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Liu J, Hayden MR, Yang Y. Research progress of RP1L1 gene in disease. Gene 2024; 912:148367. [PMID: 38485037 DOI: 10.1016/j.gene.2024.148367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/22/2024]
Abstract
Retinitis pigmentosa 1-like 1 (RP1L1) is a component of photoreceptor cilia. Pathogenic variants in RP1L1 cause photoreceptor diseases, suggesting that RP1L1 plays an important role in photoreceptor biology, although its exact function is unknown. To date, RP1L1 variants have been associated with occult macular dystrophy (cone degeneration) and retinitis pigmentosa (rod degeneration). Here, we summarize the reported RP1L1-associated photoreceptor pathogenic mutations. The association between RP1L1 and other diseases (mainly several tumors) is also summarized and RP1L1 is included in a wider range of diseases. Finally, it is necessary to further explore the influence mechanism of RP1L1 gene on the health of photoreceptors and how it participates in the occurrence and development of tumors.
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Affiliation(s)
- Jiali Liu
- Department of Endocrinology, Affiliated Hospital of Yunnan University, Kunming, PR China
| | - Melvin R Hayden
- University of Missouri School of Medicine, Departments of Internal Medicine, Columbia, RP, USA
| | - Ying Yang
- Department of Endocrinology, Affiliated Hospital of Yunnan University, Kunming, PR China; University of Missouri School of Medicine, Departments of Internal Medicine, Columbia, RP, USA.
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2
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Kunisetty B, Martin-Giacalone BA, Zhao X, Luna PN, Brooks BP, Hufnagel RB, Shaw CA, Rosenfeld JA, Agopian AJ, Lupo PJ, Scott DA. High Clinical Exome Sequencing Diagnostic Rates and Novel Phenotypic Expansions for Nonisolated Microphthalmia, Anophthalmia, and Coloboma. Invest Ophthalmol Vis Sci 2024; 65:25. [PMID: 38502138 PMCID: PMC10959191 DOI: 10.1167/iovs.65.3.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/26/2024] [Indexed: 03/20/2024] Open
Abstract
Purpose A molecular diagnosis is only made in a subset of individuals with nonisolated microphthalmia, anophthalmia, and coloboma (MAC). This may be due to underutilization of clinical (whole) exome sequencing (cES) and an incomplete understanding of the genes that cause MAC. The purpose of this study is to determine the efficacy of cES in cases of nonisolated MAC and to identify new MAC phenotypic expansions. Methods We determined the efficacy of cES in 189 individuals with nonisolated MAC. We then used cES data, a validated machine learning algorithm, and previously published expression data, case reports, and animal models to determine which candidate genes were most likely to contribute to the development of MAC. Results We found the efficacy of cES in nonisolated MAC to be between 32.3% (61/189) and 48.1% (91/189). Most genes affected in our cohort were not among genes currently screened in clinically available ophthalmologic gene panels. A subset of the genes implicated in our cohort had not been clearly associated with MAC. Our analyses revealed sufficient evidence to support low-penetrance MAC phenotypic expansions involving nine of these human disease genes. Conclusions We conclude that cES is an effective means of identifying a molecular diagnosis in individuals with nonisolated MAC and may identify putatively damaging variants that would be missed if only a clinically available ophthalmologic gene panel was obtained. Our data also suggest that deleterious variants in BRCA2, BRIP1, KAT6A, KAT6B, NSF, RAC1, SMARCA4, SMC1A, and TUBA1A can contribute to the development of MAC.
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Affiliation(s)
- Bhavana Kunisetty
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - Bailey A. Martin-Giacalone
- Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, United States
- Section of Hematology-Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Xiaonan Zhao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
- Baylor Genetics, Houston, Texas, United States
| | - Pamela N. Luna
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - Brian P. Brooks
- Ophthalmic Genetics & Visual Function Branch, National Eye Institute, NIH, Bethesda, Maryland, United States
| | - Robert B. Hufnagel
- Ophthalmic Genetics & Visual Function Branch, National Eye Institute, NIH, Bethesda, Maryland, United States
| | - Chad A. Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - A. J. Agopian
- Department of Epidemiology, Human Genetics & Environmental Sciences, UTHealth School of Public Health, Houston, Texas, United States
| | - Philip J. Lupo
- Section of Hematology-Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States
| | - Daryl A. Scott
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States
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Zufiaurre-Seijo M, García-Arumí J, Duarri A. Clinical and Molecular Aspects of C2orf71/PCARE in Retinal Diseases. Int J Mol Sci 2023; 24:10670. [PMID: 37445847 DOI: 10.3390/ijms241310670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Mutations in the photoreceptor-specific C2orf71 gene (also known as photoreceptor cilium actin regulator protein PCARE) cause autosomal recessive retinitis pigmentosa type 54 and cone-rod dystrophy. No treatments are available for patients with C2orf71 retinal ciliopathies exhibiting a severe clinical phenotype. Our understanding of the disease process and the role of PCARE in the healthy retina significantly limits our capacity to transfer recent technical developments into viable therapy choices. This study summarizes the current understanding of C2orf71-related retinal diseases, including their clinical manifestations and an unclear genotype-phenotype correlation. It discusses molecular and functional studies on the photoreceptor-specific ciliary PCARE, focusing on the photoreceptor cell and its ciliary axoneme. It is proposed that PCARE is an actin-associated protein that interacts with WASF3 to regulate the actin-driven expansion of the ciliary membrane during the development of a new outer segment disk in photoreceptor cells. This review also introduces various cellular and animal models used to model these diseases and provides an overview of potential treatments.
