1
|
Daich Varela M, Jeste M, de Guimaraes TAC, Mahroo OA, Arno G, Webster AR, Michaelides M. Clinical, Ophthalmic, and Genetic Characterization of RPGRIP1-Associated Leber Congenital Amaurosis/Early-Onset Severe Retinal Dystrophy. Am J Ophthalmol 2024; 266:255-263. [PMID: 38768745 DOI: 10.1016/j.ajo.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE To present the clinical characteristics, retinal features, natural history, and genetics of RPGRIP1-associated early-onset severe retinal dystrophy (EOSRD)/Leber congenital amaurosis (LCA). DESIGN Retrospective case series. METHODS Review of clinical notes, multimodal retinal imaging, and molecular diagnosis of 18 patients (17 families) with EOSRD/LCA and disease-causing variants in RPGRIP1. RESULTS The mean age of visual symptoms onset was 0.87 ± 1 year (birth to 3 years), and the mean age at baseline visit was 11.4 ± 10.2 years (1-39 years). At the baseline visit, 44% of patients were legally blind (range, 2-39 years), and there was no significant association found between age and best-corrected visual acuity (BCVA) in cross-sectional analysis. Retinal evaluation showed an abolished electroretinogram or a cone-rod dystrophy pattern, no or minimal pigment deposits, a hyperautofluorescent ring at the posterior pole, and a largely preserved central macular architecture, with retained outer nuclear layer and ellipsoid zone island into adulthood. Eleven variants (48%) were previously unreported, and 13 families (76%) had a double-null (DN) genotype. Twelve patients (67%) had follow-up assessments over a 15.7 ± 9.5-year period. The rate of BCVA decline was 0.02 logarithm of the minimum angle of resolution (1 letter)/year. CONCLUSIONS RPGRIP1 EOSRD/LCA often presents at birth or early infancy, with nystagmus, decreased visual acuity, hyperopia, and photophobia. Patients with a DN genotype may develop symptoms earlier and have worse vision. Multimodal imaging may show a hyperautofluorescent posterior pole ring and relatively preserved central macular architecture, suggesting that the condition is a promising candidate for gene supplementation.
Collapse
Affiliation(s)
- Malena Daich Varela
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom
| | - Mrunmayi Jeste
- St Thomas' Hospital (M.J., O.A.M), London, United Kingdom
| | - Thales A C de Guimaraes
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom
| | - Omar A Mahroo
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; St Thomas' Hospital (M.J., O.A.M), London, United Kingdom
| | - Gavin Arno
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., T.A.C.deG., O.A.M., G.A., A.R.W., M.M.), London, United Kingdom.
| |
Collapse
|
2
|
Ruggeri F, Ciancimino C, Guillot A, Fumi D, Tizio FD, Fragiotta S, Abdolrahimzadeh S. Posterior Polar Annular Choroidal Dystrophy: Genetic Insights and Differential Diagnosis in Inherited Retinal Diseases. Curr Issues Mol Biol 2024; 46:1383-1397. [PMID: 38392207 PMCID: PMC10887594 DOI: 10.3390/cimb46020089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/28/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
Posterior polar annular choroidal dystrophy (PPACD) is a rare ocular disorder and presents as symmetric degeneration of the retinal pigment epithelium (RPE) and the underlying choriocapillaris, encircling the retinal vascular arcades and optic disc. This condition distinctively preserves the foveal region, optic disc, and the outermost regions of the retina. Despite its distinct clinical presentation, due to the infrequency of its occurrence and the limited number of reported cases, the pathophysiology, and the genetic foundations of PPACD are still largely uncharted. This review aims to bridge this knowledge gap by investigating potential genetic contributors to PPACD, assessing current findings, and identifying genes that warrant further study. Emphasis is also placed on the crucial role of multimodal imaging in diagnosing PPACD, highlighting its importance in understanding disease pathophysiology. By analyzing existing case reports and drawing comparisons with similar retinal disorders, this paper endeavors to delineate the possible genetic correlations in PPACD, providing a foundation for future genetic research and the development of targeted diagnostic strategies.
