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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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2
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Grudzinska Pechhacker MK, Jacobson SG, Drack AV, Scipio MD, Strubbe I, Pfeifer W, Duncan JL, Dollfus H, Goetz N, Muller J, Vincent AL, Aleman TS, Tumber A, Van Cauwenbergh C, De Baere E, Bedoukian E, Leroy BP, Maynes JT, Munier FL, Tavares E, Saleh E, Vincent A, Heon E. Comparative Natural History of Visual Function From Patients With Biallelic Variants in BBS1 and BBS10. Invest Ophthalmol Vis Sci 2021; 62:26. [PMID: 34940782 PMCID: PMC8711006 DOI: 10.1167/iovs.62.15.26] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to compare the natural history of visual function change in cohorts of patients affected with retinal degeneration due to biallelic variants in Bardet-Biedl syndrome genes: BBS1 and BBS10. Methods Patients were recruited from nine academic centers from six countries (Belgium, Canada, France, New Zealand, Switzerland, and the United States). Inclusion criteria were: (1) female or male patients with a clinical diagnosis of retinal dystrophy, (2) biallelic disease-causing variants in BBS1 or BBS10, and (3) measures of visual function for at least one visit. Retrospective data collected included genotypes, age, onset of symptoms, and best corrected visual acuity (VA). When possible, data on refractive error, fundus images and autofluorescence (FAF), optical coherence tomography (OCT), Goldmann kinetic perimetry (VF), electroretinography (ERG), and the systemic phenotype were collected. Results Sixty-seven individuals had variants in BBS1 (n = 38; 20 female patients and 18 male patients); or BBS10 (n = 29; 14 female patients and 15 male patients). Missense variants were the most common type of variants for patients with BBS1, whereas frameshift variants were most common for BBS10. When ERGs were recordable, rod-cone dystrophy (RCD) was observed in 82% (23/28) of patients with BBS1 and 73% (8/11) of patients with BBS10; cone-rod dystrophy (CORD) was seen in 18% of patients with BBS1 only, and cone dystrophy (COD) was only seen in 3 patients with BBS10 (27%). ERGs were nondetectable earlier in patients with BBS10 than in patients with BBS1. Similarly, VA and VF declined more rapidly in patients with BBS10 compared to patients with BBS1. Conclusions Retinal degeneration appears earlier and is more severe in BBS10 cases as compared to those with BBS1 variants. The course of change of visual function appears to relate to genetic subtypes of BBS.
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Affiliation(s)
- Monika K Grudzinska Pechhacker
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Arlene V Drack
- Department of Ophthalmology, Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States
| | - Matteo Di Scipio
- Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Ine Strubbe
- Department of Ophthalmology, Ghent University Hospital & Department of Head and Skin, Ghent University, Ghent, Belgium
| | - Wanda Pfeifer
- Department of Ophthalmology, Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Helene Dollfus
- CARGO ( Centre de référence pour les affections rares génétiques ), IGMA Institut de Génétqiue Médicale d'Alsace , Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,UMRS_1112, IGMA ( Institut de génétique Médicale d'Alsace ) Université de Strasbourg, Strasbourg, France
| | - Nathalie Goetz
- UMRS_1112, IGMA ( Institut de génétique Médicale d'Alsace ) Université de Strasbourg, Strasbourg, France
| | - Jean Muller
- CARGO ( Centre de référence pour les affections rares génétiques ), IGMA Institut de Génétqiue Médicale d'Alsace , Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,UMRS_1112, IGMA ( Institut de génétique Médicale d'Alsace ) Université de Strasbourg, Strasbourg, France.,Laboratoire de diagnostique génétique, IGMA ( Institut de génétique Médicale d'Alsace ) Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Andrea L Vincent
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.,Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
| | - Tomas S Aleman
- Center for Advanced Retinal and Ocular Therapeutics, Perelman School of Medicine, Philadelphia, Pennsylvania, United States.,Scheie Eye Institute at the Perelman Center for Advanced Medicine, Philadelphia, Pennsylvania, United States.,Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
| | - Anupreet Tumber
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University Hospital & Department of Head and Skin, Ghent University, Ghent, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Emma Bedoukian
- Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
| | - Bart P Leroy
- Department of Ophthalmology, Ghent University Hospital & Department of Head and Skin, Ghent University, Ghent, Belgium.,Center for Advanced Retinal and Ocular Therapeutics, Perelman School of Medicine, Philadelphia, Pennsylvania, United States.,Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