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Affiliation(s)
- Maddalen Zufiaurre-Seijo
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - José García-Arumí
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - Anna Duarri
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
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Jacquemin V, Versbraegen N, Duerinckx S, Massart A, Soblet J, Perazzolo C, Deconinck N, Brischoux-Boucher E, De Leener A, Revencu N, Janssens S, Moorgat S, Blaumeiser B, Avela K, Touraine R, Abou Jaoude I, Keymolen K, Saugier-Veber P, Lenaerts T, Abramowicz M, Pirson I. Congenital hydrocephalus: new Mendelian mutations and evidence for oligogenic inheritance. Hum Genomics 2023; 17:16. [PMID: 36859317 PMCID: PMC9979489 DOI: 10.1186/s40246-023-00464-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
BACKGROUND Congenital hydrocephalus is characterized by ventriculomegaly, defined as a dilatation of cerebral ventricles, and thought to be due to impaired cerebrospinal fluid (CSF) homeostasis. Primary congenital hydrocephalus is a subset of cases with prenatal onset and absence of another primary cause, e.g., brain hemorrhage. Published series report a Mendelian cause in only a minority of cases. In this study, we analyzed exome data of PCH patients in search of novel causal genes and addressed the possibility of an underlying oligogenic mode of inheritance for PCH. MATERIALS AND METHODS We sequenced the exome in 28 unrelated probands with PCH, 12 of whom from families with at least two affected siblings and 9 of whom consanguineous, thereby increasing the contribution of genetic causes. Patient exome data were first analyzed for rare (MAF < 0.005) transmitted or de novo variants. Population stratification of unrelated PCH patients and controls was determined by principle component analysis, and outliers identified using Mahalanobis distance 5% as cutoff. Patient and control exome data for genes biologically related to cilia (SYScilia database) were analyzed by mutation burden test. RESULTS In 18% of probands, we identify a causal (pathogenic or likely pathogenic) variant of a known hydrocephalus gene, including genes for postnatal, syndromic hydrocephalus, not previously reported in isolated PCH. In a further 11%, we identify mutations in novel candidate genes. Through mutation burden tests, we demonstrate a significant burden of genetic variants in genes coding for proteins of the primary cilium in PCH patients compared to controls. CONCLUSION Our study confirms the low contribution of Mendelian mutations in PCH and reports PCH as a phenotypic presentation of some known genes known for syndromic, postnatal hydrocephalus. Furthermore, this study identifies novel Mendelian candidate genes, and provides evidence for oligogenic inheritance implicating primary cilia in PCH.
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Affiliation(s)
- Valerie Jacquemin
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium.
| | - Nassim Versbraegen
- grid.4989.c0000 0001 2348 0746Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles-Vrije Universiteit Brussel, Brussels, Belgium ,grid.4989.c0000 0001 2348 0746Machine Learning Group, Université Libre de Bruxelles, Brussels, Belgium
| | - Sarah Duerinckx
- grid.4989.c0000 0001 2348 0746Service de Neuropédiatrie, Hôpital Universitaire de Bruxelles and CUB Hôpital Erasme and Université Libre de Bruxelles, Brussels, Belgium
| | - Annick Massart
- grid.4989.c0000 0001 2348 0746Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium ,grid.411414.50000 0004 0626 3418Department of Nephrology, University Hospital of Antwerp, Edegem, Belgium
| | - Julie Soblet
- grid.412157.40000 0000 8571 829XHuman Genetics Department, CUB Hôpital Erasme, Brussels, Belgium
| | - Camille Perazzolo
- grid.4989.c0000 0001 2348 0746Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium
| | - Nicolas Deconinck
- grid.412209.c0000 0004 0578 1002Hopital Universitaire des Enfants Reine Fabiola and Hopital Universitaire de Bruxelles and Université Libre de Bruxelles, Brussels, Belgium
| | - Elise Brischoux-Boucher
- grid.493090.70000 0004 4910 6615Centre de génétique humaine - CHU de Besançon, Université de Bourgogne-Franche-Comté, Besançon, France
