1
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D'Arco F, Kandemirli SG, Dahmoush HM, Alves CAPF, Severino M, Dellepiane F, Robson CD, Lequin MH, Rossi-Espagnet C, O'Brien WT, Nash R, Clement E, Juliano AF. Incomplete partition type II in its various manifestations: isolated, in association with EVA, syndromic, and beyond; a multicentre international study. Neuroradiology 2024; 66:1397-1403. [PMID: 38833161 DOI: 10.1007/s00234-024-03386-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/29/2024] [Indexed: 06/06/2024]
Abstract
PURPOSE Incomplete partition type II (IP-II) is characterized by specific histological features and radiological appearance. It may occur in isolation or in association with an enlarged vestibular aqueduct (EVA). Among those with IP-II and EVA, a subset has a diagnosis of Pendred syndrome. This study aimed to explore the prevalence of isolated IP-II, IP-II with EVA, and cases with a genetic or syndromic basis in our cohort. METHODS From a large, multicentre database of dysplastic cochleae (446 patients, 892 temporal bones), those with imaging features of IP-II were examined in detail, including whether there was a genetic or syndromic association. RESULTS A total of 78 patients with IP-II were identified. Among these, 55 patients had bilateral IP-II and EVA (only 12 with typical Mondini triad), 8 with bilateral IP-II and normal VA, 2 with bilateral IP-II and unilateral EVA, and 13 with unilateral IP-II (9 with unilateral EVA). Among the group with bilateral IP-II and bilateral EVA in whom genetic analysis was available, 14 out of 29 (48%) had SLC26A4 mutations and a diagnosis of Pendred syndrome, 1 had a FOXI1 mutation, and a few other genetic abnormalities; none had KCNJ10 pathogenic variants. CONCLUSION Bilateral IP-II-bilateral EVA may be seen in the context of Pendred syndrome (SLC26A4 or FOXI1 mutations) but, in the majority of our cohort, no genetic abnormalities were found, suggesting the possibility of unknown genetic associations. IP-II in isolation (without EVA) is favored to be genetic when bilateral, although the cause is often unknown.
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Affiliation(s)
- Felice D'Arco
- Department of Radiology, Great Ormond Street Hospital for Children, London, UK
| | - Sedat G Kandemirli
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, USA
| | - Hisham M Dahmoush
- Department of Radiology, Lucile Packard Children's Hospital, Stanford University, Stanford, USA
| | - Cesar A P F Alves
- Department of Radiology, Great Ormond Street Hospital for Children, London, UK
| | | | | | - Caroline D Robson
- Department of Radiology, Great Ormond Street Hospital for Children, London, UK
| | - Maarten H Lequin
- Department of Radiology, Texas Children's Hospital, North Campus, Austin, TX, USA
| | - Camilla Rossi-Espagnet
- Functional and Interventional Neuroradiology Unit, Bambino Gesù Children's Hospital, IRCCS , Rome, Italy
| | - William T O'Brien
- Department of Radiology, Orlando Health - Arnold Palmer Hospital for Children, Orlando, FL, USA
| | - Robert Nash
- Department of Paediatric Otolaryngology, Great Ormond Street Hospital, London, UK
| | - Emma Clement
- Department of Clinical Genetics, Great Ormond Street Hospital for Children, London, UK
| | - Amy F Juliano
- Department of Radiology, Massachusetts Eye and Ear, Harvard Medical School, 243 Charles St, 02114, Boston, MA, USA.
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2
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Edouard AM, Gloria NS, Sobhi AY, Christian AM, Fidele KK, Fabrice MM, Christian BM, Deogratias NB, Patrick BB. Hearing Loss with Vision Impairment: Usher Syndrome. A Case of the East Democratic Republic of Congo. Indian J Otolaryngol Head Neck Surg 2023; 75:4093-4097. [PMID: 37974760 PMCID: PMC10646019 DOI: 10.1007/s12070-023-03970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 06/12/2023] [Indexed: 11/19/2023] Open
Abstract
Usher syndrome (USH) is a clinically heterogeneous condition characterized by sensorineural hearing loss, progressive retinal degeneration, and vestibular dysfunction. There are two phenotypically recognizable types of Usher syndrome described in the literature. Usher type 1 individual have no vestibular function and profound sensorineural hearing loss. Usher type 2 individuals have a normal vestibular function and mild-to-severe hearing loss with visual impairment that is presented later in life. We are reporting a case of 35 years old gentleman with hearing loss and visual impairment presented to the ENT clinic at the tertiary care center. Clinical evaluations as well as comprehensive testing of hearing, vestibular function, and visual function have confirmed USH. It's a rare but serious cause of hearing loss that requires comprehensive multidisciplinary evaluation in conjunction with an ophthalmology team. Further genetic, audiological, and vestibular assessments are required to help diagnose and management of specific subtypes of this syndrome. Supplementary Information The online version contains supplementary material available at 10.1007/s12070-023-03970-4.
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Affiliation(s)
- Amani Mudekereza Edouard
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
| | - Nshokano Simba Gloria
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
- Department of Ophtalmology, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
| | - Ahmed Youssef Sobhi
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Amani Muzindusi Christian
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
| | - Kabego Kulimushi Fidele
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
- Department of Ophtalmology, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
| | - Murhula Mulumeoderhwa Fabrice
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
| | - Balaluka Mulinganya Christian
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
| | - Ngoma Basedeke Deogratias
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
- Department of Ophtalmology, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
| | - Balungwe Birindwa Patrick
- Department of Otorhinolaryngology Head and Neck Surgery, Faculty of Medicine, Université Catholique de Bukavu(UCB), Bukavu, Democratic Republic of the Congo
- Otothinolaryngology ward and Ophtamology Ward, Hopital Provincial General de Référence de Bukavu (HPGRB), Bukavu, Democratic Republic of the Congo
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3
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Lau SC, Grati M, Isgrig K, Sinan M, Calabro KR, Zhu J, Ishibashi Y, Ozgur Z, Wafa T, Belyantseva IA, Fitzgerald T, Friedman TB, Boye SL, Boye SE, Chien WW. Dual-AAV vector-mediated expression of MYO7A improves vestibular function in a mouse model of Usher syndrome 1B. Mol Ther Methods Clin Dev 2023; 30:534-545. [PMID: 37693946 PMCID: PMC10491803 DOI: 10.1016/j.omtm.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 08/16/2023] [Indexed: 09/12/2023]
Abstract
Usher syndrome is the most common cause of deafness-blindness in the world. Usher syndrome type 1B (USH1B) is associated with mutations in MYO7A. Patients with USH1B experience deafness, blindness, and vestibular dysfunction. In this study, we applied adeno-associated virus (AAV)-mediated gene therapy to the shaker-1 (Myo7a4626SB/4626SB) mouse, a model of USH1B. The shaker-1 mouse has a nonsense mutation in Myo7a, is profoundly deaf throughout life, and has significant vestibular dysfunction. Because of the ∼6.7-kb size of the MYO7A cDNA, a dual-AAV approach was used for gene delivery, which involves splitting human MYO7A cDNA into 5' and 3' halves and cloning them into two separate AAV8(Y733F) vectors. When MYO7A cDNA was delivered to shaker-1 inner ears using the dual-AAV approach, cochlear hair cell survival was improved. However, stereocilium organization and auditory function were not improved. In contrast, in the vestibular system, dual-AAV-mediated MYO7A delivery significantly rescued hair cell stereocilium morphology and improved vestibular function, as reflected in a reduction of circling behavior and improved vestibular sensory-evoked potential (VsEP) thresholds. Our data indicate that dual-AAV-mediated MYO7A expression improves vestibular function in shaker-1 mice and supports further development of this approach for the treatment of disabling dizziness from vestibular dysfunction in USH1B patients.
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Affiliation(s)
- Samantha C. Lau
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mhamed Grati
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin Isgrig
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Moaz Sinan
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kaitlyn R. Calabro
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Jianliang Zhu
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yasuko Ishibashi
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zeynep Ozgur
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Talah Wafa
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Inna A. Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tracy Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sanford L. Boye
- Powell Gene Therapy Center, Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Shannon E. Boye
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Wade W. Chien
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Otolaryngology – Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
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4
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Crane R, Tebbe L, Mwoyosvi ML, Al-Ubaidi MR, Naash MI. Expression of the human usherin c.2299delG mutation leads to early-onset auditory loss and stereocilia disorganization. Commun Biol 2023; 6:933. [PMID: 37700068 PMCID: PMC10497539 DOI: 10.1038/s42003-023-05296-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness and blindness, with USH2A being the most prevalent form. The mechanisms responsible for this debilitating sensory impairment remain unclear. This study focuses on characterizing the auditory phenotype in a mouse model expressing the c.2290delG mutation in usherin equivalent to human frameshift mutation c.2299delG. Previously we described how this model reproduces patient's retinal phenotypes. Here, we present the cochlear phenotype, showing that the mutant usherin, is expressed during early postnatal stages. The c.2290delG mutation results in a truncated protein that is mislocalized within the cell body of the hair cells. The knock-in model also exhibits congenital hearing loss that remains consistent throughout the animal's lifespan. Structurally, the stereocilia bundles, particularly in regions associated with functional hearing loss, are disorganized. Our findings shed light on the role of usherin in maintaining structural support, specifically in longer inner hair cell stereocilia, during development, which is crucial for proper bundle organization and hair cell function. Overall, we present a genetic mouse model with cochlear defects associated with the c.2290delG mutation, providing insights into the etiology of hearing loss and offering potential avenues for the development of effective therapeutic treatments for USH2A patients.
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Affiliation(s)
- Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Lars Tebbe
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Maggie L Mwoyosvi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
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5
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Malvasi M, Casillo L, Avogaro F, Abbouda A, Vingolo EM. Gene Therapy in Hereditary Retinal Dystrophies: The Usefulness of Diagnostic Tools in Candidate Patient Selections. Int J Mol Sci 2023; 24:13756. [PMID: 37762059 PMCID: PMC10531171 DOI: 10.3390/ijms241813756] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
PURPOSE Gene therapy actually seems to have promising results in the treatment of Leber Congenital Amaurosis and some different inherited retinal diseases (IRDs); the primary goal of this strategy is to change gene defects with a wild-type gene without defects in a DNA sequence to achieve partial recovery of the photoreceptor function and, consequently, partially restore lost retinal functions. This approach led to the introduction of a new drug (voretigene neparvovec-rzyl) for replacement of the RPE65 gene in patients affected by Leber Congenital Amaurosis (LCA); however, the treatment results are inconstant and with variable long-lasting effects due to a lack of correctly evaluating the anatomical and functional conditions of residual photoreceptors. These variabilities may also be related to host immunoreactive reactions towards the Adenovirus-associated vector. A broad spectrum of retinal dystrophies frequently generates doubt as to whether the disease or the patient is a good candidate for a successful gene treatment, because, very often, different diseases share similar genetic characteristics, causing an inconstant genotype/phenotype correlation between clinical characteristics also within the same family. For example, mutations on the RPE65 gene cause Leber Congenital Amaurosis (LCA) but also some forms of Retinitis Pigmentosa (RP), Bardet Biedl Syndrome (BBS), Congenital Stationary Night Blindness (CSNB) and Usher syndrome (USH), with a very wide spectrum of clinical manifestations. These confusing elements are due to the different pathways in which the product protein (retinoid isomer-hydrolase) is involved and, consequently, the overlapping metabolism in retinal function. Considering this point and the cost of the drug (over USD one hundred thousand), it would be mandatory to follow guidelines or algorithms to assess the best-fitting disease and candidate patients to maximize the output. Unfortunately, at the moment, there are no suggestions regarding who to treat with gene therapy. Moreover, gene therapy might be helpful in other forms of inherited retinal dystrophies, with more frequent incidence of the disease and better functional conditions (actually, gene therapy is proposed only for patients with poor vision, considering possible side effects due to the treatment procedures), in which this approach leads to better function and, hopefully, visual restoration. But, in this view, who might be a disease candidate or patient to undergo gene therapy, in relationship to the onset of clinical trials for several different forms of IRD? Further, what is the gold standard for tests able to correctly select the patient? Our work aims to evaluate clinical considerations on instrumental morphofunctional tests to assess candidate subjects for treatment and correlate them with clinical and genetic defect analysis that, often, is not correspondent. We try to define which parameters are an essential and indispensable part of the clinical rationale to select patients with IRDs for gene therapy. This review will describe a series of models used to characterize retinal morphology and function from tests, such as optical coherence tomography (OCT) and electrophysiological evaluation (ERG), and its evaluation as a primary outcome in clinical trials. A secondary aim is to propose an ancillary clinical classification of IRDs and their accessibility based on gene therapy's current state of the art. MATERIAL AND METHODS OCT, ERG, and visual field examinations were performed in different forms of IRDs, classified based on clinical and retinal conditions; compared to the gene defect classification, we utilized a diagnostic algorithm for the clinical classification based on morphofunctional information of the retina of patients, which could significantly improve diagnostic accuracy and, consequently, help the ophthalmologist to make a correct diagnosis to achieve optimal clinical results. These considerations are very helpful in selecting IRD patients who might respond to gene therapy with possible therapeutic success and filter out those in which treatment has a lower chance or no chance of positive results due to bad retinal conditions, avoiding time-consuming patient management with unsatisfactory results.
