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Mkaouar R, Riahi Z, Marrakchi J, Mezzi N, Romdhane L, Boujemaa M, Dallali H, Sayeb M, Lahbib S, Jaouadi H, Boudabbous H, Zekri L, Chargui M, Messaoud O, Elyounsi M, Kraoua I, Zaouak A, Turki I, Mokni M, Boucher S, Petit C, Giraudet F, Mbarek C, Besbes G, Halayem S, Zainine R, Turki H, Tounsi A, Bonnet C, Mrad R, Abdelhak S, Trabelsi M, Charfeddine C. Current phenotypic and genetic spectrum of syndromic deafness in Tunisia: paving the way for precision auditory health. Front Genet 2024; 15:1384094. [PMID: 38711914 PMCID: PMC11072975 DOI: 10.3389/fgene.2024.1384094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/15/2024] [Indexed: 05/08/2024] Open
Abstract
Hearing impairment (HI) is a prevalent neurosensory condition globally, impacting 5% of the population, with over 50% of congenital cases attributed to genetic etiologies. In Tunisia, HI underdiagnosis prevails, primarily due to limited access to comprehensive clinical tools, particularly for syndromic deafness (SD), characterized by clinical and genetic heterogeneity. This study aimed to uncover the SD spectrum through a 14-year investigation of a Tunisian cohort encompassing over 700 patients from four referral centers (2007-2021). Employing Sanger sequencing, Targeted Panel Gene Sequencing, and Whole Exome Sequencing, genetic analysis in 30 SD patients identified diagnoses such as Usher syndrome, Waardenburg syndrome, cranio-facial-hand-deafness syndrome, and H syndrome. This latter is a rare genodermatosis characterized by HI, hyperpigmentation, hypertrichosis, and systemic manifestations. A meta-analysis integrating our findings with existing data revealed that nearly 50% of Tunisian SD cases corresponded to rare inherited metabolic disorders. Distinguishing between non-syndromic and syndromic HI poses a challenge, where the age of onset and progression of features significantly impact accurate diagnoses. Despite advancements in local genetic characterization capabilities, certain ultra-rare forms of SD remain underdiagnosed. This research contributes critical insights to inform molecular diagnosis approaches for SD in Tunisia and the broader North-African region, thereby facilitating informed decision-making in clinical practice.
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Affiliation(s)
- Rahma Mkaouar
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Zied Riahi
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Jihene Marrakchi
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Otorhinolaryngology, District Hospital of Menzel Bourguiba, Bizerte, Tunisia
| | - Nessrine Mezzi
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Biology, Faculty of Sciences of Bizerte, Université Tunis Carthage, Tunis, Tunisia
| | - Lilia Romdhane
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Biology, Faculty of Sciences of Bizerte, Université Tunis Carthage, Tunis, Tunisia
| | - Maroua Boujemaa
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Hamza Dallali
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Genetic Typing Service, Institut Pasteur of Tunis, Tunis, Tunisia
| | - Marwa Sayeb
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Saida Lahbib
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Hager Jaouadi
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Marseille Medical Genetics (MMG) U1251, Aix Marseille Université, INSERM, Marseille, France
| | - Hela Boudabbous
- Department of Pediatrics, La Rabta Hospital, Tunis, Tunisia
- Laboratory of Hereditary Diseases of the Metabolism Investigation and Patients Management, Faculty of Medicine in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Epidemiology and Public Health, Directorate General of Military Health, Faculty of Medicine in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Lotfi Zekri
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- ICHARA Association (International Research Institute on Sign Language), Tunis, Tunisia
| | - Mariem Chargui
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Olfa Messaoud
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Meriem Elyounsi
- Department of Congenital and Hereditary Diseases, Charles Nicolle Hospital in Tunis, Tunis, Tunisia
- LR99ES10 Laboratory of Human Genetics, Faculty of Medicine in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Ichraf Kraoua
- Child and Adolescent Neurology Department of Neurology, National Institute of Neurology, Tunis, Tunisia
- LR18SP04 Department of Child Neurology, National Institute Mongi Ben Hmida of Neurology in Tunis. University of Tunis El Manar, Tunis, Tunisia
| | - Anissa Zaouak
- Department of Dermatology, Habib Thameur Hospital, Research Unit Genodermatoses and Cancers LR12SP03, Tunis, Tunisia
| | - Ilhem Turki
- Child and Adolescent Neurology Department of Neurology, National Institute of Neurology, Tunis, Tunisia
- LR18SP04 Department of Child Neurology, National Institute Mongi Ben Hmida of Neurology in Tunis. University of Tunis El Manar, Tunis, Tunisia
| | - Mourad Mokni
- Service de dermatologie, Hôpital La Rabta, Unité de recherche UR 12SP07, Hôpital La Rabta, Tunis, Tunisia
| | - Sophie Boucher
- Service d’ORL et chirurgie cervico-faciale, CHU d’Angers, Angers, France
- Equipe Mitolab, Institut Mitovasc, CNRS UMR6015, UMR Inserm 1083, Université d’Angers, Angers, France
| | - Christine Petit
- Institut Pasteur, Université Paris Cité, Inserm UA06, Institut de l’Audition, Paris, France
- Collège de France, Paris, France
| | - Fabrice Giraudet
- Unité Mixte de Recherche (UMR) 1107, INSERM, Clermont-Ferrand, France
- Centre Auditif SoluSons, Clermont-Ferrand, France
| | - Chiraz Mbarek
- ENT Department, Habib Thameur Hospital, Tunis, Tunisia
| | - Ghazi Besbes
- Department of Otorhinolaryngology and Maxillofacial Surgery - La Rabta Hospital in Tunis, Tunis, Tunisia
| | - Soumeyya Halayem
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Service de pédopsychiatrie, Hôpital Razi, Faculté de Médecine de Tunis, Université Tunis el Manar, Tunis, Tunisia
| | - Rim Zainine
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Otorhinolaryngology and Maxillofacial Surgery - La Rabta Hospital in Tunis, Tunis, Tunisia
| | - Hamida Turki
- Dermatology Department Hedi Chaker University Hospital, Sfax University Sfax Tunisia, Tunis, Tunisia
| | | | - Crystel Bonnet
- Institut Pasteur, Université Paris Cité, Inserm UA06, Institut de l’Audition, Paris, France
| | - Ridha Mrad
- Department of Congenital and Hereditary Diseases, Charles Nicolle Hospital in Tunis, Tunis, Tunisia
- LR99ES10 Laboratory of Human Genetics, Faculty of Medicine in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Mediha Trabelsi
- Department of Congenital and Hereditary Diseases, Charles Nicolle Hospital in Tunis, Tunis, Tunisia
- LR99ES10 Laboratory of Human Genetics, Faculty of Medicine in Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Cherine Charfeddine
- Laboratory of Biomedical Genomics and Oncogenetics LR16IPT05, Pasteur Institute in Tunis, University of Tunis El Manar, Tunis, Tunisia
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Watanabe K, Nishio SY, Usami SI. The prevalence and clinical features of MYO7A-related hearing loss including DFNA11, DFNB2 and USH1B. Sci Rep 2024; 14:8326. [PMID: 38594301 PMCID: PMC11003999 DOI: 10.1038/s41598-024-57415-1] [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: 11/29/2023] [Accepted: 03/18/2024] [Indexed: 04/11/2024] Open
Abstract
The MYO7A gene is known to be responsible for both syndromic hearing loss (Usher syndrome type1B:USH1B) and non-syndromic hearing loss including autosomal dominant and autosomal recessive inheritance (DFNA11, DFNB2). However, the prevalence and detailed clinical features of MYO7A-associated hearing loss across a large population remain unclear. In this study, we conducted next-generation sequencing analysis for a large cohort of 10,042 Japanese hearing loss patients. As a result, 137 patients were identified with MYO7A-associated hearing loss so that the prevalence among Japanese hearing loss patients was 1.36%. We identified 70 disease-causing candidate variants in this study, with 36 of them being novel variants. All variants identified in autosomal dominant cases were missense or in-frame deletion variants. Among the autosomal recessive cases, all patients had at least one missense variant. On the other hand, in patients with Usher syndrome, almost half of the patients carried biallelic null variants (nonsense, splicing, and frameshift variants). Most of the autosomal dominant cases showed late-onset progressive hearing loss. On the other hand, cases with autosomal recessive inheritance or Usher syndrome showed congenital or early-onset hearing loss. The visual symptoms in the Usher syndrome cases developed between age 5-15, and the condition was diagnosed at about 6-15 years of age.
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Affiliation(s)
- Kizuki Watanabe
- Department of Otorhinolaryngology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Japan
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
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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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Bouzidi A, Charoute H, Charif M, Amalou G, Kandil M, Barakat A, Lenaers G. Clinical and genetic spectrums of 413 North African families with inherited retinal dystrophies and optic neuropathies. Orphanet J Rare Dis 2022; 17:197. [PMID: 35551639 PMCID: PMC9097391 DOI: 10.1186/s13023-022-02340-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/26/2022] [Indexed: 11/26/2022] Open
Abstract
Background Inherited retinal dystrophies (IRD) and optic neuropathies (ION) are the two major causes world-wide of early visual impairment, frequently leading to legal blindness. These two groups of pathologies are highly heterogeneous and require combined clinical and molecular diagnoses to be securely identified. Exact epidemiological studies are lacking in North Africa, and genetic studies of IRD and ION individuals are often limited to case reports or to some families that migrated to the rest of the world. In order to improve the knowledge of their clinical and genetic spectrums in North Africa, we reviewed published data, to illustrate the most prevalent pathologies, genes and mutations encountered in this geographical region, extending from Morocco to Egypt, comprising 200 million inhabitants. Main body We compiled data from 413 families with IRD or ION together with their available molecular diagnosis. The proportion of IRD represents 82.8% of index cases, while ION accounted for 17.8%. Non-syndromic IRD were more frequent than syndromic ones, with photoreceptor alterations being the main cause of non-syndromic IRD, represented by retinitis pigmentosa, Leber congenital amaurosis, and cone-rod dystrophies, while ciliopathies constitute the major part of syndromic-IRD, in which the Usher and Bardet Biedl syndromes occupy 41.2% and 31.1%, respectively. We identified 71 ION families, 84.5% with a syndromic presentation, while surprisingly, non-syndromic ION are scarcely reported, with only 11 families with autosomal recessive optic atrophies related to OPA7 and OPA10 variants, or with the mitochondrial related Leber ION. Overall, consanguinity is a major cause of these diseases within North African countries, as 76.1% of IRD and 78.8% of ION investigated families were consanguineous, explaining the high rate of autosomal recessive inheritance pattern compared to the dominant one. In addition, we identified many founder mutations in small endogamous communities. Short conclusion As both IRD and ION diseases constitute a real public health burden, their under-diagnosis in North Africa due to the absence of physicians trained to the identification of inherited ophthalmologic presentations, together with the scarcity of tools for the molecular diagnosis represent major political, economic and health challenges for the future, to first establish accurate clinical diagnoses and then treat patients with the emergent therapies. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02340-7.
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Affiliation(s)
- Aymane Bouzidi
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, CHU d'Angers, CNRS 6015, Université d'Angers, 49933, Angers, France.,Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco.,Team of Anthropogenetics and Biotechnologies, Faculty of Sciences, Chouaïb Doukkali University, Eljadida, Morocco
| | - Hicham Charoute
- Research Unit of Epidemiology, Biostatistics and Bioinformatics, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Majida Charif
- Genetics, and Immuno-Cell Therapy Team, Mohamed First University, Oujda, Morocco
| | - Ghita Amalou
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, CHU d'Angers, CNRS 6015, Université d'Angers, 49933, Angers, France.,Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco.,Team of Anthropogenetics and Biotechnologies, Faculty of Sciences, Chouaïb Doukkali University, Eljadida, Morocco
| | - Mostafa Kandil
- Team of Anthropogenetics and Biotechnologies, Faculty of Sciences, Chouaïb Doukkali University, Eljadida, Morocco
| | - Abdelhamid Barakat
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Guy Lenaers
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, CHU d'Angers, CNRS 6015, Université d'Angers, 49933, Angers, France. .,Service de Neurologie, CHU d'Angers, Angers, France.
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Sirko P, Kozlov AS. Immunohistochemistry localises myosin-7a to cochlear efferent boutons. Wellcome Open Res 2022; 7:1. [PMID: 35224213 PMCID: PMC8866907 DOI: 10.12688/wellcomeopenres.17428.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2022] [Indexed: 11/26/2022] Open
Abstract
Background: Myosin 7a is an actin-binding motor protein involved in the formation of hair-cell stereocilia both in the cochlea and in the vestibular system. Mutations in myosin 7a are linked to congenital hearing loss and are present in 50% of Type-1 Usher syndrome patients who suffer from progressive hearing loss and vestibular system dysfunction. Methods: Myosin 7a is often used to visualise sensory hair cells due to its well characterised and localised expression profile. We thus conducted myosin-7a immunostaining across all three turns of the adult rat organ of Corti to visualise hair cells. Results: As expected, we observed myosin 7a staining in both inner and outer hair cells. Unexpectedly, we also observed strong myosin 7a staining in the medial olivocochlear efferent synaptic boutons contacting the outer hair cells. Efferent bouton myosin-7a staining was present across all three turns of the cochlea. We verified this localisation by co-staining with a known efferent bouton marker, the vesicular acetylcholine transporter. Conclusions: In addition to its role in stereocilia formation and maintenance, myosin 7a or certain myosin-7a expression variants might play a role in efferent synaptic transmission in the cochlea and thus ultimately influence cochlear gain regulation. Our immunohistochemistry results should be validated with other methods to confirm these serendipitous findings.