| | - Anne De Leener
- grid.48769.340000 0004 0461 6320Centre de Génétique Humaine, Cliniques Universitaires Saint-Luc et Université Catholique de Louvain, Brussels, Belgium
| | - Nicole Revencu
- grid.48769.340000 0004 0461 6320Centre de Génétique Humaine, Cliniques Universitaires Saint-Luc et Université Catholique de Louvain, Brussels, Belgium
| | - Sandra Janssens
- grid.410566.00000 0004 0626 3303Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Stèphanie Moorgat
- grid.452439.d0000 0004 0578 0894Centre de Génétique Humaine, Institut de Pathologie et de Génétique, Gosselies, Belgium
| | - Bettina Blaumeiser
- grid.411414.50000 0004 0626 3418Center of Medical Genetics, Antwerp University and Antwerp University Hospital, Edegem, Belgium
| | - Kristiina Avela
- grid.15485.3d0000 0000 9950 5666Department of Clinical Genetics, Helsinki University Hospital, Helsinki, Finland
| | - Renaud Touraine
- grid.412954.f0000 0004 1765 1491Génétique Clinique Chromosomique et Moléculaire, CHU de Saint-Etienne, St-Priest-en-Jarez, France
| | - Imad Abou Jaoude
- Department of Gynecology and Obstetrics, Abou Jaoude Hospital, Jal El Dib, Lebanon
| | - Kathelijn Keymolen
- grid.411326.30000 0004 0626 3362Center for Medical Genetics, UZ Brussels, Jette, Belgium
| | - Pascale Saugier-Veber
- grid.10400.350000 0001 2108 3034Department of Genetics and Reference Center for Developmental Disorders, Université Rouen Normandie, Inserm U1245 and CHU Rouen, Rouen, France
| | - Tom Lenaerts
- grid.4989.c0000 0001 2348 0746Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles-Vrije Universiteit Brussel, Brussels, Belgium ,grid.4989.c0000 0001 2348 0746Machine Learning Group, Université Libre de Bruxelles, Brussels, Belgium ,grid.8767.e0000 0001 2290 8069Artificial Intelligence Lab, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marc Abramowicz
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium. .,Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.
| | - Isabelle Pirson
- grid.4989.c0000 0001 2348 0746Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium
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Spedicati B, Cocca M, Palmisano R, Faletra F, Barbieri C, Francescatto M, Mezzavilla M, Morgan A, Pelliccione G, Gasparini P, Girotto G. Natural human knockouts and Mendelian disorders: deep phenotyping in Italian isolates. Eur J Hum Genet 2021; 29:1272-1281. [PMID: 33727708 PMCID: PMC8384846 DOI: 10.1038/s41431-021-00850-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/30/2020] [Accepted: 02/23/2021] [Indexed: 02/02/2023] Open
Abstract
Whole genome sequencing (WGS) allows the identification of human knockouts (HKOs), individuals in whom loss of function (LoF) variants disrupt both alleles of a given gene. HKOs are a valuable model for understanding the consequences of genes function loss. Naturally occurring biallelic LoF variants tend to be significantly enriched in "genetic isolates," making these populations specifically suited for HKO studies. In this work, a meticulous WGS data analysis combined with an in-depth phenotypic assessment of 947 individuals from three Italian genetic isolates led to the identification of ten biallelic LoF variants in ten OMIM genes associated with known autosomal recessive diseases. Notably, only a minority of the identified HKOs (C7, F12, and GPR68 genes) displayed the expected phenotype. For most of the genes, instead, (ACADSB, FANCL, GRK1, LGI4, MPO, PGAM2, and RP1L1), the carriers showed none or few of the signs and symptoms typically associated with the related diseases. Of particular interest is a case presenting with a FANCL biallelic LoF variant and a positive diepoxybutane test but lacking a full Fanconi anemia phenotypic spectrum. Identifying KO subjects displaying expected phenotypes suggests that the lack of correct genetic diagnoses may lead to inappropriate and delayed treatment. In contrast, the presence of HKOs with phenotypes deviating from the expected patterns underlines how LoF variants may be responsible for broader phenotypic spectra. Overall, these results highlight the importance of in-depth phenotypical characterization to understand the role of LoF variants and the advantage of studying these variants in genetic isolates.