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Affiliation(s)
- Mariaelena Malvasi
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, 00185 Rome, Italy; (L.C.); (E.M.V.)
| | - Lorenzo Casillo
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, 00185 Rome, Italy; (L.C.); (E.M.V.)
| | - Filippo Avogaro
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, 00185 Rome, Italy; (L.C.); (E.M.V.)
| | - Alessandro Abbouda
- Department of Ophthalmology, Fiorini Hospital Terracina AUSL, 04019 Terracina, Italy
| | - Enzo Maria Vingolo
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, 00185 Rome, Italy; (L.C.); (E.M.V.)
- Department of Ophthalmology, Fiorini Hospital Terracina AUSL, 04019 Terracina, Italy
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6
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Tebbe L, Mwoyosvi ML, Crane R, Makia MS, Kakakhel M, Cosgrove D, Al-Ubaidi MR, Naash MI. The usherin mutation c.2299delG leads to its mislocalization and disrupts interactions with whirlin and VLGR1. Nat Commun 2023; 14:972. [PMID: 36810733 PMCID: PMC9944904 DOI: 10.1038/s41467-023-36431-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness-blindness with type 2 A (USH2A) being the most common form. Knockout models of USH proteins, like the Ush2a-/- model that develops a late-onset retinal phenotype, failed to mimic the retinal phenotype observed in patients. Since patient's mutations result in the expression of a mutant protein and to determine the mechanism of USH2A, we generated and evaluated an usherin (USH2A) knock-in mouse expressing the common human disease-mutation, c.2299delG. This mouse exhibits retinal degeneration and expresses a truncated, glycosylated protein which is mislocalized to the photoreceptor inner segment. The degeneration is associated with a decline in retinal function, structural abnormalities in connecting cilium and outer segment and mislocaliztion of the usherin interactors very long G-protein receptor 1 and whirlin. The onset of symptoms is significantly earlier compared to Ush2a-/-, proving expression of mutated protein is required to recapitulate the patients' retinal phenotype.
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Affiliation(s)
- Lars Tebbe
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Maggie L Mwoyosvi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mustafa S Makia
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mashal Kakakhel
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | | | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
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7
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Zaw K, Carvalho LS, Aung-Htut MT, Fletcher S, Wilton SD, Chen FK, McLenachan S. Pathogenesis and Treatment of Usher Syndrome Type IIA. Asia Pac J Ophthalmol (Phila) 2022; 11:369-379. [PMID: 36041150 DOI: 10.1097/apo.0000000000000546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/27/2022] [Indexed: 12/16/2022] Open
Abstract
Usher syndrome (USH) is the most common form of deaf-blindness, with an estimated prevalence of 4.4 to 16.6 per 100,000 people worldwide. The most common form of USH is type IIA (USH2A), which is caused by homozygous or compound heterozygous mutations in the USH2A gene and accounts for around half of all USH cases. USH2A patients show moderate to severe hearing loss from birth, with diagnosis of retinitis pigmentosa in the second decade of life and variable vestibular involvement. Although hearing aids or cochlear implants can provide some mitigation of hearing deficits, there are currently no treatments aimed at preventing or restoring vision loss in USH2A patients. In this review, we first provide an overview of the molecular biology of the USH2A gene and its protein isoforms, which include a transmembrane protein (TM usherin) and an extracellular protein (EC usherin). The role of these proteins in the inner ear and retina and their impact on the pathogenesis of USH2A is discussed. We review animal cell-derived and patient cell-derived models currently used in USH2A research and conclude with an overview of potential treatment strategies currently in preclinical development and clinical trials.
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Affiliation(s)
- Khine Zaw
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Livia S Carvalho
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
| | - May T Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, Nedlands, Western Australia, Australia
| | - Fred K Chen
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Nedlands, Western Australia, Australia
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8
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Fenner BJ, Tan TE, Barathi AV, Tun SBB, Yeo SW, Tsai ASH, Lee SY, Cheung CMG, Chan CM, Mehta JS, Teo KYC. Gene-Based Therapeutics for Inherited Retinal Diseases. Front Genet 2022; 12:794805. [PMID: 35069693 PMCID: PMC8782148 DOI: 10.3389/fgene.2021.794805] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a heterogenous group of orphan eye diseases that typically result from monogenic mutations and are considered attractive targets for gene-based therapeutics. Following the approval of an IRD gene replacement therapy for Leber's congenital amaurosis due to RPE65 mutations, there has been an intensive international research effort to identify the optimal gene therapy approaches for a range of IRDs and many are now undergoing clinical trials. In this review we explore therapeutic challenges posed by IRDs and review current and future approaches that may be applicable to different subsets of IRD mutations. Emphasis is placed on five distinct approaches to gene-based therapy that have potential to treat the full spectrum of IRDs: 1) gene replacement using adeno-associated virus (AAV) and nonviral delivery vectors, 2) genome editing via the CRISPR/Cas9 system, 3) RNA editing by endogenous and exogenous ADAR, 4) mRNA targeting with antisense oligonucleotides for gene knockdown and splicing modification, and 5) optogenetic approaches that aim to replace the function of native retinal photoreceptors by engineering other retinal cell types to become capable of phototransduction.
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Affiliation(s)
- Beau J Fenner
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Tien-En Tan
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | | | - Sai Bo Bo Tun
- Singapore Eye Research Institute, Singapore, Singapore
| | - Sia Wey Yeo
- Singapore Eye Research Institute, Singapore, Singapore
| | - Andrew S H Tsai
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Shu Yen Lee
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Chui Ming Gemmy Cheung
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Choi Mun Chan
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore.,School of Material Science and Engineering, Nanyang Technological University, Singapore, Singapore.,Yong Loo Lin School of Medicine, Department of Ophthalmology, National University of Singapore, Singapore, Singapore
| | - Kelvin Y C Teo
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
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9
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Galbis‐Martínez L, Blanco‐Kelly F, García‐García G, Ávila‐Fernández A, Jaijo T, Fuster‐García C, Perea‐Romero I, Zurita‐Muñoz O, Jimenez‐Rolando B, Carreño E, García‐Sandoval B, Millán JM, Ayuso C. Genotype-phenotype correlation in patients with Usher syndrome and pathogenic variants in MYO7A: implications for future clinical trials. Acta Ophthalmol 2021; 99:922-930. [PMID: 33576163 PMCID: PMC9540557 DOI: 10.1111/aos.14795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 01/22/2021] [Indexed: 12/16/2022]
Abstract
Purpose We aimed to establish correlations between the clinical features of a cohort of Usher syndrome (USH) patients with pathogenic variants in MYO7A, type of pathogenic variant, and location on the protein domain. Methods Sixty‐two USH patients from 46 families with biallelic variants in MYO7A were examined for visual and audiological features. Participants were evaluated based on self‐reported ophthalmological history and ophthalmological investigations (computerized visual field testing, best‐corrected visual acuity, and ophthalmoscopic and electrophysiological examination). Optical coherence tomography and fundus autofluorescence imaging were performed when possible. Auditory and vestibular functions were evaluated. Patients were classified according to the type of variant and the protein domain where the variants were located. Results Most patients displayed a typical USH1 phenotype, that is, prelingual severe‐profound sensorineural hearing loss, prepubertal retinitis pigmentosa (RP) and vestibular dysfunction. No statistically significant differences were observed for the variables analysed except for the onset of hearing loss due to the existence of two USH2 cases, defined as postlingual sensorineural hearing loss, postpubertal onset of RP, and absence of vestibular dysfunction, and one atypical case of USH. Conclusion We were unable to find a correlation between genotype and phenotype for MYO7A. However, our findings could prove useful for the assessment of efficacy in clinical trials, since the type of MYO7A variant does not seem to change the onset, severity or course of visual disease.
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Affiliation(s)
- Lilián Galbis‐Martínez
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Fiona Blanco‐Kelly
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Gema García‐García
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Almudena Ávila‐Fernández
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Teresa Jaijo
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Carla Fuster‐García
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Irene Perea‐Romero
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Olga Zurita‐Muñoz
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Belén Jimenez‐Rolando
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - Ester Carreño
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - Blanca García‐Sandoval
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - José M. Millán
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Carmen Ayuso
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
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10
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Establishing Genotype-phenotype Correlation in USH2A-related Disorders to Personalize Audiological Surveillance and Rehabilitation. Otol Neurotol 2021; 41:431-437. [PMID: 32176120 DOI: 10.1097/mao.0000000000002588] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE USH2A-related disorders are characterised by genetic and phenotypic heterogeneity, and are associated with a spectrum of sensory deficits, ranging from deaf blindness to blindness with normal hearing. It has been previously proposed that the presence of specific USH2A alleles can be predictive of unaffected hearing. This study reports the clinical and genetic findings in a group of patients with USH2A-related disease and evaluates the validity of the allelic hierarchy model. PATIENTS AND INTERVENTION USH2A variants from 27 adults with syndromic and nonsyndromic USH2A-related disease were analyzed according to a previously reported model of allelic hierarchy. The analysis was replicated on genotype-phenotype correlation information from 197 individuals previously reported in 2 external datasets. MAIN OUTCOME MEASURE Genotype-phenotype correlations in USH2A-related disease. RESULTS A valid allelic hierarchy model was observed in 93% of individuals with nonsyndromic USH2A-retinopathy (n = 14/15) and in 100% of patients with classic Usher syndrome type IIa (n = 8/8). Furthermore, when two large external cohorts of cases were combined, the allelic hierarchy model was valid across 85.7% (n = 78/91) of individuals with nonsyndromic USH2A-retinopathy and 95% (n = 123/129) of individuals with classic Usher syndrome type II (p = 0.012, χ test). Notably, analysis of all three patient datasets revealed that USH2A protein truncating variants were reported most frequently in individuals with hearing loss. CONCLUSION Genetic testing results in individuals suspected to have an USH2A-related disorder have the potential to facilitate personalized audiological surveillance and rehabilitation pathways.
