1
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McNamee SM, Chan NP, Akula M, Avola MO, Whalen M, Nystuen K, Singh P, Upadhyay AK, DeAngelis MM, Haider NB. Preclinical dose response study shows NR2E3 can attenuate retinal degeneration in the retinitis pigmentosa mouse model Rho P23H+/. Gene Ther 2024; 31:255-262. [PMID: 38273095 PMCID: PMC11090815 DOI: 10.1038/s41434-024-00440-6] [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: 09/14/2023] [Revised: 12/26/2023] [Accepted: 01/03/2024] [Indexed: 01/27/2024]
Abstract
Retinitis pigmentosa (RP) is a heterogeneous disease and the main cause of vision loss within the group of inherited retinal diseases (IRDs). IRDs are a group of rare disorders caused by mutations in one or more of over 280 genes which ultimately result in blindness. Modifier genes play a key role in modulating disease phenotypes, and mutations in them can affect disease outcomes, rate of progression, and severity. Our previous studies have demonstrated that the nuclear hormone receptor 2 family e, member 3 (Nr2e3) gene reduced disease progression and loss of photoreceptor cell layers in RhoP23H-/- mice. This follow up, pharmacology study evaluates a longitudinal NR2E3 dose response in the clinically relevant heterozygous RhoP23H mouse. Reduced retinal degeneration and improved retinal morphology was observed 6 months following treatment evaluating three different NR2E3 doses. Histological and immunohistochemical analysis revealed regions of photoreceptor rescue in the treated retinas of RhoP23H+/- mice. Functional assessment by electroretinogram (ERG) showed attenuated photoreceptor degeneration with all doses. This study demonstrates the effectiveness of different doses of NR2E3 at reducing retinal degeneration and informs dose selection for clinical trials of RhoP23H-associated RP.
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Affiliation(s)
- Shannon M McNamee
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Natalie P Chan
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Monica Akula
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Marielle O Avola
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Maiya Whalen
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Kaden Nystuen
- University of Massachusetts Amherst, Amherst, MA, USA
| | | | | | - Margaret M DeAngelis
- Department of Ophthalmology, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neena B Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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2
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Villasante CM, Deng X, Cohen JE, Hudspeth AJ. Nanomechanics of wild-type and mutant dimers of the tip-link protein protocadherin 15. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562769. [PMID: 37905108 PMCID: PMC10614884 DOI: 10.1101/2023.10.17.562769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Mechanical force controls the opening and closing of mechanosensitive ion channels atop the hair bundles of the inner ear. The filamentous tip link connecting transduction channels to the tallest neighboring stereocilium modulates the force transmitted to the channels and thus changes their probability of opening. Each tip link comprises four molecules: a dimer of protocadherin 15 and a dimer of cadherin 23, all of which are stabilized by Ca2+ binding. Using a high-speed optical trap to examine dimeric PCDH15, we find that the protein's configuration is sensitive to Ca2+ and that the molecule exhibits limited unfolding at a physiological Ca2+ concentration. PCDH15 can therefore modulate its stiffness without undergoing large unfolding events in physiological Ca2+ conditions. The experimentally determined stiffness of PCDH15 accords with published values for the stiffness of the gating spring, the mechanical element that controls the opening of mechanotransduction channels. When PCDH15 has a point mutation, V507D, associated with non-syndromic hearing loss, unfolding events occur more frequently under tension and refolding events occur less often than in the wild-type protein. Our results suggest that the maintenance of appropriate tension in the gating spring is critical to the appropriate transmission of force to transduction channels, and hence to hearing.
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Affiliation(s)
- Camila M Villasante
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Xinyue Deng
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Joel E Cohen
- Laboratory of Populations, The Rockefeller University, New York, NY 10065 USA
- Earth Institute and Department of Statistics, Columbia University, New York, NY 10027 USA
- Department of Statistics, University of Chicago, Chicago, IL 60637 USA
| | - A J Hudspeth
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065 USA
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3
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Guimaraes TACD, Arram E, Shakarchi AF, Georgiou M, Michaelides M. Inherited causes of combined vision and hearing loss: clinical features and molecular genetics. Br J Ophthalmol 2023; 107:1403-1414. [PMID: 36162969 DOI: 10.1136/bjo-2022-321790] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.
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Affiliation(s)
| | - Elizabeth Arram
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Ahmed F Shakarchi
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Michalis Georgiou
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
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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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Marwan M, Dawood M, Ullah M, Shah IU, Khan N, Hassan MT, Karam M, Rawlins LE, Baple EL, Crosby AH, Saleha S. Unravelling the genetic basis of retinal dystrophies in Pakistani consanguineous families. BMC Ophthalmol 2023; 23:205. [PMID: 37165311 PMCID: PMC10170854 DOI: 10.1186/s12886-023-02948-8] [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: 10/19/2022] [Accepted: 04/26/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Retinitis Pigmentosa (RP) is a clinically and genetically progressive retinal dystrophy associated with severe visual impairments and sometimes blindness, the most common syndromic form of which is Usher syndrome (USH). This study aimed to further increase understanding of the spectrum of RP in the Khyber Pakhtunkhwa region of Pakistan. METHODOLOGY Four consanguineous families of Pashtun ethnic group were investigated which were referred by the local collaborating ophthalmologists. In total 42 individuals in four families were recruited and investigated using whole exome and dideoxy sequencing. Among them, 20 were affected individuals including 6 in both family 1 and 2, 5 in family 3 and 3 in family 4. RESULT Pathogenic gene variants were identified in all four families, including two in cone dystrophy and RP genes in the same family (PDE6C; c.480delG, p.Asn161ThrfsTer33 and TULP1; c.238 C > T, p.Gln80Ter) with double-homozygous individuals presenting with more severe disease. Other pathogenic variants were identified in MERTK (c.2194C > T, p.Arg732Ter), RHO (c.448G > A, p.Glu150Lys) associated with non-syndromic RP, and MYO7A (c.487G > A, p.Gly163Arg) associated with USH. In addition, the reported variants were of clinical significance as the PDE6C variant was detected novel, whereas TULP1, MERTK, and MYO7A variants were detected rare and first time found segregating with retinal dystrophies in Pakistani consanguineous families. CONCLUSIONS This study increases knowledge of the genetic basis of retinal dystrophies in families from Pakistan providing information important for genetic testing and diagnostic provision particularly from the Khyber Pakhtunkhwa region.
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Affiliation(s)
- Muhammad Marwan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Dawood
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Mukhtar Ullah
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, 4031, Switzerland
- Department of Ophthalmology, University of Basel, Basel, 4056, Switzerland
| | - Irfan Ullah Shah
- Department of Ophthalmology, KMU Institute of Medical Sciences KIMS, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Taimur Hassan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Muhammad Karam
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Lettie E Rawlins
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Exeter, UK
| | - Emma L Baple
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Andrew H Crosby
- Medical Research, RILD Wellcome Wolfson Centre (Level 4), Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, EX2 5DW, UK
| | - Shamim Saleha
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Khyber Pakhtunkhwa, 26000, Pakistan.
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6
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Panikker P, Roy S, Ghosh A, Poornachandra B, Ghosh A. Advancing precision medicines for ocular disorders: Diagnostic genomics to tailored therapies. Front Med (Lausanne) 2022; 9:906482. [PMID: 35911417 PMCID: PMC9334564 DOI: 10.3389/fmed.2022.906482] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/29/2022] [Indexed: 11/20/2022] Open
Abstract
Successful sequencing of the human genome and evolving functional knowledge of gene products has taken genomic medicine to the forefront, soon combining broadly with traditional diagnostics, therapeutics, and prognostics in patients. Recent years have witnessed an extraordinary leap in our understanding of ocular diseases and their respective genetic underpinnings. As we are entering the age of genomic medicine, rapid advances in genome sequencing, gene delivery, genome surgery, and computational genomics enable an ever-increasing capacity to provide a precise and robust diagnosis of diseases and the development of targeted treatment strategies. Inherited retinal diseases are a major source of blindness around the world where a large number of causative genes have been identified, paving the way for personalized diagnostics in the clinic. Developments in functional genetics and gene transfer techniques has also led to the first FDA approval of gene therapy for LCA, a childhood blindness. Many such retinal diseases are the focus of various clinical trials, making clinical diagnoses of retinal diseases, their underlying genetics and the studies of natural history important. Here, we review methodologies for identifying new genes and variants associated with various ocular disorders and the complexities associated with them. Thereafter we discuss briefly, various retinal diseases and the application of genomic technologies in their diagnosis. We also discuss the strategies, challenges, and potential of gene therapy for the treatment of inherited and acquired retinal diseases. Additionally, we discuss the translational aspects of gene therapy, the important vector types and considerations for human trials that may help advance personalized therapeutics in ophthalmology. Retinal disease research has led the application of precision diagnostics and precision therapies; therefore, this review provides a general understanding of the current status of precision medicine in ophthalmology.
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Affiliation(s)
| | - Shomereeta Roy
- Grow Research Laboratory, Narayana Nethralaya Foundation, Bengaluru, India
| | - Anuprita Ghosh
- Grow Research Laboratory, Narayana Nethralaya Foundation, Bengaluru, India
| | | | - Arkasubhra Ghosh
- Grow Research Laboratory, Narayana Nethralaya Foundation, Bengaluru, India
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7
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Wadie B, Kleshchevnikov V, Sandaltzopoulou E, Benz C, Petsalaki E. Use of viral motif mimicry improves the proteome-wide discovery of human linear motifs. Cell Rep 2022; 39:110764. [PMID: 35508127 DOI: 10.1016/j.celrep.2022.110764] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 02/09/2022] [Accepted: 04/08/2022] [Indexed: 12/16/2022] Open
Abstract
Linear motifs have an integral role in dynamic cell functions, including cell signaling. However, due to their small size, low complexity, and frequent mutations, identifying novel functional motifs poses a challenge. Viruses rely extensively on the molecular mimicry of cellular linear motifs. In this study, we apply systematic motif prediction combined with functional filters to identify human linear motifs convergently evolved also in viral proteins. We observe an increase in the sensitivity of motif prediction and improved enrichment in known instances. We identify >7,300 non-redundant motif instances at various confidence levels, 99 of which are supported by all functional and structural filters. Overall, we provide a pipeline to improve the identification of functional linear motifs from interactomics datasets and a comprehensive catalog of putative human motifs that can contribute to our understanding of the human domain-linear motif code and the associated mechanisms of viral interference.
