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Vaché C, Faugère V, Baux D, Mansard L, Van Goethem C, Dhaenens CM, Grunewald O, Audo I, Zeitz C, Meunier I, Bocquet B, Cossée M, Bergougnoux A, Kalatzis V, Roux AF. Validation of Nanopore long-read sequencing to resolve RPGR ORF15 genotypes in individuals with X-linked retinitis pigmentosa. Eur J Hum Genet 2024:10.1038/s41431-024-01649-0. [PMID: 38969740 DOI: 10.1038/s41431-024-01649-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/15/2024] [Accepted: 06/11/2024] [Indexed: 07/07/2024] Open
Abstract
X-linked retinitis pigmentosa (XLRP) is characterized by progressive vision loss leading to legal blindness in males and a broad severity spectrum in carrier females. Pathogenic alterations of the retinitis pigmentosa GTPase regulator gene (RPGR) are responsible for over 70% of XLRP cases. In the retina, the RPGRORF15 transcript includes a terminal exon, called ORF15, that is altered in the large majority of RPGR-XLRP cases. Unfortunately, due to its highly repetitive sequence, ORF15 represents a considerable challenge in terms of sequencing for molecular diagnostic laboratories. However, in a recent preliminary work Yahya et al. reported a long-read sequencing approach seeming promising. Here, the aim of the study was to validate and integrate this new sequencing strategy in a routine screening workflow. For that purpose, we performed a masked test on 52 genomic DNA samples from male and female individuals carrying 32 different pathogenic ORF15 variations including 20 located in the highly repetitive region of the exon. For the latter, we have obtained a detection rate of 80-85% in males and 60-80% in females after bioinformatic analyses. These numbers raised to 100% for both status after adding a complementary visual inspection of ORF15 long-reads. In accordance with these results, and considering the frequency of ORF15 pathogenic variations in XLRP, we suggest that a long-read screening of ORF15 should be systematically considered before any other sequencing approach in subjects with a diagnosis compatible with XLRP.
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Affiliation(s)
- Christel Vaché
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France.
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France.
| | - Valérie Faugère
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
| | - David Baux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- Montpellier BioInformatique pour le Diagnostic Clinique (MOBIDIC), CHU Montpellier, Montpellier, France
| | - Luke Mansard
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
| | - Charles Van Goethem
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Montpellier BioInformatique pour le Diagnostic Clinique (MOBIDIC), CHU Montpellier, Montpellier, France
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Olivier Grunewald
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Isabelle Audo
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, Centre de Référence Maladies Rares REFERET, Inserm-DGOS CIC1423, Paris, France
| | - Christina Zeitz
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, Paris, France
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Béatrice Bocquet
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Mireille Cossée
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- PhyMedExp, Univ Montpellier, Inserm, CNRS, Montpellier, France
| | - Anne Bergougnoux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- PhyMedExp, Univ Montpellier, Inserm, CNRS, Montpellier, France
| | - Vasiliki Kalatzis
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Anne-Françoise Roux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- GCS AURAGEN, Lyon, France
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2
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Audo I, Nassisi M, Zeitz C, Sahel JA. The Extraordinary Phenotypic and Genetic Variability of Retinal and Macular Degenerations: The Relevance to Therapeutic Developments. Cold Spring Harb Perspect Med 2024; 14:a041652. [PMID: 37604589 PMCID: PMC11146306 DOI: 10.1101/cshperspect.a041652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Inherited retinal diseases (IRDs) are a clinically and genetically heterogeneous group of rare conditions leading to various degrees of visual handicap and to progressive blindness in more severe cases. Besides visual rehabilitation, educational, and socio-professional support, there are currently limited therapeutic options, but the approval of the first gene therapy product for RPE65-related IRDs raised hope for therapeutic innovations. Such developments are facing obstacles intrinsic to the disease and the affected tissue including the extreme phenotypic and genetic variability of IRDs and the fine tuning of visual processing through the complex architecture of the postmitotic neural retina. A precise phenotypic characterization is required prior to genetic testing, which now relies on high-throughput sequencing. Their challenges will be discussed within this article as well as their implications in clinical trial design.
