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Shalom S, Ben-Yosef T, Sher I, Zag A, Rotenstreich Y, Poleg T, Birk OS, Gradstein L, Ehrenberg M, Deitch I, Mezer E, Hecht I, Pras E, Ramon D, Khateb S, Zur D, Newman H, Kharouba R, Goldenberg-Cohen N, Leibu R, Soudry S, Perlman I, Banin E, Sharon D. Nationwide Prevalence of Inherited Retinal Diseases in the Israeli Population. JAMA Ophthalmol 2024; 142:609-616. [PMID: 38753338 PMCID: PMC11099844 DOI: 10.1001/jamaophthalmol.2024.1461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 03/15/2024] [Indexed: 05/19/2024]
Abstract
Importance Data regarding the prevalence of various inherited retinal diseases (IRDs) are limited and vary across populations; moreover, nationwide prevalence studies may be limited to a specific IRD phenotype, potentially leading to inaccurate prevalence estimations. Therefore, nationwide prevalence data are needed. Objective To determine the prevalence of 67 IRD phenotypes in the Israeli population. Design, Setting, and Participants This cohort study collected nationwide data regarding the number of individuals affected with IRD phenotypes assessed in 10 clinical and academic centers in Israel as part of the research activity of the Israeli inherited retinal disease consortium. Data were collected in May 2023 on 9396 individuals residing in Israel who were diagnosed by an ophthalmologist with an IRD using either electroretinography or retinal imaging where included. Individuals with retinal diseases known to have a nonmendelian basis or without a clear genetic basis and those who were reported as deceased at the time of data collection were excluded from this study. Main Outcomes and Measures Prevalence of 67 IRD phenotypes. Results Among the 9396 participants in our cohort, the most common IRD in Israel was retinitis pigmentosa with a disease prevalence of approximately 1:2400 individuals, followed by cone-rod dystrophy (approximately 1:14 000), Stargardt disease (approximately 1:16 000), Usher syndrome (approximately 1:16,000), and congenital stationary night blindness (approximately 1:18 000). The prevalence of all IRDs combined was 1:1043 individuals. Conclusions and Relevance The current study provides large prevalence dataset of 67 IRD phenotypes, some of which are extremely rare, with only a single identified case. This analysis highlights the potential importance of performing additional nationwide prevalence studies to potentially assist with determining the prevalence of IRDs worldwide.
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Affiliation(s)
- Sapir Shalom
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Military Medicine and Tzameret, Faculty of Medicine, Hebrew University of Jerusalem and Medical Corps, Israel Defense Forces, Jerusalem, Israel
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ifat Sher
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- The Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Amir Zag
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- The Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ygal Rotenstreich
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- The Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Tomer Poleg
- Genetics Institute at Soroka Medical Center and the Morris Kahn Laboratory of Human Genetics, Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel
| | - Ohad S. Birk
- Genetics Institute at Soroka Medical Center and the Morris Kahn Laboratory of Human Genetics, Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel
| | - Libe Gradstein
- Department of Ophthalmology, Soroka Medical Center and Clalit Health Services, Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel
| | - Miriam Ehrenberg
- Ophthalmology Unit, Schneider Children’s Medical Center in Israel, Petach Tikva, Israel
| | - Iris Deitch
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Department of Ophthalmology, Rabin Medical Center, Petach Tikva, Israel
| | - Eedy Mezer
- Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Ophthalmology, Rambam Healthcare Campus, Haifa, Israel
| | - Idan Hecht
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- The Matlow’s Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
| | - Eran Pras
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- The Matlow’s Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
| | - Dan Ramon
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Ophthalmology Division, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dinah Zur
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Ophthalmology Division, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Hadas Newman
- Faculty of medicine, Tel Aviv university, Tel Aviv, Israel
- Ophthalmology Division, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Rawan Kharouba
- The Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Ophthalmology, Bnai-Zion Medical Center, Haifa, Israel
| | - Nitza Goldenberg-Cohen
- The Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Ophthalmology, Bnai-Zion Medical Center, Haifa, Israel
| | - Rina Leibu
- Department of Ophthalmology, Rambam Healthcare Campus, Haifa, Israel
| | - Shiri Soudry
- Department of Ophthalmology, Rabin Medical Center, Petach Tikva, Israel
- Department of Ophthalmology, Rambam Healthcare Campus, Haifa, Israel
- Ruth and Bruce Rappaport Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel
| | - Ido Perlman
- Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
- Ophthalmology Division, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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Hanany M, Shalom S, Ben-Yosef T, Sharon D. Comparison of Worldwide Disease Prevalence and Genetic Prevalence of Inherited Retinal Diseases and Variant Interpretation Considerations. Cold Spring Harb Perspect Med 2024; 14:a041277. [PMID: 37460155 PMCID: PMC10835612 DOI: 10.1101/cshperspect.a041277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
One of the considerations in planning the development of novel therapeutic modalities is disease prevalence that is usually defined by studying large national/regional populations. Such studies are rare and might suffer from inaccuracies and challenging clinical characterization in heterogeneous diseases, such as inherited retinal diseases (IRDs). Here we collected reported disease prevalence information on various IRDs in different populations. The most common IRD, retinitis pigmentosa, has an average disease prevalence of ∼1:4500 individuals, Stargardt disease ∼1:17,000, Usher syndrome ∼1:25,000, Leber congenital amaurosis ∼1:42,000, and all IRDs ∼1:3450. We compared these values to genetic prevalence (GP) calculated based on allele frequency of autosomal-recessive IRD mutations. Although most values did correlate, some differences were observed that can be explained by discordant, presumably null mutations that are likely to be either nonpathogenic or hypomorphic. Our analysis highlights the importance of performing additional disease prevalence studies and to couple them with population-dependent allele frequency data.
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Affiliation(s)
- Mor Hanany
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120001, Israel
| | - Sapir Shalom
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120001, Israel
- Department of Military Medicine and "Tzameret," Faculty of Medicine, Hebrew University of Jerusalem and Medical Corps, Israel Defense Forces, Jerusalem 9112102, Israel
| | - Tamar Ben-Yosef
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120001, Israel
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Retinal Structure and Function in a Knock-In Mouse Model for the FAM161A-p.Arg523* Human Nonsense Pathogenic Variant. OPHTHALMOLOGY SCIENCE 2022; 3:100229. [DOI: 10.1016/j.xops.2022.100229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/28/2022] [Accepted: 09/26/2022] [Indexed: 11/05/2022]
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Khateb S, Nassisi M, Bujakowska KM, Méjécase C, Condroyer C, Antonio A, Foussard M, Démontant V, Mohand-Saïd S, Sahel JA, Zeitz C, Audo I. Longitudinal Clinical Follow-up and Genetic Spectrum of Patients With Rod-Cone Dystrophy Associated With Mutations in PDE6A and PDE6B. JAMA Ophthalmol 2020; 137:669-679. [PMID: 30998820 DOI: 10.1001/jamaophthalmol.2018.6367] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Importance A precise phenotypic characterization of retinal dystrophies is needed for disease modeling as a basis for future therapeutic interventions. Objective To compare genotype, phenotype, and structural changes in patients with rod-cone dystrophy (RCD) associated with mutations in PDE6A or PDE6B. Design, Setting, and Participants In a retrospective cohort study conducted in Paris, France, from January 2007 to September 2017, 54 patients from a cohort of 1095 index patients with RCD underwent clinical examination, including personal and familial history, best-corrected visual acuity (BCVA), color vision, slitlamp examination, full-field electroretinography, kinetic visual fields (VFs), retinophotography, optical coherence tomography, near-infrared fundus autofluorescence, and short-wavelength fundus autofluorescence imaging. Genotyping was performed using microarray analysis, targeted next-generation sequencing, and Sanger sequencing validation with familial segregation when possible. Data were analyzed from September 1, 2017, to February 1, 2018. Clinical variables were subsequently analyzed in 2018. Main Outcomes and Measures Phenotype and genotype comparison of patients carrying mutations in PDE6A or PDE6B. Results Of the 54 patients included in the study, 19 patients of 17 families (11 women [58%]; mean [SD] age at diagnosis, 14.83 [10.63] years) carried pathogenic mutations in PDE6A, and 35 patients of 26 families (17 women [49%]; mean [SD] age at diagnosis, 21.10 [11.56] years) had mutations in PDE6B, accounting for prevalences of 1.6% and 2.4%, respectively. Among 49 identified genetic variants, 14 in PDE6A and 15 in PDE6B were novel. Overall, phenotypic analysis revealed no substantial differences between the 2 groups except for night blindness as a presenting symptom that was noted to be more prevalent in the PDE6A than PDE6B group (80% vs 37%, respectively; P = .005). The mean binocular BCVA and VF decrease over time (measured as mean individual slopes coefficients) was comparable between patients with PDE6A and PDE6B mutations: 0.04 (0.12) vs 0.02 (0.05) for BCVA (P = .89) and 14.33 (7.12) vs 13.27 (6.77) for VF (P = .48). Conclusions and Relevance Mutations in PDE6A and PDE6B accounted for 1.6% and 2.4%, respectively, in a cohort of French patients with RCD. The functional and structural findings reported may constitute the basis of disease modeling that might be used for better prognostic estimation and candidate selection for photoreceptor therapeutic rescue.