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Affiliation(s)
- Bishoy Wadie
- European Molecular Biology Laboratory - European Bioinformatics Institute, Wellcome Genome Campus, Hinxton CB10 1SD, UK
| | - Vitalii Kleshchevnikov
- European Molecular Biology Laboratory - European Bioinformatics Institute, Wellcome Genome Campus, Hinxton CB10 1SD, UK
| | - Elissavet Sandaltzopoulou
- European Molecular Biology Laboratory - European Bioinformatics Institute, Wellcome Genome Campus, Hinxton CB10 1SD, UK
| | - Caroline Benz
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Evangelia Petsalaki
- European Molecular Biology Laboratory - European Bioinformatics Institute, Wellcome Genome Campus, Hinxton CB10 1SD, UK.
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8
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Sethna S, Zein WM, Riaz S, Giese AP, Schultz JM, Duncan T, Hufnagel RB, Brewer CC, Griffith AJ, Redmond TM, Riazuddin S, Friedman TB, Ahmed ZM. Proposed therapy, developed in a Pcdh15-deficient mouse, for progressive loss of vision in human Usher syndrome. eLife 2021; 10:67361. [PMID: 34751129 PMCID: PMC8577840 DOI: 10.7554/elife.67361] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Usher syndrome type I (USH1) is characterized by deafness, vestibular areflexia, and progressive retinal degeneration. The protein-truncating p.Arg245* founder variant of PCDH15 (USH1F) has an ~2% carrier frequency amongst Ashkenazi Jews accounts for ~60% of their USH1 cases. Here, longitudinal phenotyping in 13 USH1F individuals revealed progressive retinal degeneration, leading to severe vision loss with macular atrophy by the sixth decade. Half of the affected individuals were legally blind by their mid-50s. The mouse Pcdh15R250X variant is equivalent to human p.Arg245*. Homozygous Pcdh15R250X mice also have visual deficits and aberrant light-dependent translocation of the phototransduction cascade proteins, arrestin, and transducin. Retinal pigment epithelium (RPE)-specific retinoid cycle proteins, RPE65 and CRALBP, were also reduced in Pcdh15R250X mice, indicating a dual role for protocadherin-15 in photoreceptors and RPE. Exogenous 9-cis retinal improved ERG amplitudes in Pcdh15R250X mice, suggesting a basis for a clinical trial of FDA-approved retinoids to preserve vision in USH1F patients.
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Affiliation(s)
- Saumil Sethna
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Sehar Riaz
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States.,National Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Arnaud Pj Giese
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Julie M Schultz
- Laboratory of Molecular Genetics, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, United States
| | - Todd Duncan
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Carmen C Brewer
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, Bethesda, United States
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, Bethesda, United States
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, United States
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, United States.,Departments of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, United States.,Departments of Molecular Biology and Biochemistry, University of Maryland School of Medicine, Baltimore, United States
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9
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Naz S. Molecular genetic landscape of hereditary hearing loss in Pakistan. Hum Genet 2021; 141:633-648. [PMID: 34308486 DOI: 10.1007/s00439-021-02320-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/17/2021] [Indexed: 01/13/2023]
Abstract
Approximately 14.5 million Pakistani individuals have a hearing loss and half of these cases may be due to genetic causes. Though significant progress has been made in uncovering genetic variants for recessively inherited nonsyndromic deafness, Pendred syndrome, and Usher syndromes, the same is not true for dominantly inherited hearing loss, most syndromic cases and deafness with complex inheritance patterns. Variants of 57 genes have been reported to cause nonsyndromic recessive deafness in Pakistan, though most are rare. Variants of just five genes GJB2, HGF, MYO7A, SLC26A4, and TMC1 together explain 57% of profound deafness while those of GJB2, MYO15A, OTOF, SLC26A4, TMC1, and TMPRSS3 account for 47% of moderate to severe hearing loss. In contrast, although variants of at least 39 genes have been implicated in different deafness syndromes, their prevalence in the population and the spectrum of mutations have not been explored. Furthermore, research on genetics of deafness has mostly focused on individuals from the Punjab province and needs to be extended to other regions of Pakistan. Identifying the genes and their variants causing deafness in all ethnic groups is important as it will pinpoint rare as well as recurrent mutations. This information may ultimately help in offering genetic counseling and future treatments.
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Affiliation(s)
- Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan.
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10
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Salazar-Silva R, Dantas VLG, Alves LU, Batissoco AC, Oiticica J, Lawrence EA, Kawafi A, Yang Y, Nicastro FS, Novaes BC, Hammond C, Kague E, Mingroni-Netto RC. NCOA3 identified as a new candidate to explain autosomal dominant progressive hearing loss. Hum Mol Genet 2021; 29:3691-3705. [PMID: 33326993 PMCID: PMC7823111 DOI: 10.1093/hmg/ddaa240] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/21/2020] [Accepted: 10/15/2020] [Indexed: 12/27/2022] Open
Abstract
Hearing loss is a frequent sensory impairment in humans and genetic factors account for an elevated fraction of the cases. We have investigated a large family of five generations, with 15 reported individuals presenting non-syndromic, sensorineural, bilateral and progressive hearing loss, segregating as an autosomal dominant condition. Linkage analysis, using SNP-array and selected microsatellites, identified a region of near 13 cM in chromosome 20 as the best candidate to harbour the causative mutation. After exome sequencing and filtering of variants, only one predicted deleterious variant in the NCOA3 gene (NM_181659, c.2810C > G; p.Ser937Cys) fit in with our linkage data. RT-PCR, immunostaining and in situ hybridization showed expression of ncoa3 in the inner ear of mice and zebrafish. We generated a stable homozygous zebrafish mutant line using the CRISPR/Cas9 system. ncoa3-/- did not display any major morphological abnormalities in the ear, however, anterior macular hair cells showed altered orientation. Surprisingly, chondrocytes forming the ear cartilage showed abnormal behaviour in ncoa3-/-, detaching from their location, invading the ear canal and blocking the cristae. Adult mutants displayed accumulation of denser material wrapping the otoliths of ncoa3-/- and increased bone mineral density. Altered zebrafish swimming behaviour corroborates a potential role of ncoa3 in hearing loss. In conclusion, we identified a potential candidate gene to explain hereditary hearing loss, and our functional analyses suggest subtle and abnormal skeletal behaviour as mechanisms involved in the pathogenesis of progressive sensory function impairment.
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Affiliation(s)
- R Salazar-Silva
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Vitor Lima Goes Dantas
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Leandro Ucela Alves
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Ana Carla Batissoco
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
- Laboratório de Otorrinolaringologia/LIM32 –Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo , 01246-903, São Paulo, Brazil
| | - Jeanne Oiticica
- Laboratório de Otorrinolaringologia/LIM32 –Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo , 01246-903, São Paulo, Brazil
| | - Elizabeth A Lawrence
- School of Pharmacology, Physiology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Abdelwahab Kawafi
- School of Pharmacology, Physiology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Yushi Yang
- School of Physics, University of Bristol, Bristol, BS8 1TL, United Kingdom
- Centre for Nanoscience and Quantum Information, University of Bristol, Bristol, BS8 1FD, United Kingdom
- Bristol Centre for Functional Nanomaterials, University of Bristol, Bristol, BS8 1FD, United Kingdom
| | - Fernanda Stávale Nicastro
- Divisão de Educação e Reabilitação dos Distúrbios da Comunicação da Pontifícia Universidade Católica de São Paulo, 04022-040, São Paulo, Brazil
| | - Beatriz Caiuby Novaes
- Divisão de Educação e Reabilitação dos Distúrbios da Comunicação da Pontifícia Universidade Católica de São Paulo, 04022-040, São Paulo, Brazil
| | - Chrissy Hammond
- School of Pharmacology, Physiology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Erika Kague
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
- School of Pharmacology, Physiology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - R C Mingroni-Netto
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
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Pu JL, Gao T, Si XL, Zheng R, Jin CY, Ruan Y, Fang Y, Chen Y, Song Z, Yin XZ, Yan YP, Tian J, Zhang BR. Parkinson's Disease in Teneurin Transmembrane Protein 4 ( TENM4) Mutation Carriers. Front Genet 2021; 11:598064. [PMID: 33414808 PMCID: PMC7783409 DOI: 10.3389/fgene.2020.598064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/02/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction Mutations in the teneurin transmembrane protein 4 (TENM4) gene, known to be involved in neuropsychiatric disorders, have been identified in three pedigree of essential tremor (ET) from Spain. ET has overlapping clinical manifestations and epidemiological symptoms with Parkinson’s disease (PD), suggesting these two disorders may reflect common genetic risk factors. In this study, we investigated clinical and genetic manifestations in four unrelated pedigrees with both ET and PD in which TENM4 variants were identified. Methods We subsequently explored whether TENM4 variants contributed to the risk of developing PD. The frequency of TENM4 variants was evaluated from four PD pedigrees and other 407 subjects. Results The results revealed 12 different novel heterozygous variants, all at low frequency. A clear general enrichment of TENM4 variants was detected in early onset PD patients (p < 0.001, OR = 5.264, 95% CI = 1.957–14.158). Conclusion The results indicate that rare TENM4 variants may be associated with an increased risk of PD.
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Affiliation(s)
- Jia-Li Pu
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ting Gao
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Xiao-Li Si
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ran Zheng
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Chong-Yao Jin
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Yang Ruan
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Yi Fang
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ying Chen
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Zhe Song
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Xin-Zhen Yin
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ya-Ping Yan
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Jun Tian
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Bao-Rong Zhang
- Department of Neurology, College of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
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12
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Peterson J, Nishimura C, Smith RJH. Genetic Testing for Congenital Bilateral Hearing Loss in the Context of Targeted Cytomegalovirus Screening. Laryngoscope 2020; 130:2714-2718. [PMID: 31985074 DOI: 10.1002/lary.28536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 12/19/2019] [Accepted: 12/24/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVES/HYPOTHESIS To determine the prevalence of children with genetic hearing loss who are cytomegalovirus (CMV) positive at birth and the relative proportion of genetic and CMV etiology among children with congenital bilateral hearing loss. STUDY DESIGN Database review. METHODS We performed a review of clinical test results for patients undergoing comprehensive genetic testing for all known hearing loss-associated genes from January 2012 to January 2019. This population was reviewed for reported CMV status and genetic causes of congenital bilateral hearing loss. RESULTS In the OtoSCOPE database, 61/4,282 patients were found to have a documented CMV status, and 661/4282 had documented bilateral congenital hearing loss. Two patients were identified who had both a positive CMV result and a genetic cause for their hearing loss. Forty-eight percent of patients with bilateral congenital hearing loss (320/661) were found to have a genetic etiology. In 62% (198/320), the hearing loss was associated with pathogenic variants in GJB2, STRC, SLC26A4 or an Usher syndrome-associated gene. CONCLUSIONS We estimate that ~2% of CMV-positive newborns with hearing loss have a known genetic variant as a cause. The subcohort of CMV-positive newborns with symmetric mild-to-moderate bilateral hearing loss will have at least a 7% chance of having pathogenic gene variants associated with hearing loss. In a CMV-positive neonate who failed their newborn hearing screen bilaterally, genetic screening needs to be considered for accurate diagnosis and possible deferment of antiviral treatment. LEVEL OF EVIDENCE 4 Laryngoscope, 130:2714-2718, 2020.