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Affiliation(s)
- Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris 75012, France
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, Paris F-75012, France
| | - Marco Nassisi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris 75012, France
- Department of Clinical Sciences and Community Health, University of Milan, Milan 20122, Italy
- Ophthalmology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano, Milan 20122, Italy
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris 75012, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris 75012, France
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, National Rare Disease Center REFERET and INSERM-DGOS CIC 1423, Paris F-75012, France
- Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania 15213, USA
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3
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Pantrangi M, Rath J, Kaetterhenry N, Branham K, Talsness D, Weber JL. Clinical sequencing of the retinitis pigmentosa gene RPGR in over 1,000 cases of vision loss. Mol Vis 2024; 30:49-57. [PMID: 38586605 PMCID: PMC10994678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 02/17/2024] [Indexed: 04/09/2024] Open
Abstract
RPGR pathogenic variants are the major cause of X-linked retinitis pigmentosa. Here, we report the results from 1,033 clinical DNA tests that included sequencing of RPGR. A total of 184 RPGR variants were identified: 78 pathogenic or likely pathogenic, 14 uncertain, and 92 likely benign or benign. Among the pathogenic and likely pathogenic variants, 23 were novel, and most were frameshift or nonsense mutations (87%) and enriched (67%) in RPGR exon 15 (ORF15). Identical pathogenic variants found in different families were largely on different haplotype backgrounds, indicating relatively frequent, recurrent RPGR mutations. None of the 16 mother/affected son pairs showed de novo mutations; all 16 mothers were heterozygous for the pathogenic variant. These last two observations support the occurrence of most RPGR mutations in the male germline.
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Affiliation(s)
- Madhulatha Pantrangi
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY
| | - Julie Rath
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
| | | | - Kari Branham
- University of Michigan, Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, Ann Arbor, MI
| | - Dana Talsness
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
| | - James L Weber
- PreventionGenetics, part of Exact Sciences, Marshfield, WI
- University of Wisconsin, School of Medicine and Public Health, Department of Pediatrics, Madison, WI
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Bonetti G, Cozza W, Bernini A, Kaftalli J, Mareso C, Cristofoli F, Medori MC, Colombo L, Martella S, Staurenghi G, Salvetti AP, Falsini B, Placidi G, Attanasio M, Pertile G, Bengala M, Bosello F, Petracca A, D’Esposito F, Toschi B, Lanzetta P, Ricci F, Viola F, Marceddu G, Bertelli M. Towards a Long-Read Sequencing Approach for the Molecular Diagnosis of RPGR ORF15 Genetic Variants. Int J Mol Sci 2023; 24:16881. [PMID: 38069202 PMCID: PMC10706286 DOI: 10.3390/ijms242316881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/17/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Sequencing of the low-complexity ORF15 exon of RPGR, a gene correlated with retinitis pigmentosa and cone dystrophy, is difficult to achieve with NGS and Sanger sequencing. False results could lead to the inaccurate annotation of genetic variants in dbSNP and ClinVar databases, tools on which HGMD and Ensembl rely, finally resulting in incorrect genetic variants interpretation. This paper aims to propose PacBio sequencing as a feasible method to correctly detect genetic variants in low-complexity regions, such as the ORF15 exon of RPGR, and interpret their pathogenicity by structural studies. Biological samples from 75 patients affected by retinitis pigmentosa or cone dystrophy were analyzed with NGS and repeated with PacBio. The results showed that NGS has a low coverage of the ORF15 region, while PacBio was able to sequence the region of interest and detect eight genetic variants, of which four are likely pathogenic. Furthermore, molecular modeling and dynamics of the RPGR Glu-Gly repeats binding to TTLL5 allowed for the structural evaluation of the variants, providing a way to predict their pathogenicity. Therefore, we propose PacBio sequencing as a standard procedure in diagnostic research for sequencing low-complexity regions such as RPGRORF15, aiding in the correct annotation of genetic variants in online databases.
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Affiliation(s)
- Gabriele Bonetti
- MAGI’s LAB, 38068 Rovereto, Italy; (M.C.M.); (M.B.)
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
| | - William Cozza
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Andrea Bernini
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, 53100 Siena, Italy;
| | - Jurgen Kaftalli
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Chiara Mareso
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | | | | | - Leonardo Colombo
- Department of Ophthalmology, ASST Santi Paolo e Carlo Hospital, University of Milan, 20142 Milan, Italy; (L.C.); (S.M.)
| | - Salvatore Martella
- Department of Ophthalmology, ASST Santi Paolo e Carlo Hospital, University of Milan, 20142 Milan, Italy; (L.C.); (S.M.)
| | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, 20157 Milan, Italy; (G.S.); (A.P.S.)
| | - Anna Paola Salvetti
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, 20157 Milan, Italy; (G.S.); (A.P.S.)
| | - Benedetto Falsini
- UOC Oculistica, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Largo Gemelli 8, 00168 Rome, Italy (G.P.)