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11
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Abstract
Usher syndrome type 1B (USH1B) is a genetic disorder caused by mutations in the unconventional Myosin VIIa (MYO7A) protein. USH1B is characterized by hearing loss due to abnormalities in the inner ear and vision loss due to retinitis pigmentosa. Here, we present the model of human MYO7A homodimer, built using homology modeling, and refined using 5 ns molecular dynamics in water. Global computational mutagenesis was applied to evaluate the effect of missense mutations that are critical for maintaining protein structure and stability of MYO7A in inherited eye disease. We found that 43.26% (77 out of 178 in HGMD) and 41.9% (221 out of 528 in ClinVar) of the disease-related missense mutations were associated with higher protein structure destabilizing effects. Overall, most mutations destabilizing the MYO7A protein were found to associate with USH1 and USH1B. Particularly, motor domain and MyTH4 domains were found to be most susceptible to mutations causing the USH1B phenotype. Our work contributes to the understanding of inherited disease from the atomic level of protein structure and analysis of the impact of genetic mutations on protein stability and genotype-to-phenotype relationships in human disease.
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Affiliation(s)
- Annapurna Kuppa
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Yuri V Sergeev
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
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12
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Ambrosio L, Hansen RM, Moskowitz A, Oza A, Barrett D, Manganella J, Medina G, Kawai K, Fulton AB, Kenna M. Dark-adapted threshold and electroretinogram for diagnosis of Usher syndrome. Doc Ophthalmol 2021; 143:39-51. [PMID: 33511521 DOI: 10.1007/s10633-021-09818-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/07/2021] [Indexed: 12/21/2022]
Abstract
PURPOSE To determine the utility of ophthalmology evaluation, dark-adapted threshold, and full-field electroretinogram for early detection of Usher syndrome in young patients with bilateral sensorineural hearing loss. METHODS We identified 39 patients with secure genetic diagnoses of Usher Syndrome. Visual acuity, spherical equivalent, fundus appearance, dark-adapted threshold, and full-field electroretinogram results were summarized and compared to those in a group of healthy controls with normal hearing. In those Usher patients with repeated measures, regression analysis was done to evaluate for change in visual acuity and dark-adapted threshold with age. Spherical equivalent and full-field electroretinogram responses from dark- and light-adapted eyes were evaluated as a function of age. RESULTS The majority of initial visual acuity and spherical equivalent results were within normal limits for age. Visual acuity and dark-adapted threshold worsened significantly with age in Usher type 1 but not in Usher type 2. At initial test, full-field electroretinogram responses from dark- and light-adapted eyes were abnormal in 53% of patients. Remarkably, nearly half of our patients (17% of Usher type 1 and 30% of Usher type 2) would have been missed by tests of retinal function alone if evaluated before age 10. CONCLUSIONS Although there is an association of abnormal dark-adapted threshold and full-field electroretinogram at young ages in Usher patients, it appears that a small but important proportion of patients would not be detected by tests of retinal function alone. Thus, genetic testing is needed to secure a diagnosis of Usher syndrome.
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Affiliation(s)
- Lucia Ambrosio
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA. .,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - Ronald M Hansen
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Anne Moskowitz
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Andrea Oza
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, 65 Landsdowne Street, Cambridge, MA, 02139, USA
| | - Devon Barrett
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Juliana Manganella
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Genevieve Medina
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Kosuke Kawai
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Anne B Fulton
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Margaret Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
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13
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Bugge K, Staby L, Salladini E, Falbe-Hansen RG, Kragelund BB, Skriver K. αα-Hub domains and intrinsically disordered proteins: A decisive combo. J Biol Chem 2021; 296:100226. [PMID: 33361159 PMCID: PMC7948954 DOI: 10.1074/jbc.rev120.012928] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 01/02/2023] Open
Abstract
Hub proteins are central nodes in protein-protein interaction networks with critical importance to all living organisms. Recently, a new group of folded hub domains, the αα-hubs, was defined based on a shared αα-hairpin supersecondary structural foundation. The members PAH, RST, TAFH, NCBD, and HHD are found in large proteins such as Sin3, RCD1, TAF4, CBP, and harmonin, which organize disordered transcriptional regulators and membrane scaffolds in interactomes of importance to human diseases and plant quality. In this review, studies of structures, functions, and complexes across the αα-hubs are described and compared to provide a unified description of the group. This analysis expands the associated molecular concepts of "one domain-one binding site", motif-based ligand binding, and coupled folding and binding of intrinsically disordered ligands to additional concepts of importance to signal fidelity. These include context, motif reversibility, multivalency, complex heterogeneity, synergistic αα-hub:ligand folding, accessory binding sites, and supramodules. We propose that these multifaceted protein-protein interaction properties are made possible by the characteristics of the αα-hub fold, including supersite properties, dynamics, variable topologies, accessory helices, and malleability and abetted by adaptability of the disordered ligands. Critically, these features provide additional filters for specificity. With the presentations of new concepts, this review opens for new research questions addressing properties across the group, which are driven from concepts discovered in studies of the individual members. Combined, the members of the αα-hubs are ideal models for deconvoluting signal fidelity maintained by folded hubs and their interactions with intrinsically disordered ligands.
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Affiliation(s)
- Katrine Bugge
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lasse Staby
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Edoardo Salladini
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus G Falbe-Hansen
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Karen Skriver
- REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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14
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Way CM, Lima Cunha D, Moosajee M. Translational readthrough inducing drugs for the treatment of inherited retinal dystrophies. EXPERT REVIEW OF OPHTHALMOLOGY 2020. [DOI: 10.1080/17469899.2020.1762489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Christopher M Way
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, UK
| | - Dulce Lima Cunha
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, UK
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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15
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Shekerinov-Trpevska N, Dashtevska G, Ivanova M. Ocular aspects of Usher syndrome. SANAMED 2020. [DOI: 10.24125/sanamed.v15i1.400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Introduction: Usher Syndrome is a rare syndrome, which typical expressions are hearing loss, retinitis pigmentosa and in some cases impairment of balance and congenital cataract. It is inherited autosomal recessive. Nine genes whose mutations are associated with this condition have been isolated. It is diagnosed on the basis of clinical and genetic testing. The therapy is aimed at facilitating the functioning of these patients in the environment. Gene therapy is promising in treatment. The purpose of this paper is to focus attention on the specificity and multiplicity of the disease, which would be of educational significance to ophthalmologists and otorhinolaryngologists, through the use of the case report of Usher syndrome. Case report: We present the case of gene confirmed Usher syndrome with 85% hearing loss, retinitis pigmentosa and congenital cataract. Female at the age of 39, pregnant at 26 gestational week, second pregnancy. Genetic investigation by Macedonian Academy of Sciences and Arts (MANU) confirmed double heterozygosity for pathogenic changes c.13010C > T. p. (Thr4337Met) and c.13137delC; p. (Thr4380GinfsTer11) in the USH2A gene, a genotype that confirmed the diagnosis of autosomal recessive disease Usher syndrome type 2A (Usher syndrome 2A). Conclusion: Detailed anamnesis is always required in patients with retinitis pigmentosa, who are referred to an ophthalmologist for hearing and vice versa for patients with hearing loss that are examined by an otorhinolaryngologist. Early diagnosis is important in terms of quality of life, i.e. timely diagnosing and undertaking measures for genetic testing in the family, in order to inform them about the type of the disease and the earlier involvement in educational programs designed for these conditions.
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16
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Santana EE, Fuster-García C, Aller E, Jaijo T, García-Bohórquez B, García-García G, Millán JM, Lantigua A. Genetic Screening of the Usher Syndrome in Cuba. Front Genet 2019; 10:501. [PMID: 31231422 PMCID: PMC6558366 DOI: 10.3389/fgene.2019.00501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/07/2019] [Indexed: 11/17/2022] Open
Abstract
Background Usher syndrome (USH) is a recessive inherited disease characterized by sensorineural hearing loss, retinitis pigmentosa, and sometimes, vestibular dysfunction. Although the molecular epidemiology of Usher syndrome has been well studied in Europe and United States, there is a lack of studies in other regions like Africa or Central and South America. Methods We designed a NGS panel that included the 10 USH causative genes (MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, ADGRV1, WHRN, and CLRN1), four USH associated genes (HARS, PDZD7, CEP250, and C2orf71), and the region comprising the deep-intronic c.7595-2144A>G mutation in USH2A. Results NGS sequencing was performed in 11 USH patients from Cuba. All the cases were solved. We found the responsible mutations in the USH2A, ADGRV1, CDH23, PCDH15, and CLRN1 genes. Four mutations have not been previously reported. Two mutations are recurrent in this study: c.619C>T (p.Arg207∗) in CLRN1, previously reported in two unrelated Spanish families of Basque origin, and c.4488G>C (p.Gln1496His) in CDH23, first described in a large Cuban family. Additionally, c.4488G>C has been reported two more times in the literature in two unrelated families of Spanish origin. Conclusion Although the sample size is very small, it is tempting to speculate that the gene frequencies in Cuba are distinct from other populations mainly due to an “island effect” and genetic drift. The two recurrent mutations appear to be of Spanish origin. Further studies with a larger cohort are needed to elucidate the real genetic landscape of Usher syndrome in the Cuban population.
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Affiliation(s)
- Elayne E Santana
- Centro Provincial de Genética, Universidad de Ciencias Médicas de Holguín, Holguín, Cuba
| | - Carla Fuster-García
- Health Research Institute La Fe, University Hospital La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
| | - Elena Aller
- Health Research Institute La Fe, University Hospital La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
| | - Teresa Jaijo
- Health Research Institute La Fe, University Hospital La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
| | | | - Gema García-García
- Health Research Institute La Fe, University Hospital La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
| | - José M Millán
- Health Research Institute La Fe, University Hospital La Fe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
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17
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Pendse ND, Lamas V, Pawlyk BS, Maeder ML, Chen ZY, Pierce EA, Liu Q. In Vivo Assessment of Potential Therapeutic Approaches for USH2A-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:91-96. [PMID: 31884594 DOI: 10.1007/978-3-030-27378-1_15] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Mutations in USH2A gene account for most cases of Usher syndrome type II (USH2), characterized by a combination of congenital hearing loss and progressive vision loss. In particular, approximately 30% of USH2A patients harbor a single base pair deletion, c.2299delG, in exon 13 that creates a frameshift and premature stop codon, leading to a nonfunctional USH2A protein. The USH2A protein, also known as usherin, is an extremely large transmembrane protein (5202 aa), which limits the use of conventional AAV-mediated gene therapy; thus development of alternative approaches is required for the treatment of USH2A patients. As usherin contains multiple repetitive domains, we hypothesize that removal of one or more of those domains encoded by mutant exon(s) in the USH2A gene may reconstitute the reading frame and restore the production of a shortened yet adequately functional protein. In this study, we deleted the exon 12 of mouse Ush2a gene (corresponding to exon 13 of human USH2A) using CRISPR/Cas9-based exon-skipping approach and revealed that a shortened form of Ush2a that lacks exon 12 (Ush2a-∆Ex12) is produced and localized correctly in the cochlea. When the Ush2a-∆Ex12 allele is expressed on an Ush2a null background, the Ush2a-∆Ex12 protein can successfully restore the impaired hair cell structure and the auditory function in the Ush2a-/- mice. These results demonstrate that CRISPR/Cas9-based exon-skipping strategy holds a great therapeutic potential for the treatment of USH2A patients.
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Affiliation(s)
- Nachiket D Pendse
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA
| | - Veronica Lamas
- Department of Otolaryngology and Program in Neuroscience, Harvard Medical School, Boston, MA, USA.,Eaton Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA, USA
| | - Basil S Pawlyk
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA
| | | | - Zheng-Yi Chen
- Department of Otolaryngology and Program in Neuroscience, Harvard Medical School, Boston, MA, USA.,Eaton Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA, USA
| | - Eric A Pierce
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA
| | - Qin Liu
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA. .,Ocular Genomics Institute, Massachusetts Eye and Ear, Boston, MA, USA.