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Affiliation(s)
- Joseph Peterson
- Department of Otolaryngology-Head and Neck Surgery, Molecular Otolaryngology and Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa, U.S.A
| | - Carla Nishimura
- Department of Otolaryngology-Head and Neck Surgery, Molecular Otolaryngology and Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa, U.S.A
| | - Richard J H Smith
- Department of Otolaryngology-Head and Neck Surgery, Molecular Otolaryngology and Renal Research Labs, University of Iowa Hospitals and Clinics, Iowa City, Iowa, U.S.A
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13
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Friedman TB, Belyantseva IA, Frolenkov GI. Myosins and Hearing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1239:317-330. [DOI: 10.1007/978-3-030-38062-5_13] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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14
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Méjécase C, Malka S, Guan Z, Slater A, Arno G, Moosajee M. Practical guide to genetic screening for inherited eye diseases. Ther Adv Ophthalmol 2020; 12:2515841420954592. [PMID: 33015543 PMCID: PMC7513416 DOI: 10.1177/2515841420954592] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/29/2020] [Indexed: 12/16/2022] Open
Abstract
Genetic eye diseases affect around one in 1000 people worldwide for which the molecular aetiology remains unknown in the majority. The identification of disease-causing gene variant(s) allows a better understanding of the disorder and its inheritance. There is now an approved retinal gene therapy for autosomal recessive RPE65-retinopathy, and numerous ocular gene/mutation-targeted clinical trials underway, highlighting the importance of establishing a genetic diagnosis so patients can fully access the latest research developments and treatment options. In this review, we will provide a practical guide to managing patients with these conditions including an overview of inheritance patterns, required pre- and post-test genetic counselling, different types of cytogenetic and genetic testing available, with a focus on next generation sequencing using targeted gene panels, whole exome and genome sequencing. We will expand on the pros and cons of each modality, variant interpretation and options for family planning for the patient and their family. With the advent of genomic medicine, genetic screening will soon become mainstream within all ophthalmology subspecialties for prevention of disease and provision of precision therapeutics.
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Affiliation(s)
- Cécile Méjécase
- Institute of Ophthalmology, University College
London, London, UK
| | - Samantha Malka
- Institute of Ophthalmology, University College
London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
| | - Zeyu Guan
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
| | - Amy Slater
- Royal Brompton and Harefield NHS Foundation
Trust, London, UK
| | - Gavin Arno
- Institute of Ophthalmology, University College
London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Trust, London, UK
| | - Mariya Moosajee
- Professor, Institute of Ophthalmology,
University College London, 11-43 Bath Street, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Trust, London, UK
- The Francis Crick Institute, London, UK
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15
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Lee SY, Joo K, Oh J, Han JH, Park HR, Lee S, Oh DY, Woo SJ, Choi BY. Severe or Profound Sensorineural Hearing Loss Caused by Novel USH2A Variants in Korea: Potential Genotype-Phenotype Correlation. Clin Exp Otorhinolaryngol 2019; 13:113-122. [PMID: 31674169 PMCID: PMC7248602 DOI: 10.21053/ceo.2019.00990] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/16/2019] [Indexed: 11/22/2022] Open
Abstract
Objectives We, herein, report two novel USH2A variants from two unrelated Korean families and their clinical phenotypes, with attention to severe or more than severe sensorineural hearing loss (SNHL). Methods Two postlingually deafened subjects (SB237-461, M/46 and SB354-692, F/34) with more than severe SNHL and also with suspicion of Usher syndrome type II (USH2) were enrolled. A comprehensive audiological and ophthalmological assessments were evaluated. We conducted the whole exome sequencing and subsequent pathogenicity prediction analysis. Results We identified the following variants of USH2A from the two probands manifesting more than severe SNHL and retinitis pigmentosa (RP): compound heterozygosity for a nonsense (c.8176C>T: p.R2723X) and a missense variant (c.1823G>A: p.C608Y) in SB237, and compound heterozygosity for two frameshift variants (c.14835delT: p.S4945fs & c.13112_13115delAAAT: p.G4371fs) in SB354. Based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines, two novel variants, c.1823G>A: p.C608Y and c.14835delT: p.Ser4945fs, can be classified as “uncertain significance” and “pathogenic,” respectively. The audiogram exhibited more than severe SNHL and a down-sloping configuration, necessitating cochlear implantation. The ophthalmic examinations revealed typical features of RP. Interestingly, one proband (SB 354-692) carrying two truncating compound heterozygous variants exhibited more severe hearing loss than the other proband (SB 237-461), carrying one truncation with one missense variant. Conclusion Our results provide insight on the expansion of audiological spectrum encompassing more than severe SNHL in Korean subjects harboring USH2A variants, suggesting that USH2A should also be included in the candidate gene of cochlear implantation. A specific combination of USH2A variants causing truncating proteins in both alleles could demonstrate more severe audiological phenotype than that of USH2A variants carrying one truncating mutation and one missense mutation, suggesting a possible genotype-phenotype correlation. The understanding of audiological complexity associated with USH2A will be helpful for genetic counseling and treatment starategy.
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Affiliation(s)
- Sang-Yeon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jayoung Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hye-Rim Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Doo-Yi Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
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16
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Lee SY, Han JH, Kim BJ, Oh SH, Lee S, Oh DY, Choi BY. Identification of a Potential Founder Effect of a Novel PDZD7 Variant Involved in Moderate-to-Severe Sensorineural Hearing Loss in Koreans. Int J Mol Sci 2019; 20:ijms20174174. [PMID: 31454969 PMCID: PMC6747409 DOI: 10.3390/ijms20174174] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
PDZD7, a PDZ domain-containing scaffold protein, is critical for the organization of Usher syndrome type 2 (USH2) interactome. Recently, biallelic PDZD7 variants have been associated with autosomal-recessive, non-syndromic hearing loss (ARNSHL). Indeed, we identified novel, likely pathogenic PDZD7 variants based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines from Korean families manifesting putative moderate-to-severe prelingual ARNSHL; these were c.490C>T (p.Arg164Trp), c.1669delC (p.Arg557Glyfs*13), and c.1526G>A (p.Gly509Glu), with p.Arg164Trp being a predominantly recurring variant. Given the recurring missense variant (p.Arg164Trp) from our cohort, we compared the genotyping data using six short tandem-repeat (STR) markers within or flanking PDZD7 between four probands carrying p.Arg164Trp and 81 normal-hearing controls. We observed an identical haplotype across three out of six STR genotyping markers exclusively shared by two unrelated hearing impaired probands but not by any of the 81 normal-hearing controls, suggesting a potential founder effect. However, STR genotyping, based on six STR markers, revealed various p.Arg164Trp-linked haplotypes shared by all of the affected subjects. In conclusion, PDZD7 can be an important causative gene for moderate to severe ARNSHL in Koreans. Moreover, at least some, if not all, p.Arg164Trp alleles in Koreans could exert a potential founder effect and arise from diverse haplotypes as a mutational hot spot.
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Affiliation(s)
- Sang-Yeon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul 04401, Korea
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Bong Jik Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Chungnam National University Hospital, Daejeon 35015, Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul 04401, Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Doo-Yi Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea.
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17
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Jaiganesh A, De-la-Torre P, Patel AA, Termine DJ, Velez-Cortes F, Chen C, Sotomayor M. Zooming in on Cadherin-23: Structural Diversity and Potential Mechanisms of Inherited Deafness. Structure 2018; 26:1210-1225.e4. [PMID: 30033219 DOI: 10.1016/j.str.2018.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/22/2018] [Accepted: 06/08/2018] [Indexed: 12/18/2022]
Abstract
Cadherin-23 (CDH23) is an essential component of hair-cell tip links, fine filaments that mediate inner-ear mechanotransduction. The extracellular domain of CDH23 forms about three-fourths of the tip link with 27 extracellular cadherin (EC) repeats that are structurally similar but not identical to each other. Calcium (Ca2+) coordination at the EC linker regions is key for tip-link elasticity and function. There are ∼116 sites in CDH23 affected by deafness-causing mutations, many of which alter conserved Ca2+-binding residues. Here we present crystal structures showing 18 CDH23 EC repeats, including the most and least conserved, a fragment carrying disease mutations, and EC repeats with non-canonical Ca2+-binding motif sequences and unusual secondary structure. Complementary experiments show deafness mutations' effects on stability and affinity for Ca2+. Additionally, a model of nine contiguous CDH23 EC repeats reveals helicity and potential parallel dimerization faces. Overall, our studies provide detailed structural insight into CDH23 function in mechanotransduction.
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Affiliation(s)
- Avinash Jaiganesh
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Pedro De-la-Torre
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Aniket A Patel
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Domenic J Termine
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Florencia Velez-Cortes
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Conghui Chen
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210, USA.