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Affiliation(s)
- Beatrice Spedicati
- grid.5133.40000 0001 1941 4308Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Massimiliano Cocca
- grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Roberto Palmisano
- grid.5133.40000 0001 1941 4308Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Flavio Faletra
- grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Caterina Barbieri
- grid.18887.3e0000000417581884Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Margherita Francescatto
- grid.5133.40000 0001 1941 4308Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Massimo Mezzavilla
- grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Anna Morgan
- grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Giulia Pelliccione
- grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Paolo Gasparini
- grid.5133.40000 0001 1941 4308Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy ,grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
| | - Giorgia Girotto
- grid.5133.40000 0001 1941 4308Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy ,grid.418712.90000 0004 1760 7415Institute for Maternal and Child Health – I.R.C.C.S. “Burlo Garofolo”, Trieste, Italy
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Lu Y, Sun X. Retinitis pigmentosa sine pigmento masqueraded as myopia: A case report (CARE). Medicine (Baltimore) 2021; 100:e24006. [PMID: 33545995 PMCID: PMC7837948 DOI: 10.1097/md.0000000000024006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 12/03/2020] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION Retinitis pigmentosa is a major cause of visual disability and blindness. Photopsia is usually presented in patients with retinal traction caused by posterior vitreous detachment in clinic, which would occur more commonly in those suffer from moderate or high myopia. We describe a patient with leopard-like retinopathy initially complaining of photopsia caused not by myopia but by retinitis pigmentosa. PATIENT CONCERNS A 39-year-old woman with a history of moderate myopia presented to us complaining of photopsia for several days. DIAGNOSIS Fundus examination revealed leopard-like retinopathy with normal optic disc and macula appearance in both eyes. The atrophy of retinal pigment epithelium was found in peripheral retina while no bone spicule was present. Retinal multimodal imaging helped in the correct diagnosis of retinitis pigmentosa (sine pigmento), later confirmed by genetic testing. INTERVENTIONS At current no specific treatment was applied, but the patient was required for follow-up observation every six months. OUTCOMES Follow-up observation. CONCLUSION This case highlights the potential for retinitis pigmentosa sine pigmento to present with photopsia under cover of myopia and the importance of performing multimodal imaging including fundus autofluorescence for fundus disorders. Careful history review and multimodal imaging with genetic testing would help for the correct diagnosis of retinitis pigmentosa sine pigmento.
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Affiliation(s)
- Yi Lu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai JiaoTong University
- Shanghai Key Laboratory of Ocular Fundus Disease
- Shanghai Engineering Center for Visual Science and Photomedicine
- National Clinical Research Center for Eye Diseases
- Shanghai Engineering Center of Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai JiaoTong University
- Shanghai Key Laboratory of Ocular Fundus Disease
- Shanghai Engineering Center for Visual Science and Photomedicine
- National Clinical Research Center for Eye Diseases
- Shanghai Engineering Center of Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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Progressive Photoreceptor Dysfunction and Age-Related Macular Degeneration-Like Features in rp1l1 Mutant Zebrafish. Cells 2020; 9:cells9102214. [PMID: 33007938 PMCID: PMC7600334 DOI: 10.3390/cells9102214] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 12/23/2022] Open
Abstract
Photoreceptor disease results in irreparable vision loss and blindness, which has a dramatic impact on quality of life. Pathogenic mutations in RP1L1 lead to photoreceptor degenerations such as occult macular dystrophy and retinitis pigmentosa. RP1L1 is a component of the photoreceptor axoneme, the backbone structure of the photoreceptor's light-sensing outer segment. We generated an rp1l1 zebrafish mutant using CRISPR/Cas9 genome editing. Mutant animals had progressive photoreceptor functional defects as determined by electrophysiological assessment. Optical coherence tomography showed gaps in the photoreceptor layer, disrupted photoreceptor mosaics, and thinner retinas. Mutant retinas had disorganized photoreceptor outer segments and lipid-rich subretinal drusenoid deposits between the photoreceptors and retinal pigment epithelium. Our mutant is a novel model of RP1L1-associated photoreceptor disease and the first zebrafish model of photoreceptor degeneration with reported subretinal drusenoid deposits, a feature of age-related macular degeneration.
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8
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Aardema ML, Stiassny MLJ, Alter SE. Genomic Analysis of the Only Blind Cichlid Reveals Extensive Inactivation in Eye and Pigment Formation Genes. Genome Biol Evol 2020; 12:1392-1406. [PMID: 32653909 PMCID: PMC7502198 DOI: 10.1093/gbe/evaa144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2020] [Indexed: 12/21/2022] Open
Abstract
Trait loss represents an intriguing evolutionary problem, particularly when it occurs across independent lineages. Fishes in light-poor environments often evolve “troglomorphic” traits, including reduction or loss of both pigment and eyes. Here, we investigate the genomic basis of trait loss in a blind and depigmented African cichlid, Lamprologus lethops, and explore evolutionary forces (selection and drift) that may have contributed to these losses. This species, the only known blind cichlid, is endemic to the lower Congo River. Available evidence suggests that it inhabits deep, low-light habitats. Using genome sequencing, we show that genes related to eye formation and pigmentation, as well as other traits associated with troglomorphism, accumulated inactivating mutations rapidly after speciation. A number of the genes affected in L. lethops are also implicated in troglomorphic phenotypes in Mexican cavefish (Astyanax mexicanus) and other species. Analysis of heterozygosity patterns across the genome indicates that L. lethops underwent a significant population bottleneck roughly 1 Ma, after which effective population sizes remained low. Branch-length tests on a subset of genes with inactivating mutations show little evidence of directional selection; however, low overall heterozygosity may reduce statistical power to detect such signals. Overall, genome-wide patterns suggest that accelerated genetic drift from a severe bottleneck, perhaps aided by directional selection for the loss of physiologically expensive traits, caused inactivating mutations to fix rapidly in this species.