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Affiliation(s)
- Samer Khateb
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Marco Nassisi
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - Kinga M Bujakowska
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Cécile Méjécase
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Christel Condroyer
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Aline Antonio
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - Marine Foussard
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Vanessa Démontant
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Saddek Mohand-Saïd
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Fondation Ophtalmologique Adolphe de Rothschild, Paris, France.,Department of Ophthalmology, The University of Pittsburgh Medical School, Pittsburgh, Pennsylvania.,Académie des Sciences-Institut de France, Paris, France
| | - Christina Zeitz
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France
| | - Isabelle Audo
- Sorbonne Université, Institut national de la santé et de la recherche médicale, Centre national de la recherche scientifique, Institut de la Vision, Paris, France.,Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU Sight Restore, Inserm-Direction Générale de l'Offre de Soins, CIC1423, Paris, France.,Institute of Ophthalmology, University College London, London, United Kingdom
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Worldwide carrier frequency and genetic prevalence of autosomal recessive inherited retinal diseases. Proc Natl Acad Sci U S A 2020; 117:2710-2716. [PMID: 31964843 DOI: 10.1073/pnas.1913179117] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
One of the major questions in human genetics is what percentage of individuals in the general population carry a disease-causing mutation. Based on publicly available information on genotypes from six main world populations, we created a database including data on 276,921 sequence variants, present within 187 genes associated with autosomal recessive (AR) inherited retinal diseases (IRDs). Assessment of these variants revealed that 10,044 were categorized as disease-causing mutations. We developed an algorithm to compute the gene-specific prevalence of disease, as well as the mutational burden in healthy subjects. We found that the genetic prevalence of AR-IRDs corresponds approximately to 1 case in 1,380 individuals, with 5.5 million people expected to be affected worldwide. In addition, we calculated that unaffected carriers of mutations are numerous, ranging from 1 in 2.26 individuals in Europeans to 1 in 3.50 individuals in the Finnish population. Our analysis indicates that about 2.7 billion people worldwide (36% of the population) are healthy carriers of at least one mutation that can cause AR-IRD, a value that is probably the highest across any group of Mendelian conditions in humans.
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Abu Diab A, AlTalbishi A, Rosin B, Kanaan M, Kamal L, Swaroop A, Chowers I, Banin E, Sharon D, Khateb S. The combination of whole-exome sequencing and clinical analysis allows better diagnosis of rare syndromic retinal dystrophies. Acta Ophthalmol 2019; 97:e877-e886. [PMID: 30925032 DOI: 10.1111/aos.14095] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/03/2019] [Indexed: 01/05/2023]
Abstract
PURPOSE To identify the accurate clinical diagnosis of rare syndromic inherited retinal diseases (IRDs) based on the combination of clinical and genetic analyses. METHODS Four unrelated families with various autosomal recessive syndromic inherited retinal diseases were genetically investigated using whole-exome sequencing (WES). RESULTS Two affected subjects in family MOL0760 presented with a distinctive combination of short stature, developmental delay, congenital mental retardation, microcephaly, facial dysmorphism and retinitis pigmentosa (RP). Subjects were clinically diagnosed with suspected Kabuki syndrome. WES revealed a homozygous nonsense mutation (c.5492dup, p.Asn1831Lysfs*8) in VPS13B that is known to cause Cohen syndrome. The index case of family MOL1514 presented with both RP and liver dysfunction, suspected initially to be related. WES identified a homozygous frameshift mutation (c.1787_1788del, p.His596Argfs*47) in AGBL5, associated with nonsyndromic RP. The MOL1592 family included three affected subjects with crystalline retinopathy, skin ichthyosis, short stature and congenital adrenal hypoplasia, and were found to harbour a homozygous nonsense mutation (c.682C>T, p.Arg228Cys) in ALDH3A2, reported to cause Sjögren-Larsson syndrome (SLS). In the fourth family, SJ002, two siblings presented with hypotony, psychomotor delay, dysmorphic facial features, pathologic myopia, progressive external ophthalmoplegia and diffuse retinal atrophy. Probands were suspected to have atypical Kearns-Sayre syndrome, but were diagnosed with combined oxidative phosphorylation deficiency-20 due to a novel suspected missense variant (c.1691C>T, p.Ala564Val) in VARS2. CONCLUSION Our findings emphasize the important complement of WES and thorough clinical investigation in establishing precise clinical diagnosis. This approach constitutes the basis for personalized medicine in rare IRDs.
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Affiliation(s)
- Alaa Abu Diab
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
| | | | - Boris Rosin
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
| | - Moien Kanaan
- Hereditary Research Lab Bethlehem University Jerusalem Israel
| | - Lara Kamal
- Hereditary Research Lab Bethlehem University Jerusalem Israel
| | - Anand Swaroop
- Neurobiology‐Neurodegeneration & Repair Laboratory National Eye Institute National Institutes of Health Bethesda Maryland USA
| | - Itay Chowers
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
| | - Eyal Banin
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
| | - Dror Sharon
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
| | - Samer Khateb
- Department of Ophthalmology Hadassah‐Hebrew University Medical Center Jerusalem Israel
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Dysli C, Schuerch K, Escher P, Wolf S, Zinkernagel MS. Fundus Autofluorescence Lifetime Patterns in Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 59:1769-1778. [PMID: 29610860 DOI: 10.1167/iovs.17-23336] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigated whether fundus autofluorescence (FAF) lifetimes in patients with retinitis pigmentosa display a disease-specific lifetime pattern. Methods Fundus autofluorescence lifetime imaging ophthalmoscopy (FLIO) was performed in two spectral channels (498-560 and 560-720 nm) after excitation with a 473 nm pulsed laser in patients with retinitis pigmentosa and compared to healthy controls of a similar age range. Corresponding FAF intensity and spectral domain optical coherence tomography (OCT) data, as well as best corrected visual acuity (BCVA) were acquired and compared to fluorescence lifetime data. Results We investigated 43 eyes from 43 patients with retinitis pigmentosa (mean age 45 ± 15 years) and compared them to eyes of 13 age-matched healthy participants. Mean FAF lifetimes were prolonged in areas of photoreceptor atrophy with preserved retinal pigment epithelium (RPE) (P = 0.0036) and even longer in areas with total atrophy of photoreceptors and RPE (P = 0.0002). The prevalence of perifoveal ring structures characterized by prolonged fluorescence lifetimes in FLIO was higher (63% vs. 49%) and the rings were wider compared to the hyperautofluorescent rings in qualitative fundus autofluorescence intensity images. In the central fovea with intact retinal layer structure identified by OCT, fluorescence lifetimes were slightly prolonged compared to those of age-matched healthy controls (short spectral channel [SSC], P = 0.0044; long spectral channel [LSC], P = 0.0128). Short lifetimes within the macular center were negatively correlated with BCVA (R2 = 0.33, P < 0.0001) as well as the greatest diameter of the ellipsoid band in OCT. Conclusions FLIO in retinitis pigmentosa reveals characteristic patterns that allow identification of areas of photoreceptor atrophy, RPE atrophy, and remaining photoreceptor segments in areas of RPE atrophy. Fluorescence lifetimes can be used to identify ellipsoid zone loss that correlates with functional parameters.
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Affiliation(s)
- Chantal Dysli
- Department of Ophthalmology, Inselspital, Bern University Hospital, and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Kaspar Schuerch
- Department of Ophthalmology, Inselspital, Bern University Hospital, and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Pascal Escher
- Department of Ophthalmology, Inselspital, Bern University Hospital, and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Sebastian Wolf
- Department of Ophthalmology, Inselspital, Bern University Hospital, and Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, and Department of BioMedical Research, University of Bern, Bern, Switzerland
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Niketeghad S, Pouratian N. Brain Machine Interfaces for Vision Restoration: The Current State of Cortical Visual Prosthetics. Neurotherapeutics 2019; 16:134-143. [PMID: 30194614 PMCID: PMC6361050 DOI: 10.1007/s13311-018-0660-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Loss of vision alters the day to day life of blind individuals and may impose a significant burden on their family and the economy. Cortical visual prosthetics have been shown to have the potential of restoring a useful degree of vision via stimulation of primary visual cortex. Due to current advances in electrode design and wireless power and data transmission, development of these prosthetics has gained momentum in the past few years and multiple sites around the world are currently developing and testing their designs. In this review, we briefly outline the visual prosthetic approaches and describe the history of cortical visual prosthetics. Next, we focus on the state of the art of cortical visual prosthesis by briefly explaining the design of current devices that are either under development or in the clinical testing phase. Lastly, we shed light on the challenges of each design and provide some potential solutions.