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18
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Cheng L, Yu H, Jiang Y, He J, Pu S, Li X, Zhang L. Identification of a novel MYO7A mutation in Usher syndrome type 1. Oncotarget 2017; 9:2295-2303. [PMID: 29416772 PMCID: PMC5788640 DOI: 10.18632/oncotarget.23408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/05/2017] [Indexed: 12/30/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive disease characterized by deafness and retinitis pigmentosa. In view of the high phenotypic and genetic heterogeneity in USH, performing genetic screening with traditional methods is impractical. In the present study, we carried out targeted next-generation sequencing (NGS) to uncover the underlying gene in an USH family (2 USH patients and 15 unaffected relatives). One hundred and thirty-five genes associated with inherited retinal degeneration were selected for deep exome sequencing. Subsequently, variant analysis, Sanger validation and segregation tests were utilized to identify the disease-causing mutations in this family. All affected individuals had a classic USH type I (USH1) phenotype which included deafness, vestibular dysfunction and retinitis pigmentosa. Targeted NGS and Sanger sequencing validation suggested that USH1 patients carried an unreported splice site mutation, c.5168+1G>A, as a compound heterozygous mutation with c.6070C>T (p.R2024X) in the MYO7A gene. A functional study revealed decreased expression of the MYO7A gene in the individuals carrying heterozygous mutations. In conclusion, targeted next-generation sequencing provided a comprehensive and efficient diagnosis for USH1. This study revealed the genetic defects in the MYO7A gene and expanded the spectrum of clinical phenotypes associated with USH1 mutations.
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Affiliation(s)
- Ling Cheng
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China.,Department of Ophthalmology, Yongchuan Hospital, Chongqing Medical University, Chongqing, P. R. China
| | - Hongsong Yu
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China.,Department of Immunology, Special Key Laboratory of Gene Detection & Therapy of Guizhou Province, Zunyi Medical University, Guizhou, P. R. China
| | - Yan Jiang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China
| | - Juan He
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China
| | - Sisi Pu
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China
| | - Xin Li
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China
| | - Li Zhang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, P. R. China
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19
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Abdelkader E, Enani L, Schatz P, Safieh L. Severe retinal degeneration at an early age in Usher syndrome type 1B associated with homozygous splice site mutations in MYO7A gene. Saudi J Ophthalmol 2017; 32:119-125. [PMID: 29942180 PMCID: PMC6010603 DOI: 10.1016/j.sjopt.2017.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 10/08/2017] [Accepted: 10/17/2017] [Indexed: 01/10/2023] Open
Abstract
Purpose Usher syndrome is the most common cause of deafness associated with visual loss of a genetic origin. The purpose of this paper is to report very severe phenotypic features of type 1B Usher syndrome in a Saudi family affected by positive homozygous splice site mutation in MYO7A gene. Methods Affected siblings went through detailed history. Complete ophthalmic examination was done. Imaging with colour fundus photography, fundus autofluorescence (AF), and optical coherence tomography (OCT) scans was performed. Full field electroretinogram (ffERG) was recorded. Molecular genetic testing was done using next-generation sequencing. Results Visual acuity was more reduced (range 20/300–20/40) in older siblings (age>30 years), than in younger (age <30 years) siblings (range 20/70–20/25). OCT scans showed macular atrophy in all but one case that has cystoid macular edema (CME). AF demonstrated atrophy outside a small foveal area showing high signal. FfERG was flat in all cases. The homozygous splice site mutation c.470+1G>A in intron 5 of the MYO7A gene was detected in all affected siblings. Conclusions This mutation manifested with advanced retinal degeneration at a young age. This may have implications regarding future gene therapy in Usher syndrome cases with this genotype.
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Affiliation(s)
- Ehab Abdelkader
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Ophthalmology Department, Menoufia University, Shebin El-Kom, Egypt
| | - Lama Enani
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Patrik Schatz
- Vitreoretinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Department of Ophthalmology, Clinical Sciences, Skane University Hospital, University of Lund, Sweden
| | - Leen Safieh
- Genetic Laboratory, Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
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20
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Mittal R, Nguyen D, Patel AP, Debs LH, Mittal J, Yan D, Eshraghi AA, Van De Water TR, Liu XZ. Recent Advancements in the Regeneration of Auditory Hair Cells and Hearing Restoration. Front Mol Neurosci 2017; 10:236. [PMID: 28824370 PMCID: PMC5534485 DOI: 10.3389/fnmol.2017.00236] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/11/2017] [Indexed: 12/18/2022] Open
Abstract
Neurosensory responses of hearing and balance are mediated by receptors in specialized neuroepithelial sensory cells. Any disruption of the biochemical and molecular pathways that facilitate these responses can result in severe deficits, including hearing loss and vestibular dysfunction. Hearing is affected by both environmental and genetic factors, with impairment of auditory function being the most common neurosensory disorder affecting 1 in 500 newborns, as well as having an impact on the majority of elderly population. Damage to auditory sensory cells is not reversible, and if sufficient damage and cell death have taken place, the resultant deficit may lead to permanent deafness. Cochlear implants are considered to be one of the most successful and consistent treatments for deaf patients, but only offer limited recovery at the expense of loss of residual hearing. Recently there has been an increased interest in the auditory research community to explore the regeneration of mammalian auditory hair cells and restoration of their function. In this review article, we examine a variety of recent therapies, including genetic, stem cell and molecular therapies as well as discussing progress being made in genome editing strategies as applied to the restoration of hearing function.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Desiree Nguyen
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Amit P. Patel
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Luca H. Debs
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Adrien A. Eshraghi
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Thomas R. Van De Water
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
| | - Xue Z. Liu
- Department of Otolaryngology, University of Miami Miller School of MedicineMiami, FL, United States
- Department of Otolaryngology, Xiangya Hospital, Central South UniversityChangsha, China
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21
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Ghasemi H, Pourakbari MS, Entezari M, Yarmohammadi ME. Association of Age Related Macular Degeneration and Age Related Hearing Impairment. J Ophthalmic Vis Res 2016; 11:54-60. [PMID: 27195086 PMCID: PMC4860988 DOI: 10.4103/2008-322x.180699] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose: To evaluate the association between age-related macular degeneration (ARMD) and sensory neural hearing impairment (SHI). Methods: In this case-control study, hearing status of 46 consecutive patients with ARMD were compared with 46 age-matched cases without clinical ARMD as a control group. In all patients, retinal involvements were confirmed by clinical examination, fluorescein angiography (FA) and optical coherence tomography (OCT). All participants were examined with an otoscope and underwent audiological tests including pure tone audiometry (PTA), speech reception threshold (SRT), speech discrimination score (SDS), tympanometry, reflex tests and auditory brainstem response (ABR). Results: A significant (P = 0.009) association was present between ARMD, especially with exudative and choroidal neovascularization (CNV) components, and age-related hearing impairment primarily involving high frequencies. Patients had higher SRT and lower SDS against anticipated presbycusis than control subjects. Similar results were detected in exudative, CNV and scar patterns supporting an association between late ARMD with SRT and SDS abnormalities. ABR showed significantly prolonged wave I and IV latency times in ARMD (P = 0.034 and 0.022, respectively). Average latency periods for wave I in geographic atrophy (GA) and CNV, and that for wave IV in drusen patterns of ARMD were significantly higher than controls (P = 0.030, 0.007 and 0.050, respectively). Conclusion: The association between ARMD and age-related SHI may be attributed to common anatomical components such as melanin in these two sensory organs.
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Affiliation(s)
- Hassan Ghasemi
- Department of Ophthalmology, Shahid Mostafa Khomeini Hospital, Shahed University of Medical Sciences, Tehran, Iran
| | - Malihe Shahidi Pourakbari
- General Practitioner, Shahid Mostafa Khomeini Hospital, Shahed University of Medical Sciences, Tehran, Iran
| | - Morteza Entezari
- Ophthalmic Research Center, Tehran, Iran; Department of Ophthalmology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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22
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Taking the History and Performing the Physical Examination in a Child with Hearing Loss. Otolaryngol Clin North Am 2015; 48:903-12. [DOI: 10.1016/j.otc.2015.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Elkon R, Milon B, Morrison L, Shah M, Vijayakumar S, Racherla M, Leitch CC, Silipino L, Hadi S, Weiss-Gayet M, Barras E, Schmid CD, Ait-Lounis A, Barnes A, Song Y, Eisenman DJ, Eliyahu E, Frolenkov GI, Strome SE, Durand B, Zaghloul NA, Jones SM, Reith W, Hertzano R. RFX transcription factors are essential for hearing in mice. Nat Commun 2015; 6:8549. [PMID: 26469318 PMCID: PMC4634137 DOI: 10.1038/ncomms9549] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 09/04/2015] [Indexed: 01/23/2023] Open
Abstract
Sensorineural hearing loss is a common and currently irreversible disorder, because mammalian hair cells (HCs) do not regenerate and current stem cell and gene delivery protocols result only in immature HC-like cells. Importantly, although the transcriptional regulators of embryonic HC development have been described, little is known about the postnatal regulators of maturating HCs. Here we apply a cell type-specific functional genomic analysis to the transcriptomes of auditory and vestibular sensory epithelia from early postnatal mice. We identify RFX transcription factors as essential and evolutionarily conserved regulators of the HC-specific transcriptomes, and detect Rfx1,2,3,5 and 7 in the developing HCs. To understand the role of RFX in hearing, we generate Rfx1/3 conditional knockout mice. We show that these mice are deaf secondary to rapid loss of initially well-formed outer HCs. These data identify an essential role for RFX in hearing and survival of the terminally differentiating outer HCs.