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Affiliation(s)
- Matthew L Aardema
- Department of Biology, Montclair State University.,Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York
| | - Melanie L J Stiassny
- Department of Ichthyology, American Museum of Natural History, New York, New York
| | - S Elizabeth Alter
- Department of Ichthyology, American Museum of Natural History, New York, New York.,The Graduate Center, City University of New York.,Department of Biology, York College/The City University of New York
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9
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Wang DD, Gao FJ, Li JK, Chen F, Hu FY, Xu GZ, Zhang JG, Sun HX, Zhang SH, Xu P, Tian GH, Wu JH. Clinical and Genetic Characteristics of Chinese Patients with Occult Macular Dystrophy. Invest Ophthalmol Vis Sci 2020; 61:10. [PMID: 32176261 PMCID: PMC7401461 DOI: 10.1167/iovs.61.3.10] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the clinical and genetic characteristics of occult macular dystrophy (OMD) based on a Chinese patient cohort. Methods Fifteen Chinese OMD patients from nine unrelated families underwent genetic testing, and all of them harbored a pathogenic RP1L1 variant. Comprehensive ophthalmic examinations were performed in nine probands, including spectral-domain optical coherence tomography (SD-OCT), near-infrared reflectance (NIR), fundus autofluorescence (AF), and multifocal electroretinography. Results The RP1L1 variants p.R45W and p.S1199C were identified in 13 patients and two patients, respectively, and one was a de novo mutation. Among the nine probands, the median ages at onset and examination were 25.0 years (range, 6–51 years) and 27.0 years (range, 14–55 years), respectively. The median decimal visual acuity was 0.20 (range, 0.04–0.5). Foveal photoreceptor thickness and visual acuity showed a significant correlation (r = 0.591; P = 0.01). All eyes presented with an absent interdigitation zone and blurred ellipsoid zone of photoreceptors when examined by SD-OCT. In addition, central round lesions with low NIR reflectance were observed in 66.7% (12/18) of eyes by NIR reflectance imaging, corresponding to the regions with abnormal photoreceptor microstructures observed by SD-OCT. Of the 18 eyes, only four eyes showed ring-like faint hyperfluorescence around the macula by AF. Conclusions To the best of our knowledge, this is the largest study in a cohort of Chinese OMD patients with RP1L1 mutations. Our findings revealed that the two recurrent RP1L1 variants are related to OMD in the Chinese population. Furthermore, multimodal imaging combined with genetic testing is valuable for diagnosing and monitoring OMD progression.
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10
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Cogné B, Latypova X, Senaratne LDS, Martin L, Koboldt DC, Kellaris G, Fievet L, Le Meur G, Caldari D, Debray D, Nizon M, Frengen E, Bowne SJ, Cadena EL, Daiger SP, Bujakowska KM, Pierce EA, Gorin M, Katsanis N, Bézieau S, Petersen-Jones SM, Occelli LM, Lyons LA, Legeai-Mallet L, Sullivan LS, Davis EE, Isidor B, Buckley RM, Aberdein D, Alves PC, Barsh GS, Bellone RR, Bergström TF, Boyko AR, Brockman JA, Casal ML, Castelhano MG, Distl O, Dodman NH, Ellinwood NM, Fogle JE, Forman OP, Garrick DJ, Ginns EI, Häggström J, Harvey RJ, Hasegawa D, Haase B, Helps CR, Hernandez I, Hytönen MK, Kaukonen M, Kaelin CB, Kosho T, Leclerc E, Lear TL, Leeb T, Li RH, Lohi H, Longeri M, Magnuson MA, Malik R, Mane SP, Munday JS, Murphy WJ, Pedersen NC, Rothschild MF, Rusbridge C, Shapiro B, Stern JA, Swanson WF, Terio KA, Todhunter RJ, Warren WC, Wilcox EA, Wildschutte JH, Yu Y. Mutations in the Kinesin-2 Motor KIF3B Cause an Autosomal-Dominant Ciliopathy. Am J Hum Genet 2020; 106:893-904. [PMID: 32386558 DOI: 10.1016/j.ajhg.2020.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/02/2020] [Indexed: 11/26/2022] Open
Abstract
Kinesin-2 enables ciliary assembly and maintenance as an anterograde intraflagellar transport (IFT) motor. Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. Using exome sequencing, we identified heterozygous KIF3B variants in two unrelated families with hallmark ciliopathy phenotypes. In the first family, the proband presents with hepatic fibrosis, retinitis pigmentosa, and postaxial polydactyly; he harbors a de novo c.748G>C (p.Glu250Gln) variant affecting the kinesin motor domain encoded by KIF3B. The second family is a six-generation pedigree affected predominantly by retinitis pigmentosa. Affected individuals carry a heterozygous c.1568T>C (p.Leu523Pro) KIF3B variant segregating in an autosomal-dominant pattern. We observed a significant increase in primary cilia length in vitro in the context of either of the two mutations while variant KIF3B proteins retained stability indistinguishable from wild type. Furthermore, we tested the effects of KIF3B mutant mRNA expression in the developing zebrafish retina. In the presence of either missense variant, rhodopsin was sequestered to the photoreceptor rod inner segment layer with a concomitant increase in photoreceptor cilia length. Notably, impaired rhodopsin trafficking is also characteristic of recessive KIF3B models as exemplified by an early-onset, autosomal-recessive, progressive retinal degeneration in Bengal cats; we identified a c.1000G>A (p.Ala334Thr) KIF3B variant by genome-wide association study and whole-genome sequencing. Together, our genetic, cell-based, and in vivo modeling data delineate an autosomal-dominant syndromic retinal ciliopathy in humans and suggest that multiple KIF3B pathomechanisms can impair kinesin-driven ciliary transport in the photoreceptor.