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Affiliation(s)
- Soroush Niketeghad
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Nader Pouratian
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA.
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Sharon D, Wimberg H, Kinarty Y, Koch KW. Genotype-functional-phenotype correlations in photoreceptor guanylate cyclase (GC-E) encoded by GUCY2D. Prog Retin Eye Res 2018; 63:69-91. [DOI: 10.1016/j.preteyeres.2017.10.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/16/2017] [Accepted: 10/16/2017] [Indexed: 01/09/2023]
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Namburi P, Ratnapriya R, Khateb S, Lazar CH, Kinarty Y, Obolensky A, Erdinest I, Marks-Ohana D, Pras E, Ben-Yosef T, Newman H, Gross M, Swaroop A, Banin E, Sharon D. Bi-allelic Truncating Mutations in CEP78, Encoding Centrosomal Protein 78, Cause Cone-Rod Degeneration with Sensorineural Hearing Loss. Am J Hum Genet 2016; 99:777-784. [PMID: 27588452 PMCID: PMC5011076 DOI: 10.1016/j.ajhg.2016.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/07/2016] [Indexed: 12/22/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a diverse group of genetically and clinically heterogeneous retinal abnormalities. The present study was designed to identify genetic defects in individuals with an uncommon combination of autosomal recessive progressive cone-rod degeneration accompanied by sensorineural hearing loss (arCRD-SNHL). Homozygosity mapping followed by whole-exome sequencing (WES) and founder mutation screening revealed two truncating rare variants (c.893-1G>A and c.534delT) in CEP78, which encodes centrosomal protein 78, in six individuals of Jewish ancestry with CRD and SNHL. RT-PCR analysis of CEP78 in blood leukocytes of affected individuals revealed that the c.893-1G>A mutation causes exon 7 skipping leading to deletion of 65bp, predicted to result in a frameshift and therefore a truncated protein (p.Asp298Valfs(∗)17). RT-PCR analysis of 17 human tissues demonstrated ubiquitous expression of different CEP78 transcripts. RNA-seq analysis revealed three transcripts in the human retina and relatively higher expression in S-cone-like photoreceptors of Nrl-knockout retina compared to rods. Immunohistochemistry studies in the human retina showed intense labeling of cone inner segments compared to rods. CEP78 was reported previously to interact with c-nap1, encoded by CEP250 that we reported earlier to cause atypical Usher syndrome. We conclude that truncating mutations in CEP78 result in a phenotype involving both the visual and auditory systems but different from typical Usher syndrome.
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Affiliation(s)
- Prasanthi Namburi
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Rinki Ratnapriya
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-0610, USA
| | - Samer Khateb
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Csilla H Lazar
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-0610, USA; Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano Sciences, Babes-Bolyai-University, 400271, Cluj-Napoca, Romania
| | - Yael Kinarty
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel; Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, 91120, Israel
| | - Alexey Obolensky
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Inbar Erdinest
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Devorah Marks-Ohana
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Eran Pras
- Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, 70300, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 6997801, Israel
| | - Tamar Ben-Yosef
- The Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, 3525433, Israel
| | - Hadas Newman
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 6997801, Israel; Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv, 64239, Israel
| | - Menachem Gross
- Department of Otolaryngology-Head and Neck Surgery, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-0610, USA
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel.
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel.
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Khateb S, Hanany M, Khalaileh A, Beryozkin A, Meyer S, Abu-Diab A, Abu Turky F, Mizrahi-Meissonnier L, Lieberman S, Ben-Yosef T, Banin E, Sharon D. Identification of genomic deletions causing inherited retinal degenerations by coverage analysis of whole exome sequencing data. J Med Genet 2016; 53:600-7. [PMID: 27208209 DOI: 10.1136/jmedgenet-2016-103825] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 04/01/2016] [Indexed: 01/13/2023]
Abstract
BACKGROUND Inherited retinal degenerations (IRDs) are a common cause of visual disturbance with a high clinical and genetic heterogeneity. Recent sequencing techniques such as whole exome sequencing (WES) contribute to the discovery of novel genes. The aim of the current study was to use WES data to identify large deletions that include at least one exon in known IRD genes. METHODS Patients diagnosed with IRDs underwent a comprehensive ophthalmic evaluation. WES was performed using the NimbleGen V2 paired-end kit and HiSeq 2000. An analysis of exon coverage data was performed on 60 WES samples. Exonic deletions were verified by 'PCR walking' analysis. RESULTS We analysed data obtained from 60 WES samples of index patients with IRDs. By calculating the average coverage for all exons in the human genome, we were able to identify homozygous and hemizygous deletions of at least one exon in six families (10%), including a single-exon deletion in EYS, deletions of three consecutive exons in MYO7A and NPHP4, deletions of four and eight consecutive exons in RPGR and a multigene deletion on the X-chromosome, including CHM. By using PCR-walking analysis, we were able to identify the borders of five of the deletions and to screen our set of patients for these deletions. CONCLUSIONS We performed here a comprehensive analysis of WES data as a tool for identifying large genomic deletions in patients with IRDs. Our analysis indicates that large deletions are relatively frequent (about 10% of our WES cohort) and should be screened when analysing WES data.
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Affiliation(s)
- Samer Khateb
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Mor Hanany
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ayat Khalaileh
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Avigail Beryozkin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Segev Meyer
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Alaa Abu-Diab
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Fathieh Abu Turky
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | - Sari Lieberman
- Medical Genetics Institute, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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Sharon D, Kimchi A, Rivolta C. OR2W3 sequence variants are unlikely to cause inherited retinal diseases. Ophthalmic Genet 2016; 37:366-368. [PMID: 26891008 DOI: 10.3109/13816810.2015.1081252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Because of its formidable throughput, whole exome sequencing (WES) is significantly increasing the power of investigations in ophthalmic genetics. However, when applied to Mendelian conditions, WES results often contain many false positives, e.g. candidate mutations that are unrelated to the disease. For instance, highly polymorphic genes such as olfactory receptor genes carry a plethora of both common and rare alleles that are part of the normal set of variations of the human genome. Following a WES-based study, the heterozygous missense variant p.R142W in the olfactory receptor gene OR2W3 was recently reported as a pathogenic mutation causing autosomal dominant retinitis pigmentosa (RP). This variant, however, was not scored against data contained in public WES repositories, indicating that p.R142W is present in ~1 in 6500 control individuals. Therefore, if it really was pathogenic, it would be responsible for a percentage of dominant RP cases corresponding to the double of those recorded so far worldwide, or 2/3 of all RP cases (dominant, recessive, and X-linked). We therefore conclude that this sequence variant, and hence the OR2W3 gene, do not cause RP. Prompted by these findings and based on simple principles of population genetics, we suggest that WES studies should consider DNA variants as the possible cause of dominant RP only if they are present in less than 1:100,000 individuals from the general population. In addition, we propose that DNA variants belonging to highly polymorphic genes should be carefully analyzed at the functional level before inferring their pathogenicity, in RP or other genetic diseases.