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18
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Knockout of ush2a gene in zebrafish causes hearing impairment and late onset rod-cone dystrophy. Hum Genet 2018; 137:779-794. [PMID: 30242501 DOI: 10.1007/s00439-018-1936-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 09/16/2018] [Indexed: 10/28/2022]
Abstract
Most cases of Usher syndrome type II (USH2) are due to mutations in the USH2A gene. There are no effective treatments or ideal animal models for this disease, and the pathological mechanisms of USH2 caused by USH2A mutations are still unknown. Here, we constructed a ush2a knockout (ush2a-/-) zebrafish model using TALEN technology to investigate the molecular pathology of USH2. An early onset auditory disorder and abnormal morphology of inner ear stereocilia were identified in the ush2a-/- zebrafish. Consequently, the disruption of Ush2a in zebrafish led to a hearing impairment, like that in mammals. Electroretinography (ERG) test indicated that deletion of Ush2a affected visual function at an early stage, and histological analysis revealed that the photoreceptors progressively degenerated. Rod degeneration occurred prior to cone degeneration in ush2a-/- zebrafish, which is consistent with the classical description of the progression of retinitis pigmentosa (RP). Destruction of the outer segments (OSs) of rods led to the down-regulation of phototransduction cascade proteins at late stage. The expression of Ush1b and Ush1c was up-regulated when Ush2a was null. We also found that disruption of fibronectin assembly at the retinal basement membrane weakened cell adhesion in ush2a-/- mutants. In summary, for the first time, we generated a ush2a knockout zebrafish line with auditory disorder and retinal degeneration which mimicked the symptoms of patients, and revealed that disruption of fibronectin assembly may be one of the factors underlying RP. This model may help us to better understand the pathogenic mechanism and find treatment for USH2 in the future.
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19
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Baux D, Vaché C, Blanchet C, Willems M, Baudoin C, Moclyn M, Faugère V, Touraine R, Isidor B, Dupin-Deguine D, Nizon M, Vincent M, Mercier S, Calais C, García-García G, Azher Z, Lambert L, Perdomo-Trujillo Y, Giuliano F, Claustres M, Koenig M, Mondain M, Roux AF. Combined genetic approaches yield a 48% diagnostic rate in a large cohort of French hearing-impaired patients. Sci Rep 2017; 7:16783. [PMID: 29196752 PMCID: PMC5711943 DOI: 10.1038/s41598-017-16846-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 11/17/2017] [Indexed: 11/22/2022] Open
Abstract
Hearing loss is the most common sensory disorder and because of its high genetic heterogeneity, implementation of Massively Parallel Sequencing (MPS) in diagnostic laboratories is greatly improving the possibilities of offering optimal care to patients. We present the results of a two-year period of molecular diagnosis that included 207 French families referred for non-syndromic hearing loss. Our multi-step strategy involved (i) DFNB1 locus analysis, (ii) MPS of 74 genes, and (iii) additional approaches including Copy Number Variations, in silico analyses, minigene studies coupled when appropriate with complete gene sequencing, and a specific assay for STRC. This comprehensive screening yielded an overall diagnostic rate of 48%, equally distributed between DFNB1 (24%) and the other genes (24%). Pathogenic genotypes were identified in 19 different genes, with a high prevalence of GJB2, STRC, MYO15A, OTOF, TMC1, MYO7A and USH2A. Involvement of an Usher gene was reported in 16% of the genotyped cohort. Four de novo variants were identified. This study highlights the need to develop several molecular approaches for efficient molecular diagnosis of hearing loss, as this is crucial for genetic counselling, audiological rehabilitation and the detection of syndromic forms.
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Affiliation(s)
- D Baux
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - C Vaché
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - C Blanchet
- Service ORL, CHU Montpellier, Montpellier, France.,Centre National de Référence Maladies Rares "Affections Sensorielles Génétiques", CHU Montpellier, Montpellier, France
| | - M Willems
- Génétique Médicale, CHU Montpellier, Montpellier, France
| | - C Baudoin
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - M Moclyn
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - V Faugère
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - R Touraine
- Service de Génétique, CHU-Hôpital Nord, Saint-Etienne, France
| | - B Isidor
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - D Dupin-Deguine
- Service de Génétique Médicale, CHU Toulouse, Toulouse, France.,Service d'ORL, Otoneurologie et ORL pédiatrique CHU Toulouse, Toulouse, France
| | - M Nizon
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - M Vincent
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - S Mercier
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - C Calais
- Service d'ORL, CHU Nantes, Nantes, France
| | - G García-García
- Laboratoire de Génétique de Maladies Rares (LGMR) EA7402, Université de Montpellier, Montpellier, France
| | - Z Azher
- Laboratoire de Génétique de Maladies Rares (LGMR) EA7402, Université de Montpellier, Montpellier, France
| | - L Lambert
- Génétique Médicale, Centre de Compétence des Surdités Génétiques, site constitutif du Centre de Référence des Anomalies du Développement et Syndromes Malformatifs de l'Est, CHRU Nancy, Nancy, France
| | - Y Perdomo-Trujillo
- Service de Génétique Médicale, Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Civil, Strasbourg, France
| | - F Giuliano
- Service de Génétique Médicale, CHU Nice, Nice, France
| | - M Claustres
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France.,Laboratoire de Génétique de Maladies Rares (LGMR) EA7402, Université de Montpellier, Montpellier, France
| | - M Koenig
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France.,Laboratoire de Génétique de Maladies Rares (LGMR) EA7402, Université de Montpellier, Montpellier, France
| | - M Mondain
- Service ORL, CHU Montpellier, Montpellier, France.,Centre National de Référence Maladies Rares "Affections Sensorielles Génétiques", CHU Montpellier, Montpellier, France
| | - A F Roux
- Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France. .,Laboratoire de Génétique de Maladies Rares (LGMR) EA7402, Université de Montpellier, Montpellier, France.
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20
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Eandi CM, Dallorto L, Spinetta R, Micieli MP, Vanzetti M, Mariottini A, Passerini I, Torricelli F, Alovisi C, Marchese C. Targeted next generation sequencing in Italian patients with Usher syndrome: phenotype-genotype correlations. Sci Rep 2017; 7:15681. [PMID: 29142287 PMCID: PMC5688149 DOI: 10.1038/s41598-017-16014-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/31/2017] [Indexed: 11/10/2022] Open
Abstract
We report results of DNA analysis with next generation sequencing (NGS) of 21 consecutive Italian patients from 17 unrelated families with clinical diagnosis of Usher syndrome (4 USH1 and 17 USH2) searching for mutations in 11 genes: MYO7A, CDH23, PCDH15, USH1C, USH1G, USH2A, ADGVR1, DFNB31, CLRN1, PDZD7, HARS. Likely causative mutations were found in all patients: 25 pathogenic variants, 18 previously reported and 7 novel, were identified in three genes (USH2A, MYO7A, ADGRV1). All USH1 presented biallelic MYO7A mutations, one USH2 exhibited ADGRV1 mutations, whereas 16 USH2 displayed USH2A mutations. USH1 patients experienced hearing problems very early in life, followed by visual impairment at 1, 4 and 6 years. Visual symptoms were noticed at age 20 in a patient with homozygous novel MYO7A missense mutation c.849G > A. USH2 patients' auditory symptoms, instead, arose between 11 months and 14 years, while visual impairment occurred later on. A homozygous c.5933_5940del;5950_5960dup in USH2A was detected in one patient with early deafness. One patient with homozygous deletion from exon 23 to 32 in USH2A suffered early visual symptoms. Therefore, the type of mutation in USH2A and MYO7A genes seems to affect the age at which both auditory and visual impairment occur in patients with USH.
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Affiliation(s)
- Chiara M Eandi
- Department of Surgical Sciences, Eye Clinic, Università degli Studi di Torino, Torino, 10122, Italy.
| | - Laura Dallorto
- Department of Surgical Sciences, Eye Clinic, Università degli Studi di Torino, Torino, 10122, Italy
| | - Roberta Spinetta
- Department of Surgical Sciences, Eye Clinic, Università degli Studi di Torino, Torino, 10122, Italy
| | - Maria Pia Micieli
- Low vision Unit, Ospedale Oftalmico Sperino Torino, Torino, 10122, Italy
| | - Mario Vanzetti
- Inherited retinal dystrophies Unit, Azienda Ospedaliera Ordine Mauriziano Torino, Torino, 10128, Italy
| | | | - Ilaria Passerini
- Diagnostic Genetic Unit, AOU Careggi Firenze, Firenze, 50134, Italy
| | | | - Camilla Alovisi
- Department of Surgical Sciences, Eye Clinic, Università degli Studi di Torino, Torino, 10122, Italy
| | - Cristiana Marchese
- Inherited retinal dystrophies Unit, Azienda Ospedaliera Ordine Mauriziano Torino, Torino, 10128, Italy
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21
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Gupta A, Bastiampillai T. Usher syndrome and late-onset psychosis. Australas Psychiatry 2017; 25:316. [PMID: 28541731 DOI: 10.1177/1039856216679540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Dean G, Orford A, Staines R, McGee A, Smith KJ. Psychosocial well-being and health-related quality of life in a UK population with Usher syndrome. BMJ Open 2017; 7:e013261. [PMID: 28082366 PMCID: PMC5253575 DOI: 10.1136/bmjopen-2016-013261] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To determine whether psychosocial well-being is associated with the health-related quality of life (HRQOL) of people with Usher syndrome. SETTING The survey was advertised online and through deafblind-related charities, support groups and social groups throughout the UK. PARTICIPANTS 90 people with Usher syndrome took part in the survey. Inclusion criteria are having a diagnosis of Usher syndrome, being 18 or older and being a UK resident. PRIMARY AND SECONDARY OUTCOME MEASURES All participants took part in a survey that measured depressive symptoms, loneliness and social support (predictors) and their physical and mental HRQOL (outcomes). Measured confounders included age-related, sex-related and health-related characteristics. Hierarchical multiple linear regression analyses examined the association of each psychosocial well-being predictor with the physical and mental HRQOL outcomes while controlling for confounders in a stepwise manner. RESULTS After adjusting for all confounders, psychosocial well-being was shown to predict physical and mental HRQOL in our population with Usher syndrome. Increasing depressive symptoms were predictive of poorer physical (β=-0.36, p<0.01) and mental (β=-0.60, p<0.001) HRQOL. Higher levels of loneliness predicted poorer mental HRQOL (β=-0.20, p<0.05). Finally, increasing levels of social support predicted better mental HRQOL (β=0.19, p<0.05). CONCLUSIONS Depression, loneliness and social support all represent important issues that are linked with HRQOL in a UK population with Usher syndrome. Our results add to the growing body of evidence that psychosocial well-being is an important factor to consider in people with Usher syndrome alongside functional and physical impairment within research and clinical practice.
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Affiliation(s)
- Gavin Dean
- Department of Life Sciences, Brunel University London, Uxbridge, Middlesex, UK
| | - Amy Orford
- Department of Life Sciences, Brunel University London, Uxbridge, Middlesex, UK
| | | | | | - Kimberley J Smith
- Department of Life Sciences, Brunel University London, Uxbridge, Middlesex, UK
- Ageing Studies Research Group, Institute of Health, Environment and Societies. Brunel University London, Uxbridge, Middlesex, UK
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23
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Richardson R, Smart M, Tracey-White D, Webster AR, Moosajee M. Mechanism and evidence of nonsense suppression therapy for genetic eye disorders. Exp Eye Res 2017; 155:24-37. [PMID: 28065590 DOI: 10.1016/j.exer.2017.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/24/2016] [Accepted: 01/04/2017] [Indexed: 01/09/2023]
Abstract
Between 5 and 70% of genetic disease is caused by in-frame nonsense mutations, which introduce a premature termination codon (PTC) within the disease-causing gene. Consequently, during translation, non-functional or gain-of-function truncated proteins of pathological significance, are formed. Approximately 50% of all inherited retinal disorders have been associated with PTCs, highlighting the importance of novel pharmacological or gene correction therapies in ocular disease. Pharmacological nonsense suppression of PTCs could delineate a therapeutic strategy that treats the mutation in a gene- and disease-independent manner. This approach aims to suppress the fidelity of the ribosome during protein synthesis so that a near-cognate aminoacyl-tRNA, which shares two of the three nucleotides of the PTC, can be inserted into the peptide chain, allowing translation to continue, and a full-length functional protein to be produced. Here we discuss the mechanisms and evidence of nonsense suppression agents, including the small molecule drug ataluren (or PTC124) and next generation 'designer' aminoglycosides, for the treatment of genetic eye disease.