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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12
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RP1L1 and inherited photoreceptor disease: A review. Surv Ophthalmol 2020; 65:725-739. [PMID: 32360662 DOI: 10.1016/j.survophthal.2020.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 12/18/2022]
Abstract
Retinitis pigmentosa 1-like 1 (RP1L1) is a component of the photoreceptor cilium. Pathogenic variants in RP1L1 lead to photoreceptor disease, suggesting an important role for RP1L1 in photoreceptor biology, though its exact function is unknown. To date, RP1L1 variants have been associated with occult macular dystrophy (a cone degeneration) and retinitis pigmentosa (a rod disease). Here, we summarize reported RP1L1-associated photoreceptor conditions and disease-causing RP1L1 variants. We also discuss novel associations between RP1L1 and additional photoreceptor conditions-besides occult macular dystrophy and retinitis pigmentosa-and fit RP1L1 into the broader scope of photoreceptor disease. RP1L1 appears to have a complex relationship with other photoreceptor proteins and may modify disease phenotype. Ultimately, further exploration of the relationship between RP1L1, other cilium components, and their impact on photoreceptor health is needed.
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Hu YS, Song H, Li Y, Xiao ZY, Li T. Whole-exome sequencing identifies novel mutations in genes responsible for retinitis pigmentosa in 2 nonconsanguineous Chinese families. Int J Ophthalmol 2019; 12:915-923. [PMID: 31236346 DOI: 10.18240/ijo.2019.06.06] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 09/25/2018] [Indexed: 12/26/2022] Open
Abstract
AIM To detect the pathogenetic mutations responsible for nonsyndromic autosomal recessive retinitis pigmentosa (RP) in 2 nonconsanguineous Chinese families. METHODS The clinical data, including detailed medical history, best corrected visual acuity (BCVA), slit-lamp biomicroscope examination, fundus photography, optical coherence tomography, static perimetry, and full field electroretinogram, were collected from the members of 2 nonconsanguineous Chinese families preliminarily diagnosed with RP. Genomic DNA was extracted from the probands and other available family members; whole-exome sequencing was conducted with the DNA samples provided by the probands, and all mutations detected by whole-exome sequencing were verified using Sanger sequencing in the probands and the other available family members. The verified novel mutations were further sequenced in 192 ethnicity matched healthy controls. RESULTS The patients from the 2 families exhibited the typical symptoms of RP, including night blindness and progressive constriction of the visual field, and the fundus examinations showed attenuated retinal arterioles, peripheral bone spicule pigment deposits, and waxy optic discs. Whole-exome sequencing revealed a novel nonsense mutation in FAM161A (c.943A>T, p.Lys315*) and compound heterozygous mutations in RP1L1 (c.56C>A, p.Pro19His; c.5470C>T, p.Gln1824*). The nonsense c.5470C>T, p.Gln1824* mutation was novel. All mutations were verified by Sanger sequencing. The mutation p.Lys315* in FAM161A co-segregated with the phenotype, and all the nonsense mutations were absent from the ethnicity matched healthy controls and all available databases. CONCLUSION We identify 2 novel mutations in genes responsible for autosomal recessive RP, and the mutation in FAM161A is reported for the first time in a Chinese population. Our result not only enriches the knowledge of the mutation frequency and spectrum in the genes responsible for nonsyndromic RP but also provides a new target for future gene therapy.