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Affiliation(s)
- Dror Sharon
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Adva Kimchi
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Carlo Rivolta
- b Department of Computational Biology , Unit of Medical Genetics, University of Lausanne , Lausanne , Switzerland
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Sharon D, Banin E. Nonsyndromic retinitis pigmentosa is highly prevalent in the Jerusalem region with a high frequency of founder mutations. Mol Vis 2015; 21:783-92. [PMID: 26261414 PMCID: PMC4506056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 07/15/2015] [Indexed: 11/21/2022] Open
Abstract
PURPOSE Nonsyndromic retinitis pigmentosa (RP) is the most common inherited retinal degeneration, and prevalence of the disease has been reported in populations of American and European origin with a relatively low consanguinity rate. Our aim was to determine the prevalence of nonsyndromic RP in the Jerusalem region, which has a population of about 1 million individuals with a high rate of consanguinity. METHODS The patients' clinical data included eye exam findings (visual acuity, anterior segment, and funduscopy) as well as electroretinographic (ERG) testing results under scotopic and photopic conditions. Mutation analysis on a subgroup of patients was performed mainly with candidate gene analysis and homozygosity mapping. RESULTS We evaluated the medical records of patients with degenerative retinal diseases residing in the Jerusalem region who were examined over the past 20 years in a large tertiary medical center. A total of 453 individuals affected with nonsyndromic RP were diagnosed at our center, according to funduscopic findings and ERG testing. Based on the estimated population size of 945,000 individuals who reside in the vicinity of Jerusalem, the prevalence of nonsyndromic RP in this region is 1:2,086. The prevalence of RP was higher among Arab Muslims (1:1,798) compared to Jews (1:2,230), mainly due to consanguineous marriages that are more common in the Arab Muslim population. To identify the genetic causes of RP in our cohort, we recruited 383 patients from 183 different families for genetic analysis: 70 with autosomal recessive (AR) inheritance, 15 with autosomal dominant, 86 isolate cases, and 12 with an X-linked inheritance pattern. In 64 (35%) of the families, we identified the genetic cause of the disease, and we revised the inheritance pattern of 20 isolate cases to the AR pattern; 49% of the families in our cohort had AR inheritance. Interestingly, in 42 (66%) of the genetically identified families, the cause of disease was a founder mutation. CONCLUSIONS Previous studies showed an approximate prevalence of 1:5,260 on average for nonsyndromic RP in American and European populations. We show that the prevalence in the vicinity of Jerusalem is two-and-a-half times higher due to a high rate of consanguinity and highly prevalent founder mutations within the historically semi-isolated subpopulations we serve.
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Mitra A, Chinchore Y, Kinser R, Dolph PJ. Characterization of two dominant alleles of the major rhodopsin-encoding gene ninaE in Drosophila. Mol Vis 2011; 17:3224-33. [PMID: 22194648 PMCID: PMC3244490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 12/10/2011] [Indexed: 10/26/2022] Open
Abstract
PURPOSE In this study we investigated the biochemical and cell biologic characteristics of flies expressing two novel dominant alleles of the major rhodopsin encoding gene neither inactivation nor afterpotential E (ninaE) in a heterozygous background. METHODS Presence of the deep pseudopupil in flies was assayed 5 days post eclosion. For structural analysis, 1-μm-retinal cross sections were obtained from fixed and resin-embedded Drosophila heads. Confocal microscopy was performed on dissected retinas stained with antibodies specific for rhodopsin, NinaA, and F-actin. Rhodopsin levels were determined by western and slot blot analysis. RESULTS Dominant rhodopsin mutants showed progressive age-dependent and light-independent loss of the deep pseudopupil, without any apparent retinal degeneration at the morphological level. Expression of mutant rhodopsin caused rhodopsin to mislocalize to the cell body and the endoplasmic reticulum compartment. Mutant rhodopsin also caused loss of solubility of wild-type rhodopsin and its accumulation presumably as a high molecular mass complex in the photoreceptor cell body. CONCLUSIONS In heterozygous mutant flies, there is loss of wild-type rhodopsin immunoreactivity on a western assay but less reduction using slot blot analysis. This suggests that mutant rhodopsin is likely inducing the misfolding and insolubility of wild-type rhodopsin. Localization of rhodopsin revealed that in mutant flies, wild-type rhodopsin is mislocalized to the cell body and the endoplasmic reticulum.
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15
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Zelinger L, Banin E, Obolensky A, Mizrahi-Meissonnier L, Beryozkin A, Bandah-Rozenfeld D, Frenkel S, Ben-Yosef T, Merin S, Schwartz SB, Cideciyan AV, Jacobson SG, Sharon D. A missense mutation in DHDDS, encoding dehydrodolichyl diphosphate synthase, is associated with autosomal-recessive retinitis pigmentosa in Ashkenazi Jews. Am J Hum Genet 2011; 88:207-15. [PMID: 21295282 DOI: 10.1016/j.ajhg.2011.01.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/29/2010] [Accepted: 01/10/2011] [Indexed: 11/30/2022] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations caused by mutations in at least 50 genes. Using homozygosity mapping in Ashkenazi Jewish (AJ) patients with autosomal-recessive RP (arRP), we identified a shared 1.7 Mb homozygous region on chromosome 1p36.11. Sequence analysis revealed a founder homozygous missense mutation, c.124A>G (p.Lys42Glu), in the dehydrodolichyl diphosphate synthase gene (DHDDS) in 20 AJ patients with RP of 15 unrelated families. The mutation was not identified in an additional set of 109 AJ patients with RP, in 20 AJ patients with other inherited retinal diseases, or in 70 patients with retinal degeneration of other ethnic origins. The mutation was found heterozygously in 1 out of 322 ethnically matched normal control individuals. RT-PCR analysis in 21 human tissues revealed ubiquitous expression of DHDDS. Immunohistochemical analysis of the human retina with anti-DHDDS antibodies revealed intense labeling of the cone and rod photoreceptor inner segments. Clinical manifestations of patients who are homozygous for the c.124A>G mutation were within the spectrum associated with arRP. Most patients had symptoms of night and peripheral vision loss, nondetectable electroretinographic responses, constriction of visual fields, and funduscopic hallmarks of retinal degeneration. DHDDS is a key enzyme in the pathway of dolichol, which plays an important role in N-glycosylation of many glycoproteins, including rhodopsin. Our results support a pivotal role of DHDDS in retinal function and may allow for new therapeutic interventions for RP.
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Affiliation(s)
- Lina Zelinger
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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16
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Bandah-Rozenfeld D, Mizrahi-Meissonnier L, Farhy C, Obolensky A, Chowers I, Pe'er J, Merin S, Ben-Yosef T, Ashery-Padan R, Banin E, Sharon D. Homozygosity mapping reveals null mutations in FAM161A as a cause of autosomal-recessive retinitis pigmentosa. Am J Hum Genet 2010; 87:382-91. [PMID: 20705279 DOI: 10.1016/j.ajhg.2010.07.022] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 07/22/2010] [Accepted: 07/29/2010] [Indexed: 01/19/2023] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations caused by mutations in at least 45 genes. Using homozygosity mapping, we identified a ∼4 Mb homozygous region on chromosome 2p15 in patients with autosomal-recessive RP (arRP). This region partially overlaps with RP28, a previously identified arRP locus. Sequence analysis of 12 candidate genes revealed three null mutations in FAM161A in 20 families. RT-PCR analysis in 21 human tissues revealed high levels of FAM161A expression in the retina and lower levels in the brain and testis. In the human retina, we identified two alternatively spliced transcripts with an intact open reading frame, the major one lacking a highly conserved exon. During mouse embryonic development, low levels of Fam161a transcripts were detected throughout the optic cup. After birth, Fam161a expression was elevated and confined to the photoreceptor layer. FAM161A encodes a protein of unknown function that is moderately conserved in mammals. Clinical manifestations of patients with FAM161A mutations varied but were largely within the spectrum associated with arRP. On funduscopy, pallor of the optic discs and attenuation of blood vessels were common, but bone-spicule-like pigmentation was often mild or lacking. Most patients had nonrecordable electroretinographic responses and constriction of visual fields upon diagnosis. Our data suggest a pivotal role for FAM161A in photoreceptors and reveal that FAM161A loss-of-function mutations are a major cause of arRP, accounting for ∼12% of arRP families in our cohort of patients from Israel and the Palestinian territories.
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Affiliation(s)
- Dikla Bandah-Rozenfeld
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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17
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Bandah-Rozenfeld D, Collin RWJ, Banin E, van den Born LI, Coene KLM, Siemiatkowska AM, Zelinger L, Khan MI, Lefeber DJ, Erdinest I, Testa F, Simonelli F, Voesenek K, Blokland EAW, Strom TM, Klaver CCW, Qamar R, Banfi S, Cremers FPM, Sharon D, den Hollander AI. Mutations in IMPG2, encoding interphotoreceptor matrix proteoglycan 2, cause autosomal-recessive retinitis pigmentosa. Am J Hum Genet 2010; 87:199-208. [PMID: 20673862 DOI: 10.1016/j.ajhg.2010.07.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 06/25/2010] [Accepted: 07/11/2010] [Indexed: 11/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal diseases caused by progressive degeneration of the photoreceptor cells. Using autozygosity mapping, we identified two families, each with three affected siblings sharing large overlapping homozygous regions that harbored the IMPG2 gene on chromosome 3. Sequence analysis of IMPG2 in the two index cases revealed homozygous mutations cosegregating with the disease in the respective families: three affected siblings of Iraqi Jewish ancestry displayed a nonsense mutation, and a Dutch family displayed a 1.8 kb genomic deletion that removes exon 9 and results in the absence of seven amino acids in a conserved SEA domain of the IMPG2 protein. Transient transfection of COS-1 cells showed that a construct expressing the wild-type SEA domain is properly targeted to the plasma membrane, whereas the mutant lacking the seven amino acids appears to be retained in the endoplasmic reticulum. Mutation analysis in ten additional index cases that were of Dutch, Israeli, Italian, and Pakistani origin and had homozygous regions encompassing IMPG2 revealed five additional mutations; four nonsense mutations and one missense mutation affecting a highly conserved phenylalanine residue. Most patients with IMPG2 mutations showed an early-onset form of RP with progressive visual-field loss and deterioration of visual acuity. The patient with the missense mutation, however, was diagnosed with maculopathy. The IMPG2 gene encodes the interphotoreceptor matrix proteoglycan IMPG2, which is a constituent of the interphotoreceptor matrix. Our data therefore show that mutations in a structural component of the interphotoreceptor matrix can cause arRP.