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Affiliation(s)
- Rose Richardson
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Matthew Smart
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Dhani Tracey-White
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Andrew R Webster
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Mariya Moosajee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK.
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24
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Mateo Sánchez S, Freeman SD, Delacroix L, Malgrange B. The role of post-translational modifications in hearing and deafness. Cell Mol Life Sci 2016; 73:3521-33. [PMID: 27147466 PMCID: PMC11108544 DOI: 10.1007/s00018-016-2257-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 12/20/2022]
Abstract
Post-translational modifications (PTMs) are key molecular events that modify proteins after their synthesis and modulate their ultimate functional properties by affecting their stability, localisation, interaction potential or activity. These chemical changes expand the size of the proteome adding diversity to the molecular pathways governing the biological outcome of cells. PTMs are, thus, crucial in regulating a variety of cellular processes such as apoptosis, proliferation and differentiation and have been shown to be instrumental during embryonic development. In addition, alterations in protein PTMs have been implicated in the pathogenesis of many human diseases, including deafness. In this review, we summarize the recent progress made in understanding the roles of PTMs during cochlear development, with particular emphasis on the enzymes driving protein phosphorylation, acetylation, methylation, glycosylation, ubiquitination and SUMOylation. We also discuss how these enzymes may contribute to hearing impairment and deafness.
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Affiliation(s)
- Susana Mateo Sánchez
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Stephen D Freeman
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Laurence Delacroix
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Brigitte Malgrange
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium.
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25
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Ribeiro JC, Oliveiros B, Pereira P, António N, Hummel T, Paiva A, Silva ED. Accelerated age-related olfactory decline among type 1 Usher patients. Sci Rep 2016; 6:28309. [PMID: 27329700 PMCID: PMC4916436 DOI: 10.1038/srep28309] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/02/2016] [Indexed: 12/22/2022] Open
Abstract
Usher Syndrome (USH) is a rare disease with hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. A phenotype heterogeneity is reported. Recent evidence indicates that USH is likely to belong to an emerging class of sensory ciliopathies. Olfaction has recently been implicated in ciliopathies, but the scarce literature about olfaction in USH show conflicting results. We aim to evaluate olfactory impairment as a possible clinical manifestation of USH. Prospective clinical study that included 65 patients with USH and 65 normal age-gender-smoking-habits pair matched subjects. A cross culturally validated version of the Sniffin’ Sticks olfaction test was used. Young patients with USH have significantly better olfactory scores than healthy controls. We observe that USH type 1 have a faster ageing olfactory decrease than what happens in healthy subjects, leading to significantly lower olfactory scores in older USH1 patients. Moreover, USH type 1 patients showed significantly higher olfactory scores than USH type 2, what can help distinguishing them. Olfaction represents an attractive tool for USH type classification and pre diagnostic screening due to the low cost and non-invasive nature of the testing. Olfactory dysfunction should be considered among the spectrum of clinical manifestations of Usher syndrome.
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Affiliation(s)
- João Carlos Ribeiro
- Department of Otorhinolaryngology, Coimbra University Hospitals, Portugal.,Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | - Bárbara Oliveiros
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | - Paulo Pereira
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
| | | | - Thomas Hummel
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - António Paiva
- Department of Otorhinolaryngology, Coimbra University Hospitals, Portugal.,Faculty of Medicine, University of Coimbra, Portugal
| | - Eduardo D Silva
- Faculty of Medicine, University of Coimbra, Portugal.,Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal
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26
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Dinculescu A, Stupay RM, Deng WT, Dyka FM, Min SH, Boye SL, Chiodo VA, Abrahan CE, Zhu P, Li Q, Strettoi E, Novelli E, Nagel-Wolfrum K, Wolfrum U, Smith WC, Hauswirth WW. AAV-Mediated Clarin-1 Expression in the Mouse Retina: Implications for USH3A Gene Therapy. PLoS One 2016; 11:e0148874. [PMID: 26881841 PMCID: PMC4755610 DOI: 10.1371/journal.pone.0148874] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 01/23/2016] [Indexed: 02/07/2023] Open
Abstract
Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken β-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder.
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Affiliation(s)
- Astra Dinculescu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
- * E-mail:
| | - Rachel M. Stupay
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Wen-Tao Deng
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Frank M. Dyka
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Seok-Hong Min
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Sanford L. Boye
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Vince A. Chiodo
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Carolina E. Abrahan
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Ping Zhu
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | - Qiuhong Li
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
| | | | | | - Kerstin Nagel-Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - W. Clay Smith
- Ophthalmology, University of Florida, Gainesville, FL, United States of America
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27
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Högner N. Psychological Stress in People with Dual Sensory Impairment through Usher Syndrome Type II. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2015. [DOI: 10.1177/0145482x1510900303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction Due to their dual, sensory impairment, people with Usher syndrome are assumed to have a high risk of stress. The purpose of this study was to assess stress in people with Usher syndrome type II (USH2) and the influence of personal variables such as age, gender, and employment on stress. Methods Two questionnaires were used: A self-developed questionnaire (SQ) to investigate the frequency and intensity of stress by external stressors within six life domains and the German standardized stress questionnaire Trierer Inventory of Chronic Stress (TICS) to compare frequency of stress between the USH2 sample group and a reference group ( n = 604). The questionnaires were filled in by an ad hoc sample of 262 persons with USH2 (response rate: 93%), mainly recruited from self-help groups (ages 17–79, mean age = 51; 53% female; 32% employed). Differences were determined by using methods of classical test theory. Results The evaluated SQ shows good indices in terms of item and factor analysis. The greatest stress was seen in the factor “Orientation and Mobility”; in TICS it was in the scale “Chronic Worry.” In TICS the USH2 sample showed significantly higher stress on scales that indicate a lack of social-emotional need fulfillment and less stress in those with high expectations ( p = .05). In both questionnaires, stress was dependent on personal variables. Discussion The results indicate the need for rehabilitation arrangements to reduce stress in people with USH2, especially in the areas of orientation and mobility, chronic worry, and social isolation. In intervention, particular attention should be paid to older, female, and unemployed people. Implications for practitioners Internal and external resources for people with dual sensory impairment need to be strengthened and systematic programs for learning how to cope with stress need to be established in order to provide clients with successful problem- and emotion-focused coping strategies.
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Affiliation(s)
- Nadja Högner
- Institute for Rehabilitation Sciences, Department of Education and Rehabilitation of the Blind and Low Vision Individuals, Humboldt-Universität zu Berlin, Georgenstrasse 36, 10117 Berlin, Germany
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28
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Dad S, Rendtorff ND, Kann E, Albrechtsen A, Mehrjouy MM, Bak M, Tommerup N, Tranebjærg L, Rosenberg T, Jensen H, Møller LB. Partial USH2A deletions contribute to Usher syndrome in Denmark. Eur J Hum Genet 2015; 23:1646-51. [PMID: 25804404 DOI: 10.1038/ejhg.2015.54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/18/2022] Open
Abstract
Usher syndrome is an autosomal recessive disorder characterized by congenital hearing impairment, progressive visual loss owing to retinitis pigmentosa and in some cases vestibular dysfunction. Usher syndrome is divided into three subtypes, USH1, USH2 and USH3. Twelve loci and eleven genes have so far been identified. Duplications and deletions in PCDH15 and USH2A that lead to USH1 and USH2, respectively, have previously been identified in patients from United Kingdom, Spain and Italy. In this study, we investigate the proportion of exon deletions and duplications in PCDH15 and USH2A in 20 USH1 and 30 USH2 patients from Denmark using multiplex ligation-dependent probe amplification (MLPA). Two heterozygous deletions were identified in USH2A, but no deletions or duplications were identified in PCDH15. Next-generation mate-pair sequencing was used to identify the exact breakpoints of the two deletions identified in USH2A. Our results suggest that USH2 is caused by USH2A exon deletions in a small fraction of the patients, whereas deletions or duplications in PCDH15 might be rare in Danish Usher patients.
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Affiliation(s)
- Shzeena Dad
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Nanna D Rendtorff
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Erik Kann
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Anders Albrechtsen
- Department of Biology, Computational and RNA Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mana M Mehrjouy
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mads Bak
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Niels Tommerup
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lisbeth Tranebjærg
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Thomas Rosenberg
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Hanne Jensen
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Lisbeth B Møller
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
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29
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Riahi Z, Bonnet C, Zainine R, Lahbib S, Bouyacoub Y, Bechraoui R, Marrakchi J, Hardelin JP, Louha M, Largueche L, Ben Yahia S, Kheirallah M, Elmatri L, Besbes G, Abdelhak S, Petit C. Whole exome sequencing identifies mutations in Usher syndrome genes in profoundly deaf Tunisian patients. PLoS One 2015; 10:e0120584. [PMID: 25798947 PMCID: PMC4370767 DOI: 10.1371/journal.pone.0120584] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 01/24/2015] [Indexed: 01/13/2023] Open
Abstract
Usher syndrome (USH) is an autosomal recessive disorder characterized by combined deafness-blindness. It accounts for about 50% of all hereditary deafness blindness cases. Three clinical subtypes (USH1, USH2, and USH3) are described, of which USH1 is the most severe form, characterized by congenital profound deafness, constant vestibular dysfunction, and a prepubertal onset of retinitis pigmentosa. We performed whole exome sequencing in four unrelated Tunisian patients affected by apparently isolated, congenital profound deafness, with reportedly normal ocular fundus examination. Four biallelic mutations were identified in two USH1 genes: a splice acceptor site mutation, c.2283-1G>T, and a novel missense mutation, c.5434G>A (p.Glu1812Lys), in MYO7A, and two previously unreported mutations in USH1G, i.e. a frameshift mutation, c.1195_1196delAG (p.Leu399Alafs*24), and a nonsense mutation, c.52A>T (p.Lys18*). Another ophthalmological examination including optical coherence tomography actually showed the presence of retinitis pigmentosa in all the patients. Our findings provide evidence that USH is under-diagnosed in Tunisian deaf patients. Yet, early diagnosis of USH is of utmost importance because these patients should undergo cochlear implant surgery in early childhood, in anticipation of the visual loss.