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Affiliation(s)
- Piotr Sirko
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Andrei S. Kozlov
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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Sirko P, Kozlov AS. Immunohistochemistry localises myosin-7a to cochlear efferent boutons. Wellcome Open Res 2022; 7:1. [PMID: 35224213 PMCID: PMC8866907 DOI: 10.12688/wellcomeopenres.17428.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2022] [Indexed: 08/11/2023] Open
Abstract
Background: Myosin 7a is an actin-binding motor protein involved in the formation of hair-cell stereocilia both in the cochlea and in the vestibular system. Mutations in myosin 7a are linked to congenital hearing loss and are present in 50% of Type-1 Usher syndrome patients who suffer from progressive hearing loss and vestibular system dysfunction. Methods: Myosin 7a is often used to visualise sensory hair cells due to its well characterised and localised expression profile. We thus conducted myosin-7a immunostaining across all three turns of the adult rat organ of Corti to visualise hair cells. Results: As expected, we observed myosin 7a staining in both inner and outer hair cells. Unexpectedly, we also observed strong myosin 7a staining in the medial olivocochlear efferent synaptic boutons contacting the outer hair cells. Efferent bouton myosin-7a staining was present across all three turns of the cochlea. We verified this localisation by co-staining with a known efferent bouton marker, the vesicular acetylcholine transporter. Conclusions: In addition to its role in stereocilia formation and maintenance, myosin 7a or certain myosin-7a expression variants might play a role in efferent synaptic transmission in the cochlea and thus ultimately influence cochlear gain regulation. Our immunohistochemistry results should be validated with other methods to confirm these serendipitous findings.
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Affiliation(s)
- Piotr Sirko
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Andrei S. Kozlov
- Laboratory of Auditory Neuroscience and Biophysics, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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Galbis‐Martínez L, Blanco‐Kelly F, García‐García G, Ávila‐Fernández A, Jaijo T, Fuster‐García C, Perea‐Romero I, Zurita‐Muñoz O, Jimenez‐Rolando B, Carreño E, García‐Sandoval B, Millán JM, Ayuso C. Genotype-phenotype correlation in patients with Usher syndrome and pathogenic variants in MYO7A: implications for future clinical trials. Acta Ophthalmol 2021; 99:922-930. [PMID: 33576163 PMCID: PMC9540557 DOI: 10.1111/aos.14795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 01/22/2021] [Indexed: 12/16/2022]
Abstract
Purpose We aimed to establish correlations between the clinical features of a cohort of Usher syndrome (USH) patients with pathogenic variants in MYO7A, type of pathogenic variant, and location on the protein domain. Methods Sixty‐two USH patients from 46 families with biallelic variants in MYO7A were examined for visual and audiological features. Participants were evaluated based on self‐reported ophthalmological history and ophthalmological investigations (computerized visual field testing, best‐corrected visual acuity, and ophthalmoscopic and electrophysiological examination). Optical coherence tomography and fundus autofluorescence imaging were performed when possible. Auditory and vestibular functions were evaluated. Patients were classified according to the type of variant and the protein domain where the variants were located. Results Most patients displayed a typical USH1 phenotype, that is, prelingual severe‐profound sensorineural hearing loss, prepubertal retinitis pigmentosa (RP) and vestibular dysfunction. No statistically significant differences were observed for the variables analysed except for the onset of hearing loss due to the existence of two USH2 cases, defined as postlingual sensorineural hearing loss, postpubertal onset of RP, and absence of vestibular dysfunction, and one atypical case of USH. Conclusion We were unable to find a correlation between genotype and phenotype for MYO7A. However, our findings could prove useful for the assessment of efficacy in clinical trials, since the type of MYO7A variant does not seem to change the onset, severity or course of visual disease.
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Affiliation(s)
- Lilián Galbis‐Martínez
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Fiona Blanco‐Kelly
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Gema García‐García
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Almudena Ávila‐Fernández
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Teresa Jaijo
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Carla Fuster‐García
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Irene Perea‐Romero
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Olga Zurita‐Muñoz
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
| | - Belén Jimenez‐Rolando
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - Ester Carreño
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - Blanca García‐Sandoval
- CIBERER ISCIII Madrid Spain
- Department of Ophthalmology University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
| | - José M. Millán
- CIBERER ISCIII Madrid Spain
- Unit of Genetics University Hospital La Fe – IIS La Fe Valencia Spain
- Joint Unit for Rare Diseases IIS La Fe‐CIPF Valencia Spain
| | - Carmen Ayuso
- Department of Genetics University Hospital Fundacion Jimenez Diaz IIS‐FJD UAM Madrid Spain
- CIBERER ISCIII Madrid Spain
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Miles A, Blair C, Emili A, Tropepe V. Usher syndrome type 1-associated gene, pcdh15b, is required for photoreceptor structural integrity in zebrafish. Dis Model Mech 2021; 14:272551. [PMID: 34668518 PMCID: PMC8669488 DOI: 10.1242/dmm.048965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/13/2021] [Indexed: 12/23/2022] Open
Abstract
Blindness associated with Usher syndrome type 1 (USH1) is typically characterized as rod photoreceptor degeneration, followed by secondary loss of cones. The mechanisms leading to blindness are unknown because most genetic mouse models only recapitulate auditory defects. We generated zebrafish mutants for one of the USH1 genes, protocadherin-15b (pcdh15b), a putative cell adhesion molecule. Zebrafish Pcdh15 is expressed exclusively in photoreceptors within calyceal processes (CPs), at the base of the outer segment (OS) and within the synapse. In our mutants, rod and cone photoreceptor integrity is compromised, with early and progressively worsening abnormal OS disc growth and detachment, in part due to weakening CP contacts. These effects were attenuated or exacerbated by growth in dark and bright-light conditions, respectively. We also describe novel evidence for structural defects in synapses of pcdh15b mutant photoreceptors. Cell death does not accompany these defects at early stages, suggesting that photoreceptor structural defects, rather than overt cell loss, may underlie vision deficits. Thus, we present the first genetic animal model of a PCDH15-associated retinopathy that can be used to understand the aetiology of blindness in USH1. This article has an associated First Person interview with the first author of the paper. Summary: We present one of the first genetic animal mutants for PCDH15 that displays a severe, early retinopathy and suggests that zebrafish could be a useful model for PCDH15-associated retinal phenotypes.
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Affiliation(s)
- Amanda Miles
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Clarke Blair
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Andrew Emili
- Center for Network Systems Biology, Boston University, Boston, MA 02118, USA
| | - Vincent Tropepe
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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Souissi A, Gibriel AA, Masmoudi S. Genetics and meta-analysis of recessive non-syndromic hearing impairment and Usher syndrome in Maghreb population: lessons from the past, contemporary actualities and future challenges. Hum Genet 2021; 141:583-593. [PMID: 34268600 DOI: 10.1007/s00439-021-02314-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Hereditary hearing impairment (HI) is a heterogeneous condition with over 130 genes associated with genetic non-syndromic HI (NSHI) and Usher syndrome (USH). Approximately 80% of hereditary NSHI cases have autosomal recessive (AR) mode of inheritance. The high rate of consanguinity and endogamy in the Maghreb countries, including Tunisia, Algeria and Morocco, represents a major contributing factor to the development of ARHI. Since the 90s, those populations, with their particular large familiar structure, represented an effective key towards the discovery of the first HI loci and genes. In this study, we performed a deep literature database search to analyze the mutational spectrum and the distribution of pathogenic variants responsible of USH and the NSHI among those populations. To date, 124 pathogenic variants were identified in 32 genes of which over 70% represent population-specific variants. The particular variants' distribution is related to the high rate of consanguinity as well as the multiple shared features such as demographic history of migrations and social behavior that promoted the spreading of several founder mutations within those countries. This is the first study to report lessons from the past and current actualities of HI within the three Maghreb countries. However, despite the great impact placed by such population for the HI genetic studies, only a few next-generation sequencing platforms have so far been implemented with those countries. We, therefore, believe that those countries should be supported to implement this technology that would definitely be of great value in the discovery of additional novel HI genes/variants.
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Affiliation(s)
- Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia
| | - Abdullah A Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Sidi Mansour road Km 6, BP "1177", 3018, Sfax, Tunisia.
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Unraveling the genetic complexities of combined retinal dystrophy and hearing impairment. Hum Genet 2021; 141:785-803. [PMID: 34148116 PMCID: PMC9035000 DOI: 10.1007/s00439-021-02303-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/15/2021] [Indexed: 12/11/2022]
Abstract
Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf–blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15%) probands displayed other genetic entities with dual sensory impairment, including Alström syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf–blind cohort was 92%. Two (3%) probands were partially solved and only 3 (5%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.
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Long-term follow-up of a patient with JAG1-associated retinopathy. Doc Ophthalmol 2021; 143:237-247. [PMID: 33877487 DOI: 10.1007/s10633-021-09836-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/02/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE To report the long-term structural and functional changes in the posterior segments of an adult with an unusual retinal dystrophy caused by a novel mutation in JAG1. METHODS A 33-year-old female underwent comprehensive ophthalmic examination, including best corrected visual acuity (BCVA) measurement, dilated fundus imaging (wide-angle fundus colour and short wavelength autofluorescence imaging), macular and peripheral spectral-domain optical coherence tomography (SD-OCT) and electroretinography (ERG) at baseline and 10 years later at the age of 43. The patient also underwent systemic review with detailed cardiac, brain and renal investigations. During follow-up, genetic analysis using whole-exome sequencing was performed on the patient and her parents to identify disease-causing variants. RESULTS The patient's main complaint was of a recent onset of bilateral photophobia and blurred vision in the left eye. On examination, the most striking retinal finding was of bilateral well-demarcated, anterior circumferential chorioretinal atrophy with scattered pigment clumping from the mid periphery to the ora. In addition, she had posterior pole RPE hypopigmentation, peripapillary chorioretinal atrophy, left macular choroidal folds and retinal vasculature tortuosity with atypical branching. Her retinal electrophysiology was consistent with a cone rod photoreceptor dystrophy and left macular dysfunction. Ten years later, her BCVA, the anterior circumferential chorioretinal atrophy and her visual field constriction all remained stable. Her retinal electrophysiology demonstrated deterioration of left rod function, while cone dysfunction remained stable. Macular function deteriorated in both eyes. During follow-up, she was also noted to have progressive aortic root dilatation, posterior embryotoxon and an x ray diagnosis of butterfly vertebrae. Whole-exome sequencing revealed a novel c.2412C > A p.(Tyr804Ter) truncating mutation in JAG1 that was predicted to be pathogenic and suggested a diagnosis of Alagille syndrome. CONCLUSION This is the first report of the long-term detailed follow-up of a patient with Alagille syndrome whose most striking ophthalmic finding was bilateral well-demarcated, anterior circumferential chorioretinal atrophy. During follow-up, this finding remained stable, suggesting that this may be developmental in origin. This is in contrast with the progressive deterioration in the posterior pole retinal and macular function.
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Spectrum of MYO7A Mutations in an Indigenous South African Population Further Elucidates the Nonsyndromic Autosomal Recessive Phenotype of DFNB2 to Include Both Homozygous and Compound Heterozygous Mutations. Genes (Basel) 2021; 12:genes12020274. [PMID: 33671976 PMCID: PMC7919343 DOI: 10.3390/genes12020274] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 11/17/2022] Open
Abstract
MYO7A gene encodes unconventional myosin VIIA, which, when mutated, causes a phenotypic spectrum ranging from recessive hearing loss DFNB2 to deaf-blindness, Usher Type 1B (USH1B). MYO7A mutations are reported in nine DFNB2 families to date, none from sub-Saharan Africa.In DNA, from a cohort of 94 individuals representing 92 families from the Limpopo province of South Africa, eight MYO7A variations were detected among 10 individuals. Family studies identified homozygous and compound heterozygous mutations in 17 individuals out of 32 available family members. Four mutations were novel, p.Gly329Asp, p.Arg373His, p.Tyr1780Ser, and p.Pro2126Leufs*5. Two variations, p.Ser617Pro and p.Thr381Met, previously listed as of uncertain significance (ClinVar), were confirmed to be pathogenic. The identified mutations are predicted to interfere with the conformational properties of myosin VIIA through interruption or abrogation of multiple interactions between the mutant and neighbouring residues. Specifically, p.Pro2126Leufs*5, is predicted to abolish the critical site for the interactions between the tail and the motor domain essential for the autoregulation, leaving a non-functional, unregulated protein that causes hearing loss. We have identified MYO7A as a possible key deafness gene among indigenous sub-Saharan Africans. The spectrum of MYO7A mutations in this South African population points to DFNB2 as a specific entity that may occur in a homozygous or in a compound heterozygous state.
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Wafa TT, Faridi R, King KA, Zalewski C, Yousaf R, Schultz JM, Morell RJ, Muskett J, Turriff A, Tsilou E, Griffith AJ, Friedman TB, Zein WM, Brewer CC. Vestibular phenotype-genotype correlation in a cohort of 90 patients with Usher syndrome. Clin Genet 2021; 99:226-235. [PMID: 33089500 PMCID: PMC7821283 DOI: 10.1111/cge.13868] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 10/14/2020] [Accepted: 10/18/2020] [Indexed: 12/11/2022]
Abstract
Usher syndrome has been historically categorized into one of three classical types based on the patient phenotype. However, the vestibular phenotype does not infallibly predict which Usher genes are mutated. Conversely, the Usher syndrome genotype is not sufficient to reliably predict vestibular function. Here we present a characterization of the vestibular phenotype of 90 patients with clinical presentation of Usher syndrome (59 females), aged 10.9 to 75.5 years, with genetic variants in eight Usher syndromic genes and expand the description of atypical Usher syndrome. We identified unexpected horizontal semicircular canal reactivity in response to caloric and rotational stimuli in 12.5% (3 of 24) and 41.7% (10 of 24), respectively, of our USH1 cohort. These findings are not consistent with the classical phenotypic definition of vestibular areflexia in USH1. Similarly, 17% (6 of 35) of our cohort with USH2A mutations had saccular dysfunction as evidenced by absent cervical vestibular evoked myogenic potentials in contradiction to the classical assumption of normal vestibular function. The surprising lack of consistent genotypic to vestibular phenotypic findings as well as no clear vestibular phenotypic patterns among atypical USH cases, indicate that even rigorous vestibular phenotyping data will not reliably differentiate the three USH types.
