SPL with CI were evaluated at 1 year, ≥2 years (mid-term), and ≥5 years postimplantation (long-term). Each subtype was analyzed separately due to the significant variability in phenotype observed among the three subtypes. Early-implanted USH1-subjects (N = 23 ears) achieved excellent long-term phoneme scores (100% [interquartile ranges {IQR} = 95 to 100]), with younger age at implantation significantly correlating with better CI outcomes. Simultaneously implanted subjects had significantly better outcomes than sequentially implanted subjects ( p = 0.028). Late-implanted USH1 subjects (N = 3 ears) used CI solely for sound detection and showed a mean phoneme discrimination score of 12% (IQR = 0 to 12), while still expressing satisfaction with ambient sound detection. In the USH2 group (N = 23 ears), a long-term mean phoneme score of 85% (IQR = 81 to 95) was found. Better outcomes were associated with younger age at implantation and higher preimplantation speech perception scores. USH3-subjects (N = 7 ears) achieved a mean postimplantation phoneme score of 71% (IQR = 45 to 91). This study is currently one of the largest and most comprehensive studies evaluating CI outcomes in individuals with USH, demonstrating that overall, individuals with USH benefit from CI at both short- and long-term follow-up. Due to the considerable variability in phenotype observed among the three subtypes, each subtype was analyzed separately, resulting in smaller sample sizes. For USH1 subjects, optimal CI outcomes are expected with early simultaneous bilateral implantation. Late implantation in USH1 provides signaling function, but achieved speech recognition is insufficient for oral communication. In USH2 and USH3, favorable CI outcomes are expected, especially if individuals exhibit sufficient speech recognition with hearing aids and receive ample auditory stimulation preimplantation. Early implantation is recommended for USH2, given the progressive nature of hearing loss and concomitant severe visual impairment. In comparison with USH2, predicting outcomes in USH3 remains challenging due to the variability found. Counseling for USH2 and USH3 should highlight early implantation benefits and encourage hearing aid use.
2006-04-28 | Audiologic Performance and Benefit of Cochlear Implantation in Usher Syndrome Type I
Abstract Objective: The objective of this retrospective study was to evaluate the benefit and performance of cochlear implantation in patients with Usher syndrome type 1 (USH1). Methods: Fourteen patients with a clinical diagnosis of USH1 were included. Mutation analysis of USH1 genes was performed in all of them. All patients filled in the G(C)BI questionnaire, which measures the benefit of implantation. In addition, equivalent hearing level scores (EHL) were calculated to measure performance. Correlations between the mentioned parameters were studied. Results: One or two pathogenic mutations were identified in seven of the 14 examined patients. Similar to previous studies, it was demonstrated that implantation at an earlier age results in better performance than implantation at higher age. Cochlear implantation performed within the first 2 decades of life was beneficial to 13 of 14 (93%) of the patients with USH1. Finally, the EHL score and the G(C)BI score showed a significant correlation; the benefit of implantation increases with a decreasing EHL score. Conclusions: Cochlear implantation in patients with USH1 improves the audiologic performance when patients are implanted at an earlier age and is beneficial according to the G(C)BI when performed within the first 2 decades of life.
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Drug Discovery Landscape
2 orphan drug designations for Usher syndrome type 1.
2 orphan drug designations for Usher syndrome type 1.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
lentiviral vector containing the human MY07A gene | gene therapies | FDA | 2010-05-17 | — | Sanofi US Services Inc. |
Lentiviral vector containing the human MYO7A gene | gene therapies | EMA | 2010-03-23 | — | Sanofi Winthrop Industrie |
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