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Affiliation(s)
- Zied Riahi
- Institut Pasteur de Tunis, LR11IPT05, Biomedical Genomics and Oncogenetics Laboratory, 1002, Tunis, Tunisia
- Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 El Manar I Tunis, Tunis, Tunisia
| | - Crystel Bonnet
- Institut de la Vision, INSERM UMRS 1120, UPMC- Paris 6, Paris, France
| | - Rim Zainine
- La Rabta Hospital, Otorhinolaryngology Diseases, Tunis, Tunisia
| | - Saida Lahbib
- Institut Pasteur de Tunis, LR11IPT05, Biomedical Genomics and Oncogenetics Laboratory, 1002, Tunis, Tunisia
| | - Yosra Bouyacoub
- Institut Pasteur de Tunis, LR11IPT05, Biomedical Genomics and Oncogenetics Laboratory, 1002, Tunis, Tunisia
- Université de Monastir, Institut Supérieur de Biotechnologie, Monastir, Tunisia
| | - Rym Bechraoui
- La Rabta Hospital, Otorhinolaryngology Diseases, Tunis, Tunisia
| | | | - Jean-Pierre Hardelin
- Institut Pasteur, Unité de Génétique et Physiologie de l’Audition, Paris, France
| | - Malek Louha
- Laboratoire de Biochimie et de Biologie Moléculaire, Hôpital Armand Trousseau, APHP, Paris, France
| | - Leila Largueche
- Department B of Ophthalmology, Hedi Rais Institute of Ophthalmology, Tunis, Tunisia
| | - Salim Ben Yahia
- Universite de Monastir, Faculty of Medicine, Fattouma Bourguiba University Hospital, Department of Ophthalmology, 5000, Monastir, Tunisia
| | - Moncef Kheirallah
- Universite de Monastir, Faculty of Medicine, Fattouma Bourguiba University Hospital, Department of Ophthalmology, 5000, Monastir, Tunisia
| | - Leila Elmatri
- Department B of Ophthalmology, Hedi Rais Institute of Ophthalmology, Tunis, Tunisia
| | - Ghazi Besbes
- La Rabta Hospital, Otorhinolaryngology Diseases, Tunis, Tunisia
| | - Sonia Abdelhak
- Institut Pasteur de Tunis, LR11IPT05, Biomedical Genomics and Oncogenetics Laboratory, 1002, Tunis, Tunisia
- * E-mail:
| | - Christine Petit
- Institut de la Vision, INSERM UMRS 1120, UPMC- Paris 6, Paris, France
- Institut Pasteur, Unité de Génétique et Physiologie de l’Audition, Paris, France
- Collège de France, Paris, France
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Mathur P, Yang J. Usher syndrome: Hearing loss, retinal degeneration and associated abnormalities. Biochim Biophys Acta Mol Basis Dis 2014; 1852:406-20. [PMID: 25481835 DOI: 10.1016/j.bbadis.2014.11.020] [Citation(s) in RCA: 222] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/25/2014] [Accepted: 11/26/2014] [Indexed: 02/06/2023]
Abstract
Usher syndrome (USH), clinically and genetically heterogeneous, is the leading genetic cause of combined hearing and vision loss. USH is classified into three types, based on the hearing and vestibular symptoms observed in patients. Sixteen loci have been reported to be involved in the occurrence of USH and atypical USH. Among them, twelve have been identified as causative genes and one as a modifier gene. Studies on the proteins encoded by these USH genes suggest that USH proteins interact among one another and function in multiprotein complexes in vivo. Although their exact functions remain enigmatic in the retina, USH proteins are required for the development, maintenance and function of hair bundles, which are the primary mechanosensitive structure of inner ear hair cells. Despite the unavailability of a cure, progress has been made to develop effective treatments for this disease. In this review, we focus on the most recent discoveries in the field with an emphasis on USH genes, protein complexes and functions in various tissues as well as progress toward therapeutic development for USH.
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Affiliation(s)
- Pranav Mathur
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA; Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
| | - Jun Yang
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA; Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA; Department of Otolaryngology Head and Neck Surgery, University of Utah, Salt Lake City, UT 84132, USA.
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Dyka FM, Boye SL, Chiodo VA, Hauswirth WW, Boye SE. Dual adeno-associated virus vectors result in efficient in vitro and in vivo expression of an oversized gene, MYO7A. Hum Gene Ther Methods 2014; 25:166-77. [PMID: 24568220 DOI: 10.1089/hgtb.2013.212] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Usher syndrome 1B (USH1B) is a severe, autosomal recessive, deaf-blind disorder caused by mutations in myosin 7A (MYO7A). Patients are born profoundly deaf and exhibit progressive loss of vision starting in their first decade. MYO7A is expressed in human photoreceptors and retinal pigment epithelium, but disease pathology begins in photoreceptors, highlighting the need to develop a gene replacement strategy that effectively targets this cell type. For its safety and efficacy in clinical trials and ability to transduce postmitotic photoreceptors, we have focused on developing a clinically applicable adeno-associated virus (AAV) platform for delivering full-length MYO7A cDNA (∼6.7 kb). Packaging of full-length MYO7A cDNA in AAV produces vectors with heterogeneous, fragmented genomes ("fAAV") capable of reconstituting full-length cDNA postinfection. We previously showed that fAAV vectors effectively delivered full-length MYO7A in vitro and in vivo. However, fAAV vectors are relatively inefficient and their heterogeneous genomes preclude definitive characterization, a drawback for clinical translatability. The aim of this study was to overcome these limitations by creating dual-AAV-vector platforms for USH1B with defined genomes. Human MYO7A was cloned in AAV vector pairs, each containing genomes <5 kb and intact inverted terminal repeats. One vector contained a promoter and 5' portion of the cDNA and the partner vector contained a 3' portion and polyadenylation signal. "Simple overlap" vectors share a central part of the MYO7A cDNA sequence. "Trans-splicing" and "hybrid" vectors utilize splice donor and acceptor sites with and without an additional central recombinogenic sequence, respectively. Vector pairs expressed full-length MYO7A in vitro and in vivo with equal or higher efficiency than fAAV, with a hybrid platform being most efficient. Importantly, analysis of MYO7A mRNA derived from each dual-vector platform revealed 100% fidelity to the predicted sequence. Our results suggest that dual AAV vectors with defined genetic payloads are a potential treatment option for USH1B.
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Affiliation(s)
- Frank M Dyka
- Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, FL 32610
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Usher syndrome protein network functions in the retina and their relation to other retinal ciliopathies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:527-33. [PMID: 24664740 DOI: 10.1007/978-1-4614-3209-8_67] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human Usher syndrome (USH) is the most frequent cause of combined hereditary deaf-blindness. USH is genetically and clinically heterogeneous: 15 chromosomal loci assigned to 3 clinical types, USH1-3. All USH1 and 2 proteins are organized into protein networks by the scaffold proteins harmonin (USH1C), whirlin (USH2D) and SANS (USH1G). This has contributed essentially to our current understanding of the USH protein function in the eye and the ear and explains why defects in proteins of different families cause very similar phenotypes. Ongoing in depth analyses of USH protein networks in the eye indicated cytoskeletal functions as well as roles in molecular transport processes and ciliary cargo delivery in photoreceptor cells. The analysis of USH protein networks revealed molecular links of USH to other ciliopathies, including non-syndromic inner ear defects and isolated retinal dystrophies but also to kidney diseases and syndromes like the Bardet-Biedl syndrome. These findings provide emerging evidence that USH is a ciliopathy molecularly related to other ciliopathies, which opens an avenue for common therapy strategies to treat these diseases.
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Novel and recurrent MYO7A mutations in Usher syndrome type 1 and type 2. PLoS One 2014; 9:e97808. [PMID: 24831256 PMCID: PMC4022727 DOI: 10.1371/journal.pone.0097808] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/24/2014] [Indexed: 11/19/2022] Open
Abstract
Usher syndrome (USH) is a group of disorders manifested as retinitis pigmentosa and bilateral sensorineural hearing loss, with or without vestibular dysfunction. Here, we recruited three Chinese families affected with autosomal recessive USH for detailed clinical evaluations and for mutation screening in the genes associated with inherited retinal diseases. Using targeted next-generation sequencing (NGS) approach, three new alleles and one known mutation in MYO7A gene were identified in the three families. In two families with USH type 1, novel homozygous frameshift variant p.Pro194Hisfs*13 and recurrent missense variant p.Thr165Met were demonstrated as the causative mutations respectively. Crystal structural analysis denoted that p.Thr165Met would very likely change the tertiary structure of the protein encoded by MYO7A. In another family affected with USH type 2, novel biallelic mutations in MYO7A, c.[1343+1G>A];[2837T>G] or p.[?];[Met946Arg], were identified with clinical significance. Because MYO7A, to our knowledge, has rarely been correlated with USH type 2, our findings therefore reveal distinguished clinical phenotypes associated with MYO7A. We also conclude that targeted NGS is an effective approach for genetic diagnosis for USH, which can further provide better understanding of genotype-phenotype relationship of the disease.
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Piatti G, De Santi MM, Brogi M, Castorina P, Ambrosetti U. Emerging ciliopathies: are respiratory cilia compromised in Usher syndrome? Am J Otolaryngol 2014; 35:340-6. [PMID: 24602455 DOI: 10.1016/j.amjoto.2014.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 01/26/2014] [Indexed: 01/19/2023]
Abstract
PURPOSE Usher syndrome is a ciliopathy involving photoreceptors and cochlear hair cells (sensory cilia): since sensory and motor ciliopathies can overlap, we analysed the respiratory cilia (motile) in 17 patients affected by Usher syndrome and 18 healthy control subject. PATIENTS AND METHODS We studied the mucociliary transport time with the saccharine test, ciliary motility and ultrastructure of respiratory cilia obtained by nasal brushing; we also recorded the classical respiratory function values by spirometry. RESULTS All enrolled subjects showed normal respiratory function values. The mean mucociliary transport time with saccharine was 22.33 ± 17.96 min, which is in the range of normal values. The mean ciliary beat frequency of all subjects was 8.81 ± 2.18 Hz, which is a value approaching the lower physiological limit. None of the classical ciliary alterations characterizing the "ciliary primary dyskinesia" was detected, although two patients showed alterations in number and arrangement of peripheral microtubules and one patient had abnormal ciliary roots. CONCLUSIONS Respiratory cilia in Usher patients don't seem to have evident ultrastructural alterations, as expected, but the fact that the ciliary motility appeared slightly reduced could emphasize that a rigid distinction between sensory and motor ciliopathies may not reflect what really occurs.
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Affiliation(s)
- G Piatti
- Department of Pathophysiology and Transplantation, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy.
| | - M M De Santi
- Department of Human Pathology and Oncology, University of Siena, Italy
| | - M Brogi
- Department of Human Pathology and Oncology, University of Siena, Italy
| | - P Castorina
- Department of Clinical Sciences and Community, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy
| | - U Ambrosetti
- Department of Clinical Sciences and Community, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy
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Bauß K, Knapp B, Jores P, Roepman R, Kremer H, Wijk EV, Märker T, Wolfrum U. Phosphorylation of the Usher syndrome 1G protein SANS controls Magi2-mediated endocytosis. Hum Mol Genet 2014; 23:3923-42. [PMID: 24608321 DOI: 10.1093/hmg/ddu104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The human Usher syndrome (USH) is a complex ciliopathy with at least 12 chromosomal loci assigned to three clinical subtypes, USH1-3. The heterogeneous USH proteins are organized into protein networks. Here, we identified Magi2 (membrane-associated guanylate kinase inverted-2) as a new component of the USH protein interactome, binding to the multifunctional scaffold protein SANS (USH1G). We showed that the SANS-Magi2 complex assembly is regulated by the phosphorylation of an internal PDZ-binding motif in the sterile alpha motif domain of SANS by the protein kinase CK2. We affirmed Magi2's role in receptor-mediated, clathrin-dependent endocytosis and showed that phosphorylated SANS tightly regulates Magi2-mediated endocytosis. Specific depletions by RNAi revealed that SANS and Magi2-mediated endocytosis regulates aspects of ciliogenesis. Furthermore, we demonstrated the localization of the SANS-Magi2 complex in the periciliary membrane complex facing the ciliary pocket of retinal photoreceptor cells in situ. Our data suggest that endocytotic processes may not only contribute to photoreceptor cell homeostasis but also counterbalance the periciliary membrane delivery accompanying the exocytosis processes for the cargo vesicle delivery. In USH1G patients, mutations in SANS eliminate Magi2 binding and thereby deregulate endocytosis, lead to defective ciliary transport modules and ultimately disrupt photoreceptor cell function inducing retinal degeneration.