| | - Jason T Maynes
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Departments of Biochemistry and Anesthesiology and Pain Medicine, University of Toronto, Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Canada
| | - Francis L Munier
- Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, University of Lausanne, Lausanne, Switzerland
| | - Erika Tavares
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Eman Saleh
- Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
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3
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Meng X, Long Y, Ren J, Wang G, Yin X, Li S. Ocular Characteristics of Patients With Bardet-Biedl Syndrome Caused by Pathogenic BBS Gene Variation in a Chinese Cohort. Front Cell Dev Biol 2021; 9:635216. [PMID: 33777945 PMCID: PMC7991091 DOI: 10.3389/fcell.2021.635216] [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: 11/30/2020] [Accepted: 02/08/2021] [Indexed: 12/29/2022] Open
Abstract
Bardet–Biedl syndrome (BBS; OMIM 209900) is a rare genetic disease causing damage to multiple organs and affecting patients’ quality of life in late adolescence or early adulthood. In this study, the ocular characteristics including morphology and function, were analyzed in 12 BBS patients from 10 Chinese families by molecular diagnostics. A total of five known and twelve novel variants in four BBS genes (BBS2, 58.33%; BBS4, 8.33%; BBS7, 16.67%; and BBS9, 16.67%) were identified in 10 Chinese families with BBS. All patients had typical phenotypes of retinitis pigmentosa with unrecordable or severely damaged cone and rod responses on full-field flash electroretinography (ffERG). Most of the patients showed unremarkable reactions in pattern visual evoked potential (PVEP) and multifocal electroretinography (mfERG), while their flash visual evoked potentials (FVEP) indicated display residual visual function. Changes in the fundus morphology, including color fundus photography and autofluorescence (AF) imaging, were heterogeneous and not consistent with the patients’ functional tests. Overall, our study expands the variation spectrum of the BBS gene, showing that the ocular characteristics of BBS patients are clinically highly heterogeneous, and demonstrates the usefulness of a combination of the ffERG and FVEP assessments of visual function in the advanced stage of retinopathy in BBS.
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Affiliation(s)
- Xiaohong Meng
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yanling Long
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Jiayun Ren
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Gang Wang
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Xin Yin
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Shiying Li
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
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4
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Abstract
Inherited retinal degeneration (IRD) may occur in isolation or as part of a multi-systemic condition. Ocular manifestations may be the presenting symptom of a syndromic disease and can include retinitis pigmentosa, cone-rod dystrophy, or maculopathy. Alternatively, patients affected with syndromic disease may already have other systemic manifestations at the time retinal disease is diagnosed. Some of these systemic diseases can cause significant morbidity. Here, we review several of these syndromic IRDs and their underlying genetic causes. Early recognition and referral for systemic evaluation and surveillance may lead to early intervention and an improved outcome. Obtaining a molecular diagnosis can be beneficial in securing a definitive diagnosis, especially in cases with atypical presentations. A genetic diagnosis may also be informative with regard to prognosis and potential therapies. Effective management and rehabilitation for patients with syndromic retinal dystrophy requires a comprehensive genetic-based team approach involving patients, family members, ophthalmologists, primary care physicians, and geneticists.
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Affiliation(s)
- Xiang Q Werdich
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School , Boston, Massachusetts , USA
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5
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Chiu CS, Mantopoulos D, Lessell S, Cestari DM. A Rod-Sparing Retinopathy in Bardet-Biedl Syndrome. Case Rep Ophthalmol 2015; 6:30-3. [PMID: 25759667 PMCID: PMC4327332 DOI: 10.1159/000375136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Bardet-Biedl syndrome is a continuum of disorders characterized by systemic and ocular findings. Retinal abnormalities typically present as diffuse photoreceptor degeneration. Here, we report a novel case that suggests a rod-sparing variant of Bardet-Biedl syndrome.