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Affiliation(s)
- Dikla Bandah-Rozenfeld
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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18
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Ayuso C, Millan JM. Retinitis pigmentosa and allied conditions today: a paradigm of translational research. Genome Med 2010; 2:34. [PMID: 20519033 PMCID: PMC2887078 DOI: 10.1186/gm155] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Monogenic human retinal dystrophies are a group of disorders characterized by progressive loss of photoreceptor cells leading to visual handicap. Retinitis pigmentosa is a type of retinal dystrophy where degeneration of rod photoreceptors occurs at the early stages. At present, there are no available effective therapies to maintain or improve vision in patients affected with retinitis pigmentosa, but post-genomic studies are allowing the development of potential therapeutic approaches. This review summarizes current knowledge on genes that have been identified to be responsible for retinitis pigmentosa, the involvement of these genes in the different forms of the disorder, the role of the proteins encoded by these genes in retinal function, the utility of genotyping, and current efforts to develop novel therapies.
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Affiliation(s)
- Carmen Ayuso
- Department of Medical Genetics, IIS-Fundación Jiménez Díaz/CIBERER, Av/Reyes Católicos no, 2; 28040, Madrid, Spain.
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20
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Retinal Pigment Epithelium and Photoreceptor Transplantation Frontiers. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50159-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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21
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Abstract
A nation-wide registration of Danish cases of retinitis pigmentosa (RP) provided 1890 persons diagnosed during the period 1850-1989. Prevalent at 1 January 1988 were 1301 persons (1:3943) comprising a multitude of different RP-types. Age specific prevalence rates demonstrated increasing rates of RP during the first four decades of life and a rather stable prevalence over the next 20-30 years. Corrected for incompleteness, a late decrease was found, reflecting an incomplete ascertainment of the oldest patients. A moving average method indicated an even later steady state value for the age-specific prevalence. The Danish prevalence figures were standardized according to the WHO World Standardized Prevalence Rates and compared with large studies from the USA and UK. No statistically significant difference was found. Usher syndrome was present in 12% of all RP-cases and Bardet-Biedl syndrome comprised 5%. Mental retardation was found in 144 cases (11%), mostly characterized by atypical RP. Nineteen per cent of patients affected by nonsystemic RP had an onset later than 30 years of age, whereas only a few per cent of persons with systemic RP had an RP onset after age 30 years. The Mendelian inheritance type of all cases was evaluated according to an unambiguous genetic classification, finding a larger amount of X-linked RP compared with other studies. Among nonsystemic RP-cases, 14.3% were found to be inherited as an X-linked trait whereas only 8.4% were autosomal dominantly inherited. The largest fraction was, as in previous materials, the simplex group (isolated cases) comprising 42.9% of the nonsystemic RP patients. Some factors influencing the results are discussed, with special emphasis on the problems associated with precise definitions of the Mendelian inheritance groups. A diagram according to the author's definition was constructed as a guideline ready for clinical application.
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Affiliation(s)
- Marianne Haim
- National Eye Clinic for the Visually Impaired, Rymarksvej I, DK-2900 Hellerup, Denmark
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22
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Sung CH, Tai AW. Rhodopsin trafficking and its role in retinal dystrophies. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 195:215-67. [PMID: 10603577 DOI: 10.1016/s0074-7696(08)62706-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We review the sorting/targeting steps involved in the delivery of rhodopsin to the outer segment compartment of highly polarized photoreceptor cells. The transport of rhodopsin includes (1) the sorting/budding of rhodopsin-containing vesicles at the trans-Golgi network, (2) the directional translocation of rhodopsin-bearing vesicles through the inner segment, and (3) the delivery of rhodopsin across the connecting cilium to the outer segment. Several independent lines of evidence suggest that the carboxyl-terminal, cytoplasmic tail of rhodopsin is involved in the post-Golgi trafficking of rhodopsin. Inappropriate subcellular targeting of naturally occurring rhodopsin mutants in vivo leads to photoreceptor cell death. Thus, the genes encoding mutations in the cellular components involved in photoreceptor protein transport are likely candidate genes for retinal dystrophies.
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Affiliation(s)
- C H Sung
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021, USA.
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Abstract
Retinal dystrophies are a heterogeneous group of diseases in which the retina degenerates, leading to either partial or complete blindness. The severe and clearly hereditary forms, retinitis pigmentosa (RP) and various macular degenerations, affect approximately 1 in 3000 people, but many more suffer from aging macular dystrophy in later life. Patients with RP present with narrowing visual fields and night blindness, while those with diseases of the macula lose central vision first. Even before the advent of molecular genetics it was evident that these were heterogeneous disorders, with wide variation in severity, mode of inheritance and phenotype. However, with the widespread application of linkage analysis and mutation detection techniques, a complex underlying pathology has now been revealed. In total, 66 distinct non-overlapping genes or gene loci have been implicated in the various forms of retinal dystrophy, with more being reported regularly in the literature. Within the category of non-syndromic RP alone there are at least 22 genes (and probably many more) involved, with further allelic heterogeneity arising from different mutations in the same gene. This complexity presents a problem for those involved in counselling patients, and also compounds the search for therapies. Nevertheless, several lines of research raise the hope of generic treatments applicable to all such patients, while the greater understanding of normal visual function that arises from genetic studies may open up new avenues for therapy.
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Affiliation(s)
- C F Inglehearn
- Molecular Medicine Unit, St James's University Hospital, Leeds, UK.
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Inglehearn CF, Tarttelin EE, Plant C, Peacock RE, al-Maghtheh M, Vithana E, Bird AC, Bhattacharya SS. A linkage survey of 20 dominant retinitis pigmentosa families: frequencies of the nine known loci and evidence for further heterogeneity. J Med Genet 1998; 35:1-5. [PMID: 9475085 PMCID: PMC1051177 DOI: 10.1136/jmg.35.1.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autosomal dominant retinitis pigmentosa (ADRP) is caused by mutations in two known genes, rhodopsin and peripherin/Rds, and seven loci identified only by linkage analysis. Rhodopsin and peripherin/Rds have been estimated to account for 20-31% and less than 5% of ADRP, respectively. No estimate of frequency has previously been possible for the remaining loci, since these can only be implicated when families are large enough for linkage analysis. We have carried out such analyses on 20 unrelated pedigrees with 11 or more meioses. Frequency estimates based on such a small sample provide only broad approximations, while the above estimations are based on mutation detection in much larger clinic based patient series. However, when markers are informative, linkage analysis cannot fail to detect disease causation at a locus, whereas mutation detection techniques might miss some mutations. Also diagnosing dominant RP from a family history taken in a genetic clinic may not be reliable. It is therefore interesting that 10 (50%) of the families tested have rhodopsin-RP, suggesting that, in large clearly dominant RP pedigrees, rhodopsin may account for a higher proportion of disease than had previously been suspected. Four (20%) map to chromosome 19q, implying that this is the second most common ADRP locus. One maps to chromosome 7p, one to 17p, and one to 17q, while none maps to 1cen, peripherin/Rds, 8q, or 7q. Three give exclusion of all of these loci, showing that while the majority of dominant RP maps to the known loci, a small proportion derives from loci yet to be identified.
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Affiliation(s)
- C F Inglehearn
- Department of Molecular Genetics, Institute of Ophthalmology, London, UK
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Atmaca LS, Sayli BS, Akarsu N, Gündüz K. Genetic features of retinitis pigmentosa in Turkey. Doc Ophthalmol 1995; 89:387-92. [PMID: 7493540 DOI: 10.1007/bf01203714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sixty-two cases with retinitis pigmentosa from 42 index families were investigated to reveal the genetic features of the disease in Turkey. There were 42 propositi of whom 5 had a systemic syndrome associated with retinitis pigmentosa. Of the remaining 37 cases the condition was autosomal recessive in 21 (56.8%), sporadic in 12 (32.4%), autosomal dominant in 3 (8.1%) and X-linked recessive in one (2.7%). Sporadic cases may be more frequent as many hereditary cases are not brought to medical attention in rural families. Male preponderance among sporadic cases may indicate that there may be more X-linked cases. Nine out of 21 cases initially classified as sporadic displayed parental consanguinity and they were included as having autosomal recessive trait. Large families with autosomal recessive inheritance may prove valuable in linkage analysis and in defining future gene abnormalities.