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Affiliation(s)
- Katharina Bauß
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Barbara Knapp
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Pia Jores
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Ronald Roepman
- Department of Human Genetics, Institute for Genetic and Metabolic Disease, Nijmegen Centre for Molecular Life Sciences and
| | - Hannie Kremer
- Department of Human Genetics, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen Centre for Molecular Life Sciences and Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, 6500 HB, Nijmegen, Netherlands
| | - Erwin V Wijk
- Department of Human Genetics, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen Centre for Molecular Life Sciences and Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, 6500 HB, Nijmegen, Netherlands
| | - Tina Märker
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
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Tian M, Wang W, Delimont D, Cheung L, Zallocchi M, Cosgrove D, Peng YW. Photoreceptors in whirler mice show defective transducin translocation and are susceptible to short-term light/dark changes-induced degeneration. Exp Eye Res 2014; 118:145-53. [PMID: 24211856 PMCID: PMC4408763 DOI: 10.1016/j.exer.2013.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/26/2013] [Accepted: 10/29/2013] [Indexed: 12/12/2022]
Abstract
Usher syndrome combines congenital hearing loss and retinitis pigmentosa (RP). Mutations in the whirlin gene (DFNB31/WHRN) cause a subtype of Usher syndrome (USH2D). Whirler mice have a defective whirlin gene. They have inner ear defects but usually do not develop retinal degeneration. Here we report that, in whirler mouse photoreceptors, the light-activated rod transducin translocation is delayed and its activation threshold is shifted to a higher level. Rhodopsin mis-localization is observed in rod inner segments. Continuous moderate light exposure can induce significant rod photoreceptor degeneration. Whirler mice reared under a 1500 lux light/dark cycle also develop severe photoreceptor degeneration. Previously, we have reported that shaker1 mice, a USH1B model, show moderate light-induced photoreceptor degeneration with delayed transducin translocation. Here, we further show that, in both whirler and shaker1 mice, short-term moderate light/dark changes can induce rod degeneration as severe as that induced by continuous light exposure. The results from shaker1 and whirler mice suggest that defective transducin translocation may be functionally related to light-induced degeneration, and these two symptoms may be caused by defects in Usher protein function in rods. Furthermore, these results indicate that both Usher syndrome mouse models possess a light-induced retinal phenotype and may share a closely related pathobiological mechanism.
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Affiliation(s)
- Mei Tian
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA; National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing 100088, China
| | - Weimin Wang
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA
| | - Duane Delimont
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA
| | - Linda Cheung
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA
| | - Marisa Zallocchi
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA
| | - Dominic Cosgrove
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA; University of Nebraska Medical Center, 600 S 42nd, Omaha, NE 68198, USA
| | - You-Wei Peng
- Sensory Neuroscience Department, Boys Town National Research Hospital, 555 North 30th St., Omaha, NE 68131, USA.
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Steele-Stallard HB, Le Quesne Stabej P, Lenassi E, Luxon LM, Claustres M, Roux AF, Webster AR, Bitner-Glindzicz M. Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing. Orphanet J Rare Dis 2013; 8:122. [PMID: 23924366 PMCID: PMC3751126 DOI: 10.1186/1750-1172-8-122] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 08/04/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Usher Syndrome is the leading cause of inherited deaf-blindness. It is divided into three subtypes, of which the most common is Usher type 2, and the USH2A gene accounts for 75-80% of cases. Despite recent sequencing strategies, in our cohort a significant proportion of individuals with Usher type 2 have just one heterozygous disease-causing mutation in USH2A, or no convincing disease-causing mutations across nine Usher genes. The purpose of this study was to improve the molecular diagnosis in these families by screening USH2A for duplications, heterozygous deletions and a common pathogenic deep intronic variant USH2A: c.7595-2144A>G. METHODS Forty-nine Usher type 2 or atypical Usher families who had missing mutations (mono-allelic USH2A or no mutations following Sanger sequencing of nine Usher genes) were screened for duplications/deletions using the USH2A SALSA MLPA reagent kit (MRC-Holland). Identification of USH2A: c.7595-2144A>G was achieved by Sanger sequencing. Mutations were confirmed by a combination of reverse transcription PCR using RNA extracted from nasal epithelial cells or fibroblasts, and by array comparative genomic hybridisation with sequencing across the genomic breakpoints. RESULTS Eight mutations were identified in 23 Usher type 2 families (35%) with one previously identified heterozygous disease-causing mutation in USH2A. These consisted of five heterozygous deletions, one duplication, and two heterozygous instances of the pathogenic variant USH2A: c.7595-2144A>G. No variants were found in the 15 Usher type 2 families with no previously identified disease-causing mutations. In 11 atypical families, none of whom had any previously identified convincing disease-causing mutations, the mutation USH2A: c.7595-2144A>G was identified in a heterozygous state in one family. All five deletions and the heterozygous duplication we report here are novel. This is the first time that a duplication in USH2A has been reported as a cause of Usher syndrome. CONCLUSIONS We found that 8 of 23 (35%) of 'missing' mutations in Usher type 2 probands with only a single heterozygous USH2A mutation detected with Sanger sequencing could be attributed to deletions, duplications or a pathogenic deep intronic variant. Future mutation detection strategies and genetic counselling will need to take into account the prevalence of these types of mutations in order to provide a more comprehensive diagnostic service.
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Besnard T, García-García G, Baux D, Vaché C, Faugère V, Larrieu L, Léonard S, Millan JM, Malcolm S, Claustres M, Roux AF. Experience of targeted Usher exome sequencing as a clinical test. Mol Genet Genomic Med 2013; 2:30-43. [PMID: 24498627 PMCID: PMC3907913 DOI: 10.1002/mgg3.25] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/06/2013] [Indexed: 12/15/2022] Open
Abstract
We show that massively parallel targeted sequencing of 19 genes provides a new and reliable strategy for molecular diagnosis of Usher syndrome (USH) and nonsyndromic deafness, particularly appropriate for these disorders characterized by a high clinical and genetic heterogeneity and a complex structure of several of the genes involved. A series of 71 patients including Usher patients previously screened by Sanger sequencing plus newly referred patients was studied. Ninety-eight percent of the variants previously identified by Sanger sequencing were found by next-generation sequencing (NGS). NGS proved to be efficient as it offers analysis of all relevant genes which is laborious to reach with Sanger sequencing. Among the 13 newly referred Usher patients, both mutations in the same gene were identified in 77% of cases (10 patients) and one candidate pathogenic variant in two additional patients. This work can be considered as pilot for implementing NGS for genetically heterogeneous diseases in clinical service.
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Affiliation(s)
- Thomas Besnard
- U827, Inserm Montpellier, F-34000, France ; Univ, Montpellier I Montpellier, F-34000, France
| | - Gema García-García
- U827, Inserm Montpellier, F-34000, France ; Grupo de Investigación en Enfermedades Neurosensoriales, Instituto de Investigación Sanitaria IIS-La Fe and CIBERER Valencia, Spain
| | - David Baux
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Christel Vaché
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Valérie Faugère
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Lise Larrieu
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Susana Léonard
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Jose M Millan
- Grupo de Investigación en Enfermedades Neurosensoriales, Instituto de Investigación Sanitaria IIS-La Fe and CIBERER Valencia, Spain
| | - Sue Malcolm
- Clinical and Molecular Genetics, Institute of Child Health, University College London London, United Kingdom
| | - Mireille Claustres
- U827, Inserm Montpellier, F-34000, France ; Univ, Montpellier I Montpellier, F-34000, France ; Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Anne-Françoise Roux
- U827, Inserm Montpellier, F-34000, France ; Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
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Västinsalo H, Jalkanen R, Bergmann C, Neuhaus C, Kleemola L, Jauhola L, Bolz HJ, Sankila EM. Extended mutation spectrum of Usher syndrome in Finland. Acta Ophthalmol 2013; 91:325-34. [PMID: 22681893 DOI: 10.1111/j.1755-3768.2012.02397.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE The Finnish distribution of clinical Usher syndrome (USH) types is 40% USH3, 34% USH1 and 12% USH2. All patients with USH3 carry the founder mutation in clarin 1 (CLRN1), whereas we recently reported three novel myosin VIIA (MYO7A) mutations in two unrelated patients with USH1. This study was carried out to further investigate the USH mutation spectrum in Finnish patients. METHODS We analysed samples from nine unrelated USH patients/families without known mutations and two USH3 families with atypically severe phenotype. The Asper Ophthalmics USH mutation chip was used to screen for known mutations and to evaluate the chip in molecular diagnostics of Finnish patients. RESULTS The chip revealed a heterozygous usherin (USH2A) mutation, p.N346H, in one patient. Sequencing of MYO7A and/or USH2A in three index patients revealed two novel heterozygous mutations, p.R873W in MYO7A and c.14343+2T>C in USH2A. We did not identify definite pathogenic second mutations in the patients, but identified several probably nonpathogenic variations that may modify the disease phenotype. Possible digenism could not be excluded in two families segregating genomic variations in both MYO7A and USH2A, and two families with CLRN1 and USH2A. CONCLUSION We conclude that there is considerable genetic heterogeneity of USH1 and USH2 in Finland, making molecular diagnostics and genetic counselling of patients and families challenging.
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Affiliation(s)
- Hanna Västinsalo
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.
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Bocquet B, Lacroux A, Surget MO, Baudoin C, Marquette V, Manes G, Hebrard M, Sénéchal A, Delettre C, Roux AF, Claustres M, Dhaenens CM, Rozet JM, Perrault I, Bonnefont JP, Kaplan J, Dollfus H, Amati-Bonneau P, Bonneau D, Reynier P, Audo I, Zeitz C, Sahel JA, Paquis-Flucklinger V, Calvas P, Arveiler B, Kohl S, Wissinger B, Blanchet C, Meunier I, Hamel CP. Relative Frequencies of Inherited Retinal Dystrophies and Optic Neuropathies in Southern France: Assessment of 21-year Data Management. Ophthalmic Epidemiol 2013; 20:13-25. [DOI: 10.3109/09286586.2012.737890] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Miller KA, Williams LH, Rose E, Kuiper M, Dahl HHM, Manji SSM. Inner ear morphology is perturbed in two novel mouse models of recessive deafness. PLoS One 2012; 7:e51284. [PMID: 23251483 PMCID: PMC3520982 DOI: 10.1371/journal.pone.0051284] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 10/31/2012] [Indexed: 11/29/2022] Open
Abstract
Human MYO7A mutations can cause a variety of conditions involving the inner ear. These include dominant and recessive non-syndromic hearing loss and syndromic conditions such as Usher syndrome. Mouse models of deafness allow us to investigate functional pathways involved in normal and abnormal hearing processes. We present two novel mouse models with mutations in the Myo7a gene with distinct phenotypes. The mutation in Myo7aI487N/I487N ewaso is located within the head motor domain of Myo7a. Mice exhibit a profound hearing loss and manifest behaviour associated with a vestibular defect. A mutation located in the linker region between the coiled-coil and the first MyTH4 domains of the protein is responsible in Myo7aF947I/F947I dumbo. These mice show a less severe hearing loss than in Myo7aI487N/I487N ewaso; their hearing loss threshold is elevated at 4 weeks old, and progressively worsens with age. These mice show no obvious signs of vestibular dysfunction, although scanning electron microscopy reveals a mild phenotype in vestibular stereocilia bundles. The Myo7aF947I/F947I dumbo strain is therefore the first reported Myo7a mouse model without an overt vestibular phenotype; a possible model for human DFNB2 deafness. Understanding the molecular basis of these newly identified mutations will provide knowledge into the complex genetic pathways involved in the maintenance of hearing, and will provide insight into recessively inherited sensorineural hearing loss in humans.
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Affiliation(s)
- Kerry A Miller
- Genetic Hearing Research, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia.