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Affiliation(s)
- Yan-Shan Hu
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Hui Song
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Yin Li
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Zi-Yun Xiao
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Tuo Li
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
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14
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Fujinami K, Yang L, Joo K, Tsunoda K, Kameya S, Hanazono G, Fujinami-Yokokawa Y, Arno G, Kondo M, Nakamura N, Kurihara T, Tsubota K, Zou X, Li H, Park KH, Iwata T, Miyake Y, Woo SJ, Sui R. Clinical and Genetic Characteristics of East Asian Patients with Occult Macular Dystrophy (Miyake Disease): East Asia Occult Macular Dystrophy Studies Report Number 1. Ophthalmology 2019; 126:1432-1444. [PMID: 31028767 DOI: 10.1016/j.ophtha.2019.04.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 10/27/2022] Open
Abstract
PURPOSE To describe the clinical and genetic characteristics of the cohort enrolled in the East Asian studies of occult macular dystrophy (OMD). DESIGN International, multicenter, retrospective cohort studies. PARTICIPANTS A total of 36 participants from 21 families with a clinical diagnosis of OMD and harboring pathogenic RP1L1 variants (i.e., Miyake disease) were enrolled from 3 centers in Japan, China, and South Korea. METHODS A detailed history was obtained, and comprehensive ophthalmological examinations including spectral-domain OCT were performed. All detected sequence variants in the RP1L1 gene were reviewed, and in silico analysis was performed, including allele frequency analyses and pathogenicity predictions. MAIN OUTCOME MEASURES Onset of disease, visual acuity (VA) converted to the logarithm of the minimum angle of resolution (logMAR), OCT findings, and effect of detected variants. RESULTS Eleven families from Japan, 6 from South Korea, and 4 from China were recruited. There were 12 female and 24 male participants. The median age of onset was 25.5 years (range, 2-73), and the median age at the latest examination was 46.0 years (range, 11-86). The median VA (logMAR) was 0.65 (range, -0.08-1.22) in the right eye and 0.65 (-0.08-1.10) in the left eye. A significant correlation between onset of disease and VA was revealed. The Classical morphologic phenotype showing both blurred ellipsoid zone and absence of interdigitation zone of the photoreceptors was demonstrated in 30 patients (83.3%), and subtle photoreceptor architectural changes were demonstrated in 6 patients (16.6%). Eight pathogenic RP1L1 variants were identified, including 6 reported variants and 1 novel variant: p.R45W, p.T1194M/p.T1196I (complex), p.S1199C, p.G1200A, p.G1200D, p.V1201G, and p.S1198F, respectively. Two variants were recurrent: p.R45W (11 families, 52.4%) and p.S1199C (5 families, 23.8%). The pathogenic missense variants in 10 families (47.6%) were located within the previously reported unique motif, including 6 amino acids (1196-1201). CONCLUSIONS There is a large spectrum of clinical findings in Miyake disease, including various onset of disease and VA, whereas the characteristic photoreceptor microstructures were shared in most cases. Two hot spots including amino acid numbers 45 and 1196-1201 in the RP1L1 gene were confirmed in the East Asian population.
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Affiliation(s)
- Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; UCL Institute of Ophthalmology, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom.
| | - Lizhu Yang
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Shuhei Kameya
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Inzai, Chiba, Japan
| | - Gen Hanazono
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Yu Fujinami-Yokokawa
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Graduate School of Health Management, Keio University, Tokyo, Japan
| | - Gavin Arno
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; UCL Institute of Ophthalmology, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom
| | - Mineo Kondo
- Department of Ophthalmology, Graduate School of Medicine, Mie University, Mie, Japan
| | - Natsuko Nakamura
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Toshihide Kurihara
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Yozo Miyake
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Aichi Medical University, Nagakute, Aichi, Japan
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
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15
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Khan M, Fadaie Z, Cornelis SS, Cremers FPM, Roosing S. Identification and Analysis of Genes Associated with Inherited Retinal Diseases. Methods Mol Biol 2019; 1834:3-27. [PMID: 30324433 DOI: 10.1007/978-1-4939-8669-9_1] [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] [Indexed: 12/14/2022]
Abstract
Inherited retinal diseases (IRDs) display a very high degree of clinical and genetic heterogeneity, which poses challenges in finding the underlying defects in known IRD-associated genes and in identifying novel IRD-associated genes. Knowledge on the molecular and clinical aspects of IRDs has increased tremendously in the last decade. Here, we outline the state-of-the-art techniques to find the causative genetic variants, with special attention for next-generation sequencing which can combine molecular diagnostics and retinal disease gene identification. An important aspect is the functional assessment of rare variants with RNA and protein effects which can only be predicted in silico. We therefore describe the in vitro assessment of putative splice defects in human embryonic kidney cells. In addition, we outline the use of stem cell technology to generate photoreceptor precursor cells from patients' somatic cells which can subsequently be used for RNA and protein studies. Finally, we outline the in silico methods to interpret the causality of variants associated with inherited retinal disease and the registry of these variants.