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Affiliation(s)
- L S Atmaca
- Vitreoretinal Department, Faculty of Medicine, Ankara University, Turkey
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Evans K, al-Maghtheh M, Fitzke FW, Moore AT, Jay M, Inglehearn CF, Arden GB, Bird AC. Bimodal expressivity in dominant retinitis pigmentosa genetically linked to chromosome 19q. Br J Ophthalmol 1995; 79:841-6. [PMID: 7488604 PMCID: PMC505271 DOI: 10.1136/bjo.79.9.841] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A clinical, psychophysical, and electrophysiologic study was undertaken of two autosomal dominant retinitis pigmentosa pedigrees with a genetic mutation assigned to chromosome 19q by linkage analysis. Members with the abnormal haplotype were either symptomatic with adolescent onset nyctalopia, restricted visual fields, and non-detectable electroretinographic responses by 30 years of age, or asymptomatic with normal fundus appearance and minimal or no psychophysical or electroretinographic abnormalities. There was no correlation in the severity in parents and their offspring. Pedigree analysis suggested that although the offspring of parents with the genetic mutation were at 50% risk of having the genetic defect, the risk of being symptomatic during a working lifetime was only 31%. Such bimodal phenotypic expressivity in these particular pedigrees may be explained by a second, allelic genetic influence and may be a phenomenon unique to this genetic locus. Genetic counselling in families expressing this phenotype can only be based on haplotype analysis since clinical investigations, even in the most elderly, would not preclude the presence of the mutant gene.
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Affiliation(s)
- K Evans
- Department of Clinical Ophthalmology and Electrodiagnostics, Moorfields Eye Hospital, London
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Evans K, Gregory CY, Fryer A, Whittaker J, Duvall-Young J, Bird AC, Jay MR, Bhattacharya SS. The role of molecular genetics in the prenatal diagnosis of retinal dystrophies. Eye (Lond) 1995; 9 ( Pt 1):24-8. [PMID: 7713246 DOI: 10.1038/eye.1995.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Inherited retinal dystrophies are important causes of incurable blindness in developed countries. Advances in molecular genetics promise significant improvements in their management. Immediate benefits of present knowledge are presymptomatic and prenatal diagnosis in selected cases. To study the predictive power of these techniques a simulated genetic risk estimation was undertaken in a cone-rod retinal dystrophy pedigree known to be linked to chromosome 19. Using data on five fully informative, flanking DNA markers, phenotype was correctly assigned with only a 2% probability of error. If the two most closely linked markers were found to be uninformative, this error probability remained unchanged. Using genetic risk calculations and direct mutation detection many retinal dystrophies could now be identified by prenatal diagnosis.
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Affiliation(s)
- K Evans
- Department of Clinical Ophthalmology, Moorfields Eye Hospital, London, UK
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28
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Aldred MA, Teague PW, Jay M, Bundey S, Redmond RM, Jay B, Bird AC, Bhattacharya SS, Wright AF. Retinitis pigmentosa families showing apparent X linked inheritance but unlinked to the RP2 or RP3 loci. J Med Genet 1994; 31:848-52. [PMID: 7853368 PMCID: PMC1016657 DOI: 10.1136/jmg.31.11.848] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Three families with retinitis pigmentosa (RP) are described in which the disorder shows apparent X linked inheritance but does not show linkage to the RP2 and RP3 regions of the short arm of the X chromosome. The families are also inconsistent with a localisation of the disease gene between DXS164 and DXS28. In one case, reassessment of the family in the light of these results suggested that the family may have an autosomal dominant form of RP. The remaining two families are consistent with X linkage and suggest the possibility of a new X linked RP (XLRP) locus. These families highlight the difficulties in determining the mode of inheritance on the basis of pedigree structure and clinical data alone. Molecular genetics plays an important role in confirming the mode of inheritance and in detecting potential misclassifications, particularly in a group of disorders as heterogeneous as RP. They emphasise that caution is required in genetic counselling of RP families, particularly in the absence of any molecular genetic analysis.
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Affiliation(s)
- M A Aldred
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, UK
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29
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Haim M, Rosenberg T. Retinitis pigmentosa and allied disorders in Denmark. IV. Ophthalmic features in systemic and non-systemic cases. Acta Ophthalmol 1993; 71:597-605. [PMID: 8109205 DOI: 10.1111/j.1755-3768.1993.tb04648.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We analyzed the composition of a retinitis pigmentosa (RP) sample with respect to clinical appearance. The material included 1301 affected persons derived from a national Danish survey with a high degree of completeness. The cases were grouped according to ocular signs and symptoms into typical RP, atypical RP, vitreoretinal RP, chorioretinal dystrophy, and unclassified. The relative frequency with which these groups were nosologically allocated to systemic and non-systemic retinitis pigmentosa is presented. Among 837 cases of non-systemic RP 60% had ophthalmoscopic abnormalities and visual symptoms in accordance with typical RP, 29% were characterized as atypical and 6% presented with chorioretinal dystrophy. The results of earlier epidemiological studies, sex distribution, and new diagnostic concepts based on DNA analysis are discussed.
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Affiliation(s)
- M Haim
- National Eye Clinic for the Visually Impaired, Copenhagen, Denmark
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30
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al-Maghtheh M, Gregory C, Inglehearn C, Hardcastle A, Bhattacharya S. Rhodopsin mutations in autosomal dominant retinitis pigmentosa. Hum Mutat 1993; 2:249-55. [PMID: 8401533 DOI: 10.1002/humu.1380020403] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Retinitis pigmentosa is an inherited progressive disease which is a major cause of blindness in western communities. It can be inherited as an autosomal dominant, autosomal recessive, or X-linked recessive disorder. In the autosomal dominant form (adRP), which comprises about 25% of total cases, approximately 30% of families have mutations in the gene encoding the rod photoreceptor-specific protein rhodopsin. This is the transmembrane protein which, when photoexcited, initiates the visual transduction cascade. So far, 41 single-base-pair (bp) substitutions, one two-bp substitution, and four deletions ranging from 3 to 42 bp have been identified in this gene. These mutations do not appear to be significantly clustered in a specific part of the protein, but occur in all three major domains, namely the intradiscal, transmembrane, and cytoplasmic regions. Different mutations appear to cause differences in the severity of the disease, though there is considerable variability in severity even within the same family, at least in certain of these mutations. Identification of all the mutations involved in rhodopsin-RP should allow accurate and early detection of affected individuals, informed genetic counselling, as well as furthering our knowledge of the disease process involved.
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Affiliation(s)
- M al-Maghtheh
- Department of Molecular Genetics, University of London, England
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31
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Jay M, Bird AC, Moore AN, Jay B. Nine generations of a family with autosomal dominant retinitis pigmentosa and evidence of variable expressivity from census records. J Med Genet 1992; 29:906-10. [PMID: 1479605 PMCID: PMC1016211 DOI: 10.1136/jmg.29.12.906] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We present a nine generation family with autosomal dominant retinitis pigmentosa (ADRP). Evidence of blindness in the early generations, as obtained from census returns and clinical records, and examination of current patients show variable expressivity with a spectrum which ranges from asymptomatic in late life to blindness in the third decade of life. The family is not linked to any of the chromosomal locations so far described in ADRP and further illustrates the heterogeneity of the disorder.
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Affiliation(s)
- M Jay
- Department of Clinical Ophthalmology, Moorfields Eye Hospital, London
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32
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Kaplan J, Pelet A, Martin C, Delrieu O, Aymé S, Bonneau D, Briard ML, Hanauer A, Larget-Piet L, Lefrançois P. Phenotype-genotype correlations in X linked retinitis pigmentosa. J Med Genet 1992; 29:615-23. [PMID: 1357178 PMCID: PMC1016091 DOI: 10.1136/jmg.29.9.615] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Retinitis pigmentosa (RP) represents a group of clinically heterogeneous retinal degenerations in which all modes of inheritance have been described. We have previously found two different clinical profiles in X linked RP as a function of age and mode of onset. The first clinical form has very early onset with severe myopia. The second form starts later with night blindness with mild myopia or none. At least two genes have been identified in X linked forms, namely RP2 (linked to DXS7, DXS255, and DXS14) and RP3 (linked to DXS84 and OTC) on the short arm of the X chromosome. In order to contribute to phenotype-genotype correlations in X linked RP, we tested the hypothesis that the two clinical profiles could be accounted for by the two different gene loci. The present study provides evidence for linkage of the clinical form with early myopia as the onset symptom with the RP2 gene (pairwise linkage to DXS255: Z = 3.13 at theta = 0), while the clinical form with later night blindness as the onset symptom is linked to the RP3 gene (pairwise linkage to OTC: Z = 4.16 at theta = 0).