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The mechanosensory structure of the hair cell requires clarin-1, a protein encoded by Usher syndrome III causative gene. J Neurosci 2012; 32:9485-98. [PMID: 22787034 DOI: 10.1523/jneurosci.0311-12.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutation in the clarin-1 gene (Clrn1) results in loss of hearing and vision in humans (Usher syndrome III), but the role of clarin-1 in the sensory hair cells is unknown. Clarin-1 is predicted to be a four transmembrane domain protein similar to members of the tetraspanin family. Mice carrying null mutation in the clarin-1 gene (Clrn1(-/-)) show loss of hair cell function and a possible defect in ribbon synapse. We investigated the role of clarin-1 using various in vitro and in vivo approaches. We show by immunohistochemistry and patch-clamp recordings of Ca(2+) currents and membrane capacitance from inner hair cells that clarin-1 is not essential for formation or function of ribbon synapse. However, reduced cochlear microphonic potentials, FM1-43 [N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] loading, and transduction currents pointed to diminished cochlear hair bundle function in Clrn1(-/-) mice. Electron microscopy of cochlear hair cells revealed loss of some tall stereocilia and gaps in the v-shaped bundle, although tip links and staircase arrangement of stereocilia were not primarily affected by Clrn1(-/-) mutation. Human clarin-1 protein expressed in transfected mouse cochlear hair cells localized to the bundle; however, the pathogenic variant p.N48K failed to localize to the bundle. The mouse model generated to study the in vivo consequence of p.N48K in clarin-1 (Clrn1(N48K)) supports our in vitro and Clrn1(-/-) mouse data and the conclusion that CLRN1 is an essential hair bundle protein. Furthermore, the ear phenotype in the Clrn1(N48K) mouse suggests that it is a valuable model for ear disease in CLRN1(N48K), the most prevalent Usher syndrome III mutation in North America.
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Fakin A, Jarc-Vidmar M, Glavač D, Bonnet C, Petit C, Hawlina M. Fundus autofluorescence and optical coherence tomography in relation to visual function in Usher syndrome type 1 and 2. Vision Res 2012; 75:60-70. [PMID: 23000274 DOI: 10.1016/j.visres.2012.08.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/23/2012] [Accepted: 08/27/2012] [Indexed: 11/19/2022]
Abstract
Purpose of this study was to characterize retinal disease in Usher syndrome using fundus autofluorescence and optical coherence tomography. Study included 54 patients (26 male, 28 female) aged 7-70 years. There were 18 (33%) USH1 and 36 (67%) USH2 patients. 49/52 (94%) patients were found to carry at least one mutation in Usher genes. Ophthalmological examination included assessment of Snellen visual acuity, color vision with Ishihara tables, Goldmann visual fields (targets II/1-4 and V/4), microperimetry, fundus autofluorescence imaging and optical coherence tomography. Average age at disease onset (nyctalopia) was significantly lower in USH1 than USH2 patients (average 9 vs. 17 years, respectively; p<0.01); however no significant differences were found regarding type of autofluorescence patterns, frequency of foveal lesions and CME, rate of disease progression and age at legal blindness. All representative eyes had abnormal fundus autofluorescence of either hyperautofluorescent ring (55%), hyperautofluorescent foveal patch (35%) or foveal atrophy (10%). Disease duration of more than 30 years was associated with a high incidence of abnormal central fundus autofluorescence (patch or atrophy) and visual acuity loss.
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Affiliation(s)
- Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia.
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Albert ES, Bec JM, Desmadryl G, Chekroud K, Travo C, Gaboyard S, Bardin F, Marc I, Dumas M, Lenaers G, Hamel C, Muller A, Chabbert C. TRPV4 channels mediate the infrared laser-evoked response in sensory neurons. J Neurophysiol 2012; 107:3227-34. [PMID: 22442563 DOI: 10.1152/jn.00424.2011] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Infrared laser irradiation has been established as an appropriate stimulus for primary sensory neurons under conditions where sensory receptor cells are impaired or lost. Yet, development of clinical applications has been impeded by lack of information about the molecular mechanisms underlying the laser-induced neural response. Here, we directly address this question through pharmacological characterization of the biological response evoked by midinfrared irradiation of isolated retinal and vestibular ganglion cells from rodents. Whole cell patch-clamp recordings reveal that both voltage-gated calcium and sodium channels contribute to the laser-evoked neuronal voltage variations (LEVV). In addition, selective blockade of the LEVV by micromolar concentrations of ruthenium red and RN 1734 identifies thermosensitive transient receptor potential vanilloid channels as the primary effectors of the chain reaction triggered by midinfrared laser irradiation. These results have the potential to facilitate greatly the design of future prosthetic devices aimed at restoring neurosensory capacities in disabled patients.
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Affiliation(s)
- E S Albert
- U-1051, INSERM Institut des Neurosciences de Montpellier, Montpellier, France.
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Besnard T, Vaché C, Baux D, Larrieu L, Abadie C, Blanchet C, Odent S, Blanchet P, Calvas P, Hamel C, Dollfus H, Lina-Granade G, Lespinasse J, David A, Isidor B, Morin G, Malcolm S, Tuffery-Giraud S, Claustres M, Roux AF. Non-USH2A mutations in USH2 patients. Hum Mutat 2012; 33:504-10. [PMID: 22147658 DOI: 10.1002/humu.22004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 11/28/2011] [Indexed: 11/08/2022]
Abstract
We have systematically analyzed the two known minor genes involved in Usher syndrome type 2, DFNB31 and GPR98, for mutations in a cohort of 31 patients not linked to USH2A. PDZD7, an Usher syndrome type 2 (USH2) related gene, was analyzed when indicated. We found that mutations in GPR98 contribute significantly to USH2. We report 17 mutations in 10 individuals, doubling the number of GPR98 mutations reported to date. In contrast to mutations in usherin, the mutational spectrum of GPR98 predominantly results in a truncated protein product. This is true even when the mutation affects splicing, and we have incorporated a splicing reporter minigene assay to show this, where appropriate. Only two mutations were found which we believe to be genuine missense changes. Discrepancy in the mutational spectrum between GPR98 and USH2A is discussed. Only two patients were found with mutations in DFNB31, showing that mutations of this gene contribute to only a very small extent to USH2. Close examination of the clinical details, where available, for patients in whom no mutation was found in USH2A, GPR98, or DFNB31, showed that most of them had atypical features. In effect, these three genes account for the vast majority of USH2 patients and their analysis provide a robust pathway for routine molecular diagnosis.
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Affiliation(s)
- Thomas Besnard
- CHU Montpellier, Laboratoire de Génétique Moléculaire, Montpellier, France
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Speech Recognition and Communication Outcomes With Cochlear Implantation in Usher Syndrome Type 3. Otol Neurotol 2012; 33:38-41. [DOI: 10.1097/mao.0b013e31823dbc56] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Yang J, Wang L, Song H, Sokolov M. Current understanding of usher syndrome type II. Front Biosci (Landmark Ed) 2012; 17:1165-83. [PMID: 22201796 DOI: 10.2741/3979] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Usher syndrome is the most common deafness-blindness caused by genetic mutations. To date, three genes have been identified underlying the most prevalent form of Usher syndrome, the type II form (USH2). The proteins encoded by these genes are demonstrated to form a complex in vivo. This complex is localized mainly at the periciliary membrane complex in photoreceptors and the ankle-link of the stereocilia in hair cells. Many proteins have been found to interact with USH2 proteins in vitro, suggesting that they are potential additional components of this USH2 complex and that the genes encoding these proteins may be the candidate USH2 genes. However, further investigations are critical to establish their existence in the USH2 complex in vivo. Based on the predicted functional domains in USH2 proteins, their cellular localizations in photoreceptors and hair cells, the observed phenotypes in USH2 mutant mice, and the known knowledge about diseases similar to USH2, putative biological functions of the USH2 complex have been proposed. Finally, therapeutic approaches for this group of diseases are now being actively explored.
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Affiliation(s)
- Jun Yang
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, Utah 84132
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Le Quesne Stabej P, Saihan Z, Rangesh N, Steele-Stallard HB, Ambrose J, Coffey A, Emmerson J, Haralambous E, Hughes Y, Steel KP, Luxon LM, Webster AR, Bitner-Glindzicz M. Comprehensive sequence analysis of nine Usher syndrome genes in the UK National Collaborative Usher Study. J Med Genet 2011; 49:27-36. [PMID: 22135276 PMCID: PMC3678402 DOI: 10.1136/jmedgenet-2011-100468] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background Usher syndrome (USH) is an autosomal recessive disorder comprising retinitis pigmentosa, hearing loss and, in some cases, vestibular dysfunction. It is clinically and genetically heterogeneous with three distinctive clinical types (I–III) and nine Usher genes identified. This study is a comprehensive clinical and genetic analysis of 172 Usher patients and evaluates the contribution of digenic inheritance. Methods The genes MYO7A, USH1C, CDH23, PCDH15, USH1G, USH2A, GPR98, WHRN, CLRN1 and the candidate gene SLC4A7 were sequenced in 172 UK Usher patients, regardless of clinical type. Results No subject had definite mutations (nonsense, frameshift or consensus splice site mutations) in two different USH genes. Novel missense variants were classified UV1-4 (unclassified variant): UV4 is ‘probably pathogenic’, based on control frequency <0.23%, identification in trans to a pathogenic/probably pathogenic mutation and segregation with USH in only one family; and UV3 (‘likely pathogenic’) as above, but no information on phase. Overall 79% of identified pathogenic/UV4/UV3 variants were truncating and 21% were missense changes. MYO7A accounted for 53.2%, and USH1C for 14.9% of USH1 families (USH1C:c.496+1G>A being the most common USH1 mutation in the cohort). USH2A was responsible for 79.3% of USH2 families and GPR98 for only 6.6%. No mutations were found in USH1G, WHRN or SLC4A7. Conclusions One or two pathogenic/likely pathogenic variants were identified in 86% of cases. No convincing cases of digenic inheritance were found. It is concluded that digenic inheritance does not make a significant contribution to Usher syndrome; the observation of multiple variants in different genes is likely to reflect polymorphic variation, rather than digenic effects.
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Song J, Smaoui N, Ayyagari R, Stiles D, Benhamed S, MacDonald IM, Daiger SP, Tumminia SJ, Hejtmancik F, Wang X. High-throughput retina-array for screening 93 genes involved in inherited retinal dystrophy. Invest Ophthalmol Vis Sci 2011; 52:9053-60. [PMID: 22025579 DOI: 10.1167/iovs.11-7978] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Retinal dystrophy (RD) is a broad group of hereditary disorders with heterogeneous genotypes and phenotypes. Current available genetic testing for these diseases is complicated, time consuming, and expensive. This study was conducted to develop and apply a microarray-based, high-throughput resequencing system to detect sequence alterations in genes related to inherited RD. METHODS A customized 300-kb resequencing chip, Retina-Array, was developed to detect sequence alterations of 267,550 bases of both sense and antisense sequence in 1470 exons spanning 93 genes involved in inherited RD. Retina-Array was evaluated in 19 patient samples with inherited RD provided by the eyeGENE repository and four Centre d'Etudes du Polymorphisme Humaine reference samples through a high-throughput experimental approach that included an automated PCR assay setup and quantification, efficient post-quantification data processing, optimized pooling and fragmentation, and standardized chip processing. RESULTS The performance of the chips demonstrated that the average base pair call rate and accuracy were 93.56% and 99.86%, respectively. In total, 304 candidate variations were identified using a series of customized screening filters. Among 174 selected variations, 123 (70.7%) were further confirmed by dideoxy sequencing. Analysis of patient samples using Retina-Array resulted in the identification of 10 known mutations and 12 novel variations with high probability of deleterious effects. CONCLUSIONS This study suggests that Retina-Array might be a valuable tool for the detection of disease-causing mutations and disease severity modifiers in a single experiment. Retinal-Array may provide a powerful and feasible approach through which to study genetic heterogeneity in retinal diseases.
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Affiliation(s)
- Jin Song
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, 10 Center Drive, Bethesda,MD 20892, USA
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