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Martínez-Pizarro A, Picó S, López-Márquez A, Rodriguez-López C, Montalvo E, Alvarez M, Castro M, Ramón-Maiques S, Pérez B, Lucas JJ, Richard E, Desviat LR. PAH deficient pathology in humanized c.1066-11G>A phenylketonuria mice. Hum Mol Genet 2024; 33:1074-1089. [PMID: 38520741 PMCID: PMC11153335 DOI: 10.1093/hmg/ddae051] [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: 12/26/2023] [Revised: 02/12/2024] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
We have generated using CRISPR/Cas9 technology a partially humanized mouse model of the neurometabolic disease phenylketonuria (PKU), carrying the highly prevalent PAH variant c.1066-11G>A. This variant creates an alternative 3' splice site, leading to the inclusion of 9 nucleotides coding for 3 extra amino acids between Q355 and Y356 of the protein. Homozygous Pah c.1066-11A mice, with a partially humanized intron 10 sequence with the variant, accurately recapitulate the splicing defect and present almost undetectable hepatic PAH activity. They exhibit fur hypopigmentation, lower brain and body weight and reduced survival. Blood and brain phenylalanine levels are elevated, along with decreased tyrosine, tryptophan and monoamine neurotransmitter levels. They present behavioral deficits, mainly hypoactivity and diminished social interaction, locomotor deficiencies and an abnormal hind-limb clasping reflex. Changes in the morphology of glial cells, increased GFAP and Iba1 staining signals and decreased myelinization are observed. Hepatic tissue exhibits nearly absent PAH protein, reduced levels of chaperones DNAJC12 and HSP70 and increased autophagy markers LAMP1 and LC3BII, suggesting possible coaggregation of mutant PAH with chaperones and subsequent autophagy processing. This PKU mouse model with a prevalent human variant represents a useful tool for pathophysiology research and for novel therapies development.
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Affiliation(s)
- Ainhoa Martínez-Pizarro
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
| | - Sara Picó
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Arístides López-Márquez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Claudia Rodriguez-López
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Elena Montalvo
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Mar Alvarez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Margarita Castro
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
- Centro de Diagnóstico de Enfermedades Moleculares (CEDEM), Francisco Tomás y Valiente 7, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Santiago Ramón-Maiques
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Biomedicina de Valencia (IBV-CSIC), Jaume Roig, 11, 46010 València, Valencia, Spain
| | - Belén Pérez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
- Centro de Diagnóstico de Enfermedades Moleculares (CEDEM), Francisco Tomás y Valiente 7, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - José J Lucas
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
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2
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Corradi Z, Hitti-Malin RJ, de Rooij LA, Garanto A, Collin RWJ, Cremers FPM. Antisense Oligonucleotide-Based Rescue of Complex Intronic Splicing Defects in ABCA4. Nucleic Acid Ther 2024. [PMID: 38800942 DOI: 10.1089/nat.2024.0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024] Open
Abstract
The ABCA4 gene, involved in Stargardt disease, has a high percentage of splice-altering pathogenic variants, some of which cause complex RNA defects. Although antisense oligonucleotides (AONs) have shown promising results in splicing modulation, they have not yet been used to target complex splicing defects. Here, we performed AON-based rescue studies on ABCA4 complex splicing defects. Intron 13 variants c.1938-724A>G, c.1938-621G>A, c.1938-619A>G, and c.1938-514A>G all lead to the inclusion of different pseudo-exons (PEs) with and without an upstream PE (PE1). Intron 44 variant c.6148-84A>T results in multiple PE inclusions and/or exon skipping events. Five novel AONs were designed to target these defects. AON efficacy was assessed by in vitro splice assays using midigenes containing the variants of interest. All screened complex splicing defects were effectively rescued by the AONs. Although varying levels of efficacy were observed between AONs targeting the same PEs, for all variants at least one AON restored splicing to levels comparable or better than wildtype. In conclusion, AONs are a promising approach to target complex splicing defects in ABCA4.
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Affiliation(s)
- Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rebekkah J Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura A de Rooij
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
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3
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Suárez-Herrera N, Garanto A, Collin RWJ. Understanding and Rescuing the Splicing Defect Caused by the Frequent ABCA4 Variant c.4253+43G>A Underlying Stargardt Disease. Nucleic Acid Ther 2024; 34:73-82. [PMID: 38466963 DOI: 10.1089/nat.2023.0076] [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] [Indexed: 03/13/2024] Open
Abstract
Pathogenic variants in ABCA4 are the underlying molecular cause of Stargardt disease (STGD1), an autosomal recessive macular dystrophy characterized by a progressive loss of central vision. Among intronic ABCA4 variants, c.4253+43G>A is frequently detected in STGD1 cases and is classified as a hypomorphic allele, generally associated with late-onset cases. This variant was previously reported to alter splicing regulatory sequences, but the splicing outcome is not fully understood yet. In this study, we attempted to better understand its effect on splicing and to rescue the aberrant splicing via antisense oligonucleotides (AONs). Wild-type and c.4253+43G>A variant-harboring maxigene vectors revealed additional skipping events, which were not previously detected upon transfection in HEK293T cells. To restore exon inclusion, we designed a set of 27 AONs targeting either splicing silencer motifs or the variant region and screened these in maxigene-transfected HEK293T cells. Candidate AONs able to promote exon inclusion were selected for further testing in patient-derived photoreceptor precursor cells. Surprisingly, no robust splicing modulation was observed in this model system. Overall, this research helped to adequately characterize the splicing alteration caused by the c.4253+43G>A variant, although future development of AON-mediated exon inclusion therapy for ABCA4 is needed.