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Affiliation(s)
- J Kaplan
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant, INSERM U12, Hôpital des Enfants Malades, Paris, France
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33
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Bell C, Converse CA, Collins MF, Esakowitz L, Kelly KF, Haites NE. Autosomal dominant retinitis pigmentosa (ADRP): a rhodopsin mutation in a Scottish family. J Med Genet 1992; 29:667-8. [PMID: 1404299 PMCID: PMC1016102 DOI: 10.1136/jmg.29.9.667] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- C Bell
- Department of Molecular and Cell Biology, University Medical School, Foresterhill, Aberdeen
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34
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Haim M, Holm NV, Rosenberg T. Prevalence of retinitis pigmentosa and allied disorders in Denmark. I Main results. Acta Ophthalmol 1992; 70:178-86. [PMID: 1609565 DOI: 10.1111/j.1755-3768.1992.tb04121.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In a nation-wide study we utilized all available sources to characterize the prevalence rates of retinitis pigmentosa. 1301 persons, 715 males and 586 females, were identified, with a diagnosis of retinitis pigmentosa or some other tapetoretinal dystrophy, and living in Denmark per January 1, 1988. The corresponding completeness corrected prevalence rate of retinitis pigmentosa was 1:3026. All cases were classified as 'certain', 'probable', or 'possible'. The age specific prevalence rates increased until 40-50 years, reaching a level of 35-40 male cases per 100,000 and 25-30 female cases per 100,000. Age specific prevalence rates were standardized to the WHO World Standard Population and compared to rates reported from Britain and The United States. World standardized prevalence rate for males was 25.29 per 100,000 and for females 19.31 per 100,000. The preponderance of males was highly statistically significant, (P less than 0.01).
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Affiliation(s)
- M Haim
- National Eye Clinic for the Visually Impaired, Copenhagen
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35
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Keen TJ, Inglehearn CF, Lester DH, Bashir R, Jay M, Bird AC, Jay B, Bhattacharya SS. Autosomal dominant retinitis pigmentosa: four new mutations in rhodopsin, one of them in the retinal attachment site. Genomics 1991; 11:199-205. [PMID: 1765377 DOI: 10.1016/0888-7543(91)90119-y] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Several mutations in the rhodopsin gene in patients affected by autosomal dominant retinitis pigmentosa (ADRP) have recently been described. We report four new rhodopsin mutations in ADRP families, initially identified as hetero-duplexed PCR fragments on hydrolink gels. One is an in-frame 12-bp deletion of codons 68 to 71. The other three are point mutations involving codons 190, 211, and 296. Each alters the amino acid encoded. The codon 190 mutation has been detected in 2 from a panel of 34 ADRP families, while the remaining mutations were seen in single families. This suggests that, consistent with a dominant condition, no single mutation will account for a large fraction of ADRP cases. The base substitution in codon 296 alters the lysine residue that functions as the attachment site for 11-cis-retinal, mutating it to glutamic acid. This mutation occurs in a family with an unusually severe phenotype, resulting in early onset of disease and cataracts in the third or fourth decade of life. This result demonstrates a correlation between the location of the mutation and the severity of phenotype in rhodopsin RP.
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Affiliation(s)
- T J Keen
- Molecular Genetics Unit, Department of Human Genetics, Newcastle upon Tyne, United Kingdom
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36
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Wright AF, Bhattacharya SS, Aldred MA, Jay M, Carothers AD, Thomas NS, Bird AC, Jay B, Evans HJ. Genetic localisation of the RP2 type of X linked retinitis pigmentosa in a large kindred. J Med Genet 1991; 28:453-7. [PMID: 1895315 PMCID: PMC1016954 DOI: 10.1136/jmg.28.7.453] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Genetic linkage and deletion studies have led to the proposal that there are at least two loci on the X chromosome which are responsible for X linked retinitis pigmentosa (XLRP). One locus (RP3) has been closely defined by genetic linkage and deletion analyses and localised to the region between the ornithine transcarbamylase (OTC) and chronic granulomatous disease (CYBB) loci in Xp21.1-p11.4. The other locus (RP2) has been assigned by linkage analysis alone to region Xp11.4-p11.2, but its localisation is less well defined. The results of a multipoint linkage analysis of a single large XLRP kindred using eight informative loci provide further evidence on the localisation of RP2 to this region. The maximum likelihood location of this locus shows a multipoint lod score of 7.17 close to DXS255 (in Xp11.22) and TIMP (in Xp11.3-p11.23), neither of which show recombination with RP2, in an area extending from 2 cM proximal to DXS7 to 1 cM distal to DXS14 (approximate 95% confidence limits).
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Affiliation(s)
- A F Wright
- Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh
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37
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Inglehearn CF, Bashir R, Lester DH, Jay M, Bird AC, Bhattacharya SS. A 3-bp deletion in the rhodopsin gene in a family with autosomal dominant retinitis pigmentosa. Am J Hum Genet 1991; 48:26-30. [PMID: 1985460 PMCID: PMC1682750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Autosomal dominant retinitis pigmentosa (ADRP) has recently been linked to locus D3S47 (probe C17), with no recombination, in a single large Irish family. Other ADRP pedigrees have shown linkage at zero recombination, linkage with recombination, and no linkage, demonstrating genetic heterogeneity. The gene encoding rhodopsin, the rod photoreceptor pigment, is closely linked to locus D3S47 on chromosome 3q. A point mutation changing a conserved proline to histidine in the 23d codon of the gene has been demonstrated in affected members of one ADRP family and in 17 of 148 unrelated ADRP patients. We have sequenced the rhodopsin gene in a C17-linked ADRP family and have identified in the 4th exon and in-frame 3-bp deletion which deletes one of the two isoleucine monomers at codons 255 and 256. This mutation was not found in 30 other unrelated ADRP families. The deletion has arisen in the sequence TCATCATCAT, deleting one of a run of three x 3-bp repeats. The mechanism by which this occurred may be similar to that which creates length variation in so-called mini- and microsatellites. Thus ADRP is an extremely heterogeneous disorder which can result from a range of defects in rhodopsin and which can have a locus or loci elsewhere in the genome.
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38
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Kaplan J, Bonneau D, Frézal J, Munnich A, Dufier JL. Clinical and genetic heterogeneity in retinitis pigmentosa. Hum Genet 1990; 85:635-42. [PMID: 2227956 DOI: 10.1007/bf00193589] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The clinical course of defective vision and blindness has been investigated in relation to different modes of genetic transmission in a large series of 93 families with retinitis pigmentosa (RP). For autosomal dominant RP, two clinical subtypes could be distinguished according to the delay in macular involvement. In the severe form, macular involvement occurred within 10 years, while in the mild form, macular involvement occurred after 20 years. Interestingly, a significant increase of mean paternal age (38.8 years, mean controls in France = 29.1 years, P less than 0.001) was found in this form of RP, a feature which is suggestive of new mutations. For autosomal recessive RP, four significantly different clinical subtypes could be recognized, according to both age of onset and the pattern of development (P less than 0.001), namely cone-rod dystrophy and early-onset severe forms on the one hand (mean age of onset = 7.6 years), late-onset mild forms and senile forms on the other. Similarly, two significantly different clinical subtypes could be recognized in X-linked RP, according to both mode and age of onset, which were either myopia (mean age = 3.5 +/- 0.5 years) or night blindness (mean age = 10.6 +/- 4.1 years. P less than 0.001). By contrast, no difference was noted regarding the clinical course of the disease, which was remarkably severe whatever the clinical subtype (blindness before 25 years). In addition, all obligate carriers in our series were found to have either severe myopia or pigment deposits in their peripheral retina. Finally, sporadic RP represented the majority of cases in our series (42%). There was a considerable heterogeneity in this group, and at least three clinical forms could be recognized, namely cone-rod dystrophy, early onset-severe forms and late onset moderate forms. At the beginning of the disease, the hereditary nature of the sporadic forms was very difficult to ascertain (especially between 7-10 years) and only the clinical course could possibly provide information regarding the mode of inheritance. However, the high level of consanguinity, and the high sex ratio in early onset and severe sporadic forms (including cone-rod dystrophy), was suggestive of an autosomal or X-linked recessive inheritance, while increased paternal age in late onset forms was suggestive of autosomal dominant mutations.