Collapse
Affiliation(s)
- Francesco Ruggeri
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Chiara Ciancimino
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Antonio Guillot
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Daniele Fumi
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
| | - Federico Di Tizio
- St. Andrea Hospital, Via di Grottarossa 1035/1039, 00189 Rome, Italy
| | - Serena Fragiotta
- UOC Ophthalmology, Department of Surgical Areas, S.M. Goretti Hospital, 04100 Latina, Italy
| | - Solmaz Abdolrahimzadeh
- Ophthalmology Unit, Neurosciences, Mental Health, and Sense Organs (NESMOS) Department, Faculty of Medicine and Psychology, University of Rome Sapienza, 00185 Roma, Italy
- St. Andrea Hospital, Via di Grottarossa 1035/1039, 00189 Rome, Italy
| |
Collapse
|
3
|
Beryozkin A, Aweidah H, Carrero Valenzuela RD, Berman M, Iguzquiza O, Cremers FPM, Khan MI, Swaroop A, Amer R, Khateb S, Ben-Yosef T, Sharon D, Banin E. Retinal Degeneration Associated With RPGRIP1: A Review of Natural History, Mutation Spectrum, and Genotype-Phenotype Correlation in 228 Patients. Front Cell Dev Biol 2021; 9:746781. [PMID: 34722527 PMCID: PMC8551679 DOI: 10.3389/fcell.2021.746781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 09/15/2021] [Indexed: 12/03/2022] Open
Abstract
Purpose:RPGRIP1 encodes a ciliary protein expressed in the photoreceptor connecting cilium. Mutations in this gene cause ∼5% of Leber congenital amaurosis (LCA) worldwide, but are also associated with cone–rod dystrophy (CRD) and retinitis pigmentosa (RP) phenotypes. Our purpose was to clinically characterize RPGRIP1 patients from our cohort, collect clinical data of additional RPGRIP1 patients reported previously in the literature, identify common clinical features, and seek genotype–phenotype correlations. Methods: Clinical data were collected from 16 patients of our cohort and 212 previously reported RPGRIP1 patients and included (when available) family history, best corrected visual acuity (BCVA), refraction, comprehensive ocular examination, optical coherence tomography (OCT) imaging, visual fields (VF), and full-field electroretinography (ffERG). Results: Out of 228 patients, the majority (197, 86%) were diagnosed with LCA, 18 (7%) with RP, and 13 (5%) with CRD. Age of onset was during early childhood (n = 133, average of 1.7 years). All patients but 6 had moderate hyperopia (n = 59, mean of 4.8D), and average BCVA was 0.06 Snellen (n = 124; only 10 patients had visual acuity [VA] > 0.10 Snellen). On funduscopy, narrowing of blood vessels was noted early in life. Most patients had mild bone spicule-like pigmentation starting in the midperiphery and later encroaching upon the posterior pole. OCT showed thinning of the outer nuclear layer (ONL), while cystoid changes and edema were relatively rare. VF were usually very constricted from early on. ffERG responses were non-detectable in the vast majority of cases. Most of the mutations are predicted to be null (363 alleles), and 93 alleles harbored missense mutations. Missense mutations were identified only in two regions: the RPGR-interacting domain and the C2 domains. Biallelic null mutations are mostly associated with a severe form of the disease, whereas biallelic missense mutations usually cause a milder disease (mostly CRD). Conclusion: Our results indicate that RPGRIP1 biallelic mutations usually cause severe retinal degeneration at an early age with a cone–rod pattern. However, most of the patients exhibit preservation of some (usually low) BCVA for a long period and can potentially benefit from gene therapy. Missense changes appear only in the conserved domains and are associated with a milder phenotype.