- Istituto di Oftalmologia, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Giorgio Placidi
- UOC Oculistica, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Largo Gemelli 8, 00168 Rome, Italy (G.P.)
| | - Marcella Attanasio
- Ospedale Sacrocuore Don Calabria, Viale Luigi Rizzardi, 4, 37024 Negrar di Valpolicella, Italy; (M.A.); (G.P.)
| | - Grazia Pertile
- Ospedale Sacrocuore Don Calabria, Viale Luigi Rizzardi, 4, 37024 Negrar di Valpolicella, Italy; (M.A.); (G.P.)
| | - Mario Bengala
- Medical Genetics Unit, Department of Oncohematology, Policlinico Tor Vergata, 00133 Rome, Italy;
| | - Francesca Bosello
- Department of Surgical Sciences, Dentistry, Paediatrics and Gynaecology, Section of Ophthalmology, University of Verona, 37134 Verona, Italy;
| | - Antonio Petracca
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Fabiana D’Esposito
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
- Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London NW1 5QH, UK
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, 80138 Naples, Italy
| | - Benedetta Toschi
- Section of Medical Genetics, Department of Medical and Oncological Area, University Hospital of Pisa, 56126 Pisa, Italy;
| | - Paolo Lanzetta
- Department of Medicine-Ophthalmology, University of Udine, 33100 Udine, Italy;
- Istituto Europeo di Microchirurgia Oculare (IEMO), 33100 Udine, Italy
| | - Federico Ricci
- Department of Experimental Medicine, Tor Vergata University of Rome, Viale Oxford, 00133 Rome, Italy;
| | - Francesco Viola
- Department of Ophthalmology, Fondazione IRCCS Cà Granda, Clinica Regina Elena, 20122 Milan, Italy;
| | - Giuseppe Marceddu
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Matteo Bertelli
- MAGI’s LAB, 38068 Rovereto, Italy; (M.C.M.); (M.B.)
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
- MAGISNAT, Atlanta Tech Park, 107 Technology Parkway, Peachtree Corners, GA 30092, USA
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Nowomiejska K, Baltaziak K, Całka P, Ciesielka M, Teresiński G, Rejdak R. Identification of the RPGR Gene Pathogenic Variants in a Cohort of Polish Male Patients with Retinitis Pigmentosa Phenotype. Genes (Basel) 2023; 14:1950. [PMID: 37895299 PMCID: PMC10606843 DOI: 10.3390/genes14101950] [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: 09/17/2023] [Revised: 10/13/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
The goal of the study was to explore the spectrum of pathogenic variants in the RPGR gene in a group of male Polish patients with a retinitis pigmentosa (RP) phenotype. A total of 45 male index patients, including twins, being members of 44 families, were screened for pathogenic variants in the RPGR gene via the direct sequencing of PCR-amplified genomic DNA and underwent a comprehensive ophthalmological examination in one center located in Poland. A total of two pathogenic and five likely pathogenic variants in eight patients (18%) were detected in the studied cohort. Of these, five variants were novel, and five disease-causing variants (71%) were identified within the ORF15 mutational hotspot of the RPGR gene. The median age of onset of the disease was 10 years (range 6-14 years), the median age during the examination was 30 years (range 20-47 years), and the median visual acuity was 0.4 (range 0.01-0.7). The majority of patients had middle constriction of the visual field and thinning of the central foveal thickness. Dizygotic twins bearing the same hemizygous mutation showed a different retinal phenotype in regard to the severity of the symptoms. This is the first RPGR mutation screening in Poland showing a prevalence of 18% of RPGR pathogenic mutations and likely pathogenic variants in the studied cohort of male patients with an RP phenotype.
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Affiliation(s)
- Katarzyna Nowomiejska
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-059 Lublin, Poland; (K.B.); (R.R.)
| | - Katarzyna Baltaziak
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-059 Lublin, Poland; (K.B.); (R.R.)
| | - Paulina Całka
- Department of Forensic Medicine, Medical University of Lublin, 20-059 Lublin, Poland; (P.C.); (M.C.); (G.T.)
| | - Marzanna Ciesielka
- Department of Forensic Medicine, Medical University of Lublin, 20-059 Lublin, Poland; (P.C.); (M.C.); (G.T.)
| | - Grzegorz Teresiński
- Department of Forensic Medicine, Medical University of Lublin, 20-059 Lublin, Poland; (P.C.); (M.C.); (G.T.)
| | - Robert Rejdak
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-059 Lublin, Poland; (K.B.); (R.R.)