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Affiliation(s)
- J Kaplan
- Clinique de Génétique Médicale, Unité de Recherches sur les Handicaps Génétiques de l'Enfant, INSERM U.12, Hôpital des Enfants-Malades, Paris, France
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39
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Lester DH, Inglehearn CF, Bashir R, Ackford H, Esakowitz L, Jay M, Bird AC, Wright AF, Papiha SS, Bhattacharya SS. Linkage to D3S47 (C17) in one large autosomal dominant retinitis pigmentosa family and exclusion in another: confirmation of genetic heterogeneity. Am J Hum Genet 1990; 47:536-41. [PMID: 2393026 PMCID: PMC1683865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recently Dryja and his co-workers observed a mutation in the 23d codon of the rhodopsin gene in a proportion of autosomal dominant retinitis pigmentosa (ADRP) patients. Linkage analysis with a rhodopsin-linked probe C17 (D3S47) was carried out in two large British ADRP families, one with diffuse-type (D-type) RP and the other with regional-type (R-type) RP. Significantly positive lod scores (lod score maximum [Zmax] = +5.58 at recombination fraction [theta] = .0) were obtained between C17 and our D-type ADRP family showing complete penetrance. Sequence and oligonucleotide analysis has, however, shown that no point mutation at the 23d codon exists in affected individuals in our complete-penetrance pedigree, indicating that another rhodopsin mutation is probably responsible for ADRP in this family. Significantly negative lod scores (Z less than -2 at theta = .045) were, however, obtained between C17 and our R-type family which showed incomplete penetrance. Previous results presented by this laboratory also showed no linkage between C17 and another large British R-type ADRP family with incomplete penetrance. This confirms genetic heterogeneity. Some types of ADRP are being caused by different mutations in the rhodopsin locus (3q21-24) or another tightly linked gene in this region, while other types of ADRP are the result of mutations elsewhere in the genome.
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Affiliation(s)
- D H Lester
- Department of Human Genetics, University of Newcastle upon Tyne, England
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40
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41
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Inglehearn CF, Jay M, Lester DH, Bashir R, Jay B, Bird AC, Wright AF, Evans HJ, Papiha SS, Bhattacharya SS. No evidence for linkage between late onset autosomal dominant retinitis pigmentosa and chromosome 3 locus D3S47 (C17): evidence for genetic heterogeneity. Genomics 1990; 6:168-73. [PMID: 2303257 DOI: 10.1016/0888-7543(90)90462-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Retinitis pigmentosa is an inherited form of blindness caused by progressive retinal degeneration. P. McWilliam et al. (1989, Genomics 5: 619-622) demonstrated close genetic linkage between autosomal dominant retinitis pigmentosa (ADRP) and locus D3S47 (C17) in a single early onset pedigree. The marker C17 maps to the long arm of chromosome 3. Clinically, the disease phenotype has been subdivided into at least two forms on the basis of age of onset, as well as electrodiagnostic criteria. We demonstrate that C17 is unlinked in a late onset pedigree, indicating that the phenotypic variation seen reflects underlying genetic heterogeneity.
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Affiliation(s)
- C F Inglehearn
- Molecular Genetics Unit, University of Newcastle upon Tyne, United Kingdom
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42
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Abstract
Over a ten year period of running a joint ophthalmological/genetic clinic, 387 index patients were advised, and a further 260 individuals (relatives of the above) were examined and counselled. Determination of the precise diagnoses and modes of inheritance in the index patients necessitated retinal function tests in 267 (69%) and examination of 84 of their parents and 23 sisters and daughters. Finally, 41% of index patients and 39% of their relatives were given high risks for transmitting an autosomal dominant or X-linked disorder to their children. It is noteworthy that 16% of these high-risk index patients and 66% of these high-risk relatives had no visual symptoms; ophthalmological expertise was required to assess the significance of their minor signs. It was concluded that an active Register is required for contacting relatives outside the nuclear family, and for future recall of children currently too young for carrier tests or genetic counselling.
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Affiliation(s)
- S Bundey
- Regional Clinical Genetics Unit, Birmingham Maternity Hospital, Edgbaston
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43
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Abstract
Retinitis pigmentosa is a clinically and genetically heterogeneous group of hereditary disorders in which there is progressive loss of photoreceptor and pigment epithelial function. The prevalence of retinitis pigmentosa is between 1/3000 and 1/5000 making it one of the most common causes of visual impairment in all age groups. The natural history, differential diagnosis, diagnostic clinical and electrophysiologic findings are reviewed. Generalization about the different genetic subtypes of retinitis pigmentosa are reviewed along with the uses of DNA probes for linkage studies. Syndromes in which retinitis pigmentosa is a manifestation are summarized.
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Affiliation(s)
- R A Pagon
- Department of Pediatrics, University of Washington School of Medicine, Seattle
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44
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Farrar GJ, Geraghty MT, Moloney JM, McConnell DJ, Humphries P. Linkage analysis of X linked retinitis pigmentosa in the Irish population. J Med Genet 1988; 25:222-6. [PMID: 3163380 PMCID: PMC1015500 DOI: 10.1136/jmg.25.4.222] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
There is significant evidence for genetic and phenotypic heterogeneity in X linked retinitis pigmentosa (XLRP). We have studied the linkage of XLRP in four Irish families to a number of polymorphic DNA markers. We report linkage between the DXS7 (L1.28) locus and the XLRP locus (Z = 3.445, theta = 0.00). Combined with the previously published data on British and Danish families, the genetic distance between the DXS7 and XLRP loci is now estimated at 5 cM with a maximum lod score of 13.026 and a 1-lod confidence interval of 0.75 to 9.5 cM. Linkage was also observed between 754 and XLRP (Z = 3.41, theta = 0.00) and between pERT87 and XLRP (Z = 1.37, theta = 0.1). The heterogeneity of XLRP is discussed in relation to these observations.
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Affiliation(s)
- G J Farrar
- Genetics Department, Trinity College Dublin, Ireland
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45
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Abstract
Retinitis pigmentosa was diagnosed in 101 persons from 53 families. The prognosis for visual function was most favourable for the autosomal dominant group (38 patients from 8 families). The autosomal recessive group (40 patients from 25 families) and the 19 solitary cases were very heterogeneous, with prognosis ranging from favourable to very bad. There was a higher intrafamiliar correlation in the autosomal recessive than in the autosomal dominant group. In 28 patients from 18 families with Usher syndrome, almost all had good visual function until 30 years of age, and few had useful visual function after the age of 50. The age when the patients were registered varied between the different genetic types of retinitis pigmentosa, reflecting differences in prognosis. Therefore, ascertainment probability and prevalence were calculated for each genetic group separately. The prevalence of retinitis pigmentosa in Norway, all genetic groups included, was calculated to be 1/4440, the autosomal dominant type of the disease being the most frequent. The prevalence of Usher syndrome was calculated to be 3.6/100,000. Both retinitis pigmentosa and Usher syndrome were more prevalent in Laps.
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46
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Beaty TH, Boughman JA. Problems in detecting etiological heterogeneity in genetic disease illustrated with retinitis pigmentosa. AMERICAN JOURNAL OF MEDICAL GENETICS 1986; 24:493-504. [PMID: 3728568 DOI: 10.1002/ajmg.1320240312] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Simulated data were generated under four etiologic mechanisms for each of 20 different pedigree structures drawn from a study of families ascertained through a proband with retinitis pigmentosa. These simulated data were then used to identify subgroups of pedigrees which best supported each of three genetic mechanisms (autosomal dominant, autosomal recessive, X-linked recessive with 10% penetrance of disease in heterozygous females) and a non-genetic, sporadic mechanism. Results of these studies show that pedigrees identified as supporting one genetic model in a 'model choice' approach tend to be etiologically homogeneous, but are not truly representative of all the phenotypic combinations possible under that mechanism. The problem of etiologic heterogeneity is most acute when dealing with pedigrees less than size 10. Pedigrees lumped under a non-genetic, sporadic mechanism are extremely heterogeneous and studies of the natural history of diseases where both genetic and non-genetic mechanisms may be operating (such as with retinitis pigmentosa) should avoid using this group of largely simplex pedigrees.
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47
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Khoury MJ, Beaty TH, Cohen BH. The interface of genetics and epidemiology. JOURNAL OF CHRONIC DISEASES 1986; 39:963-78. [PMID: 3539975 DOI: 10.1016/0021-9681(86)90134-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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