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Affiliation(s)
- Cynthia S. Chiu
- Department of Ophthalmology, University of California San Francisco, San Francisco, Calif., USA
| | - Dimosthenis Mantopoulos
- Department of Ophthalmology and Visual Science, Havener Eye Institute, The Ohio State University, Columbus, Ohio., USA
- Neuro-Ophthalmology Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Mass., USA
- *Dimosthenis Mantopoulos, MD, The Ohio State University, 915 Olentangy River Rd., Columbus, OH 43212 (USA), E-Mail
| | - Simmons Lessell
- Neuro-Ophthalmology Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Mass., USA
| | - Dean M. Cestari
- Neuro-Ophthalmology Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Mass., USA
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6
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Multifocal electroretinogram contributes to differentiation of various clinical pictures within a family with Bardet-Biedl syndrome. Eye (Lond) 2014; 28:1136-42. [PMID: 24993321 DOI: 10.1038/eye.2014.150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 05/24/2014] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To demonstrate the use of the multifocal electroretinogram (mfERG) in addition to the full-field electroretinogram (ERG) in defining varying clinical pictures in children within a family with Bardet-Biedl syndrome (BBS). METHODS All members from a family generation underwent a detailed history and examination before proceeding to a detailed ERG in accordance with the International Society of Clinical Electrophysiology for Vision protocol and a rapid, low-resolution mfERG. Of the sibling pair, the 13-year-old boy showed reduced vision and atypical maculopathy and the 10-year-old sister showed normal vision and atrophic maculopathy. Parents had normal ocular examination. RESULTS The male sibling had reduced rod and cone full-field ERG responses with a relatively spared central response from the mfERG suggesting central macular sparing. In contrast, for the female sibling, the ERG was normal for the cone pathway although reduced for rod pathway, with mfERG showing central involvement. The mother had rod responses at the lower end of normal range, a normal cone pathway, and a normal mfERG. The father showed a normal ERG and mfERG. CONCLUSION The mfERG is a useful adjunct to full-field ERG in the paediatric population and in family studies.
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7
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Berezovsky A, Rocha DM, Sacai PY, Watanabe SS, Cavascan NN, Salomão SR. Visual acuity and retinal function in patients with Bardet-Biedl syndrome. Clinics (Sao Paulo) 2012; 67:145-9. [PMID: 22358239 PMCID: PMC3275121 DOI: 10.6061/clinics/2012(02)09] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 08/06/2011] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype. METHODS The visual acuity of a group of 23 patients (15 males) with ages ranging from 6-36 years (mean = 15.8 ± 6.4; median = 14.7) was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed. RESULTS Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%), 20/50-20/150 in 13 (56.5%) patients, 20/200-20/400 in 2 (8.7%) patients and worse than 20/400 in one (4.3%) patient. The mean acuity in the better-seeing eye was 0.7 ± 0.6 logMAR (20/100, Snellen equivalent). Scotopic rod and maximal responses were nondetectable in 21 (91.3%) patients, and cone responses were non-detectable in 15 (65.2%) patients. Elevated dark-adapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6%) patients having thresholds greater than 30 dB. CONCLUSIONS In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition.
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Affiliation(s)
- Adriana Berezovsky
- Universidade Federal de São Paulo/Escola Paulista de Medicina, Departamento de Oftalmologia, Brazil.
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8
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Aliferis K, Hellé S, Gyapay G, Duchatelet S, Stoetzel C, Mandel JL, Dollfus H. Differentiating Alström from Bardet-Biedl syndrome (BBS) using systematic ciliopathy genes sequencing. Ophthalmic Genet 2011; 33:18-22. [PMID: 22004009 DOI: 10.3109/13816810.2011.620055] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Early onset retinal degeneration associated with obesity can present a diagnostic challenge in paediatric ophthalmology practice. Clinical overlap between Bardet-Biedl syndrome (BBS) and Alström syndrome has been described, although the two entities are genetically distinct. To date, 16 genes are known to be associated with BBS (BBS1-16) and only one gene has been identified for Alström syndrome (ALMS1). MATERIALS AND METHODS In collaboration with the French National Center for Sequencing (CNS, Evry), all coding exons and flanking introns were sequenced for 27 ciliopathy genes (BBS1-12, MGC1203, TTC21b, AHI1, NPHP2-8 (NPHP6=BBS14), MKS1(BBS13), MKS3, C2ORF86, SDCCAG8, ALMS1) in 96 patients referred with a clinical diagnosis of BBS. ALMS1 gene analysis included sequencing of all coding exons. RESULTS BBS known gene mutations were found in 44 patients (36 with two mutations and 8 heterozygous). ALMS1 mutations were found in four cases. The rate of ALMS1 mutations among patients suspected of having BBS was 4.2%. DISCUSSION Clinically, all four patients presented early-onset severe retinal degeneration with congenital nystagmus associated with obesity. The difficult early differential diagnosis between the two syndromes is outlined. One mutation had already been reported (c.11310delAGAG/p.R3770fsX) and three were novel (c.2293C > T/p.Q765X, c.6823insA/p.R2275fsX, c.9046delA/p.N3016fsX). CONCLUSIONS Ciliopathy genes sequencing can be very helpful in providing a timely diagnosis in this group of patients, hence appropriate genetic counselling for families and adequate medical follow-up for affected children.