Collapse
Affiliation(s)
- Avigail Beryozkin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hamzah Aweidah
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Myriam Berman
- Ophthalmology, Clinical Department, Faculty of Medicine, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Oscar Iguzquiza
- Neurology, Clinical Department, Faculty of Medicine, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Radgonde Amer
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Ben-Yosef
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
4
|
Sallum JMF, Motta FL, Arno G, Porto FBO, Resende RG, Belfort R. Clinical and molecular findings in a cohort of 152 Brazilian severe early onset inherited retinal dystrophy patients. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:728-752. [PMID: 32865313 DOI: 10.1002/ajmg.c.31828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022]
Abstract
Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD) are severe inherited retinal dystrophy that can cause deep blindness childhood. They represent 5% of all retinal dystrophies in the world population and about 10% in Brazil. Clinical findings and molecular basis of syndromic and nonsyndromic LCA/EORD in a Brazilian sample (152 patients/137 families) were studied. In this population, 15 genes were found to be related to the phenotype, 38 new variants were detected and four new complex alleles were discovered. Among 123 variants found, the most common were CEP290: c.2991+1655A>G, CRB1: p.Cys948Tyr, and RPGRIP1: exon10-18 deletion.
Collapse
Affiliation(s)
- Juliana Maria Ferraz Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Fabiana Louise Motta
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Gavin Arno
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | - Fernanda Belga Ottoni Porto
- INRET Clínica e Centro de Pesquisa, Belo Horizonte, Minas Gerais, Brazil.,Centro Oftalmológico de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Rubens Belfort
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil
| |
Collapse
|
5
|
Imani S, Cheng J, Mobasher‐Jannat A, Wei C, Fu S, Yang L, Jadidi K, Khosravi MH, Mohazzab‐Torabi S, Shasaltaneh MD, Li Y, Chen R, Fu J. Identification of a novel RPGRIP1 mutation in an Iranian family with leber congenital amaurosis by exome sequencing. J Cell Mol Med 2018; 22:1733-1742. [PMID: 29193763 PMCID: PMC5824405 DOI: 10.1111/jcmm.13454] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/13/2017] [Indexed: 12/18/2022] Open
Abstract
Leber congenital amaurosis (LCA) is a heterogeneous, early-onset inherited retinal dystrophy, which is associated with severe visual impairment. We aimed to determine the disease-causing variants in Iranian LCA and evaluate the clinical implications. Clinically, a possible LCA disease was found through diagnostic imaging, such as fundus photography, autofluorescence and optical coherence tomography. All affected patients showed typical eye symptoms associated with LCA including narrow arterioles, blindness, pigmentary changes and nystagmus. Target exome sequencing was performed to analyse the proband DNA. A homozygous novel c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene was identified, which was likely the deleterious and pathogenic mutation in the proband. Structurally, this mutation lost a retinitis pigmentosa GTPase regulator (RPGR)-interacting domain at the C-terminus which most likely impaired stability in the RPGRIP1 with the distribution of polarised proteins in the cilium connecting process. Sanger sequencing showed complete co-segregation in this pedigree. This study provides compelling evidence that the c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene works as a pathogenic mutation that contributes to the progression of LCA.