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Affiliation(s)
- Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Beatrice Milon
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Laura Morrison
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Manan Shah
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska Lincoln, Lincoln, Nebraska 68583-0738, USA
| | - Manoj Racherla
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Carmen C. Leitch
- Department of Medicine, Division of Endocrinology, Diabetes and Nutrition, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland 21201, USA
| | - Lorna Silipino
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Shadan Hadi
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0298, USA
| | - Michèle Weiss-Gayet
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, 69622 Villeurbanne, France
| | - Emmanuèle Barras
- Department of Pathology and Immunology, University of Geneva Medical School, CH-1211 Geneva, Switzerland
| | - Christoph D. Schmid
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, and University of Basel, 4051 Basel, Switzerland
| | - Aouatef Ait-Lounis
- Department of Pathology and Immunology, University of Geneva Medical School, CH-1211 Geneva, Switzerland
| | - Ashley Barnes
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - David J. Eisenman
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Efrat Eliyahu
- Department of Genetics and Genomic Sciences, Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Gregory I. Frolenkov
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0298, USA
| | - Scott E. Strome
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA
| | - Bénédicte Durand
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, 69622 Villeurbanne, France
| | - Norann A. Zaghloul
- Department of Medicine, Division of Endocrinology, Diabetes and Nutrition, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland 21201, USA
| | - Sherri M. Jones
- Department of Special Education and Communication Disorders, University of Nebraska Lincoln, Lincoln, Nebraska 68583-0738, USA
| | - Walter Reith
- Department of Pathology and Immunology, University of Geneva Medical School, CH-1211 Geneva, Switzerland
| | - Ronna Hertzano
- Department of Otorhinolaryngology, School of Medicine, University of Maryland Baltimore, 16 South Eutaw Street Suite 500, Baltimore, Maryland 21201, USA,Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA,
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Chen DY, Zhu WD, Chai YC, Chen Y, Sun L, Yang T, Wu H. Mutation in PCDH15 may modify the phenotypic expression of the 7511T>C mutation in MT-TS1 in a Chinese Han family with maternally inherited nonsyndromic hearing loss. Int J Pediatr Otorhinolaryngol 2015; 79:1654-7. [PMID: 26279247 DOI: 10.1016/j.ijporl.2015.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/29/2015] [Accepted: 07/03/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Mutations in MT-TS1 have been found to be associated with nonsyndromic sensorineural hearing loss (SNHL). PCDH15 codes for protocadherin-15, a member of the cadherin superfamily of calcium-dependent cell-cell adhesion molecules. In this study, we analyzed the correlation of both MT-TS1 and PCDH15 mutations in a Chinese Han family segregating maternally inherited nonsyndromic SNHL. METHODS We ascertained a Chinese Han family segregating maternally inherited nonsyndromic sensorineural hearing loss. Eight of 10 maternal members in this family exhibited late-onset, progressive hearing impairment. Mutation screening of 79 known deafness genes was performed for the proband by targeted next-generation sequencing. RESULTS A total of 651 variants were detected in this individual. Among them, a homoplasmic 7511T>C variant in MT-TS1, the mitochondrial tRNA (Ser(UCN)) gene, and a heterozygous p.Asp1010Gly variant in PCDH15 were more likely to be pathogenic. Consistent with the matrilineal inheritance with reduced penetrance, the 7511T>C variant in MT-TS1 was found in all 10 maternal members and an additional heterozygous p.Asp1010Gly variant in PCDH15 cosegregated with the hearing loss in this family. CONCLUSION Our results suggested that the PCDH15 p.Asp1010Gly variant probably modified the phenotypic expression of the 7511T>C mutation in MT-TS1.
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Affiliation(s)
- Dong-ye Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China
| | - Wei-dong Zhu
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China
| | - Yong-chuan Chai
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China
| | - Ying Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China
| | - Lianhua Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China
| | - Tao Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China.
| | - Hao Wu
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, China.
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25
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Hope WC, Cordovez JA, Capasso JE, Hammersmith KM, Eagle RC, Lall-Trail J, Levin AV. Peters anomaly in cri-du-chat syndrome. J AAPOS 2015; 19:277-9. [PMID: 26059676 DOI: 10.1016/j.jaapos.2015.01.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 11/18/2022]
Abstract
The cri-du-chat syndrome is a rare genetic disorder caused by deletions in the short arm of chromosome 5. It presents with a distinctive catlike high-pitched cry, psychomotor delays, microcephaly, craniofacial abnormalities, and, in many cases, ocular findings. We report the first child with cri-du-chat and the findings of unilateral corneal staphyloma due to Peters anomaly and retinal dysplasia.
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Affiliation(s)
- William C Hope
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jose A Cordovez
- Pediatric Ophthalmology and Ocular Genetics, Philadelphia, Pennsylvania
| | - Jenina E Capasso
- Pediatric Ophthalmology and Ocular Genetics, Philadelphia, Pennsylvania
| | - Kristin M Hammersmith
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania; Cornea Service, Philadelphia, Pennsylvania
| | - Ralph C Eagle
- Cornea Service, Philadelphia, Pennsylvania; Pathology, Wills Eye Hospital, Philadelphia, Pennsylvania
| | - Joel Lall-Trail
- Children's Hospital of the King's Daughters, Norfolk, Virginia
| | - Alex V Levin
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania; Children's Hospital of the King's Daughters, Norfolk, Virginia.
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26
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Ben-Salem S, Rehm HL, Willems PJ, Tamimi ZA, Ayadi H, Ali BR, Al-Gazali L. Analysis of two Arab families reveals additional support for a DFNB2 nonsyndromic phenotype of MYO7A. Mol Biol Rep 2013; 41:193-200. [PMID: 24194196 DOI: 10.1007/s11033-013-2851-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 10/29/2013] [Indexed: 02/05/2023]
Abstract
Variants in the head and tail domains of the MYO7A gene, encoding myosin VIIA, cause Usher syndrome type 1B (USH1B) and nonsyndromic deafness (DFNB2, DFNA11). In order to identify the genetic defect(s) underling profound deafness in two consanguineous Arab families living in UAE, we have sequenced a panel of 19 genes involved in Usher syndrome and nonsyndromic deafness in the index cases of the two families. This analysis revealed a novel homozygous insertion of AG (c.1952_1953insAG/p.C652fsX11) in exon 17 of the MYO7A gene in an Iraqi family, and a homozygous point mutation (c.5660C>T/p.P1887L) in exon 41 affecting the same gene in a large Palestinian family. Moreover, some individuals from the Palestinian family also harbored a novel heterozygous truncating variant (c.1267C>T/p.R423X) in the DFNB31 gene, which is involved in autosomal recessive nonsyndromic deafness type DFNB31 and Usher syndrome type II. Assuming an autosomal recessive mode of inheritance in the two inbred families, we conclude that the homozygous variants in the MYO7A gene are the disease-causing mutations in these families. Furthermore, given the absence of retinal disease in all affected patients examined, particularly a 28 year old patient, suggests that at least one family may segregate a DFNB2 presentation rather than USH1B. This finding further supports the premise that the MYO7A gene is responsible for two distinct diseases and gives evidence that the p.P1887L mutation in a homozygous state may be responsible for nonsyndromic hearing loss.
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Affiliation(s)
- Salma Ben-Salem
- Department of Pathology, College of Medicine and Heath Sciences, United Arab Emirates University, Al Ain, United Arab Emirates,
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27
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Abstract
Usher syndrome (USH) is a neurosensory disorder affecting both hearing and vision in humans. Linkage studies of families of USH patients, studies in animals, and characterization of purified proteins have provided insight into the molecular mechanisms of hearing. To date, 11 USH proteins have been identified, and evidence suggests that all of them are crucial for the function of the mechanosensory cells of the inner ear, the hair cells. Most USH proteins are localized to the stereocilia of the hair cells, where mechano-electrical transduction (MET) of sound-induced vibrations occurs. Therefore, elucidation of the functions of USH proteins in the stereocilia is a prerequisite to understanding the exact mechanisms of MET.
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Affiliation(s)
- Zubair M Ahmed
- Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Ohio
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28
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Longitudinal fundus and retinal studies with SD-OCT: a comparison of five mouse inbred strains. Mamm Genome 2013; 24:198-205. [PMID: 23681115 DOI: 10.1007/s00335-013-9457-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 04/24/2013] [Indexed: 02/05/2023]
Abstract
Spectral domain optical coherence tomography (SD-OCT) has recently been established as a method for in vivo imaging of fundus and retina in the mouse. It enables more effective studies of retinal diseases including investigations of etiopathologic mechanisms. In order to learn more about longitudinal fundus development and to enable recognition of disease-associated irregularities, we performed confocal scanning laser ophthalmoscopy (cSLO) and SD-OCT measurements in the inbred strains C57BL/6J, C3HeB/FeJ, FVB/NCrl, BALB/cByJ, and 129S2/SvJ when they were between 2 and 6 months of age. In general, cSLO and SD-OCT data did not reveal sex-specific or unilateral differences. C3HeB/FeJ and FVB/NCrl mice showed diffuse choroidal dysplasia. Choroidal vein-like structures appeared as dark fundus stripes in C3HeB/FeJ. In FVB/NCrl, fundus fleck accumulation was found. In contrast, only minor time-dependent changes of fundus appearance were observed in C57BL/6J, BALB/cByJ, and 129S2/SvJ. This was also found for individual fundic main blood vessel patterns in all inbred strains. Vessel numbers varied between 6 and 13 in C57BL/6J. This was comparable in most cases. We further found that retinae were significantly thicker in C57BL/6J compared to the other strains. Total retinal thickness generally did not change between 2 and 6 months of age. As a conclusion, our results indicate lifelong pathologic processes in C3HeB/FeJ and FVB/NCrl that affect choroid and orbital tissues. Inbred strains with regular retinal development did not reveal major time-dependent variations of fundus appearance, blood vessel pattern, or retinal thickness. Consequently, progressive changes of these parameters are suitable indicators for pathologic outliers.
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29
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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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Roeseler DA, Sachdev S, Buckley DM, Joshi T, Wu DK, Xu D, Hannink M, Waters ST. Elongation factor 1 alpha1 and genes associated with Usher syndromes are downstream targets of GBX2. PLoS One 2012; 7:e47366. [PMID: 23144817 PMCID: PMC3493575 DOI: 10.1371/journal.pone.0047366] [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: 04/13/2012] [Accepted: 09/12/2012] [Indexed: 11/18/2022] Open
Abstract
Gbx2 encodes a DNA-binding transcription factor that plays pivotal roles during embryogenesis. Gain-and loss-of-function studies in several vertebrate species have demonstrated a requirement for Gbx2 in development of the anterior hindbrain, spinal cord, inner ear, heart, and neural crest cells. However, the target genes through which GBX2 exerts its effects remain obscure. Using chromatin immunoprecipitation coupled with direct sequencing (ChIP-Seq) analysis in a human prostate cancer cell line, we identified cis-regulatory elements bound by GBX2 to provide insight into its direct downstream targets. The analysis revealed more than 286 highly significant candidate target genes, falling into various functional groups, of which 51% are expressed in the nervous system. Several of the top candidate genes include EEF1A1, ROBO1, PLXNA4, SLIT3, NRP1, and NOTCH2, as well as genes associated with the Usher syndrome, PCDH15 and USH2A, and are plausible candidates contributing to the developmental defects in Gbx2(-/-) mice. We show through gel shift analyses that sequences within the promoter or introns of EEF1A1, ROBO1, PCDH15, USH2A and NOTCH2, are directly bound by GBX2. Consistent with these in vitro results, analyses of Gbx2(-/-) embryos indicate that Gbx2 function is required for migration of Robo1-expressing neural crest cells out of the hindbrain. Furthermore, we show that GBX2 activates transcriptional activity through the promoter of EEF1A1, suggesting that GBX2 could also regulate gene expression indirectly via EEF1A. Taken together, our studies show that GBX2 plays a dynamic role in development and diseases.