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Affiliation(s)
- Mubeen Khan
- Department of Human Genetics, Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Zeinab Fadaie
- Department of Human Genetics, Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Stéphanie S Cornelis
- Department of Human Genetics, Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
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C2orf71a/pcare1 is important for photoreceptor outer segment morphogenesis and visual function in zebrafish. Sci Rep 2018; 8:9675. [PMID: 29946172 PMCID: PMC6018674 DOI: 10.1038/s41598-018-27928-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/17/2018] [Indexed: 02/03/2023] Open
Abstract
Mutations in C2orf71 are causative for autosomal recessive retinitis pigmentosa and occasionally cone-rod dystrophy. We have recently discovered that the protein encoded by this gene is important for modulation of the ciliary membrane through the recruitment of an actin assembly module, and have therefore renamed the gene to PCARE (photoreceptor cilium actin regulator). Here, we report on the identification of two copies of the c2orf71/pcare gene in zebrafish, pcare1 and pcare2. To study the role of the gene most similar to human PCARE, pcare1, we have generated a stable pcare1 mutant zebrafish model (designated pcare1rmc100/rmc100) in which the coding sequence was disrupted using CRISPR/Cas9 technology. Retinas of both embryonic (5 dpf) and adult (6 mpf) pcare1rmc100/rmc100 zebrafish display a clear disorganization of photoreceptor outer segments, resembling the phenotype observed in Pcare−/− mice. Optokinetic response and visual motor response measurements indicated visual impairment in pcare1rmc100/rmc100 zebrafish larvae at 5 dpf. In addition, electroretinogram measurements showed decreased b-wave amplitudes in pcare1rmc100/rmc100 zebrafish as compared to age- and strain-matched wild-type larvae, indicating a defect in the transretinal current. Altogether, our data show that lack of pcare1 causes a retinal phenotype in zebrafish and indicate that the function of the PCARE gene is conserved across species.
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17
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Zobor D, Zobor G, Hipp S, Baumann B, Weisschuh N, Biskup S, Sliesoraityte I, Zrenner E, Kohl S. Phenotype Variations Caused by Mutations in theRP1L1Gene in a Large Mainly German Cohort. ACTA ACUST UNITED AC 2018; 59:3041-3052. [DOI: 10.1167/iovs.18-24033] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Gergely Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Stephanie Hipp
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Britta Baumann
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Saskia Biskup
- Praxis für Humangenetik Tübingen & CeGaT GmbH, Tübingen, Tübingen, Germany
| | - Ieva Sliesoraityte
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
- Institut de La Vision, INSERM Paris, France
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
- Werner Reichardt Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
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18
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Hasan S, Balobaid A, Grottesi A, Dabbagh O, Cenciarini M, Rawashdeh R, Al-Sagheir A, Bove C, Macchioni L, Pessia M, Al-Owain M, D'Adamo MC. Lethal digenic mutations in the K + channels Kir4.1 ( KCNJ10) and SLACK ( KCNT1) associated with severe-disabling seizures and neurodevelopmental delay. J Neurophysiol 2017; 118:2402-2411. [PMID: 28747464 DOI: 10.1152/jn.00284.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/05/2017] [Accepted: 07/21/2017] [Indexed: 01/14/2023] Open
Abstract
A 2-yr-old boy presented profound developmental delay, failure to thrive, ataxia, hypotonia, and tonic-clonic seizures that caused the death of the patient. Targeted and whole exome sequencing revealed two heterozygous missense variants: a novel mutation in the KCNJ10 gene that encodes for the inward-rectifying K+ channel Kir4.1 and another previously characterized mutation in KCNT1 that encodes for the Na+-activated K+ channel known as Slo2.2 or SLACK. The objectives of this study were to perform the clinical and genetic characterization of the proband and his family and to examine the functional consequence of the Kir4.1 mutation. The mutant and wild-type KCNJ10 constructs were generated and heterologously expressed in Xenopus laevis oocytes, and whole cell K+ currents were measured using the two-electrode voltage-clamp technique. The KCNJ10 mutation c.652C>T resulted in a p.L218F substitution at a highly conserved residue site. Wild-type KCNJ10 expression yielded robust Kir current, whereas currents from oocytes expressing the mutation were reduced, remarkably. Western Blot analysis revealed reduced protein expression by the mutation. Kir5.1 subunits display selective heteromultimerization with Kir4.1 constituting channels with unique kinetics. The effect of the mutation on Kir4.1/5.1 channel activity was twofold: a reduction in current amplitudes and an increase in the pH-dependent inhibition. We thus report a novel loss-of-function mutation in Kir4.1 found in a patient with a coexisting mutation in SLACK channels that results in a fatal disease.NEW & NOTEWORTHY We present and characterize a novel mutation in KCNJ10 Unlike previously reported EAST/SeSAME patients, our patient was heterozygous, and contrary to previous studies, mimicking the heterozygous state by coexpression resulted in loss of channel function. We report in the same patient co-occurrence of a KCNT1 mutation resulting in a more severe phenotype. This study provides new insights into the phenotypic spectrum and to the genotype-phenotype correlations associated with EAST/SeSAME and MMFSI.
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Affiliation(s)
- Sonia Hasan
- Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Ameera Balobaid
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Omar Dabbagh
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Marta Cenciarini
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Rifaat Rawashdeh
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Afaf Al-Sagheir
- Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Cecilia Bove
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Lara Macchioni
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy
| | - Mauro Pessia
- Section of Physiology and Biochemistry, Department of Experimental Medicine, School of Medicine, University of Perugia, Perugia, Italy.,Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.,College of Medicine, AlFaisal University, Riyadh, Saudi Arabia; and
| | - Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; .,Fondazione Santa Lucia, IRCCS, Rome, Italy
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