Collapse
Affiliation(s)
- Saber Imani
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
- Hunan Normal University Medical CollegeChangshaHunanChina
- Chemical Injuries Research CenterBaqiyatallah University of Medical SciencesTehranIran
| | - Jingliang Cheng
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Abdolkarim Mobasher‐Jannat
- Chemical Injuries Research CenterBaqiyatallah University of Medical SciencesTehranIran
- Student Research CommitteeBaqiyatallah University of Medical SciencesTehran Iran
| | - Chunli Wei
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Shangyi Fu
- The Honors CollegeUniversity of HoustonHoustonTXUSA
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Lisha Yang
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Khosrow Jadidi
- Department of OphthalmologyBaqiyatallah University of Medical SciencesTehranIran
| | | | - Saman Mohazzab‐Torabi
- Eye Research CenterFarabi Eye HospitalTehran University of Medical SciencesTehranIran
| | - Marzieh Dehghan Shasaltaneh
- Laboratory of Neuro‐organic ChemistryInstitute of Biochemistry and Biophysics (IBB)University of TehranTehranIran
- Laboratory of Systems Biology and Bioinformatics (LBB)Institute of Biochemistry and BiophysicsUniversity of TehranTehranIran
| | - Yumei Li
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Rui Chen
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Junjiang Fu
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
- Hunan Normal University Medical CollegeChangshaHunanChina
| |
Collapse
|
6
|
Eblimit A, Agrawal SA, Thomas K, Anastassov IA, Abulikemu T, Moayedi Y, Mardon G, Chen R. Conditional loss of Spata7 in photoreceptors causes progressive retinal degeneration in mice. Exp Eye Res 2018; 166:120-130. [PMID: 29100828 PMCID: PMC5756513 DOI: 10.1016/j.exer.2017.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/31/2022]
Abstract
The mammalian retina consists of multiple cell layers including photoreceptor cells, which are light sensing neurons that play essential functions in the visual process. Previously, we identified mutations in SPATA7, encoding spermatogenesis associated protein 7, in families with Leber Congenital Amaurosis (LCA) and juvenile Retinitis Pigmentosa (RP), and showed that Spata7 null mice recapitulate the human disease phenotype of retinal degeneration. SPATA7 is expressed in the connecting cilium of photoreceptor (PR) cells in the mouse retina, as well as in retinal pigment epithelium (RPE) cells, but the functional role of Spata7 in the RPE remains unknown. To investigate whether Spata7 is required in PRs, the RPE, or both, we conditionally knocked out Spata7 in photoreceptors and RPE cells using Crx-Cre and Best1-Cre transgenic mouse lines, respectively. In Spata7 photoreceptor-specific conditional (cKO) mice, both rod and cone photoreceptor dysfunction and degeneration is observed, characterized by progressive thinning of the outer nuclear layer and reduced response to light; however, RPE-specific deletion of Spata7 does not impair retinal function or cell survival. Furthermore, our findings show that both Rhodopsin and RPGRIP1 are mislocalized in the Spata7Flox/-; Crx-Cre cKO mice, suggesting that loss of Spata7 in photoreceptors alone can result in altered trafficking of these proteins in the connecting cilium. Together, our findings suggest that loss of Spata7 in photoreceptors alone is sufficient to cause photoreceptor degeneration, but its function in the RPE is not required for photoreceptor survival; therefore, loss of Spata7 in photoreceptors alters both rod and cone function and survival, consistent with the clinical phenotypes observed in LCA and RP patients with mutations in SPATA7.
Collapse
Affiliation(s)
- Aiden Eblimit
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Smriti Akshay Agrawal
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Kandace Thomas
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Ivan Assenov Anastassov
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Tajiguli Abulikemu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA; The Key Laboratory of Plant Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, Xinjiang, 830011, China
| | | | - Graeme Mardon
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030-3411, USA.
| | - Rui Chen
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA.
| |
Collapse
|
7
|
Li T. Leber congenital amaurosis caused by mutations in RPGRIP1. Cold Spring Harb Perspect Med 2014; 5:cshperspect.a017384. [PMID: 25414380 DOI: 10.1101/cshperspect.a017384] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recessive null mutations in retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1) gene are the cause of LCA6 and account for 5% to 6% of the total patient population. RPGRIP1 has an essential role in the photoreceptor connecting cilia, and photoreceptors lacking RPGRIP1 are unable to maintain the light sensing outer segments. As a result, patients lose retinal functions at an early age but retain photoreceptors in the central retina well into adulthood thus holding out the prospect for gene augmentation therapies. Laboratory studies in animal models have demonstrated efficacy of gene therapy in slowing disease progression. With further refinement in the design of the replacement gene construct, clinical trials for Leber congenital amaurosis (LCA) caused by RPGRIP1 mutations could be in the offing in the near future.