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Affiliation(s)
- K Aliferis
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique, CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
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9
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Impaired photoreceptor protein transport and synaptic transmission in a mouse model of Bardet-Biedl syndrome. Vision Res 2008; 47:3394-407. [PMID: 18022666 DOI: 10.1016/j.visres.2007.09.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 09/12/2007] [Accepted: 09/13/2007] [Indexed: 11/24/2022]
Abstract
Bardet-Biedl syndrome (BBS) is an oligogenic syndrome whose manifestations include retinal degeneration, renal abnormalities, obesity and polydactylia. Evidence suggests that the main etiopathophysiology of this syndrome is impaired intraflagellar transport (IFT). In this study, we study the Bbs4-null mouse and investigate photoreceptor structure and function after loss of this gene. We find that Bbs4-null mice have defects in the transport of phototransduction proteins from the inner segments to the outer segments, before signs of cell death. Additionally, we show defects in synaptic transmission from the photoreceptors to secondary neurons of the visual system, demonstrating multiple functions for BBS4 in photoreceptors.
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10
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Abstract
While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present.
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Affiliation(s)
- N A Adams
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
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11
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Eichers ER, Abd-El-Barr MM, Paylor R, Lewis RA, Bi W, Lin X, Meehan TP, Stockton DW, Wu SM, Lindsay E, Justice MJ, Beales PL, Katsanis N, Lupski JR. Phenotypic characterization of Bbs4 null mice reveals age-dependent penetrance and variable expressivity. Hum Genet 2006; 120:211-26. [PMID: 16794820 DOI: 10.1007/s00439-006-0197-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 04/28/2006] [Indexed: 10/24/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a rare oligogenic disorder exhibiting both clinical and genetic heterogeneity. Although the BBS phenotype is variable both between and within families, the syndrome is characterized by the hallmarks of developmental and learning difficulties, post-axial polydactylia, obesity, hypogenitalism, renal abnormalities, retinal dystrophy, and several less frequently observed features. Eleven genes mutated in BBS patients have been identified, and more are expected to exist, since about 20-30% of all families cannot be explained by the known loci. To investigate the etiopathogenesis of BBS, we created a mouse null for one of the murine homologues, Bbs4, to assess the contribution of one gene to the pleiotropic murine Bbs phenotype. Bbs4 null mice, although initially runted compared to their littermates, ultimately become obese in a gender-dependent manner, females earlier and with more severity than males. Blood chemistry tests indicated abnormal lipid profiles, signs of liver dysfunction, and elevated insulin and leptin levels reminiscent of metabolic syndrome. As in patients with BBS, we found age-dependent retinal dystrophy. Behavioral assessment revealed that mutant mice displayed more anxiety-related responses and reduced social dominance. We noted the rare occurrence of birth defects, including neural tube defects and hydrometrocolpos, in the null mice. Evaluations of these null mice have uncovered phenotypic features with age-dependent penetrance and variable expressivity, partially recapitulating the human BBS phenotype.
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Affiliation(s)
- Erica R Eichers
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza Room 604B, Houston, TX 77030, USA
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12
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Chen CL, Chung CY, Cheng PT, Chen CH, Chen MH. Linguistic and gait disturbance in a child with Laurence-Moon-Biedl syndrome: left temporal and parietal lobe hypoplasia. Am J Phys Med Rehabil 2004; 83:69-74. [PMID: 14709978 DOI: 10.1097/01.phm.0000091989.01773.1c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Laurence-Moon-Biedl syndrome is an autosomal recessive disorder characterized by retinitis pigmentosa, obesity, polydactyly, hypogenitalism, mental retardation, and renal abnormalities. We report the linguistic and gait disorders in a child with Laurence-Moon-Biedl syndrome associated with left temporal and parietal hypoplasia as determined by magnetic resonance imaging. Our patient was mildly mentally retarded, scoring better on the performance subtest than on the verbal subtest. He received serial assessments for developmental, language, speech, and gait functions, before and after rehabilitation, at age 4.5 and 6 yr, respectively. After comprehensive rehabilitation, the boy achieved improvement in speech, language, fine motor, and gait functions. Early comprehensive rehabilitation programs seem beneficial for improving functional development for children with Laurence-Moon-Biedl syndrome.