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Affiliation(s)
- Talah T. Wafa
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Rabia Faridi
- Laboratory of Molecular GeneticsNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Kelly A. King
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Christopher Zalewski
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Rizwan Yousaf
- Laboratory of Molecular GeneticsNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Julie M. Schultz
- Laboratory of Molecular GeneticsNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
- Review Analysis DepartmentGeneDxGaithersburgMarylandUSA
| | - Robert J. Morell
- Genomics and Computational Biology CoreNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Julie Muskett
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Amy Turriff
- Ophthalmic Genetics and Visual Function BranchNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - Ekaterini Tsilou
- Ophthalmic Genetics and Visual Function BranchNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - Andrew J. Griffith
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Thomas B. Friedman
- Laboratory of Molecular GeneticsNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
| | - Wadih M. Zein
- Ophthalmic Genetics and Visual Function BranchNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - Carmen C. Brewer
- Otolaryngology BranchNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaMarylandUSA
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Souissi A, Ben Said M, Ben Ayed I, Elloumi I, Bouzid A, Mosrati MA, Hasnaoui M, Belcadhi M, Idriss N, Kamoun H, Gharbi N, Gibriel AA, Tlili A, Masmoudi S. Novel pathogenic mutations and further evidence for clinical relevance of genes and variants causing hearing impairment in Tunisian population. J Adv Res 2021; 31:13-24. [PMID: 34194829 PMCID: PMC8240103 DOI: 10.1016/j.jare.2021.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/14/2020] [Accepted: 01/07/2021] [Indexed: 12/22/2022] Open
Abstract
Introduction Hearing impairment (HI) is characterized by complex genetic heterogeneity. The evolution of next generation sequencing, including targeted enrichment panels, has revolutionized HI diagnosis. Objectives In this study, we investigated genetic causes in 22 individuals with non-GJB2 HI. Methods We customized a HaloplexHS kit to include 30 genes known to be associated with autosomal recessive nonsyndromic HI (ARNSHI) and Usher syndrome in North Africa. Results In accordance with the ACMG/AMP guidelines, we report 11 pathogenic variants; as follows; five novel variants including three missense (ESRRB-Tyr295Cys, MYO15A-Phe2089Leu and MYO7A-Tyr560Cys) and two nonsense (USH1C-Gln122Ter and CIB2-Arg104Ter) mutations; two previously reported mutations (OTOF-Glu57Ter and PNPT1-Glu475Gly), but first time identified among Tunisian families; and four other identified mutations namely WHRN-Gly808AspfsX11, SLC22A4-Cys113Tyr and two MYO7A compound heterozygous splice site variants that were previously described in Tunisia. Pathogenic variants in WHRN and CIB2 genes, in patients with convincing phenotype ruling out retinitis pigmentosa, provide strong evidence supporting their association with ARNSHI. Moreover, we shed lights on the pathogenic implication of mutations in PNPT1 gene in auditory function providing new evidence for its association with ARNSHI. Lack of segregation of a previously identified causal mutation OTOA-Val603Phe further supports its classification as variant of unknown significance. Our study reports absence of otoacoustic emission in subjects using bilateral hearing aids for several years indicating the importance of screening genetic alteration in OTOF gene for proper management of those patients. Conclusion In conclusion, our findings do not only expand the spectrum of HI mutations in Tunisian patients, but also improve our knowledge about clinical relevance of HI causing genes and variants.
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Affiliation(s)
- Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mariem Ben Said
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Ikhlas Ben Ayed
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Ines Elloumi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mohamed Ali Mosrati
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Mehdi Hasnaoui
- Department of Otorhinolaryngology, Taher Sfar University Hospital of Mahdia, Tunisia
| | - Malek Belcadhi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Nabil Idriss
- Department of Otorhinolaryngology, Taher Sfar University Hospital of Mahdia, Tunisia
| | - Hassen Kamoun
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Nourhene Gharbi
- Medical Genetic Department, University Hedi Chaker Hospital of Sfax, Tunisia
- Faculty of Medicine of Sfax, University of Sfax, Tunisia
| | - Abdullah A. Gibriel
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy. The British University in Egypt (BUE) Cairo, Egypt
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
- Human Genetics and Stem Cell Laboratory, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Center of Biotechnology of Sfax, University of Sfax, Tunisia
- Corresponding author at: Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, Sidi Mansour road Km 6, BP “1177”, 3018 Sfax, Tunisia.
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Whatley M, Francis A, Ng ZY, Khoh XE, Atlas MD, Dilley RJ, Wong EYM. Usher Syndrome: Genetics and Molecular Links of Hearing Loss and Directions for Therapy. Front Genet 2020; 11:565216. [PMID: 33193648 PMCID: PMC7642844 DOI: 10.3389/fgene.2020.565216] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive (AR) disorder that permanently and severely affects the senses of hearing, vision, and balance. Three clinically distinct types of USH have been identified, decreasing in severity from Type 1 to 3, with symptoms of sensorineural hearing loss (SNHL), retinitis pigmentosa (RP), and vestibular dysfunction. There are currently nine confirmed and two suspected USH-causative genes, and a further three candidate loci have been mapped. The proteins encoded by these genes form complexes that play critical roles in the development and maintenance of cellular structures within the inner ear and retina, which have minimal capacity for repair or regeneration. In the cochlea, stereocilia are located on the apical surface of inner ear hair cells (HC) and are responsible for transducing mechanical stimuli from sound pressure waves into chemical signals. These signals are then detected by the auditory nerve fibers, transmitted to the brain and interpreted as sound. Disease-causing mutations in USH genes can destabilize the tip links that bind the stereocilia to each other, and cause defects in protein trafficking and stereocilia bundle morphology, thereby inhibiting mechanosensory transduction. This review summarizes the current knowledge on Usher syndrome with a particular emphasis on mutations in USH genes, USH protein structures, and functional analyses in animal models. Currently, there is no cure for USH. However, the genetic therapies that are rapidly developing will benefit from this compilation of detailed genetic information to identify the most effective strategies for restoring functional USH proteins.
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Affiliation(s)
- Meg Whatley
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Abbie Francis
- Ear Science Institute Australia, Nedlands, WA, Australia
- Emergency Medicine, The University of Western Australia, Nedlands, WA, Australia
| | - Zi Ying Ng
- Ear Science Institute Australia, Nedlands, WA, Australia
| | - Xin Ee Khoh
- Ear Science Institute Australia, Nedlands, WA, Australia
- School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Marcus D. Atlas
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
| | - Rodney J. Dilley
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, WA, Australia
| | - Elaine Y. M. Wong
- Ear Science Institute Australia, Nedlands, WA, Australia
- Ear Sciences Centre, The University of Western Australia, Nedlands, WA, Australia
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
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Vaché C, Puechberty J, Faugère V, Darmaisin F, Liquori A, Baux D, Blanchet C, Garcia-Garcia G, Meunier I, Pellestor F, Koenig M, Roux AF. A 4.6 Mb Inversion Leading to PCDH15- LINC00844 and BICC1- PCDH15 Fusion Transcripts as a New Pathogenic Mechanism Implicated in Usher Syndrome Type 1. Front Genet 2020; 11:623. [PMID: 32714370 PMCID: PMC7343966 DOI: 10.3389/fgene.2020.00623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 05/22/2020] [Indexed: 01/17/2023] Open
Abstract
Usher type 1 syndrome is a rare autosomal recessive disorder involving congenital severe-to-profound hearing loss, development of vision impairment in the first decade, and severe balance difficulties. The PCDH15 gene, one of the five genes implicated in this disease, is involved in 8–20% of cases. In this study, we aimed to identify and characterize the two causal variants in a French patient with typical Usher syndrome clinical features. Massively parallel sequencing-based gene panel and screening for large rearrangements were used, which detected a single multi-exon deletion in the PCDH15 gene. As the second pathogenic event was likely localized in the unscreened regions of the gene, PCDH15 transcripts from cultured nasal cells were analyzed and revealed a loss of junction between exon 13 and exon 14. This aberration could be explained by the identification of two fusion transcripts, PCDH15-LINC00844 and BICC1-PCDH15, originating from a 4.6 Mb inversion. This complex chromosomal rearrangement could not be detected by our diagnostic approach but was instead characterized by long-read sequencing, which offers the possibility of detecting balanced structural variants (SVs). This finding extends our knowledge of the mutational spectrum of the PCDH15 gene with the first ever identification of a large causal paracentric inversion of chromosome 10 and illustrates the utility of screening balanced SVs in an exhaustive molecular diagnostic approach.
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Affiliation(s)
- Christel Vaché
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | | | - Valérie Faugère
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Floriane Darmaisin
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Alessandro Liquori
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - David Baux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Catherine Blanchet
- Service ORL, CHU de Montpellier, Montpellier, France.,Centre de Référence Maladies Sensorielles Génétiques, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Gema Garcia-Garcia
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Isabelle Meunier
- Centre de Référence Maladies Sensorielles Génétiques, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Franck Pellestor
- Laboratoire de Génétique Chromosomique, Plateforme ChromoStem, CHU de Montpellier, Montpellier, France
| | - Michel Koenig
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Anne-Françoise Roux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
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Nolen RM, Hufnagel RB, Friedman TB, Turriff AE, Brewer CC, Zalewski CK, King KA, Wafa TT, Griffith AJ, Brooks BP, Zein WM. Atypical and ultra-rare Usher syndrome: a review. Ophthalmic Genet 2020; 41:401-412. [PMID: 32372680 DOI: 10.1080/13816810.2020.1747090] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Usher syndrome has classically been described as a combination of hearing loss and rod-cone dystrophy; vestibular dysfunction is present in many patients. Three distinct clinical subtypes were documented in the late 1970s. Genotyping efforts have led to the identification of several genes associated with the disease. Recent literature has seen multiple publications referring to "atypical" Usher syndrome presentations. This manuscript reviews the molecular etiology of Usher syndrome, highlighting rare presentations and molecular causes. Reports of "atypical" disease are summarized noting the wide discrepancy in the spectrum of phenotypic deviations from the classical presentation. Guidelines for establishing a clear nomenclature system are suggested.
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Affiliation(s)
- Rosalie M Nolen
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Amy E Turriff
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Carmen C Brewer
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Christopher K Zalewski
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Kelly A King
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Talah T Wafa
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute of Deafness and Other Communication Disorders, National Institutes of Health , Bethesda, MD, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health , Bethesda, MD, USA
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Role of Targeted Next Generation Sequencing in the Etiological Work-Up of Congenitally Deaf Children. Otol Neurotol 2019; 39:732-738. [PMID: 29889784 DOI: 10.1097/mao.0000000000001847] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVES The purpose of this study is to report the results of a comprehensive etiological work-up for congenitally deaf children including targeted next generation sequencing. STUDY DESIGN Retrospective case review. SETTING Tertiary referral center. PATIENTS Fifty children with congenital, bilateral profound hearing loss (HL) (>90 dBnHL). INTERVENTIONS Etiological work-up included testing for pathogenic variants in GJB2, a phenotype driven genetic analysis, screening for congenital infections and imaging. When no etiology could be found, comprehensive genetic testing was performed using a HL gene panel including 45 syndromic and 96 non-syndromic HL genes. RESULTS Eleven patients carried bi-allelic pathogenic variants in GJB2. Phenotype driven genetic analysis identified two homozygous KCNQ1 patients (Jervell and Lange Nielsen syndrome) and one heterozygous CHD7 patient (CHARGE syndrome). One patient was diagnosed with achondroplasia and one had a clinical diagnosis of Waardenburg syndrome. A deafness gene panel evaluated 16 patients. In 12 out of 16, we identified a pathogenic (n = 12) or likely pathogenic (n = 2) variant and one variant of unknown significance (VUS). A definite diagnosis of non-syndromic or syndromic HL was made in 18 and seven patients, respectively. Non-genetic causes were congenital cytomegalovirus infection (n = 11), anatomic abnormalities (n = 2), neurological/metabolic/polymalformative conditions (n = 3), meningitis (n = 1), and auditory neuropathy (n = 1). CONCLUSIONS A definite genetic cause was found in 25 (50%) of congenital, bilaterally deaf children. Our data show that implementation of a gene panel improves the diagnostic yield for etiological work-up of congenital profound HL to 86%. Identification of the etiology of congenital HL may contribute to predicting outcomes of cochlear implantation.
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19
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Okano S, Makita Y, Katada A, Harabuchi Y, Kohmoto T, Naruto T, Masuda K, Imoto I. Novel compound heterozygous CDH23 variants in a patient with Usher syndrome type I. Hum Genome Var 2019; 6:8. [PMID: 30774966 PMCID: PMC6348282 DOI: 10.1038/s41439-019-0037-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 11/10/2018] [Accepted: 12/09/2018] [Indexed: 01/31/2023] Open
Abstract
Usher syndrome type I (USH1) is characterized by congenital, bilateral, profound sensorineural hearing loss, vestibular areflexia, and adolescent-onset retinitis pigmentosa. Here, we report a 12-year-old female patient with typical USH1. Targeted panel sequencing revealed compound heterozygous variants of the Cadherin 23 (CDH23) gene, which confirmed the USH1 diagnosis. A novel NM_022124.5:c.130G>A/p.(Glu44Lys) was identified, expanding the mutation spectrum of CDH23.
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Affiliation(s)
- Satomi Okano
- Hokkaido Asahikawa Habilitation Center for Disabled Children, Asahikawa, Japan
| | - Yoshio Makita
- 2Education Center, Asahikawa Medical University, Asahikawa, Japan
| | - Akihiro Katada
- 3Department of Otolaryngology-Head and Neck Surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Yasuaki Harabuchi
- 3Department of Otolaryngology-Head and Neck Surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Tomohiro Kohmoto
- 4Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Takuya Naruto
- 4Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Kiyoshi Masuda
- 4Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Issei Imoto
- 4Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan.,5Risk Assessment Center, Aichi Cancer Center Hospital, Nagoya, Japan
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20
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Fuster-García C, García-García G, Jaijo T, Fornés N, Ayuso C, Fernández-Burriel M, Sánchez-De la Morena A, Aller E, Millán JM. High-throughput sequencing for the molecular diagnosis of Usher syndrome reveals 42 novel mutations and consolidates CEP250 as Usher-like disease causative. Sci Rep 2018; 8:17113. [PMID: 30459346 PMCID: PMC6244211 DOI: 10.1038/s41598-018-35085-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/17/2018] [Indexed: 01/09/2023] Open
Abstract
Usher syndrome is a rare disorder causing retinitis pigmentosa, together with sensorineural hearing loss. Due to the phenotypic and genetic heterogeneity of this disease, the best method to screen the causative mutations is by high-throughput sequencing. In this study, we tested a semiconductor chip based sequencing approach with 77 unrelated patients, as a molecular diagnosis routine. In addition, Multiplex Ligation-dependent Probe Amplification and microarray-based Comparative Genomic Hybridization techniques were applied to detect large rearrangements, and minigene assays were performed to confirm the mRNA processing aberrations caused by splice-site mutations. The designed panel included all the USH causative genes (MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, ADGRV1, WHRN and CLRN1) as well as four uncertainly associated genes (HARS, PDZD7, CEP250 and C2orf71). The outcome showed an overall mutation detection ratio of 82.8% and allowed the identification of 42 novel putatively pathogenic mutations. Furthermore, we detected two novel nonsense mutations in CEP250 in a patient with a disease mimicking Usher syndrome that associates visual impairment due to cone-rod dystrophy and progressive hearing loss. Therefore, this approach proved reliable results for the molecular diagnosis of the disease and also allowed the consolidation of the CEP250 gene as disease causative for an Usher-like phenotype.