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Affiliation(s)
- David A. Roeseler
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Shrikesh Sachdev
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Desire M. Buckley
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
| | - Trupti Joshi
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Computer Science, University of Missouri, Columbia, Missouri, United States of America
- Informatics Institute, University of Missouri, Columbia, Missouri, United States of America
| | - Doris K. Wu
- Laboratory of Molecular Biology, NIDCD, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Dong Xu
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Computer Science, University of Missouri, Columbia, Missouri, United States of America
- Informatics Institute, University of Missouri, Columbia, Missouri, United States of America
| | - Mark Hannink
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Samuel T. Waters
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
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Parallel evolution of auditory genes for echolocation in bats and toothed whales. PLoS Genet 2012; 8:e1002788. [PMID: 22761589 PMCID: PMC3386236 DOI: 10.1371/journal.pgen.1002788] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 05/12/2012] [Indexed: 11/24/2022] Open
Abstract
The ability of bats and toothed whales to echolocate is a remarkable case of convergent evolution. Previous genetic studies have documented parallel evolution of nucleotide sequences in Prestin and KCNQ4, both of which are associated with voltage motility during the cochlear amplification of signals. Echolocation involves complex mechanisms. The most important factors include cochlear amplification, nerve transmission, and signal re-coding. Herein, we screen three genes that play different roles in this auditory system. Cadherin 23 (Cdh23) and its ligand, protocadherin 15 (Pcdh15), are essential for bundling motility in the sensory hair. Otoferlin (Otof) responds to nerve signal transmission in the auditory inner hair cell. Signals of parallel evolution occur in all three genes in the three groups of echolocators—two groups of bats (Yangochiroptera and Rhinolophoidea) plus the dolphin. Significant signals of positive selection also occur in Cdh23 in the Rhinolophoidea and dolphin, and Pcdh15 in Yangochiroptera. In addition, adult echolocating bats have higher levels of Otof expression in the auditory cortex than do their embryos and non-echolocation bats. Cdh23 and Pcdh15 encode the upper and lower parts of tip-links, and both genes show signals of convergent evolution and positive selection in echolocators, implying that they may co-evolve to optimize cochlear amplification. Convergent evolution and expression patterns of Otof suggest the potential role of nerve and brain in echolocation. Our synthesis of gene sequence and gene expression analyses reveals that positive selection, parallel evolution, and perhaps co-evolution and gene expression affect multiple hearing genes that play different roles in audition, including voltage and bundle motility in cochlear amplification, nerve transmission, and brain function. The convergent origins of laryngeal echolocation in two groups of bats (Yangochiroptera and Rhinolophoidea) and toothed whales have long been a focus of interest for biologists. We screened three candidate genes—Cdh23, Pcdh15, and Otof—involved in different steps in the echolocation system. Signals of parallel evolution occurred in all three genes in the three groups of echolocators. Cdh23 and Pcdh15 constitute part of the mechanical link within the hair bundle of the ear. Both genes showed signals of both convergent evolution and positive selection, which implied they may have co-evolved to optimize cochlear amplification. Further, three lines of evidence suggest that Otof plays an important role in the transmission of signals in the brain during echolocation. First, the gene is more highly expressed in the auditory cortex of the brain in echolocating adult bats than in other cerebral cortexes. Second, this expression is higher in adult echolocating female bats than in their embryos, which do not use echolocation. Third, echolocators also have a higher level of expression in their cerebral cortexes than do non-echolocating bats. Taken with other evidence, the independent origins of echolocation involve the same genes that have evolved in precisely identical ways.
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Jaworek TJ, Bhatti R, Latief N, Khan SN, Riazuddin S, Ahmed ZM. USH1K, a novel locus for type I Usher syndrome, maps to chromosome 10p11.21-q21.1. J Hum Genet 2012; 57:633-7. [PMID: 22718019 PMCID: PMC3596105 DOI: 10.1038/jhg.2012.79] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We ascertained two large Pakistani consanguineous families (PKDF231 and PKDF608) segregating profound hearing loss, vestibular dysfunction, and retinitis pigmentosa; the defining features of Usher syndrome type 1 (USH1). To date, seven USH1 loci have been reported. Here, we map a novel locus, USH1K, on chromosome 10p11.21-q21.1. In family PKDF231, we performed a genome-wide linkage screen and found a region of homozygosity shared among the affected individuals at chromosome 10p11.21-q21.1. Meiotic recombination events in family PKDF231 define a critical interval of 11.74 cM (20.20 Mb) bounded by markers D10S1780 (63.83 cM) and D10S546 (75.57 cM). Affected individuals of family PKDF608 were also homozygous for chromosome 10p11.21-q21.1-linked STR markers. Of the 85 genes within the linkage interval, PCDH15, GJD4, FZD4, RET and LRRC18 were sequenced in both families, but no potential pathogenic mutation was identified. The USH1K locus overlaps the non-syndromic deafness locus DFNB33 raising the possibility that the two disorders may be caused by allelic mutations.
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Affiliation(s)
- Thomas J Jaworek
- Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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33
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Pan L, Zhang M. Structures of usher syndrome 1 proteins and their complexes. Physiology (Bethesda) 2012; 27:25-42. [PMID: 22311968 DOI: 10.1152/physiol.00037.2011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Usher syndrome 1 (USH1) is the most common and severe form of hereditary loss of hearing and vision. Genetic, physiological, and cell biological studies, together with recent structural investigations, have not only uncovered the physiological functions of the five USH1 proteins but also provided mechanistic explanations for the hearing and visual deficiencies in humans caused by USH1 mutations. This review focuses on the structural basis of the USH1 protein complex organization.
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Affiliation(s)
- Lifeng Pan
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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The dynamic architecture of photoreceptor ribbon synapses: cytoskeletal, extracellular matrix, and intramembrane proteins. Vis Neurosci 2012; 28:453-71. [PMID: 22192503 DOI: 10.1017/s0952523811000356] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rod and cone photoreceptors possess ribbon synapses that assist in the transmission of graded light responses to second-order bipolar and horizontal cells of the vertebrate retina. Proper functioning of the synapse requires the juxtaposition of presynaptic release sites immediately adjacent to postsynaptic receptors. In this review, we focus on the synaptic, cytoskeletal, and extracellular matrix proteins that help to organize photoreceptor ribbon synapses in the outer plexiform layer. We examine the proteins that foster the clustering of release proteins, calcium channels, and synaptic vesicles in the presynaptic terminals of photoreceptors adjacent to their postsynaptic contacts. Although many proteins interact with one another in the presynaptic terminal and synaptic cleft, these protein-protein interactions do not create a static and immutable structure. Instead, photoreceptor ribbon synapses are remarkably dynamic, exhibiting structural changes on both rapid and slow time scales.
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Sigismund S, Confalonieri S, Ciliberto A, Polo S, Scita G, Di Fiore PP. Endocytosis and signaling: cell logistics shape the eukaryotic cell plan. Physiol Rev 2012; 92:273-366. [PMID: 22298658 DOI: 10.1152/physrev.00005.2011] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our understanding of endocytosis has evolved remarkably in little more than a decade. This is the result not only of advances in our knowledge of its molecular and biological workings, but also of a true paradigm shift in our understanding of what really constitutes endocytosis and of its role in homeostasis. Although endocytosis was initially discovered and studied as a relatively simple process to transport molecules across the plasma membrane, it was subsequently found to be inextricably linked with almost all aspects of cellular signaling. This led to the notion that endocytosis is actually the master organizer of cellular signaling, providing the cell with understandable messages that have been resolved in space and time. In essence, endocytosis provides the communications and supply routes (the logistics) of the cell. Although this may seem revolutionary, it is still likely to be only a small part of the entire story. A wealth of new evidence is uncovering the surprisingly pervasive nature of endocytosis in essentially all aspects of cellular regulation. In addition, many newly discovered functions of endocytic proteins are not immediately interpretable within the classical view of endocytosis. A possible framework, to rationalize all this new knowledge, requires us to "upgrade" our vision of endocytosis. By combining the analysis of biochemical, biological, and evolutionary evidence, we propose herein that endocytosis constitutes one of the major enabling conditions that in the history of life permitted the development of a higher level of organization, leading to the actuation of the eukaryotic cell plan.
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Affiliation(s)
- Sara Sigismund
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy
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Akoury E, El Zir E, Mansour A, Mégarbané A, Majewski J, Slim R. A novel 5-bp deletion in Clarin 1 in a family with Usher syndrome. Ophthalmic Genet 2011; 32:245-9. [PMID: 21675857 DOI: 10.3109/13816810.2011.587083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND To identify the genetic defect in a Lebanese family with two sibs diagnosed with Usher Syndrome. MATERIALS AND METHODS Exome capture and sequencing were performed on DNA from one affected member using Agilent in solution bead capture, followed by Illumina sequencing. RESULTS This analysis revealed the presence of a novel homozygous 5-bp deletion, in Clarin 1 (CLRN1), a known gene responsible for Usher syndrome type III. The deletion is inherited from both parents and segregates with the disease phenotype in the family. The 5-bp deletion, c.301_305delGTCAT, p.Val101SerfsX27, is predicted to result in a frameshift and protein truncation after 27 amino acids. Sequencing all the coding regions of the CLRN1 gene in the proband did not reveal any other mutation or variant. CONCLUSION Here we describe a novel deletion in CLRN1. Our data support previously reported intra familial variability in the clinical features of Usher syndrome type I and III.
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Affiliation(s)
- Elie Akoury
- Department of Human Genetics, McGill University Health Centre, Montreal, Canada
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Alteration of rod and cone function in children with Usher syndrome. Eur J Ophthalmol 2011; 21:30-8. [PMID: 20544672 DOI: 10.5301/ejo.2010.5433] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the retinal function, with emphasis on phenotype and rate of progression, in infants and children with different genotypes of Usher syndrome. METHODS Fourteen children (2-10 years of age) with retinitis pigmentosa and hearing impairment were examined with full-field electroretinography (ERG) during general anesthesia, ophthalmologic examination, and genetic analysis. Five children were repeatedly examined (follow-up 5-10 years) with full-field ERG under local anesthesia and in 2 children multifocal ERG and optical coherence tomography (OCT) were performed. These results were compared to full-field ERG data from 58 children without retinal eye disorder. RESULTS Six children were genotyped as Usher 1B, 2A, and 3A. Full-field ERG demonstrated early alterations corresponding to a rod-cone dystrophy in all children. A remaining rod function could be verified in the majority of the children up to 4 years of age. After 4 years of age, there was a further deterioration of the rod function; the progress was severe in Usher types 1 and 2 and moderate in Usher type 3. In all children, the cone function was moderately reduced, in a few cases almost normal. The results from the 58 children without retinal disorder confirm that full-field ERG during general anesthesia is reliable. Multifocal ERG confirmed a preserved central cone function and in OCT there were discrete structural alterations. CONCLUSIONS Full-field ERG during general anesthesia in children with Usher syndrome demonstrates variable phenotypes and different degrees in rate of progression during childhood.