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Affiliation(s)
- Chia-Ling Chen
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial and Childrens Hospital, Tao-Yuan, Taiwan
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13
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Baskin E, Kayiran SM, Oto S, Alehan F, Agildere AM, Saatçi U. Cerebellar vermis hypoplasia in a patient with Bardet-Biedl syndrome. J Child Neurol 2002; 17:385-7. [PMID: 12150587 DOI: 10.1177/088307380201700514] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Laurence-Moon-Bardet-Biedl syndome is an autosomal recessive condition characterized by retinal dystrophy, obesity, mental retardation, distal limb anomaly, hypogonadism, and renal dysfunction. The symptoms vary among families and even among affected siblings. Certain clinical signs have been used to identify subgroups of patients with this complex condition. Laurence-Moon syndrome as a distinct entity is rare and features paraplegia in the absence of polydactyly or obesity. Bardet-Biedl syndrome is characterized by distal limb anomaly, obesity, and renal involvement, but neurologic symptoms are very unusual. We report a patient exhibiting characteristic features of Bardet-Biedl syndrome in addition to cerebellar vermis hypoplasia and mega cisterna magna.
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Affiliation(s)
- Esra Baskin
- Department of Pediatrics, Başkent University Faculty of Medicine, Ankara, Turkey.
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14
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Abstract
This case report describes the presentation of a patient with Bardet-Biedl syndrome. Bardet-Biedl Syndrome is an autosomal recessive condition that includes retinal dystrophy, dystrophic extremities (commonly polydactyly), obesity, hypogenitalism, and renal disease. Cognitive deficit has also been considered part of the syndrome. The historically associated Laurence-Moon syndrome includes spastic paraparesis but not the obesity and polydactyly. They are now considered separate conditions. The most common feature of Bardet-Biedl syndrome is retinal dystrophy. The appearance of the retina in the condition is quite variable with typical retinitis pigmentosa being present in only a minority of cases. The associated optic atrophy can be primary in nature and might play a role in the decreased central vision. Diagnosis of the condition is important for visual prognosis and low vision management. The renal disease often goes undetected until specific radiological testing is done after diagnosis of Bardet-Biedl syndrome. This is significant in that early death often occurs in this condition because of the renal disease.
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Affiliation(s)
- P K Hrynchak
- University of Waterloo, School of Optometry, Ontario, Canada.
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Riise R, Andréasson S, Borgaström MK, Wright AF, Tommerup N, Rosenberg T, Tornqvist K. Intrafamilial variation of the phenotype in Bardet-Biedl syndrome. Br J Ophthalmol 1997; 81:378-85. [PMID: 9227203 PMCID: PMC1722198 DOI: 10.1136/bjo.81.5.378] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AIMS To describe the variation of the phenotype within families with several individuals with Bardet-Biedl syndrome. METHODS The phenotypes of affected siblings in 11 Scandinavian families with two or more members who had at least three of the features: retinal dystrophy, polydactyly, obesity, hypogenitalism, and mental retardation, were compared [corrected]. Individuals without retinal dystrophy were excluded. RESULTS Intrafamilial variation of expressivity of the features obesity, polydactyly, abnormal radiograms of the extremities, hypogenitalism, short stature, paraplegia, and dental abnormalities was found. The retinal dystrophy varied with respect to both the onset of symptoms and the course of the disease. The morphology of the fundus, however, was consistent within the families. The disorder showed statistically significant genetic linkage to the BBS4 locus on chromosome 15 in the affected siblings in two of the families, but the clinical features in these patients did not differ from the other cases of Bardet-Biedl syndrome. CONCLUSION Comparison of siblings with the Bardet-Biedl syndrome showed variation of the typical features. In addition, the course of retinal dystrophy varied. No distinctive clinical features were found to separate the BBS4 phenotype from the remaining patients.
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Affiliation(s)
- R Riise
- Department of Ophthalmology, Central Hospital of Hedmark, Hamar, Norway
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