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Affiliation(s)
- Carla Fuster-García
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain
| | - Gema García-García
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain.
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain.
| | - Teresa Jaijo
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
- Unidad de Genética y Diagnóstico Prenatal, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Neus Fornés
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain
| | - Carmen Ayuso
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
- Servicio de Genética, Fundación Jiménez Díaz, University Hospital, Instituto de Investigación Sanitaria Fundación Jiménez Díaz IIS-FJD, UAM, Madrid, Spain
| | | | | | - Elena Aller
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
- Unidad de Genética y Diagnóstico Prenatal, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - José M Millán
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
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21
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Richard EM, Santos-Cortez RLP, Faridi R, Rehman AU, Lee K, Shahzad M, Acharya A, Khan AA, Imtiaz A, Chakchouk I, Takla C, Abbe I, Rafeeq M, Liaqat K, Chaudhry T, Bamshad MJ, Nickerson DA, Schrauwen I, Khan SN, Morell RJ, Zafar S, Ansar M, Ahmed ZM, Ahmad W, Riazuddin S, Friedman TB, Leal SM, Riazuddin S. Global genetic insight contributed by consanguineous Pakistani families segregating hearing loss. Hum Mutat 2018; 40:53-72. [PMID: 30303587 DOI: 10.1002/humu.23666] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/04/2018] [Accepted: 10/07/2018] [Indexed: 12/14/2022]
Abstract
Consanguineous Pakistani pedigrees segregating deafness have contributed decisively to the discovery of 31 of the 68 genes associated with nonsyndromic autosomal recessive hearing loss (HL) worldwide. In this study, we utilized genome-wide genotyping, Sanger and exome sequencing to identify 163 DNA variants in 41 previously reported HL genes segregating in 321 Pakistani families. Of these, 70 (42.9%) variants identified in 29 genes are novel. As expected from genetic studies of disorders segregating in consanguineous families, the majority of affected individuals (94.4%) are homozygous for HL-associated variants, with the other variants being compound heterozygotes. The five most common HL genes in the Pakistani population are SLC26A4, MYO7A, GJB2, CIB2 and HGF, respectively. Our study provides a profile of the genetic etiology of HL in Pakistani families, which will allow for the development of more efficient genetic diagnostic tools, aid in accurate genetic counseling, and guide application of future gene-based therapies. These findings are also valuable in interpreting pathogenicity of variants that are potentially associated with HL in individuals of all ancestries. The Pakistani population, and its infrastructure for studying human genetics, will continue to be valuable to gene discovery for HL and other inherited disorders.
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Affiliation(s)
- Elodie M Richard
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Regie Lyn P Santos-Cortez
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Rabia Faridi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland.,National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Atteeq U Rehman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Kwanghyuk Lee
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Mohsin Shahzad
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland.,Pakistan Institute of Medical Sciences, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Anushree Acharya
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Asma A Khan
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Ayesha Imtiaz
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Imen Chakchouk
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Christina Takla
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Izoduwa Abbe
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Maria Rafeeq
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Khurram Liaqat
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Taimur Chaudhry
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Michael J Bamshad
- Department of Genome Sciences, University of Washington, Seattle, Washington
| | - Deborah A Nickerson
- Department of Genome Sciences, University of Washington, Seattle, Washington
| | | | - Isabelle Schrauwen
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Shaheen N Khan
- National Center for Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Robert J Morell
- The Genomics and Computational Biology Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Saba Zafar
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Muhammad Ansar
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Zubair M Ahmed
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- Pakistan Institute of Medical Sciences, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan.,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Suzanne M Leal
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Saima Riazuddin
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland.,Pakistan Institute of Medical Sciences, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
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22
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Jaiganesh A, Narui Y, Araya-Secchi R, Sotomayor M. Beyond Cell-Cell Adhesion: Sensational Cadherins for Hearing and Balance. Cold Spring Harb Perspect Biol 2018; 10:a029280. [PMID: 28847902 PMCID: PMC6008173 DOI: 10.1101/cshperspect.a029280] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cadherins form a large family of proteins often involved in calcium-dependent cellular adhesion. Although classical members of the family can provide a physical bond between cells, a subset of special cadherins use their extracellular domains to interlink apical specializations of single epithelial sensory cells. Two of these cadherins, cadherin-23 (CDH23) and protocadherin-15 (PCDH15), form extracellular "tip link" filaments that connect apical bundles of stereocilia on hair cells essential for inner-ear mechanotransduction. As these bundles deflect in response to mechanical stimuli from sound or head movements, tip links gate hair-cell mechanosensitive channels to initiate sensory perception. Here, we review the unusual and diverse structural properties of these tip-link cadherins and the functional significance of their deafness-related missense mutations. Based on the structural features of CDH23 and PCDH15, we discuss the elasticity of tip links and models that bridge the gap between the nanomechanics of cadherins and the micromechanics of hair-cell bundles during inner-ear mechanotransduction.
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Affiliation(s)
- Avinash Jaiganesh
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Yoshie Narui
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Raul Araya-Secchi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
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23
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Utility of whole exome sequencing in the diagnosis of Usher syndrome: Report of novel compound heterozygous MYO7A mutations. Int J Pediatr Otorhinolaryngol 2018; 108:17-21. [PMID: 29605349 DOI: 10.1016/j.ijporl.2018.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/05/2018] [Accepted: 02/11/2018] [Indexed: 12/30/2022]
Abstract
Next generation sequencing (NGS), such as targeted panel sequencing, whole-exome sequencing and whole-genome sequencing has led to an exponential increase of elucidated genetic causes in both rare diseases, and common but heterogeneous disorders. NGS is applied in both research and clinical settings, and the clinical exome sequencing (CES), which provides not only the sequence variation data but also clinical interpretation, aids in reaching a final conclusion with regards to a genetic diagnosis. Usher syndrome is a group of disorders, characterized by bilateral sensorineural hearing loss, with or without vestibular dysfunction and retinitis pigmentosa. The index patient, a 2-year-old child was initially diagnosed with nonsyndromic hearing impairment. Homozygosity mapping followed by CES was utilized as a diagnostic tool to identify the genetic basis of his hearing loss. A paternally inherited novel insertion, c.198_199insA (p.Val67Serfs*73) and a maternally inherited novel deletion, c.1219_1226del (p.Phe407Aspfs*33) in gene MYO7A were found in compound heterozygous state in the index patient. The result expands the mutational spectrum of MYO7A. In addition it helped in early diagnosis of the syndrome, for planning and adjustments for the patient, and as well as for future family planning. This study highlights the clinical effectiveness of CES for Usher syndrome diagnosis in a child presented with congenital hearing loss.
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24
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Lu Y, Zhou D, King R, Zhu S, Simpson CL, Jones BC, Zhang W, Geisert EE, Lu L. The genetic dissection of Myo7a gene expression in the retinas of BXD mice. Mol Vis 2018; 24:115-126. [PMID: 29430167 PMCID: PMC5802760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/31/2018] [Indexed: 11/16/2022] Open
Abstract
Purpose Usher syndrome (US) is characterized by a loss of vision due to retinitis pigmentosa (RP) and deafness. US has three clinical subtypes, but even within each subtype, the severity varies. Myosin VIIA, coded by Myo7a, has been identified as one of the causal genes of US. This study aims to identify pathways and other genes through which Myo7a interacts to affect the presentation of US symptoms. Methods In this study, we used the retinal tissue of BXD recombinant inbred (RI) mice to examine the expression of Myo7a and perform genetic mapping. Expression quantitative trait locus (eQTL), single nucleotide polymorphism (SNP), and gene correlation analysis were performed using GeneNetwork. Gene set enrichment analysis was performed using WebGestalt, and gene network construction was performed using the Gene Cohesion Analysis Tool. Results We found Myo7a to be cis-regulated, with varied levels of expression across BXD strains. Here, we propose a genetic network with 40 genes whose expression is highly correlated with Myo7a. Among these genes, six have been linked to retinal diseases, three to deafness, and five share a transcription factor with Myo7a. Gene ontology and pathway analysis revealed a strong connection among ion channel activity, Myo7a, and US. Conclusions Although Myo7a is a causal gene of US type I, this gene works with many other genes and pathways to affect the severity of US. Many of the genes found in the genetic network, pathways, and gene ontology categories of Myo7a are related to either deafness or blindness. Further investigation is needed to examine the specific relationships between these genes, which may assist in the treatment of US.
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Affiliation(s)
- Ye Lu
- Department of Ophthalmology, The First Affiliated Hospital, Zhejiang University College of Medicine, Hangzhou, China
| | - Diana Zhou
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN
| | - Rebecca King
- Department of Ophthalmology and Emory Eye Center, Emory University, Atlanta, GA
| | - Shuang Zhu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Claire L. Simpson
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN
| | - Byron C. Jones
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN
| | - Wenbo Zhang
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Eldon E. Geisert
- Department of Ophthalmology and Emory Eye Center, Emory University, Atlanta, GA
| | - Lu Lu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN
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25
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Maddalena A, Tornabene P, Tiberi P, Minopoli R, Manfredi A, Mutarelli M, Rossi S, Simonelli F, Naggert JK, Cacchiarelli D, Auricchio A. Triple Vectors Expand AAV Transfer Capacity in the Retina. Mol Ther 2017; 26:524-541. [PMID: 29292161 PMCID: PMC5835116 DOI: 10.1016/j.ymthe.2017.11.019] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 11/23/2017] [Accepted: 11/28/2017] [Indexed: 01/05/2023] Open
Abstract
Retinal gene transfer with adeno-associated viral (AAV) vectors holds great promise for the treatment of inherited retinal degenerations (IRDs). One limit of AAV is its transfer capacity of about 5 kb, which can be expanded to about 9 kb, using dual AAV vectors. This strategy would still not suffice for treatment of IRDs such as Usher syndrome type 1D or Alström syndrome type I (ALMS) due to mutations in CDH23 or ALMS1, respectively. To overcome this limitation, we generated triple AAV vectors, with a maximal transfer capacity of about 14 kb. Transcriptomic analysis following triple AAV transduction showed the expected full-length products along a number of aberrant transcripts. However, only the full-length transcripts are efficiently translated in vivo. We additionally showed that approximately 4% of mouse photoreceptors are transduced by triple AAV vectors and showed correct localization of recombinant ALMS1. The low-photoreceptor transduction levels might justify the modest and transient improvement we observe in the retina of a mouse model of ALMS. However, the levels of transduction mediated by triple AAV vectors in pig retina reached 40% of those observed with single vectors, and this bodes well for further improving the efficiency of triple AAV vectors in the retina.
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Affiliation(s)
- Andrea Maddalena
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy
| | - Patrizia Tornabene
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy
| | - Paola Tiberi
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy
| | - Renato Minopoli
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy
| | - Anna Manfredi
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy; Armenise/Harvard Laboratory of Integrative Genomics, TIGEM, Pozzuoli 80078, Italy
| | | | - Settimio Rossi
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Naples 80121, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Naples 80121, Italy
| | | | - Davide Cacchiarelli
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy; Armenise/Harvard Laboratory of Integrative Genomics, TIGEM, Pozzuoli 80078, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli 80078, Italy; Medical Genetics, Department of Advanced Biomedicine, Federico II University, Naples 80131, Italy.
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26
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Recurrence of reported
CDH23
mutations causing DFNB12 in a special cohort of South Indian hearing impaired assortative mating families – an evaluation. Ann Hum Genet 2017; 82:119-126. [DOI: 10.1111/ahg.12228] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 11/26/2022]
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27
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Neuhaus C, Eisenberger T, Decker C, Nagl S, Blank C, Pfister M, Kennerknecht I, Müller-Hofstede C, Charbel Issa P, Heller R, Beck B, Rüther K, Mitter D, Rohrschneider K, Steinhauer U, Korbmacher HM, Huhle D, Elsayed SM, Taha HM, Baig SM, Stöhr H, Preising M, Markus S, Moeller F, Lorenz B, Nagel-Wolfrum K, Khan AO, Bolz HJ. Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and PEX26 mutated in Heimler syndrome. Mol Genet Genomic Med 2017; 5:531-552. [PMID: 28944237 PMCID: PMC5606877 DOI: 10.1002/mgg3.312] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/06/2017] [Accepted: 06/09/2017] [Indexed: 12/23/2022] Open
Abstract
Background Combined retinal degeneration and sensorineural hearing impairment is mostly due to autosomal recessive Usher syndrome (USH1: congenital deafness, early retinitis pigmentosa (RP); USH2: progressive hearing impairment, RP). Methods Sanger sequencing and NGS of 112 genes (Usher syndrome, nonsyndromic deafness, overlapping conditions), MLPA, and array‐CGH were conducted in 138 patients clinically diagnosed with Usher syndrome. Results A molecular diagnosis was achieved in 97% of both USH1 and USH2 patients, with biallelic mutations in 97% (USH1) and 90% (USH2), respectively. Quantitative readout reliably detected CNVs (confirmed by MLPA or array‐CGH), qualifying targeted NGS as one tool for detecting point mutations and CNVs. CNVs accounted for 10% of identified USH2A alleles, often in trans to seemingly monoallelic point mutations. We demonstrate PTC124‐induced read‐through of the common p.Trp3955* nonsense mutation (13% of detected USH2A alleles), a potential therapy target. Usher gene mutations were found in most patients with atypical Usher syndrome, but the diagnosis was adjusted in case of double homozygosity for mutations in OTOA and NR2E3, genes implicated in isolated deafness and RP. Two patients with additional enamel dysplasia had biallelic PEX26 mutations, for the first time linking this gene to Heimler syndrome. Conclusion Targeted NGS not restricted to Usher genes proved beneficial in uncovering conditions mimicking Usher syndrome.