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Benson MD, Mukherjee S, Agather AR, Blain D, Cunningham D, Mays R, Sun X, Li T, Hufnagel RB, Brooks BP, Huryn LA, Zein WM, Cukras CA. RPGR: Deep Phenotyping and Genetic Characterization With Findings Specific to the 3'-end of ORF15. Invest Ophthalmol Vis Sci 2023; 64:19. [PMID: 37695603 PMCID: PMC10501488 DOI: 10.1167/iovs.64.12.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 07/27/2023] [Indexed: 09/12/2023] Open
Abstract
Purpose To describe a group of patients with retinitis pigmentosa GTPase regulator (RPGR)-related retinopathy with a tapetal-like retinal sheen and corresponding changes in the reflectivity of the ellipsoid zone on optical coherence tomography (OCT) imaging. Methods A retrospective case series of 66 patients with a disease-causing variant in RPGR was performed. An expert examiner, masked to patient demographics, clinical evaluations, and specific RPGR variant, analyzed color fundus photographs for the presence of a tapetal-like retinal sheen and assessed OCT images for the presence of an abnormally broad hyper-reflective band in the outer retina. Longitudinal reflectivity profiles were generated and compared with healthy controls. Results Twelve patients (18.2%) had a retinal sheen on color images that cosegregated with an abnormally broad hyper-reflective ellipsoid zone band on OCT imaging. Three-fourths of these patients were male, had a cone-rod dystrophy, and had pathogenic RPGR variants located toward the 3'-end of ORF15. This group had a different longitudinal reflectivity profile signature compared with controls. After a period of prolonged dark adaptation, the abnormal hyper-reflective band on OCT became less apparent, and the outer retinal layers adopted a more normal appearance. Conclusions RPGR-related retinopathy should be considered for males presenting with retinal sheen, abnormal ellipsoid zone hyper-reflectivity, and cone or cone-rod dysfunction on ERG, and pursued with molecular testing. Our results have implications for understanding the role of the C-terminal domain encoded by RPGR ORF15 in the phototransduction cascade. Further, the findings may be important to incorporate into both inclusion criteria and outcome measure developments in future RPGR-related cone or cone-rod dystrophy clinical trials.
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Affiliation(s)
- Matthew D. Benson
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Souvick Mukherjee
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Aime R. Agather
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Delphine Blain
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Denise Cunningham
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert Mays
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Xun Sun
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Tiansen Li
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert B. Hufnagel
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brian P. Brooks
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Laryssa A. Huryn
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Wadih M. Zein
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Catherine A. Cukras
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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Moran AL, Fehilly JD, Blacque O, Kennedy BN. Gene therapy for RAB28: What can we learn from zebrafish? Vision Res 2023; 210:108270. [PMID: 37321111 DOI: 10.1016/j.visres.2023.108270] [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: 02/02/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
The eye is particularly suited to gene therapy due to its accessibility, immunoprivileged state and compartmentalised structure. Indeed, many clinical trials are underway for therapeutic gene strategies for inherited retinal degenerations (IRDs). However, as there are currently 281 genes associated with IRD, there is still a large unmet need for effective therapies for the majority of IRD-causing genes. In humans, RAB28 null and hypomorphic alleles cause autosomal recessive cone-rod dystrophy (arCORD). Previous work demonstrated that restoring wild type zebrafish Rab28 via germline transgenesis, specifically in cone photoreceptors, is sufficient to rescue the defects in outer segment phagocytosis (OSP) observed in zebrafish rab28-/- knockouts (KO). This rescue suggests that gene therapy for RAB28-associated CORD may be successful by RAB28 gene restoration to cones. It also inspired us to critically consider the scenarios in which zebrafish can provide informative preclinical data for development of gene therapies. Thus, this review focuses on RAB28 biology and disease, and delves into both the opportunities and limitations of using zebrafish as a model for both gene therapy development and as a diagnostic tool for patient variants of unknown significance (VUS).