Collapse
Affiliation(s)
- Tiansen Li
- Retinal Cell Biology and Degeneration Section, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, Bethesda, Maryland 20892
| |
Collapse
|
8
|
A novel exon 17 deletion mutation of RPGRIP1 gene in two siblings with Leber congenital amaurosis. Jpn J Ophthalmol 2014; 58:528-35. [DOI: 10.1007/s10384-014-0339-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 06/30/2014] [Indexed: 11/25/2022]
|
9
|
Janicijevic-Petrovic MA, Sarenac-Vulovic TS, Janicijevic KM, Vujic DI, Vulovic DD. Congenital blindness and visual impairment cause infection or non infection. Mater Sociomed 2013; 25:101-4. [PMID: 24082833 PMCID: PMC3769158 DOI: 10.5455/msm.2013.25.101-104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 03/25/2013] [Indexed: 12/04/2022] Open
Abstract
Conflict of interest: none declared.
Collapse
|
10
|
Khan AO, Abu-Safieh L, Eisenberger T, Bolz HJ, Alkuraya FS. TheRPGRIP1-related retinal phenotype in children. Br J Ophthalmol 2013; 97:760-4. [DOI: 10.1136/bjophthalmol-2012-303050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
11
|
Busse C, Barnett KC, Mellersh CS, Adams VJ. Ophthalmic and cone derived electrodiagnostic findings in outbred Miniature Long-haired Dachshunds homozygous for a RPGRIP1 mutation. Vet Ophthalmol 2011; 14:146-52. [PMID: 21521437 DOI: 10.1111/j.1463-5224.2010.00848.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate ophthalmic and cone-derived electrodiagnostic findings in outbred Miniature Long-haired Dachshunds (MLHD) homozygous for a mutation in the RPGRIP1 gene previously associated with cone-rod dystrophy 1 (cord1). ANIMALS A total of 36 MLHD homozygous for the RPGRIP1 mutation and 23 dogs clear of the mutation (control group). PROCEDURES The dogs underwent ophthalmic examination and photopic electroretinogram (ERG) recordings. RESULTS None of the control dogs presented with clinical or ophthalmic signs consistent with cord1. Amongst the dogs homozygous for the mutation one presented with bilateral symmetrical total retinal atrophy. None of the other dogs in this group showed signs consistent with cord1. Photopic ERG recordings were available in 23 control dogs and 34 dogs homozygous for the mutation. Photopic a- and b-waves following four light stimuli (3 cdS/m(2) ) at a rate of 5.1 Hz were not significantly different between groups. The amplitudes of the 30 Hz flicker (128 flashes, 3 cdS/m(2) ) response were significantly reduced in the dogs homozygous for the PRGRIP1 mutation. The difference in age between the two groups did not significantly affect the difference. CONCLUSION Homozygosity of the RPGRIP1 mutation does not invariably result in early onset cord1. However, cone derived ERG recordings show evidence of a reduced cone or inner retinal function in homozygous but clinically normal MLHD. Modifying genes that have yet to be identified may influence an individual dog's risk of developing the blinding cord1 and also the age of onset and rate of progression.
Collapse
|
12
|
Mockel A, Perdomo Y, Stutzmann F, Letsch J, Marion V, Dollfus H. Retinal dystrophy in Bardet-Biedl syndrome and related syndromic ciliopathies. Prog Retin Eye Res 2011; 30:258-74. [PMID: 21477661 DOI: 10.1016/j.preteyeres.2011.03.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/03/2011] [Accepted: 03/04/2011] [Indexed: 01/26/2023]
Abstract
Primary cilia are almost ubiquitously expressed in eukaryotic cells where they function as sensors relaying information either from the extracellular environment or between two compartments of the same cell, such as in the photoreceptor cell. In ciliopathies, a continuously growing class of genetic disorders related to ciliary defects, the modified primary cilium of the photoreceptor, also known as the connecting cilium, is frequently defective. Ciliary dysfunction involves disturbances in the trafficking and docking of specific proteins involved in its biogenesis or maintenance. The main well-conserved ciliary process, intraflagellar transport (IFT), is a complex process carried out by multimeric ciliary particles and molecular motors of major importance in the photoreceptor cell. It is defective in a growing number of ciliopathies leading to retinal degeneration. Retinitis pigmentosa related to ciliary dysfunction can be an isolated feature or a part of a syndrome such as Bardet-Biedl syndrome (BBS). Research on ciliopathies and BBS has led to the discovery of several major cellular processes carried out by the primary cilium structure and has highlighted their genetic heterogeneity.