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Affiliation(s)
| | | | | | - Sandra Nagl
- Bioscientia Center for Human GeneticsIngelheimGermany
| | | | - Markus Pfister
- HNO-Praxis SarnenSarnenSwitzerland.,Molecular Genetics, THRCDepartment of OtolaryngologyUniversity of TübingenTübingenGermany
| | - Ingo Kennerknecht
- Institute of Human GeneticsWestfälische Wilhelms-UniversitätMünsterGermany
| | | | - Peter Charbel Issa
- Department of OphthalmologyUniversity of BonnBonnGermany.,Center for Rare Diseases Bonn (ZSEB)University of BonnBonnGermany.,Oxford Eye HospitalUniversity of OxfordOxfordUK
| | - Raoul Heller
- Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
| | - Bodo Beck
- Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
| | | | - Diana Mitter
- Institute of Human GeneticsUniversity of Leipzig Hospitals and ClinicsLeipzigGermany
| | | | | | - Heike M Korbmacher
- Department of OrthodonticsGiessen and Marburg University Hospital, Marburg CampusMarburgGermany
| | | | - Solaf M Elsayed
- Medical Genetics CenterCairoEgypt.,Children's HospitalAin Shams UniversityCairoEgypt
| | | | - Shahid M Baig
- Human Molecular Genetics LaboratoryHealth Biotechnology DivisionNational Institute for Biotechnology and Genetic Engineering (NIBGE)FaisalabadPakistan
| | - Heidi Stöhr
- Department of Human GeneticsUniversity Medical Center RegensburgRegensburgGermany
| | - Markus Preising
- Department of OphthalmologyJustus-Liebig-University GiessenGiessenGermany
| | | | - Fabian Moeller
- Department of Cell and Matrix BiologyInstitute of Zoology, Johannes GutenbergUniversity of MainzMainzGermany
| | - Birgit Lorenz
- Department of OphthalmologyJustus-Liebig-University GiessenGiessenGermany
| | - Kerstin Nagel-Wolfrum
- Department of Cell and Matrix BiologyInstitute of Zoology, Johannes GutenbergUniversity of MainzMainzGermany
| | - Arif O Khan
- Division of Pediatric OphthalmologyKing Khaled Eye Specialist HospitalRiyadhSaudi Arabia.,Eye InstituteCleveland ClinicAbu DhabiUAE
| | - Hanno J Bolz
- Bioscientia Center for Human GeneticsIngelheimGermany.,Institute of Human GeneticsUniversity Hospital of CologneCologneGermany
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28
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Whole exome sequencing using Ion Proton system enables reliable genetic diagnosis of inherited retinal dystrophies. Sci Rep 2017; 7:42078. [PMID: 28181551 PMCID: PMC5299602 DOI: 10.1038/srep42078] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/05/2017] [Indexed: 01/17/2023] Open
Abstract
Inherited retinal dystrophies (IRD) comprise a wide group of clinically and genetically complex diseases that progressively affect the retina. Over recent years, the development of next-generation sequencing (NGS) methods has transformed our ability to diagnose heterogeneous diseases. In this work, we have evaluated the implementation of whole exome sequencing (WES) for the molecular diagnosis of IRD. Using Ion ProtonTM system, we simultaneously analyzed 212 genes that are responsible for more than 25 syndromic and non-syndromic IRD. This approach was used to evaluate 59 unrelated families, with the pathogenic variant(s) successfully identified in 71.18% of cases. Interestingly, the mutation detection rate varied substantially depending on the IRD subtype. Overall, we found 63 different mutations (21 novel) in 29 distinct genes, and performed in vivo functional studies to determine the deleterious impact of variants identified in MERTK, CDH23, and RPGRIP1. In addition, we provide evidences that support CDHR1 as a gene responsible for autosomal recessive retinitis pigmentosa with early macular affectation, and present data regarding the disease mechanism of this gene. Altogether, these results demonstrate that targeted WES of all IRD genes is a reliable, hypothesis-free approach, and a cost- and time-effective strategy for the routine genetic diagnosis of retinal dystrophies.
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29
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Kletke S, Batmanabane V, Dai T, Vincent A, Li S, Gordon KA, Papsin BC, Cushing SL, Héon E. The combination of vestibular impairment and congenital sensorineural hearing loss predisposes patients to ocular anomalies, including Usher syndrome. Clin Genet 2017; 92:26-33. [PMID: 27743452 DOI: 10.1111/cge.12895] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/05/2016] [Accepted: 10/12/2016] [Indexed: 11/29/2022]
Abstract
The co-occurrence of hearing impairment and visual dysfunction is devastating. Most deaf-blind etiologies are genetically determined, the commonest being Usher syndrome (USH). While studies of the congenitally deaf population reveal a variable degree of visual problems, there are no effective ophthalmic screening guidelines. We hypothesized that children with congenital sensorineural hearing loss (SNHL) and vestibular impairment were at an increased risk of having USH. A retrospective chart review of 33 cochlear implants recipients for severe to profound SNHL and measured vestibular dysfunction was performed to determine the ocular phenotype. All the cases had undergone ocular examination and electroretinogram (ERG). Patients with an abnormal ERG underwent genetic testing for USH. We found an underlying ocular abnormality in 81.81% (27/33) of cases; of which 75% had refractive errors, and 50% of those patients showed visual improvement with refractive correction. A total of 14 cases (42.42%; 14/33) had generalized rod-cone dysfunction on ERG suggestive of Usher syndrome type 1, confirmed by mutational analysis. This work shows that adding vestibular impairment as a criterion for requesting an eye exam and adding the ERG to detect USH increases the chances of detecting ocular anomalies, when compared with previous literature focusing only on congenital SNHL.
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Affiliation(s)
- S Kletke
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
| | - V Batmanabane
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - T Dai
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
| | - A Vincent
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - S Li
- Program of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - K A Gordon
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Otolaryngology - Head & Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada.,Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - B C Papsin
- Department of Otolaryngology - Head & Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada.,Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - S L Cushing
- Department of Otolaryngology - Head & Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada.,Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - E Héon
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada.,Program of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
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30
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Lebeko K, Manyisa N, Chimusa ER, Mulder N, Dandara C, Wonkam A. A Genomic and Protein-Protein Interaction Analyses of Nonsyndromic Hearing Impairment in Cameroon Using Targeted Genomic Enrichment and Massively Parallel Sequencing. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2017; 21:90-99. [PMID: 28075205 DOI: 10.1089/omi.2016.0171] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hearing impairment (HI) is one of the leading causes of disability in the world, impacting the social, economic, and psychological well-being of the affected individual. This is particularly true in sub-Saharan Africa, which carries one of the highest burdens of this condition. Despite this, there are limited data on the most prevalent genes or mutations that cause HI among sub-Saharan Africans. Next-generation technologies, such as targeted genomic enrichment and massively parallel sequencing, offer new promise in this context. This study reports, for the first time to the best of our knowledge, on the prevalence of novel mutations identified through a platform of 116 HI genes (OtoSCOPE®), among 82 African probands with HI. Only variants OTOF NM_194248.2:c.766-2A>G and MYO7A NM_000260.3:c.1996C>T, p.Arg666Stop were found in 3 (3.7%) and 5 (6.1%) patients, respectively. In addition and uniquely, the analysis of protein-protein interactions (PPI), through interrogation of gene subnetworks, using a custom script and two databases (Enrichr and PANTHER), and an algorithm in the igraph package of R, identified the enrichment of sensory perception and mechanical stimulus biological processes, and the most significant molecular functions of these variants pertained to binding or structural activity. Furthermore, 10 genes (MYO7A, MYO6, KCTD3, NUMA1, MYH9, KCNQ1, UBC, DIAPH1, PSMC2, and RDX) were identified as significant hubs within the subnetworks. Results reveal that the novel variants identified among familial cases of HI in Cameroon are not common, and PPI analysis has highlighted the role of 10 genes, potentially important in understanding HI genomics among Africans.
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Affiliation(s)
- Kamogelo Lebeko
- 1 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
| | - Noluthando Manyisa
- 1 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
| | - Emile R Chimusa
- 1 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
| | - Nicola Mulder
- 2 Division of Computational Biology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
| | - Collet Dandara
- 1 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
| | - Ambroise Wonkam
- 1 Division of Human Genetics, Department of Pathology, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa .,3 Department of Medicine, Faculty of Health Sciences - University of Cape Town , Cap Town, South Africa
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31
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Qu C, Liang F, Long Q, Zhao M, Shang H, Fan L, Wang L, Foster J, Yan D, Liu X. Genetic screening revealed usher syndrome in a paediatric Chinese patient. HEARING BALANCE AND COMMUNICATION 2017; 15:98-106. [PMID: 30800556 DOI: 10.1080/21695717.2017.1321217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Introduction Usher syndrome is the most common cause of hereditary deaf-blindness. Three clinical subtypes have been classified. Usher syndrome type I is the most severe subtype characterized by congenital severe-to-profound hearing loss, retinitis pigmentosa and vestibular dysfunction. Methods One family was analyzed and the analysis included the combination of a custom capture/next-generation sequencing panel of 180 known deafness gene, Sanger sequencing and bioinformatics approaches. Results Compound heterozygous mutations in the MYO7A gene: a known missense mutation c.494C>T (p.Thr165Met) and a novel missense mutation c.6113G>A (p.Gly2038Glu) were identified in a proband. This Chinese hearing-impaired child was misdiagnosed as non-syndromic hearing loss which was later changed to the diagnosis of Usher syndrome type I after comprehensive audiometric, vestibular and ophthalmological examinations at 9 years old. Conclusions Due to the features of genetic heterogeneity and variation in clinical manifestation, molecular diagnosis and ophthalmological examinations by skilled ophthalmologists with knowledge of Usher syndrome should be suggested as a routine assessment which may improve the accuracy and reliability of etiological diagnosis for hearing loss.
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Affiliation(s)
- Chunyan Qu
- China Rehabilitation and Research Center for Deaf Children, Beijing 100029, China
| | - Fenghe Liang
- Department of Otolaryngology-Head and Neck Surgery, Capital Medical University, Beijing Tongren Hospital, Beijing 100730, China
| | - Qin Long
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Min Zhao
- China Rehabilitation and Research Center for Deaf Children, Beijing 100029, China
| | - Haiqiong Shang
- Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
| | - Lynn Fan
- BSc, University of Miami, Miami, FL 33136, USA
| | - Li Wang
- Institute of Medical Genetics, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Joseph Foster
- Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami, FL 33136, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xuezhong Liu
- Department of Human Genetics, John P. Hussman Institute for Human Genomics, University of Miami, FL 33136, USA.,Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.,Dr. John T. Macdonald Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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32
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Abdi S, Bahloul A, Behlouli A, Hardelin JP, Makrelouf M, Boudjelida K, Louha M, Cheknene A, Belouni R, Rous Y, Merad Z, Selmane D, Hasbelaoui M, Bonnet C, Zenati A, Petit C. Diversity of the Genes Implicated in Algerian Patients Affected by Usher Syndrome. PLoS One 2016; 11:e0161893. [PMID: 27583663 PMCID: PMC5008642 DOI: 10.1371/journal.pone.0161893] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/12/2016] [Indexed: 11/18/2022] Open
Abstract
Usher syndrome (USH) is an autosomal recessive disorder characterized by a dual sensory impairment affecting hearing and vision. USH is clinically and genetically heterogeneous. Ten different causal genes have been reported. We studied the molecular bases of the disease in 18 unrelated Algerian patients by targeted-exome sequencing, and identified the causal biallelic mutations in all of them: 16 patients carried the mutations at the homozygous state and 2 at the compound heterozygous state. Nine of the 17 different mutations detected in MYO7A (1 of 5 mutations), CDH23 (4 of 7 mutations), PCDH15 (1 mutation), USH1C (1 mutation), USH1G (1 mutation), and USH2A (1 of 2 mutations), had not been previously reported. The deleterious consequences of a missense mutation of CDH23 (p.Asp1501Asn) and the in-frame single codon deletion in USH1G (p.Ala397del) on the corresponding proteins were predicted from the solved 3D-structures of extracellular cadherin (EC) domains of cadherin-23 and the sterile alpha motif (SAM) domain of USH1G/sans, respectively. In addition, we were able to show that the USH1G mutation is likely to affect the binding interface between the SAM domain and USH1C/harmonin. This should spur the use of 3D-structures, not only of isolated protein domains, but also of protein-protein interaction interfaces, to predict the functional impact of mutations detected in the USH genes.