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Affiliation(s)
- Ailis L Moran
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - John D Fehilly
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Oliver Blacque
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Breandán N Kennedy
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland
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8
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Comander J, Weigel DiFranco C, Sanderson K, Place E, Maher M, Zampaglione E, Zhao Y, Huckfeldt RM, Bujakowska KM, Pierce E. Natural history of retinitis pigmentosa based on genotype, vitamin A/E supplementation, and an electroretinogram biomarker. JCI Insight 2023; 8:e167546. [PMID: 37261916 PMCID: PMC10445682 DOI: 10.1172/jci.insight.167546] [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: 01/27/2023] [Accepted: 05/26/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUNDA randomized clinical trial from 1984 to 1992 indicated that vitamin A supplementation had a beneficial effect on the progression of retinitis pigmentosa (RP), while vitamin E had an adverse effect.METHODSSequencing of banked DNA samples from that trial provided the opportunity to determine whether certain genotypes responded preferentially to vitamin supplementation.RESULTSThe genetic solution rate was 587 out of 765 (77%) of sequenced samples. Combining genetic solutions with electroretinogram outcomes showed that there were systematic differences in severity and progression seen among different genetic subtypes of RP, extending findings made for USH2A, RHO, RPGR, PRPF31, and EYS. Baseline electroretinogram 30-Hz flicker implicit time was an independent, strong predictor of progression rate. Using additional data and baseline implicit time as a predictor, the deleterious effect of vitamin E was still present. Surprisingly, the effect of vitamin A progression in the cohort as a whole was not detectable, with or without data from subsequent trials. Subgroup analyses are also discussed.CONCLUSIONOverall, genetic subtype and implicit time have significant predictive power for a patient's rate of progression, which is useful prognostically. While vitamin E supplementation should still be avoided, these data do not support a generalized neuroprotective effect of vitamin A for all types of RP.TRIAL REGISTRATIONClinicalTrials.gov NCT00000114, NCT00000116, and NCT00346333.FUNDINGFoundation Fighting Blindness and the National Eye Institute: R01 EY012910, R01 EY031036, R01 EY026904, and P30 EY014104.
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Affiliation(s)
- Jason Comander
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Carol Weigel DiFranco
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Kit Sanderson
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
- University of Toronto, Toronto, Ontario, Canada
| | - Emily Place
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew Maher
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Erin Zampaglione
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Yan Zhao
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Rachel M. Huckfeldt
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Kinga M. Bujakowska
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
| | - Eric Pierce
- Mass Eye and Ear, Ocular Genomics Institute, Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Boston, Massachusetts, USA
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Hadalin V, Buscarino M, Sajovic J, Meglič A, Jarc-Vidmar M, Hawlina M, Volk M, Fakin A. Genetic Characteristics and Long-Term Follow-Up of Slovenian Patients with RPGR Retinal Dystrophy. Int J Mol Sci 2023; 24:ijms24043840. [PMID: 36835250 PMCID: PMC9958649 DOI: 10.3390/ijms24043840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Genetic characteristics and a long-term clinical follow-up of 18 Slovenian retinitis pigmentosa GTPase regulator (RPGR) patients from 10 families with retinitis pigmentosa (RP) or cone/cone-rod dystrophy (COD/CORD) are reported. RP (eight families) was associated with two already known (p.(Ser407Ilefs*46) and p.(Glu746Argfs*23)) and five novel variants (c.1245+704_1415-2286del, p.(Glu660*), p.(Ala153Thr), c.1506+1G>T, and p.(Arg780Serfs*54)). COD (two families) was associated with p.(Ter1153Lysext*38). The median age of onset in males with RP (N = 9) was 6 years. At the first examination (median age of 32 years), the median best corrected visual acuity (BCVA) was 0.30 logMAR, and all patients had a hyperautofluorescent ring on fundus autofluorescence (FAF) encircling preserved photoreceptors. At the last follow-up (median age of 39 years), the median BCVA was 0.48 logMAR, and FAF showed ring constriction transitioning to patch in 2/9. Among females (N = 6; median age of 40 years), two had normal/near-normal FAF, one had unilateral RP (male pattern), and three had a radial and/or focal pattern of retinal degeneration. After a median of 4 years (4-21) of follow-up, 2/6 exhibited disease progression. The median age of onset in males with COD was 25 years. At first examination (median age of 35 years), the median BCVA was 1.00 logMAR, and all patients had a hyperautofluorescent FAF ring encircling foveal photoreceptor loss. At the last follow-up (median age of 42 years), the median BCVA was 1.30 logMAR, and FAF showed ring enlargement. The majority of the identified variants (75%; 6/8) had not been previously reported in other RPGR cohorts, which suggested the presence of distinct RPGR alleles in the Slovenian population.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Maša Buscarino
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
| | - Marija Volk
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, Šlajmerjeva 4, 1000 Ljubljana, Slovenia
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia
- Correspondence:
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