Collapse
Affiliation(s)
- A Mockel
- Laboratoire de physiopathologie des syndromes rares et héréditaires, Strasbourg, France
| | | | | | | | | | | |
Collapse
|
13
|
Pawlyk BS, Bulgakov OV, Liu X, Xu X, Adamian M, Sun X, Khani SC, Berson EL, Sandberg MA, Li T. Replacement gene therapy with a human RPGRIP1 sequence slows photoreceptor degeneration in a murine model of Leber congenital amaurosis. Hum Gene Ther 2011; 21:993-1004. [PMID: 20384479 DOI: 10.1089/hum.2009.218] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
RPGR-interacting protein-1 (RPGRIP1) is localized in the photoreceptor-connecting cilium, where it anchors the RPGR (retinitis pigmentosa GTPase regulator) protein, and its function is essential for photoreceptor maintenance. Genetic defect in RPGRIP1 is a known cause of Leber congenital amaurosis (LCA), a severe, early-onset form of retinal degeneration. We evaluated the efficacy of replacement gene therapy in a murine model of LCA carrying a targeted disruption of RPGRIP1. The replacement construct, packaged in an adeno-associated virus serotype 8 (AAV8) vector, used a rhodopsin kinase gene promoter to drive RPGRIP1 expression. Both promoter and transgene were of human origin. After subretinal delivery of the replacement gene in the mutant mice, human RPGRIP1 was expressed specifically in photoreceptors, localized correctly in the connecting cilia, and restored the normal localization of RPGR. Electroretinogram and histological examinations showed better preservation of rod and cone photoreceptor function and improved photoreceptor survival in the treated eyes. This study demonstrates the efficacy of human gene replacement therapy and validates a gene therapy design for future clinical trials in patients afflicted with this condition. Our results also have therapeutic implications for other forms of retinal degenerations attributable to a ciliary defect.
Collapse
Affiliation(s)
- Basil S Pawlyk
- Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, and Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Gerner M, Haribaskar R, Pütz M, Czerwitzki J, Walz G, Schäfer T. The retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1) links RPGR to the nephronophthisis protein network. Kidney Int 2010; 77:891-6. [DOI: 10.1038/ki.2010.27] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
15
|
Kennedy B, Malicki J. What drives cell morphogenesis: a look inside the vertebrate photoreceptor. Dev Dyn 2009; 238:2115-38. [PMID: 19582864 DOI: 10.1002/dvdy.22010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Vision mediating photoreceptor cells are specialized light-sensitive neurons in the outer layer of the vertebrate retina. The human retina contains approximately 130 million of such photoreceptors, which enable images of the external environment to be captured at high resolution and high sensitivity. Rod and cone photoreceptor subtypes are further specialized for sensing light in low and high illumination, respectively. To enable visual function, these photoreceptors have developed elaborate morphological domains for the detection of light (outer segments), for changing cell shape (inner segments), and for communication with neighboring retinal neurons (synaptic terminals). Furthermore, rod and cone subtypes feature unique morphological variations of these specialized characteristics. Here, we review the major aspects of vertebrate photoreceptor morphology and key genetic mechanisms that drive their formation. These mechanisms are necessary for cell differentiation as well as function. Their defects lead to cell death.