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Affiliation(s)
- Samia Abdi
- Laboratoire de biochimie génétique, Service de biologie - CHU de Bab El Oued, Université d'Alger 1, 16 Alger, Algérie
- Laboratoire central de biologie, CHU Frantz Fanon, 09 Blida, Algérie
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
| | - Amel Bahloul
- Unité de génétique et physiologie de l’audition, INSERM UMRS1120, Institut Pasteur, 75015, Paris, France
| | - Asma Behlouli
- Laboratoire de biochimie génétique, Service de biologie - CHU de Bab El Oued, Université d'Alger 1, 16 Alger, Algérie
- Faculté des sciences biologiques, Université des sciences et de la technologie Houari Boumédiène, 16 Alger, Algérie
| | - Jean-Pierre Hardelin
- Unité de génétique et physiologie de l’audition, INSERM UMRS1120, Institut Pasteur, 75015, Paris, France
| | - Mohamed Makrelouf
- Laboratoire de biochimie génétique, Service de biologie - CHU de Bab El Oued, Université d'Alger 1, 16 Alger, Algérie
| | - Kamel Boudjelida
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
- Service d’ophtalmologie, CHU Frantz Fanon, 09 Blida, Algérie
| | - Malek Louha
- Service de biochimie et de biologie moléculaire, Hôpital Armand Trousseau, APHP, 75012, Paris, France
| | - Ahmed Cheknene
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
- Service d’ORL, CHU Frantz Fanon, 09 Blida, Algérie
| | - Rachid Belouni
- Laboratoire central de biologie, CHU Frantz Fanon, 09 Blida, Algérie
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
| | - Yahia Rous
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
- Service d’ORL, CHU Frantz Fanon, 09 Blida, Algérie
| | - Zahida Merad
- Faculté de médecine, Université Saad Dahleb, 09 Blida, Algérie
- Service d’ophtalmologie, CHU Frantz Fanon, 09 Blida, Algérie
| | | | | | - Crystel Bonnet
- INSERM UMRS 1120, Institut de la vision, Université Pierre et Marie Curie, 75005, Paris, France
| | - Akila Zenati
- Laboratoire de biochimie génétique, Service de biologie - CHU de Bab El Oued, Université d'Alger 1, 16 Alger, Algérie
| | - Christine Petit
- Unité de génétique et physiologie de l’audition, INSERM UMRS1120, Institut Pasteur, 75015, Paris, France
- INSERM UMRS 1120, Institut de la vision, Université Pierre et Marie Curie, 75005, Paris, France
- Collège de France, 75005, Paris, France
- * E-mail:
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33
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An innovative strategy for the molecular diagnosis of Usher syndrome identifies causal biallelic mutations in 93% of European patients. Eur J Hum Genet 2016; 24:1730-1738. [PMID: 27460420 PMCID: PMC5117943 DOI: 10.1038/ejhg.2016.99] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/23/2016] [Accepted: 06/04/2016] [Indexed: 11/08/2022] Open
Abstract
Usher syndrome (USH), the most prevalent cause of hereditary deafness–blindness, is an autosomal recessive and genetically heterogeneous disorder. Three clinical subtypes (USH1–3) are distinguishable based on the severity of the sensorineural hearing impairment, the presence or absence of vestibular dysfunction, and the age of onset of the retinitis pigmentosa. A total of 10 causal genes, 6 for USH1, 3 for USH2, and 1 for USH3, and an USH2 modifier gene, have been identified. A robust molecular diagnosis is required not only to improve genetic counseling, but also to advance gene therapy in USH patients. Here, we present an improved diagnostic strategy that is both cost- and time-effective. It relies on the sequential use of three different techniques to analyze selected genomic regions: targeted exome sequencing, comparative genome hybridization, and quantitative exon amplification. We screened a large cohort of 427 patients (139 USH1, 282 USH2, and six of undefined clinical subtype) from various European medical centers for mutations in all USH genes and the modifier gene. We identified a total of 421 different sequence variants predicted to be pathogenic, about half of which had not been previously reported. Remarkably, we detected large genomic rearrangements, most of which were novel and unique, in 9% of the patients. Thus, our strategy led to the identification of biallelic and monoallelic mutations in 92.7% and 5.8% of the USH patients, respectively. With an overall 98.5% mutation characterization rate, the diagnosis efficiency was substantially improved compared with previously reported methods.
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34
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Khan KN, Chana R, Ali N, Wright G, Webster AR, Moore AT, Michaelides M. Advanced diagnostic genetic testing in inherited retinal disease: experience from a single tertiary referral centre in the UK National Health Service. Clin Genet 2016; 91:38-45. [PMID: 27160483 DOI: 10.1111/cge.12798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 04/15/2016] [Accepted: 05/05/2016] [Indexed: 11/29/2022]
Abstract
In 2013, as part of our genetic investigation of patients with inherited retinal disease, we utilized multigene panel testing of 105 genes known to cause retinal disease in our patient cohorts. This test was performed in a UK National Health Service (NHS) accredited laboratory. The results of all multigene panel tests requested between 1.4.13 and 31.8.14 were retrospectively reviewed. All patients had been previously seen at Moorfields Eye Hospital, London, UK and diagnosed with an inherited retinal dystrophy after clinical examination and detailed retinal imaging. The results were categorized into three groups: (i) Testing helped establish a certain molecular diagnosis in 45 out of 115 (39%). Variants in USH2A (n = 6) and RP1 (n = 4) were most common. (ii) Definitive conclusions could not be drawn from molecular testing alone in 13 out of 115 (11%) as either insufficient pathogenic variants were discovered or those identified were not consistent with the phenotype. (iii) Testing did not identify any pathogenic variants responsible for the phenotype in 57 out of 115 (50%). Multigene panel testing performed in an NHS setting has enabled a molecular diagnosis to be confidently made in 40% of cases. Novel variants accounted for 38% of all identified variants. Detailed retinal phenotyping helped the interpretation of specific variants. Additional care needs to be taken when assessing polymorphisms in genes that have been infrequently associated with disease, as historical techniques were not as rigorous as contemporary ones. Future iterations of sequencing are likely to offer higher sensitivity, testing a broader range of genes, more rapidly and at a reduced cost.
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Affiliation(s)
- K N Khan
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK.,St. James's University Hospital, Leeds, UK
| | - R Chana
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
| | - N Ali
- Moorfields Eye Hospital, London, UK
| | - G Wright
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
| | - A R Webster
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
| | - A T Moore
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
| | - M Michaelides
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
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35
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Dad S, Rendtorff ND, Tranebjærg L, Grønskov K, Karstensen HG, Brox V, Nilssen Ø, Roux AF, Rosenberg T, Jensen H, Møller LB. Usher syndrome in Denmark: mutation spectrum and some clinical observations. Mol Genet Genomic Med 2016; 4:527-539. [PMID: 27957503 PMCID: PMC5023938 DOI: 10.1002/mgg3.228] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 12/22/2022] Open
Abstract
Background Usher syndrome (USH) is a genetically heterogeneous deafness‐blindness syndrome, divided into three clinical subtypes: USH1, USH2 and USH3. Methods Mutations in 21 out of 26 investigated Danish unrelated individuals with USH were identified, using a combination of molecular diagnostic methods. Results Before Next Generation Sequencing (NGS) became available mutations in nine individuals (1 USH1, 7 USH2, 1 USH3) were identified by Sanger sequencing of USH1C,USH2A or CLRN1 or by Arrayed Primer EXtension (APEX) method. Mutations in 12 individuals (7 USH1, 5 USH2) were found by targeted NGS of ten known USH genes. Five novel pathogenic variants were identified. We combined our data with previously published, and obtained an overview of the USH mutation spectrum in Denmark, including 100 unrelated individuals; 32 with USH1, 67 with USH2, and 1 with USH3. Macular edema was observed in 44 of 117 individuals. Olfactory function was tested in 12 individuals and found to be within normal range in all. Conclusion Mutations that lead to USH1 were predominantly identified in MYO7A (75%), whereas all mutations in USH2 cases were identified in USH2A. The MYO7A mutation c.93C>A, p.(Cys31*) accounted for 33% of all USH1 mutations and the USH2A c.2299delG, p.(Glu767Serfs*21) variant accounted for 45% of all USH2 mutations in the Danish cohort.
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Affiliation(s)
- Shzeena Dad
- Applied Human Genetics Kennedy Center Department of Clinical Genetics Copenhagen University Rigshospitalet Glostrup Denmark
| | - Nanna Dahl Rendtorff
- Applied Human GeneticsKennedy CenterDepartment of Clinical GeneticsCopenhagen UniversityRigshospitaletGlostrupDenmark; Department of Cellular and Molecular MedicineThe Faculty of Health SciencesUniversity of Copenhagen2200CopenhagenDenmark; Department of Otorhinolaryngology, Head & Neck Surgery and AudiologyBispebjerg Hospital/RigshospitaletCopenhagenDenmark
| | - Lisbeth Tranebjærg
- Applied Human GeneticsKennedy CenterDepartment of Clinical GeneticsCopenhagen UniversityRigshospitaletGlostrupDenmark; Department of Cellular and Molecular MedicineThe Faculty of Health SciencesUniversity of Copenhagen2200CopenhagenDenmark; Department of Otorhinolaryngology, Head & Neck Surgery and AudiologyBispebjerg Hospital/RigshospitaletCopenhagenDenmark
| | - Karen Grønskov
- Applied Human GeneticsKennedy CenterDepartment of Clinical GeneticsCopenhagen UniversityRigshospitaletGlostrupDenmark; Department of Cellular and Molecular MedicineThe Faculty of Health SciencesUniversity of Copenhagen2200CopenhagenDenmark
| | - Helena Gásdal Karstensen
- Department of Cellular and Molecular Medicine The Faculty of Health Sciences University of Copenhagen 2200 Copenhagen Denmark
| | - Vigdis Brox
- Department of Medical Genetics University Hospital of North-Norway N-9038 Tromsø Norway
| | - Øivind Nilssen
- Department of Medical GeneticsUniversity Hospital of North-NorwayN-9038TromsøNorway; Department of Clinical Medicine, Medical GeneticsUniversity of TromsøNO-9037TromsøNorway
| | - Anne-Françoise Roux
- Laboratoire de Génétique MoléculaireCHU MontpellierMontpellierF-34000France; U827InsermMontpellierF-34000France
| | - Thomas Rosenberg
- The National Eye ClinicThe Kennedy CenterDepartment of OphthalmologyCopenhagen University Hospital2600RigshospitaletGlostrupDenmark; Institute of Clinical MedicineThe Faculty of Health SciencesUniversity of Copenhagen2200Copenhagen NDenmark
| | - Hanne Jensen
- The National Eye Clinic The Kennedy Center Department of Ophthalmology Copenhagen University Hospital 2600 Rigshospitalet Glostrup Denmark
| | - Lisbeth Birk Møller
- Applied Human GeneticsKennedy CenterDepartment of Clinical GeneticsCopenhagen UniversityRigshospitaletGlostrupDenmark; Department of Cellular and Molecular MedicineThe Faculty of Health SciencesUniversity of Copenhagen2200CopenhagenDenmark; Department of Science Systems and Models (NSM)Roskilde UniversityDK 4000RoskildeDenmark
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36
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Lebeko K, Sloan-Heggen CM, Noubiap JJN, Dandara C, Kolbe DL, Ephraim SS, Booth KT, Azaiez H, Santos-Cortez RLP, Leal SM, Smith RJH, Wonkam A. Targeted genomic enrichment and massively parallel sequencing identifies novel nonsyndromic hearing impairment pathogenic variants in Cameroonian families. Clin Genet 2016; 90:288-90. [PMID: 27246798 DOI: 10.1111/cge.12799] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/19/2016] [Accepted: 05/01/2016] [Indexed: 01/22/2023]
Abstract
In sub-Saharan Africa GJB2-related nonsyndromic hearing impairment (NSHI) is rare. Ten Cameroonian families was studied using a platform (OtoSCOPE®) with 116 genes. In seven of 10 families (70%), 12 pathogenic variants were identified in six genes. Five of the 12 (41.6%) variants are novel. These results confirm the efficiency of comprehensive genetic testing in defining the causes of NSHI in sub-Saharan Africa.
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Affiliation(s)
- K Lebeko
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences University of Cape Town, Cape Town, South Africa
| | - C M Sloan-Heggen
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - J J N Noubiap
- Department of Medicine, Faculty of Health Sciences University of Cape Town, Cape Town, South Africa
| | - C Dandara
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences University of Cape Town, Cape Town, South Africa
| | - D L Kolbe
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - S S Ephraim
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - K T Booth
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - H Azaiez
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - R L P Santos-Cortez
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - S M Leal
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - R J H Smith
- Department of Otolaryngology, Molecular Otolaryngology and Renal Research Laboratories, The University of Iowa, Iowa City, IA, USA
| | - A Wonkam
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences University of Cape Town, Cape Town, South Africa.,Department of Medicine, Faculty of Health Sciences University of Cape Town, Cape Town, South Africa
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37
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Comprehensive Analysis of Deafness Genes in Families with Autosomal Recessive Nonsyndromic Hearing Loss. PLoS One 2015; 10:e0142154. [PMID: 26561413 PMCID: PMC4641619 DOI: 10.1371/journal.pone.0142154] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/19/2015] [Indexed: 11/25/2022] Open
Abstract
Comprehensive genetic testing has the potential to become the standard of care for individuals with hearing loss. In this study, we investigated the genetic etiology of autosomal recessive nonsyndromic hearing loss (ARNSHL) in a Turkish cohort including individuals with cochlear implant, who had a pedigree suggestive of an autosomal recessive inheritance. A workflow including prescreening of GJB2 and a targeted next generation sequencing panel (Illumına TruSightTM Exome) covering 2761 genes that we briefly called as mendelian exome sequencing was used. This panel includes 102 deafness genes and a number of genes causing Mendelian disorders. Using this approach, we identified causative variants in 21 of 29 families. Three different GJB2 variants were present in seven families. Remaining 14 families had 15 different variants in other known NSHL genes (MYO7A, MYO15A, MARVELD2, TMIE, DFNB31, LOXHD1, GPSM2, TMC1, USH1G, CDH23). Of these variants, eight are novel. Mutation detection rate of our workflow is 72.4%, confirming the usefulness of targeted sequencing approach in NSHL.