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Wu L, Pan L, Wei Z, Zhang M. Structure of MyTH4-FERM domains in myosin VIIa tail bound to cargo. Science 2011; 331:757-60. [PMID: 21311020 DOI: 10.1126/science.1198848] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The unconventional myosin VIIa (MYO7A) is one of the five proteins that form a network of complexes involved in formation of stereocilia. Defects in these proteins cause syndromic deaf-blindness in humans [Usher syndrome I (USH1)]. Many disease-causing mutations occur in myosin tail homology 4-protein 4.1, ezrin, radixin, moesin (MyTH4-FERM) domains in the myosin tail that binds to another USH1 protein, Sans. We report the crystal structure of MYO7A MyTH4-FERM domains in complex with the central domain (CEN) of Sans at 2.8 angstrom resolution. The MyTH4 and FERM domains form an integral structural and functional supramodule binding to two highly conserved segments (CEN1 and 2) of Sans. The MyTH4-FERM/CEN complex structure provides mechanistic explanations for known deafness-causing mutations in MYO7A MyTH4-FERM. The structure will also facilitate mechanistic and functional studies of MyTH4-FERM domains in other myosins.
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Affiliation(s)
- Lin Wu
- Division of Life Science, Molecular Neuroscience Center, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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Raviv D, Dror AA, Avraham KB. Hearing loss: a common disorder caused by many rare alleles. Ann N Y Acad Sci 2011; 1214:168-79. [PMID: 21175685 DOI: 10.1111/j.1749-6632.2010.05868.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Perception of sound is a fundamental role of the auditory system. Traveling with the force of their mechanical energy, sound waves are captured by the ear and activate the sensory pathway of this complex organ. The hair cells, specialized sensory cells within the inner ear, transmit the mechanical energy into electrical nerve stimuli that reach the brain. A large number of proteins are responsible for the overarching tasks required to maintain the complex mechanism of sound sensation. Many hearing disorders are due to single gene defects inherited in a Mendelian fashion, thus enabling clinical diagnostics. However, at the same time, hearing impairment is genetically heterogeneous, with both common and rare forms occurring due to mutations in over 100 genes. The crosstalk between human and mouse genetics has enabled comprehensive studies on gene identification and protein function, taking advantage of the tools animal models have to offer. The aim of the following review is to provide background and examples of human deafness genes and the discovery of their function in the auditory system.
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Affiliation(s)
- Dorith Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Booij JC, Bakker A, Kulumbetova J, Moutaoukil Y, Smeets B, Verheij J, Kroes HY, Klaver CCW, van Schooneveld M, Bergen AAB, Florijn RJ. Simultaneous mutation detection in 90 retinal disease genes in multiple patients using a custom-designed 300-kb retinal resequencing chip. Ophthalmology 2011; 118:160-167.e1-3. [PMID: 20801516 DOI: 10.1016/j.ophtha.2010.04.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 04/14/2010] [Accepted: 04/14/2010] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To develop a high-throughput, cost-effective diagnostic strategy for the identification of known and new mutations in 90 retinal disease genes. DESIGN Evidence-based study. PARTICIPANTS Sixty patients with a variety of retinal disorders, including Leber's congenital amaurosis, ocular albinism, pseudoxanthoma elasticum, retinitis pigmentosa, and Stargardt's disease. METHODS We designed a custom 300-kb resequencing chip. Polymerase chain reaction (PCR) amplification, DNA fragmentation, and chip hybridization were performed according to Affymetrix recommendations. Hybridization signals were analyzed using Sequence pilot module seq-C mutation detection software (2009). This resequencing approach was validated by Sanger sequence technology. MAIN OUTCOME MEASURES Disease-causing sequence changes. RESULTS We developed a retinal resequencing chip that covers all exons of 90 retinal disease genes. We developed and tested multiplex primer sets for 1445 amplicons representing the genes included on the chip. We validated our approach by screening 87 exons from 25 retinal disease genes containing 87 known sequence changes previously identified in our patient group using Sanger sequencing. Call rates for successfully hybridized amplicons were 98% to 100%. Of the known single nucleotide changes, 99% could be detected on the chip. As expected, deletions could not be detected reliably. CONCLUSIONS We designed a custom resequencing chip that can detect known and new sequence changes in 90 retinal disease genes using a new high-throughput strategy with a high sensitivity and specificity for one tenth of the cost of conventional direct sequencing. The developed amplification strategy allows for the pooling of multiple patients with non-overlapping phenotypes, enabling many patients to be analyzed simultaneously in a fast and cost-effective manner.
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Affiliation(s)
- Judith C Booij
- Department of Clinical and Molecular Ophthalmogenetics, Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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Millán JM, Aller E, Jaijo T, Blanco-Kelly F, Gimenez-Pardo A, Ayuso C. An update on the genetics of usher syndrome. J Ophthalmol 2010; 2011:417217. [PMID: 21234346 PMCID: PMC3017948 DOI: 10.1155/2011/417217] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 11/15/2010] [Indexed: 11/18/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive disease characterized by hearing loss, retinitis pigmentosa (RP), and, in some cases, vestibular dysfunction. It is clinically and genetically heterogeneous and is the most common cause underlying deafness and blindness of genetic origin. Clinically, USH is divided into three types. Usher type I (USH1) is the most severe form and is characterized by severe to profound congenital deafness, vestibular areflexia, and prepubertal onset of progressive RP. Type II (USH2) displays moderate to severe hearing loss, absence of vestibular dysfunction, and later onset of retinal degeneration. Type III (USH3) shows progressive postlingual hearing loss, variable onset of RP, and variable vestibular response. To date, five USH1 genes have been identified: MYO7A (USH1B), CDH23 (USH1D), PCDH15 (USH1F), USH1C(USH1C), and USH1G(USH1G). Three genes are involved in USH2, namely, USH2A (USH2A), GPR98 (USH2C), and DFNB31 (USH2D). USH3 is rare except in certain populations, and the gene responsible for this type is USH3A.
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Affiliation(s)
- José M. Millán
- Unidad de Genética, Instituto de Investigación Sanitaria-La Fe, 46009 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Elena Aller
- Unidad de Genética, Instituto de Investigación Sanitaria-La Fe, 46009 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Teresa Jaijo
- Unidad de Genética, Instituto de Investigación Sanitaria-La Fe, 46009 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Fiona Blanco-Kelly
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
- Departamento de Genética Médica, Instituto de Investigación Sanitaria, Fundación Jiménez Díaz, Avenida Reyes Católicos, 2, 28040 Madrid, Spain
| | - Ascensión Gimenez-Pardo
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
- Departamento de Genética Médica, Instituto de Investigación Sanitaria, Fundación Jiménez Díaz, Avenida Reyes Católicos, 2, 28040 Madrid, Spain
| | - Carmen Ayuso
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
- Departamento de Genética Médica, Instituto de Investigación Sanitaria, Fundación Jiménez Díaz, Avenida Reyes Católicos, 2, 28040 Madrid, Spain
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Malm E, Ponjavic V, Möller C, Kimberling WJ, Andréasson S. Phenotypes in defined genotypes including siblings with Usher syndrome. Ophthalmic Genet 2010; 32:65-74. [PMID: 21174530 DOI: 10.3109/13816810.2010.536064] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To characterize visual function in defined genotypes including siblings with Usher syndrome. METHODS Thirteen patients with phenotypically different subtypes of Usher syndrome, including 3 families with affected siblings, were selected. Genetic analysis and ophthalmological examinations including visual fields, full-field electroretinography (ERG), multifocal electroretinography (mf ERG), and optical coherence tomography (OCT) were assessed. The patients' degree of visual handicap was evaluated by a questionnaire (ADL). RESULTS Twelve of thirteen patients were genotyped as Usher 1B, 1D, 1F, 2A, 2C or 3A. In 12 of 13 patients examined with ERG the 30 Hz flickering light response revealed remaining cone function. In 3 of the patients with Usher type 1 mf ERG demonstrated a specific pattern, with a sharp distinction between the area with reduced function and the central area with remaining macular function and normal peak time. OCT demonstrated loss of foveal depression with distortion of the foveal architecture in the macula in all patients. The foveal thickness ranged from 159 to 384 µm and was not correlated to retinal function. Three siblings shared the same mutation for Usher 2C but in contrast to previous reports regarding this genotype, 1 of them diverged in phenotype with substantially normal visual fields, almost normal OCT and mf ERG findings, and only moderately reduced rod and cone function according to ERG. CONCLUSIONS Evaluation of visual function comprising both the severity of the rod cone degeneration and the function in the macular region confirm phenotypical heterogeneity within siblings and between different genotypes of Usher syndrome.
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Affiliation(s)
- Eva Malm
- Department of Ophthalmology, Skåne University Hospital, Lund, Sweden.
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Yan D, Kamiya K, Ouyang XM, Liu XZ. Analysis of subcellular localization of Myo7a, Pcdh15 and Sans in Ush1c knockout mice. Int J Exp Pathol 2010; 92:66-71. [PMID: 21156003 DOI: 10.1111/j.1365-2613.2010.00751.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Usher syndrome (USH) is the most frequent cause of combined deaf-blindness in man. An important finding from mouse models and molecular studies is that the USH proteins are integrated into a protein network that regulates inner ear morphogenesis. To understand further the function of harmonin in the pathogenesis of USH1, we have generated a targeted null mutation Ush1c mouse model. Here, we examine the effects of null mutation of the Ush1c gene on subcellular localization of Myo7a, Pcdh15 and Sans in the inner ear. Morphology and proteins distributions were analysed in cochlear sections and whole mount preparations from Ush1c(-/-) and Ush1c(-/+) controls mice. We observed the same distribution of Myo7a throughout the cytoplasm in knockout and control mice. However, we detected Pcdh15 at the base of stereocilia and in the cuticular plate in cochlear hair cells from Ush1c(+/-) controls, whereas in the knockout Ush1c(-/-) mice, Pcdh15 staining was concentrated in the apical region of the outer hair cells and no defined staining was detected at the base of stereocilia nor in the cuticular plate. We showed localization of Sans in the stereocilia of controls mouse cochlear hair cells. However, in cochleae from Ush1c(-/-) mice, strong Sans signals were detected towards the base of stereocilia close to their insertion point into the cuticular plate. Our data indicate that the disassembly of the USH1 network caused by absence of harmonin may have led to the mis-localization of the Protocadherin 15 and Sans proteins in the cochlear hair cells of Ush1c(-/-) knockout mice.