Collapse
Affiliation(s)
- Breandán Kennedy
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.
| | | |
Collapse
|
16
|
Keller LC, Geimer S, Romijn E, Yates J, Zamora I, Marshall WF. Molecular architecture of the centriole proteome: the conserved WD40 domain protein POC1 is required for centriole duplication and length control. Mol Biol Cell 2009; 20:1150-66. [PMID: 19109428 PMCID: PMC2642750 DOI: 10.1091/mbc.e08-06-0619] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 11/12/2008] [Accepted: 12/08/2008] [Indexed: 12/11/2022] Open
Abstract
Centrioles are intriguing cylindrical organelles composed of triplet microtubules. Proteomic data suggest that a large number of proteins besides tubulin are necessary for the formation and maintenance of a centriole's complex structure. Expansion of the preexisting centriole proteome from the green alga Chlamydomonas reinhardtii revealed additional human disease genes, emphasizing the significance of centrioles in normal human tissue homeostasis. We found that two classes of ciliary disease genes were highly represented among the basal body proteome: cystic kidney disease (especially nephronophthisis) syndromes, including Meckel/Joubert-like and oral-facial-digital syndrome, caused by mutations in CEP290, MKS1, OFD1, and AHI1/Jouberin proteins and cone-rod dystrophy syndrome genes, including UNC-119/HRG4, NPHP4, and RPGR1. We further characterized proteome of the centriole (POC) 1, a highly abundant WD40 domain-containing centriole protein. We found that POC1 is recruited to nascent procentrioles and localizes in a highly asymmetrical pattern in mature centrioles corresponding to sites of basal-body fiber attachment. Knockdown of POC1 in human cells caused a reduction in centriole duplication, whereas overexpression caused the appearance of elongated centriole-like structures. Together, these data suggest that POC1 is involved in early steps of centriole duplication as well as in the later steps of centriole length control.
Collapse
Affiliation(s)
- Lani C. Keller
- *Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Stefan Geimer
- Zellbiologie/Elektronenmikroskopie, Universitaet Bayreuth, 95440 Bayreuth, Germany; and
| | - Edwin Romijn
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - John Yates
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Ivan Zamora
- *Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Wallace F. Marshall
- *Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| |
Collapse
|
17
|
Colella P, Cotugno G, Auricchio A. Ocular gene therapy: current progress and future prospects. Trends Mol Med 2008; 15:23-31. [PMID: 19097940 DOI: 10.1016/j.molmed.2008.11.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 11/04/2008] [Accepted: 11/04/2008] [Indexed: 12/16/2022]
Abstract
As gene therapy begins to produce its first clinical successes, interest in ocular gene transfer has grown owing to the favorable safety and efficacy characteristics of the eye as a target organ for drug delivery. Important advances also include the availability of viral and non-viral vectors that are able to efficiently transduce various ocular cell types, the use of intraocular delivery routes and the development of transcriptional regulatory elements that allow sustained levels of gene transfer in small and large animal models after a single administration. Here, we review recent progress in the field of ocular gene therapy. The first experiments in humans with severe inherited forms of blindness seem to confirm the good safety and efficacy profiles observed in animal models and suggest that gene transfer has the potential to become a valuable therapeutic strategy for otherwise untreatable blinding diseases.
Collapse
Affiliation(s)
- Pasqualina Colella
- Telethon Institute of Genetics and Medicine (TIGEM), Via Pietro Castellino 111, 80131 Naples, Italy
| | | | | |
Collapse
|
18
|
Abstract
While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present.
Collapse
Affiliation(s)
- N A Adams
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
| | | | | |
Collapse
|
19
|
Neidhardt J, Glaus E, Barthelmes D, Zeitz C, Fleischhauer J, Berger W. Identification and characterization of a novel RPGR isoform in human retina. Hum Mutat 2007; 28:797-807. [PMID: 17405150 DOI: 10.1002/humu.20521] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Retinitis pigmentosa (RP) constitutes a major cause of blindness and the Retinitis Pigmentosa GTPase Regulator (RPGR) gene accounts for up to 80% of all X-linked RP cases. A novel isoform of RPGR, expressed in the human retina, was identified and characterized. It truncates the Regulator of Chromosome Condensation 1 (RCC1) homologous protein domain (RCC1h) of RPGR and mediates the formation of isoform-specific complexes with the RPGR-interacting protein 1 (RPGRIP1). Immunohistochemistry localized the novel RPGR isoform predominantly to inner segments of cone photoreceptors, where it colocalizes with RPGRIP1 in the human retina. In a patient with a mild RP phenotype, we identified a nucleotide substitution in a splicing regulator, which leads to 3.5 times higher levels of the transcripts coding for the novel RPGR isoform. The nucleotide substitution affects regulated alternative splicing of the novel RPGR isoform and suggests a tight adjustment of splicing as a prerequisite for proper function of photoreceptors.