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38
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Mizutari K, Mutai H, Namba K, Miyanaga Y, Nakano A, Arimoto Y, Masuda S, Morimoto N, Sakamoto H, Kaga K, Matsunaga T. High prevalence of CDH23 mutations in patients with congenital high-frequency sporadic or recessively inherited hearing loss. Orphanet J Rare Dis 2015; 10:60. [PMID: 25963016 PMCID: PMC4451718 DOI: 10.1186/s13023-015-0276-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 04/28/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Mutations in CDH23 are responsible for Usher syndrome 1D and recessive non-syndromic hearing loss. In this study, we revealed the prevalence of CDH23 mutations among patients with specific clinical characteristics. METHODS After excluding patients with GJB2 mutations and mitochondrial m.1555A > G and m.3243A > G mutations, subjects for CDH23 mutation analysis were selected according to the following criteria: 1) Sporadic or recessively inherited hearing loss 2) bilateral non-syndromic congenital hearing loss, 3) no cochlear malformation, 4) a poorer hearing level at high frequencies than at low frequencies, and 5) severe or profound hearing loss at higher frequencies. RESULTS Seventy-two subjects were selected from 621 consecutive probands who did not have environmental causes for their hearing loss. After direct sequencing, 13 of the 72 probands (18.1%) had homozygous or compound heterozygous CDH23 mutations. In total, we identified 16 CDH23 mutations, including five novel mutations. The 16 mutations included 12 missense, two frameshift, and two splice-site mutations. CONCLUSIONS These results revealed that CDH23 mutations are highly prevalent in patients with congenital high-frequency sporadic or recessively inherited hearing loss and that the mutation spectrum was diverse, indicating that patients with these clinical features merit genetic analysis.
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Affiliation(s)
- Kunio Mizutari
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan. .,Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 160-8582, Japan.
| | - Hideki Mutai
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
| | - Kazunori Namba
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
| | - Yuko Miyanaga
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
| | - Atsuko Nakano
- Division of Otorhinolaryngology, Chiba Children's Hospital, 579-1 Hetacho, Midori-ku, Chiba, Chiba, 266-0007, Japan.
| | - Yukiko Arimoto
- Division of Otorhinolaryngology, Chiba Children's Hospital, 579-1 Hetacho, Midori-ku, Chiba, Chiba, 266-0007, Japan.
| | - Sawako Masuda
- Department of Otorhinolaryngology, National Mie Hospital, 357 Osato-Kubota, Tsu, Mie, 514-0125, Japan.
| | - Noriko Morimoto
- Division of Otolaryngology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan.
| | - Hirokazu Sakamoto
- Department of Otorhinolaryngology, Hyogo Prefectural Kobe Children's Hospital, 1-1-1 Takakuradai, Suma-ku, Kobe, Hyogo, 654-0081, Japan.
| | - Kimitaka Kaga
- National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
| | - Tatsuo Matsunaga
- Laboratory of Auditory Disorders, National Institute of Sensory Organs, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan. .,Medical Genetics Center, National Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
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Dad S, Rendtorff ND, Kann E, Albrechtsen A, Mehrjouy MM, Bak M, Tommerup N, Tranebjærg L, Rosenberg T, Jensen H, Møller LB. Partial USH2A deletions contribute to Usher syndrome in Denmark. Eur J Hum Genet 2015; 23:1646-51. [PMID: 25804404 DOI: 10.1038/ejhg.2015.54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/18/2022] Open
Abstract
Usher syndrome is an autosomal recessive disorder characterized by congenital hearing impairment, progressive visual loss owing to retinitis pigmentosa and in some cases vestibular dysfunction. Usher syndrome is divided into three subtypes, USH1, USH2 and USH3. Twelve loci and eleven genes have so far been identified. Duplications and deletions in PCDH15 and USH2A that lead to USH1 and USH2, respectively, have previously been identified in patients from United Kingdom, Spain and Italy. In this study, we investigate the proportion of exon deletions and duplications in PCDH15 and USH2A in 20 USH1 and 30 USH2 patients from Denmark using multiplex ligation-dependent probe amplification (MLPA). Two heterozygous deletions were identified in USH2A, but no deletions or duplications were identified in PCDH15. Next-generation mate-pair sequencing was used to identify the exact breakpoints of the two deletions identified in USH2A. Our results suggest that USH2 is caused by USH2A exon deletions in a small fraction of the patients, whereas deletions or duplications in PCDH15 might be rare in Danish Usher patients.
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Affiliation(s)
- Shzeena Dad
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Nanna D Rendtorff
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Erik Kann
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
| | - Anders Albrechtsen
- Department of Biology, Computational and RNA Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mana M Mehrjouy
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mads Bak
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Niels Tommerup
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lisbeth Tranebjærg
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
| | - Thomas Rosenberg
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Hanne Jensen
- Department of Ophthalmology, The National Eye Clinic, Copenhagen University Hospital, The Kennedy Center, Glostrup, Denmark
| | - Lisbeth B Møller
- Clinical Genetics Clinic, The Kennedy Center, Rigshospitalet, University of Copenhagen, Glostrup, Denmark
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40
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Sodi A, Mariottini A, Passerini I, Murro V, Tachyla I, Bianchi B, Menchini U, Torricelli F. MYO7A and USH2A gene sequence variants in Italian patients with Usher syndrome. Mol Vis 2014; 20:1717-31. [PMID: 25558175 PMCID: PMC4279600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 12/20/2014] [Indexed: 10/28/2022] Open
Abstract
PURPOSE To analyze the spectrum of sequence variants in the MYO7A and USH2A genes in a group of Italian patients affected by Usher syndrome (USH). METHODS Thirty-six Italian patients with a diagnosis of USH were recruited. They received a standard ophthalmologic examination, visual field testing, optical coherence tomography (OCT) scan, and electrophysiological tests. Fluorescein angiography and fundus autofluorescence imaging were performed in selected cases. All the patients underwent an audiologic examination for the 0.25-8,000 Hz frequencies. Vestibular function was evaluated with specific tests. DNA samples were analyzed for sequence variants of the MYO7A gene (for USH1) and the USH2A gene (for USH2) with direct sequencing techniques. A few patients were analyzed for both genes. RESULTS In the MYO7A gene, ten missense variants were found; three patients were compound heterozygous, and two were homozygous. Thirty-four USH2A gene variants were detected, including eight missense variants, nine nonsense variants, six splicing variants, and 11 duplications/deletions; 19 patients were compound heterozygous, and three were homozygous. Four MYO7A and 17 USH2A variants have already been described in the literature. Among the novel mutations there are four USH2A large deletions, detected with multiplex ligation dependent probe amplification (MLPA) technology. Two potentially pathogenic variants were found in 27 patients (75%). Affected patients showed variable clinical pictures without a clear genotype-phenotype correlation. CONCLUSIONS Ten variants in the MYO7A gene and 34 variants in the USH2A gene were detected in Italian patients with USH at a high detection rate. A selective analysis of these genes may be valuable for molecular analysis, combining diagnostic efficiency with little time wastage and less resource consumption.
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Affiliation(s)
- Andrea Sodi
- Department of Ophthalmology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Alessandro Mariottini
- Department of Genetic Diagnosis, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Vittoria Murro
- Department of Ophthalmology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Iryna Tachyla
- Department of Ophthalmology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Benedetta Bianchi
- Department of Otolaryngology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Ugo Menchini
- Department of Ophthalmology, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Francesca Torricelli
- Department of Genetic Diagnosis, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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Velez Edwards DR, Tsosie KS, Williams SM, Edwards TL, Russell SB. Admixture mapping identifies a locus at 15q21.2-22.3 associated with keloid formation in African Americans. Hum Genet 2014; 133:1513-23. [PMID: 25280642 PMCID: PMC4334317 DOI: 10.1007/s00439-014-1490-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/23/2014] [Indexed: 12/20/2022]
Abstract
Keloids are benign dermal tumors that occur ~20 times more often in African versus Caucasian descent individuals. While most keloids occur sporadically, a genetic predisposition is supported by both familial aggregation of some keloids and the large differences in risk among populations. Yet, no well-established genetic risk factors for keloids have been identified. In this study, we conducted admixture mapping and whole-exome association using 478 African Americans (AAs) samples (122 cases, 356 controls) with exome genotyping data to identify regions where local ancestry associated with keloid risk. Logistic regression was used to evaluate associations under admixture peaks. A significant mapping peak was observed on chr15q21.2-22.3. This peak included NEDD4, a gene previously implicated in a keloid genome-wide association study (GWAS) of Japanese individuals later validated in a Chinese cohort. While we observed modest evidence for association with NEDD4, a more significant association was observed at (myosin 1E) MYO1E. A genome scan not including the 15q21-22 region also identified associations at MYO7A (rs35641839, odds ratio [OR] = 4.71, 95% confidence interval [CI] 2.38-9.32, p = 8.34 × 10(-6)) at 11q13.5. The identification of SNPs in two myosin genes strongly associated with keloid formation suggests that an altered cytoskeleton contributes to the enhanced migratory and invasive properties of keloid fibroblasts. Our findings support the admixture mapping approach for the study of keloid risk, and indicate potentially common genetic elements on chr15q21.2-22.3 in causation of keloids in AAs, Japanese, and Chinese populations.
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Affiliation(s)
- Digna R Velez Edwards
- Vanderbilt Epidemiology Center, 2525 West End Ave., Suite 600 6th Floor, Nashville, TN, 37203, USA,
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Aparisi MJ, Aller E, Fuster-García C, García-García G, Rodrigo R, Vázquez-Manrique RP, Blanco-Kelly F, Ayuso C, Roux AF, Jaijo T, Millán JM. Targeted next generation sequencing for molecular diagnosis of Usher syndrome. Orphanet J Rare Dis 2014; 9:168. [PMID: 25404053 PMCID: PMC4245769 DOI: 10.1186/s13023-014-0168-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/27/2014] [Indexed: 11/17/2022] Open
Abstract
Background Usher syndrome is an autosomal recessive disease that associates sensorineural hearing loss, retinitis pigmentosa and, in some cases, vestibular dysfunction. It is clinically and genetically heterogeneous. To date, 10 genes have been associated with the disease, making its molecular diagnosis based on Sanger sequencing, expensive and time-consuming. Consequently, the aim of the present study was to develop a molecular diagnostics method for Usher syndrome, based on targeted next generation sequencing. Methods A custom HaloPlex panel for Illumina platforms was designed to capture all exons of the 10 known causative Usher syndrome genes (MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, GPR98, DFNB31 and CLRN1), the two Usher syndrome-related genes (HARS and PDZD7) and the two candidate genes VEZT and MYO15A. A cohort of 44 patients suffering from Usher syndrome was selected for this study. This cohort was divided into two groups: a test group of 11 patients with known mutations and another group of 33 patients with unknown mutations. Results Forty USH patients were successfully sequenced, 8 USH patients from the test group and 32 patients from the group composed of USH patients without genetic diagnosis. We were able to detect biallelic mutations in one USH gene in 22 out of 32 USH patients (68.75%) and to identify 79.7% of the expected mutated alleles. Fifty-three different mutations were detected. These mutations included 21 missense, 8 nonsense, 9 frameshifts, 9 intronic mutations and 6 large rearrangements. Conclusions Targeted next generation sequencing allowed us to detect both point mutations and large rearrangements in a single experiment, minimizing the economic cost of the study, increasing the detection ratio of the genetic cause of the disease and improving the genetic diagnosis of Usher syndrome patients.
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Affiliation(s)
- María J Aparisi
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Elena Aller
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Carla Fuster-García
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain.
| | - Gema García-García
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CHU Montpellier, Laboratoire de Génétique Moléculaire and Inserm, U827, Montpellier, F-34000, France.
| | - Regina Rodrigo
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Rafael P Vázquez-Manrique
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Fiona Blanco-Kelly
- CIBER de Enfermedades Raras (CIBERER), Valencia, Spain. .,Servicio de Genética, IIS - Fundación Jiménez Díaz, University Hospital, UAM, Madrid, Spain.
| | - Carmen Ayuso
- CIBER de Enfermedades Raras (CIBERER), Valencia, Spain. .,Servicio de Genética, IIS - Fundación Jiménez Díaz, University Hospital, UAM, Madrid, Spain.
| | - Anne-Françoise Roux
- CHU Montpellier, Laboratoire de Génétique Moléculaire and Inserm, U827, Montpellier, F-34000, France.
| | - Teresa Jaijo
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - José M Millán
- Grupo de Investigación en Enfermedades Neurosensoriales. Instituto de Investigación Sanitaria IIS-La Fe, Semisótano Escuela de Enfermería, Hospital Universitario La Fe, Avda. Campanar, 21, 46009, Valencia, Spain. .,CIBER de Enfermedades Raras (CIBERER), Valencia, Spain. .,Unidad de Genética y Diagnóstico Prenatal, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
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Reddy R, Fahiminiya S, El Zir E, Mansour A, Megarbane A, Majewski J, Slim R. Molecular genetics of the Usher syndrome in Lebanon: identification of 11 novel protein truncating mutations by whole exome sequencing. PLoS One 2014; 9:e107326. [PMID: 25211151 PMCID: PMC4161397 DOI: 10.1371/journal.pone.0107326] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/09/2014] [Indexed: 12/02/2022] Open
Abstract
Background Usher syndrome (USH) is a genetically heterogeneous condition with ten disease-causing genes. The spectrum of genes and mutations causing USH in the Lebanese and Middle Eastern populations has not been described. Consequently, diagnostic approaches designed to screen for previously reported mutations were unlikely to identify the mutations in 11 unrelated families, eight of Lebanese and three of Middle Eastern origins. In addition, six of the ten USH genes consist of more than 20 exons, each, which made mutational analysis by Sanger sequencing of PCR-amplified exons from genomic DNA tedious and costly. The study was aimed at the identification of USH causing genes and mutations in 11 unrelated families with USH type I or II. Methods Whole exome sequencing followed by expanded familial validation by Sanger sequencing. Results We identified disease-causing mutations in all the analyzed patients in four USH genes, MYO7A, USH2A, GPR98 and CDH23. Eleven of the mutations were novel and protein truncating, including a complex rearrangement in GPR98. Conclusion Our data highlight the genetic diversity of Usher syndrome in the Lebanese population and the time and cost-effectiveness of whole exome sequencing approach for mutation analysis of genetically heterogeneous conditions caused by large genes.