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Affiliation(s)
- Denise Yan
- Department of Otolaryngology, University of Miami, Miami, FL, USA
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Sacconi S, Baillif-Gostoli S, Desnuelle C. [Retinal involvement and genetic myopathy]. Rev Neurol (Paris) 2010; 166:998-1009. [PMID: 21071050 DOI: 10.1016/j.neurol.2010.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/25/2010] [Accepted: 09/22/2010] [Indexed: 01/06/2023]
Abstract
INTRODUCTION In genetic diseases, association between retinal and muscular involvement is uncommon, quite specific and frequently allows the diagnosis. In this context, three types of retinal involvement have been described: retinitis pigmentosa (RP), pattern retinal dystrophy (PRD) and exudative retinitis resembling Coats disease (CD). STATE OF THE ART The association between RP, PRD and muscle weakness is highly evocative of a mitochondrial disorder. Extra ocular muscles may be affected, but limb girdle or distal weakness can also be present in association or not with symptoms and signs of multisystemic involvement. In a large number of patients suffering from facioscapulohumeral muscular dystrophy (FSHD), retinal vessels telangectasia can be found at the fundoscopic examination. This finding, which corresponds to a developmental abnormality of peripheral retinal blood vessels, is not progressive and remains clinically asymptomatic. Nevertheless, a few patients with FSHD can develop an exsudative retinopathy resembling Coats disease with the risk of the major complication, recurrent retinal detachments. PERSPECTIVES AND CONCLUSIONS Considering the diagnostic interest and the deleterious consequences that may follow retinal involvement, close collaboration between the neurologist and ophthalmologist is needed in order to establish the diagnosis, detect complications early, and set up appropriate therapies.
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Affiliation(s)
- S Sacconi
- Centre de référence des maladies neuromusculaires et SLA, hôpital Archet 1, CHU de Nice, 151, route de Saint-Antoine-de-Ginestière, 06202 Nice, France.
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Nakanishi H, Ohtsubo M, Iwasaki S, Hotta Y, Takizawa Y, Hosono K, Mizuta K, Mineta H, Minoshima S. Mutation analysis of the MYO7A and CDH23 genes in Japanese patients with Usher syndrome type 1. J Hum Genet 2010; 55:796-800. [DOI: 10.1038/jhg.2010.115] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zallocchi M, Sisson JH, Cosgrove D. Biochemical characterization of native Usher protein complexes from a vesicular subfraction of tracheal epithelial cells. Biochemistry 2010; 49:1236-47. [PMID: 20058854 DOI: 10.1021/bi9020617] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Usher syndrome is the major cause of deaf/blindness in the world. It is a genetic heterogeneous disorder, with nine genes already identified as causative for the disease. We noted expression of all known Usher proteins in bovine tracheal epithelial cells and exploited this system for large-scale biochemical analysis of Usher protein complexes. The dissected epithelia were homogenized in nondetergent buffer and sedimented on sucrose gradients. At least two complexes were evident after the first gradient: one formed by specific isoforms of CDH23, PCDH15, and VLGR-1 and a different one at the top of the gradient that included all of the Usher proteins and rab5, a transport vesicle marker. TEM analysis of these top fractions found them enriched in 100-200 nm vesicles, confirming a vesicular association of the Usher complex(es). Immunoisolation of these vesicles confirmed some of the associations already predicted and identified novel interactions. When the vesicles are lysed in the presence of phenylbutyrate, most of the Usher proteins cosediment into the gradient at a sedimentation coefficient of approximately 50 S, correlating with a predicted molecular mass of 2 x 10(6) Da. Although it is still unclear whether there is only one complex or several independent complexes that are trafficked within distinct vesicular pools, this work shows for the first time that native Usher protein complexes occur in vivo. This complex(es) is present primarily in transport vesicles at the apical pole of tracheal epithelial cells, predicting that Usher proteins may be directionally transported as complexes in hair cells and photoreceptors.
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Affiliation(s)
- Marisa Zallocchi
- Usher Syndrome Center, Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA
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Tian C, Liu XZ, Han F, Yu H, Longo-Guess C, Yang B, Lu C, Yan D, Zheng QY. Ush1c gene expression levels in the ear and eye suggest different roles for Ush1c in neurosensory organs in a new Ush1c knockout mouse. Brain Res 2010; 1328:57-70. [PMID: 20211154 DOI: 10.1016/j.brainres.2010.02.079] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 01/15/2010] [Accepted: 02/26/2010] [Indexed: 02/03/2023]
Abstract
Usher syndrome (USH) is the most common form of deaf-blindness in humans. Molecular characterization revealed that the USH gene products form a macromolecular protein network in hair cells of the inner ear and in photoreceptor cells of the retina via binding to PDZ domains in the scaffold protein harmonin encoded by the Ush1c gene in mice and humans. Although several mouse mutants for the Ush1c gene have been described, we generated a targeted null mutation Ush1c mouse model in which the first four exons of the Ush1c gene were replaced with a reporter gene. Here, we assessed the expression pattern of the reporter gene under control of Ush1c regulatory elements and characterized the phenotype of mice defective for Ush1c. These Ush1 knockout mice are deaf but do not recapitulate vision defects before 10 months of age. Our data show LacZ expression in multiple layers of the retina but in neither outer nor inner segments of the photoreceptor layers in mice bearing the knockout construct at 1-5 months of age. The fact that Ush1c expression is much higher in the ear than in the eye suggests a different role for Ush1c in ear function than in the eye and may explain why Ush1c mutant mice do not recapitulate vision defects.
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Affiliation(s)
- Cong Tian
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH 44106, USA
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The structure of the harmonin/sans complex reveals an unexpected interaction mode of the two Usher syndrome proteins. Proc Natl Acad Sci U S A 2010; 107:4040-5. [PMID: 20142502 DOI: 10.1073/pnas.0911385107] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hereditary hearing-vision loss disease, Usher syndrome I (USH1), is caused by defects in several proteins that can interact with each other in vitro. Defects in USH1 proteins are thought to be responsible for the developmental and functional impairments of sensory cells in the retina and inner ear. Harmonin/USH1C and Sans/USH1G are two of the USH1 proteins that interact with each other. Harmonin also binds to other USH1 proteins such as cadherin 23 (CDH23) and protocadherin 15 (PCDH15). However, the molecular basis governing the harmonin and Sans interaction is largely unknown. Here, we report an unexpected assembly mode between harmonin and Sans. We demonstrate that the N-terminal domain and the first PDZ domain of harmonin are tethered by a small-domain C-terminal to PDZ1 to form a structural and functional supramodule responsible for binding to Sans. We discover that the SAM domain of Sans, specifically, binds to the PDZ domain of harmonin, revealing previously unknown interaction modes for both PDZ and SAM domains. We further show that the synergistic PDZ1/SAM and PDZ1/carboxyl PDZ binding-motif interactions, between harmonin and Sans, lock the two scaffold proteins into a highly stable complex. Mutations in harmonin and Sans found in USH1 patients are shown to destabilize the complex formation of the two proteins.
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Galvan A, Ioannidis JPA, Dragani TA. Beyond genome-wide association studies: genetic heterogeneity and individual predisposition to cancer. Trends Genet 2010; 26:132-41. [PMID: 20106545 DOI: 10.1016/j.tig.2009.12.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 12/22/2009] [Accepted: 12/22/2009] [Indexed: 02/06/2023]
Abstract
Genome-wide association studies (GWAS) using population-based designs have identified many genetic loci associated with risk of a range of complex diseases including cancer; however, each locus exerts a very small effect and most heritability remains unexplained. Family-based pedigree studies have also suggested tentative loci linked to increased cancer risk, often characterized by pedigree-specificity. However, comparison between the results of population- and family-based studies shows little concordance. Explanations for this unidentified genetic 'dark matter' of cancer include phenotype ascertainment issues, limited power, gene-gene and gene-environment interactions, population heterogeneity, parent-of-origin-specific effects, and rare and unexplored variants. Many of these reasons converge towards the concept of genetic heterogeneity that might implicate hundreds of genetic variants in regulating cancer risk. Dissecting the dark matter is a challenging task. Further insights can be gained from both population association and pedigree studies.
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Affiliation(s)
- Antonella Galvan
- Department of Predictive and for Prevention Medicine, Fondazione IRCCS, Istituto Nazionale Tumori, Via G. Venezian 1, 20133 Milan, Italy
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Grillet N, Kazmierczak P, Xiong W, Schwander M, Reynolds A, Sakaguchi H, Tokita J, Kachar B, Müller U. The mechanotransduction machinery of hair cells. Sci Signal 2009; 2:pt5. [PMID: 19706872 DOI: 10.1126/scisignal.285pt5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mechanotransduction, the conversion of mechanical force into an electrochemical signal, allows living organisms to detect touch, hear, register movement and gravity, and sense changes in cell volume and shape. Hair cells in the vertebrate inner ear are mechanoreceptor cells specialized for the detection of sound and head movement. Each hair cell contains, at the apical surface, rows of stereocilia that are connected by extracellular filaments to form an exquisitely organized bundle. Mechanotransduction channels, localized near the tips of the stereocilia, are gated by the gating spring, an elastic element that is stretched upon stereocilia deflection and mediates rapid channel opening. Components of the mechanotransduction machinery in hair cells have been identified and several are encoded by genes linked to deafness in humans, which indicates that defects in the mechanotransduction machinery are the underlying cause of some forms of hearing impairment.
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Affiliation(s)
- Nicolas Grillet
- Department of Cell Biology, Institute for Childhood and Neglected Disease, Scripps Research Institute, La Jolla, CA 92037, USA
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