Collapse
Affiliation(s)
- John Neidhardt
- Division of Medical Molecular Genetics and Gene Diagnostics, Institute of Medical Genetics, University of Zurich, Zurich, Switzerland.
| | | | | | | | | | | |
Collapse
|
20
|
Jacobson SG, Cideciyan AV, Aleman TS, Sumaroka A, Schwartz SB, Roman AJ, Stone EM. Leber Congenital Amaurosis Caused by an RPGRIP1 Mutation Shows Treatment Potential. Ophthalmology 2007; 114:895-8. [PMID: 17306875 DOI: 10.1016/j.ophtha.2006.10.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 10/04/2006] [Accepted: 10/05/2006] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To determine the treatment potential in Leber congenital amaurosis (LCA) resulting from an RPGRIP1 (retinitis pigmentosa GTPase regulating-interacting protein 1) mutation, a form of LCA with recent gene therapy success in an animal model. DESIGN Case report of a rare genetic eye disease investigated for intervention potential. PARTICIPANTS A 19-year-old man with LCA. METHODS We studied the retinal structure and function in an LCA patient with a novel homozygous Val1211Glu mutation in the RPGRIP1 gene using optical coherence tomography and colocalized dark-adapted thresholds. MAIN OUTCOME MEASURE Optical coherence tomography results. RESULTS Central retinal laminar architecture was preserved, and there was a measurable outer nuclear layer. The retained retinal structure corresponded to the region of visual sensitivity. With increasing eccentricity, there was no measurable visual function, and retinal laminar disorganization suggested a remodeling process. CONCLUSIONS The RPGRIP1-LCA patient has treatment potential for a gene replacement strategy if targeted to central, but not pericentral or peripheral, retina. The results differ from similarly studied RPE65-LCA and CRB1-LCA patients. Preclinical progress toward therapy in LCA patients warrants detailed structure-function studies in humans to determine feasibility and candidacy for clinical trials.
Collapse
Affiliation(s)
- Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | | | | | | | |
Collapse
|
21
|
Shu X, Black GC, Rice JM, Hart-Holden N, Jones A, O'Grady A, Ramsden S, Wright AF. RPGRmutation analysis and disease: an update. Hum Mutat 2007; 28:322-8. [PMID: 17195164 DOI: 10.1002/humu.20461] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene are the most common single cause of retinitis pigmentosa, accounting for up to 15 to 20% of cases in Caucasians. A total of 240 different RPGR mutations have been reported, including 24 novel ones in this work, which are associated with X-linked retinitis pigmentosa (XLRP) (95%), cone, cone-rod dystrophy, or atrophic macular atrophy (3%), and syndromal retinal dystrophies with ciliary dyskinesia and hearing loss (2%). All disease-causing mutations occur in one or more RPGR isoforms containing the carboxyl-terminal exon open reading frame 15 (ORF15), which are widely expressed but show their highest expression in the connecting cilia of rod and cone photoreceptors. Of reported RPGR mutations, 55% occur in a glutamic acid-rich domain within exon ORF15, which accounts for only 31% of the protein. RPGR forms complexes with a variety of other proteins and appears to have a role in microtubular organization and transport between photoreceptor inner and outer segments.
Collapse
Affiliation(s)
- Xinhua Shu
- Medical Research Council Human Genetics Unit, Edinburgh, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|