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Affiliation(s)
- Ramesh Reddy
- Departments of Human Genetics and Obstetrics-Gynecology, McGill University Health Centre, Montreal, Canada
| | - Somayyeh Fahiminiya
- McGill University and Genome Quebec Innovation Centre and Department of Human Genetics, Montreal, Canada
| | - Elie El Zir
- Department of Otorhinolaryngology, Hôpital Sacré-Coeur, Baabda, Lebanon
| | - Ahmad Mansour
- Department of Ophthalmology, American University of Beirut, Beirut, Lebanon
| | - Andre Megarbane
- Unité de génétique médicale, Faculté de médecine, Université Saint Joseph, Beirut, Lebanon
| | - Jacek Majewski
- McGill University and Genome Quebec Innovation Centre and Department of Human Genetics, Montreal, Canada
| | - Rima Slim
- Departments of Human Genetics and Obstetrics-Gynecology, McGill University Health Centre, Montreal, Canada
- * E-mail:
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Gao X, Wang GJ, Yuan YY, Xin F, Han MY, Lu JQ, Zhao H, Yu F, Xu JC, Zhang MG, Dong J, Lin X, Dai P. Novel compound heterozygous mutations in MYO7A Associated with Usher syndrome 1 in a Chinese family. PLoS One 2014; 9:e103415. [PMID: 25080338 PMCID: PMC4117490 DOI: 10.1371/journal.pone.0103415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 06/28/2014] [Indexed: 11/19/2022] Open
Abstract
Usher syndrome is an autosomal recessive disease characterized by sensorineural hearing loss, age-dependent retinitis pigmentosa (RP), and occasionally vestibular dysfunction. The most severe form is Usher syndrome type 1 (USH1). Mutations in the MYO7A gene are responsible for USH1 and account for 29–55% of USH1 cases. Here, we characterized a Chinese family (no. 7162) with USH1. Combining the targeted capture of 131 known deafness genes, next-generation sequencing, and bioinformatic analysis, we identified two deleterious compound heterozygous mutations in the MYO7A gene: a reported missense mutation c.73G>A (p.G25R) and a novel nonsense mutation c.462C>A (p.C154X). The two compound variants are absent in 219 ethnicity-matched controls, co-segregates with the USH clinical phenotypes, including hearing loss, vestibular dysfunction, and age-dependent penetrance of progressive RP, in family 7162. Therefore, we concluded that the USH1 in this family was caused by compound heterozygous mutations in MYO7A.
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Affiliation(s)
- Xue Gao
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
- Department of Otolaryngology, the Second Artillery General Hospital, Beijing, P. R. China
| | - Guo-Jian Wang
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Yong-Yi Yuan
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Feng Xin
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Ming-Yu Han
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Jing-Qiao Lu
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Hui Zhao
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
| | - Fei Yu
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
| | - Jin-Cao Xu
- Department of Otolaryngology, the Second Artillery General Hospital, Beijing, P. R. China
| | - Mei-Guang Zhang
- Department of Otolaryngology, the Second Artillery General Hospital, Beijing, P. R. China
| | - Jiang Dong
- Xi’an Research Institute of Hi_tech, Hongqing, Xi’an, Shaanxi, P. R. China
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail: (PD); (XL)
| | - Pu Dai
- Department of Otolaryngology, Head and Neck Surgery, PLA General Hospital, Beijing, P. R. China
- Department of Otolaryngology, Hainan Branch of PLA General Hospital, Sanya, P. R. China
- * E-mail: (PD); (XL)
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Novel and recurrent MYO7A mutations in Usher syndrome type 1 and type 2. PLoS One 2014; 9:e97808. [PMID: 24831256 PMCID: PMC4022727 DOI: 10.1371/journal.pone.0097808] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/24/2014] [Indexed: 11/19/2022] Open
Abstract
Usher syndrome (USH) is a group of disorders manifested as retinitis pigmentosa and bilateral sensorineural hearing loss, with or without vestibular dysfunction. Here, we recruited three Chinese families affected with autosomal recessive USH for detailed clinical evaluations and for mutation screening in the genes associated with inherited retinal diseases. Using targeted next-generation sequencing (NGS) approach, three new alleles and one known mutation in MYO7A gene were identified in the three families. In two families with USH type 1, novel homozygous frameshift variant p.Pro194Hisfs*13 and recurrent missense variant p.Thr165Met were demonstrated as the causative mutations respectively. Crystal structural analysis denoted that p.Thr165Met would very likely change the tertiary structure of the protein encoded by MYO7A. In another family affected with USH type 2, novel biallelic mutations in MYO7A, c.[1343+1G>A];[2837T>G] or p.[?];[Met946Arg], were identified with clinical significance. Because MYO7A, to our knowledge, has rarely been correlated with USH type 2, our findings therefore reveal distinguished clinical phenotypes associated with MYO7A. We also conclude that targeted NGS is an effective approach for genetic diagnosis for USH, which can further provide better understanding of genotype-phenotype relationship of the disease.
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Piatti G, De Santi MM, Brogi M, Castorina P, Ambrosetti U. Emerging ciliopathies: are respiratory cilia compromised in Usher syndrome? Am J Otolaryngol 2014; 35:340-6. [PMID: 24602455 DOI: 10.1016/j.amjoto.2014.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 01/26/2014] [Indexed: 01/19/2023]
Abstract
PURPOSE Usher syndrome is a ciliopathy involving photoreceptors and cochlear hair cells (sensory cilia): since sensory and motor ciliopathies can overlap, we analysed the respiratory cilia (motile) in 17 patients affected by Usher syndrome and 18 healthy control subject. PATIENTS AND METHODS We studied the mucociliary transport time with the saccharine test, ciliary motility and ultrastructure of respiratory cilia obtained by nasal brushing; we also recorded the classical respiratory function values by spirometry. RESULTS All enrolled subjects showed normal respiratory function values. The mean mucociliary transport time with saccharine was 22.33 ± 17.96 min, which is in the range of normal values. The mean ciliary beat frequency of all subjects was 8.81 ± 2.18 Hz, which is a value approaching the lower physiological limit. None of the classical ciliary alterations characterizing the "ciliary primary dyskinesia" was detected, although two patients showed alterations in number and arrangement of peripheral microtubules and one patient had abnormal ciliary roots. CONCLUSIONS Respiratory cilia in Usher patients don't seem to have evident ultrastructural alterations, as expected, but the fact that the ciliary motility appeared slightly reduced could emphasize that a rigid distinction between sensory and motor ciliopathies may not reflect what really occurs.
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Affiliation(s)
- G Piatti
- Department of Pathophysiology and Transplantation, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy.
| | - M M De Santi
- Department of Human Pathology and Oncology, University of Siena, Italy
| | - M Brogi
- Department of Human Pathology and Oncology, University of Siena, Italy
| | - P Castorina
- Department of Clinical Sciences and Community, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy
| | - U Ambrosetti
- Department of Clinical Sciences and Community, University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy
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Identity-by-descent-guided mutation analysis and exome sequencing in consanguineous families reveals unusual clinical and molecular findings in retinal dystrophy. Genet Med 2014; 16:671-80. [PMID: 24625443 DOI: 10.1038/gim.2014.24] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 02/05/2014] [Indexed: 01/26/2023] Open
Abstract
PURPOSE Autosomal recessive retinal dystrophies are clinically and genetically heterogeneous, which hampers molecular diagnosis. We evaluated identity-by-descent-guided Sanger sequencing or whole-exome sequencing in 26 families with nonsyndromic (19) or syndromic (7) autosomal recessive retinal dystrophies to identify disease-causing mutations. METHODS Patients underwent genome-wide identity-by-descent mapping followed by Sanger sequencing (16) or whole-exome sequencing (10). Whole-exome sequencing data were filtered against identity-by-descent regions and known retinal dystrophy genes. The medical history was reviewed in mutation-positive families. RESULTS We identified mutations in 14 known retinal dystrophy genes in 20/26 (77%) families: ABCA4, CERKL, CLN3, CNNM4, C2orf71, IQCB1, LRAT, MERTK, NMNAT1, PCDH15, PDE6B, RDH12, RPGRIP1, and USH2A. Whole-exome sequencing in single individuals revealed mutations in either the largest or smaller identity-by-descent regions, and a compound heterozygous genotype in NMNAT1. Moreover, a novel deletion was found in PCDH15. In addition, we identified mutations in CLN3, CNNM4, and IQCB1 in patients initially diagnosed with nonsyndromic retinal dystrophies. CONCLUSION Our study emphasized that identity-by-descent-guided mutation analysis and/or whole-exome sequencing are powerful tools for the molecular diagnosis of retinal dystrophy. Our approach uncovered unusual molecular findings and unmasked syndromic retinal dystrophies, guiding future medical management. Finally, elucidating ABCA4, LRAT, and MERTK mutations offers potential gene-specific therapeutic perspectives.
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Structures and target recognition modes of PDZ domains: recurring themes and emerging pictures. Biochem J 2013; 455:1-14. [DOI: 10.1042/bj20130783] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PDZ domains are highly abundant protein–protein interaction modules and are often found in multidomain scaffold proteins. PDZ-domain-containing scaffold proteins regulate multiple biological processes, including trafficking and clustering receptors and ion channels at defined membrane regions, organizing and targeting signalling complexes at specific cellular compartments, interfacing cytoskeletal structures with membranes, and maintaining various cellular structures. PDZ domains, each with ~90-amino-acid residues folding into a highly similar structure, are best known to bind to short C-terminal tail peptides of their target proteins. A series of recent studies have revealed that, in addition to the canonical target-binding mode, many PDZ–target interactions involve amino acid residues beyond the regular PDZ domain fold, which we refer to as extensions. Such extension sequences often form an integral structural and functional unit with the attached PDZ domain, which is defined as a PDZ supramodule. Correspondingly, PDZ-domain-binding sequences from target proteins are frequently found to require extension sequences beyond canonical short C-terminal tail peptides. Formation of PDZ supramodules not only affords necessary binding specificities and affinities demanded by physiological functions of PDZ domain targets, but also provides regulatory switches to be built in the PDZ–target interactions. At the 20th anniversary of the discovery of PDZ domain proteins, we try to summarize structural features and target-binding properties of such PDZ supramodules emerging from studies in recent years.
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Besnard T, García-García G, Baux D, Vaché C, Faugère V, Larrieu L, Léonard S, Millan JM, Malcolm S, Claustres M, Roux AF. Experience of targeted Usher exome sequencing as a clinical test. Mol Genet Genomic Med 2013; 2:30-43. [PMID: 24498627 PMCID: PMC3907913 DOI: 10.1002/mgg3.25] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/06/2013] [Indexed: 12/15/2022] Open
Abstract
We show that massively parallel targeted sequencing of 19 genes provides a new and reliable strategy for molecular diagnosis of Usher syndrome (USH) and nonsyndromic deafness, particularly appropriate for these disorders characterized by a high clinical and genetic heterogeneity and a complex structure of several of the genes involved. A series of 71 patients including Usher patients previously screened by Sanger sequencing plus newly referred patients was studied. Ninety-eight percent of the variants previously identified by Sanger sequencing were found by next-generation sequencing (NGS). NGS proved to be efficient as it offers analysis of all relevant genes which is laborious to reach with Sanger sequencing. Among the 13 newly referred Usher patients, both mutations in the same gene were identified in 77% of cases (10 patients) and one candidate pathogenic variant in two additional patients. This work can be considered as pilot for implementing NGS for genetically heterogeneous diseases in clinical service.
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Affiliation(s)
- Thomas Besnard
- U827, Inserm Montpellier, F-34000, France ; Univ, Montpellier I Montpellier, F-34000, France
| | - Gema García-García
- U827, Inserm Montpellier, F-34000, France ; Grupo de Investigación en Enfermedades Neurosensoriales, Instituto de Investigación Sanitaria IIS-La Fe and CIBERER Valencia, Spain
| | - David Baux
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Christel Vaché
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Valérie Faugère
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Lise Larrieu
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Susana Léonard
- Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Jose M Millan
- Grupo de Investigación en Enfermedades Neurosensoriales, Instituto de Investigación Sanitaria IIS-La Fe and CIBERER Valencia, Spain
| | - Sue Malcolm
- Clinical and Molecular Genetics, Institute of Child Health, University College London London, United Kingdom
| | - Mireille Claustres
- U827, Inserm Montpellier, F-34000, France ; Univ, Montpellier I Montpellier, F-34000, France ; Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
| | - Anne-Françoise Roux
- U827, Inserm Montpellier, F-34000, France ; Laboratoire de Génétique Moléculaire, CHU Montpellier Montpellier, F-34000, France
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Shahzad M, Sivakumaran TA, Qaiser TA, Schultz JM, Hussain Z, Flanagan M, Bhinder MA, Kissell D, Greinwald JH, Khan SN, Friedman TB, Zhang K, Riazuddin S, Riazuddin S, Ahmed ZM. Genetic analysis through OtoSeq of Pakistani families segregating prelingual hearing loss. Otolaryngol Head Neck Surg 2013; 149:478-87. [PMID: 23770805 DOI: 10.1177/0194599813493075] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To identify the genetic cause of prelingual sensorineural hearing loss in Pakistani families using a next-generation sequencing (NGS)-based mutation screening test named OtoSeq. STUDY DESIGN Prospective study. SETTING Research laboratory. SUBJECTS AND METHODS We used 3 fluorescently labeled short tandem repeat (STR) markers for each of the known autosomal recessive nonsyndromic (DFNB) and Usher syndrome (USH) locus to perform a linkage analysis of 243 multigenerational Pakistani families segregating prelingual hearing loss. After genotyping, we focused on 34 families with potential linkage to MYO7A, CDH23, and SLC26A4. We screened affected individuals from a subset of these families using the OtoSeq platform to identify underlying genetic variants. Sanger sequencing was performed to confirm and study the segregation of mutations in other family members. For novel mutations, normal hearing individuals from ethnically matched backgrounds were also tested. RESULTS Hearing loss was found to co-segregate with locus-specific STR markers for MYO7A in 32 families, CDH23 in 1 family, and SLC26A4 in 1 family. Using the OtoSeq platform, a microdroplet PCR-based enrichment followed by NGS, we identified mutations in 28 of the 34 families including 11 novel mutations. Sanger sequencing of these mutations showed 100% concordance with NGS data and co-segregation of the mutant alleles with the hearing loss phenotype in the respective families. CONCLUSION Using NGS-based platforms like OtoSeq in families segregating hearing loss will contribute to the identification of common and population-specific mutations, early diagnosis, genetic counseling, and molecular epidemiology.
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Affiliation(s)
- Mohsin Shahzad
- Divisions of Ophthalmology, Cincinnati Children's Hospital Research Foundation, Cincinnati, Ohio USA
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