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Affiliation(s)
- Nuria Suárez-Herrera
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
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4
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Suárez-Herrera N, Li CHZ, Leijsten N, Karjosukarso DW, Corradi Z, Bukkems F, Duijkers L, Cremers FPM, Hoyng CB, Garanto A, Collin RWJ. Preclinical Development of Antisense Oligonucleotides to Rescue Aberrant Splicing Caused by an Ultrarare ABCA4 Variant in a Child with Early-Onset Stargardt Disease. Cells 2024; 13:601. [PMID: 38607040 PMCID: PMC11011354 DOI: 10.3390/cells13070601] [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: 12/21/2023] [Revised: 03/19/2024] [Accepted: 03/27/2024] [Indexed: 04/13/2024] Open
Abstract
Precision medicine is rapidly gaining recognition in the field of (ultra)rare conditions, where only a few individuals in the world are affected. Clinical trial design for a small number of patients is extremely challenging, and for this reason, the development of N-of-1 strategies is explored to accelerate customized therapy design for rare cases. A strong candidate for this approach is Stargardt disease (STGD1), an autosomal recessive macular degeneration characterized by high genetic and phenotypic heterogeneity. STGD1 is caused by pathogenic variants in ABCA4, and amongst them, several deep-intronic variants alter the pre-mRNA splicing process, generally resulting in the insertion of pseudoexons (PEs) into the final transcript. In this study, we describe a 10-year-old girl harboring the unique deep-intronic ABCA4 variant c.6817-713A>G. Clinically, she presents with typical early-onset STGD1 with a high disease symmetry between her two eyes. Molecularly, we designed antisense oligonucleotides (AONs) to block the produced PE insertion. Splicing rescue was assessed in three different in vitro models: HEK293T cells, fibroblasts, and photoreceptor precursor cells, the last two being derived from the patient. Overall, our research is intended to serve as the basis for a personalized N-of-1 AON-based treatment to stop early vision loss in this patient.
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Affiliation(s)
- Nuria Suárez-Herrera
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Catherina H. Z. Li
- Department of Ophthalmology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (C.H.Z.L.); (C.B.H.)
| | - Nico Leijsten
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Dyah W. Karjosukarso
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Femke Bukkems
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Lonneke Duijkers
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
| | - Carel B. Hoyng
- Department of Ophthalmology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (C.H.Z.L.); (C.B.H.)
- Dutch Center for RNA Therapeutics, 2311 EZ Leiden, The Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
- Dutch Center for RNA Therapeutics, 2311 EZ Leiden, The Netherlands
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Rob W. J. Collin
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (N.S.-H.); (N.L.); (D.W.K.); (Z.C.); (F.B.); (L.D.); (F.P.M.C.); (A.G.)
- Dutch Center for RNA Therapeutics, 2311 EZ Leiden, The Netherlands
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Fujinami K, Waheed N, Laich Y, Yang P, Fujinami-Yokokawa Y, Higgins JJ, Lu JT, Curtiss D, Clary C, Michaelides M. Stargardt macular dystrophy and therapeutic approaches. Br J Ophthalmol 2024; 108:495-505. [PMID: 37940365 PMCID: PMC10958310 DOI: 10.1136/bjo-2022-323071] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Stargardt macular dystrophy (Stargardt disease; STGD1; OMIM 248200) is the most prevalent inherited macular dystrophy. STGD1 is an autosomal recessive disorder caused by multiple pathogenic sequence variants in the large ABCA4 gene (OMIM 601691). Major advances in understanding both the clinical and molecular features, as well as the underlying pathophysiology, have culminated in many completed, ongoing and planned human clinical trials of novel therapies.The aims of this concise review are to describe (1) the detailed phenotypic and genotypic characteristics of the disease, multimodal imaging findings, natural history of the disease, and pathogenesis, (2) the multiple avenues of research and therapeutic intervention, including pharmacological, cellular therapies and diverse types of genetic therapies that have either been investigated or are under investigation and (3) the exciting novel therapeutic approaches on the translational horizon that aim to treat STGD1 by replacing the entire 6.8 kb ABCA4 open reading frame.
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Affiliation(s)
- Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Nadia Waheed
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Yannik Laich
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Eye Center, Medical Center, University of Freiburg Faculty of Medicine, Freiburg, Germany
| | - Paul Yang
- Oregon Health and Science University Casey Eye Institute, Portland, Oregon, USA
| | - Yu Fujinami-Yokokawa
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Meguro-ku, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
- Department of Health Policy and Management, Keio University School of Medicine Graduate School of Medicine, Shinjuku-ku, Tokyo, Japan
| | | | - Jonathan T Lu
- SalioGen Therapeutics Inc, Lexington, Massachusetts, USA
| | - Darin Curtiss
- Applied Genetic Technologies Corporation, Alachua, Florida, USA
| | - Cathryn Clary
- SalioGen Therapeutics Inc, Lexington, Massachusetts, USA
| | - Michel Michaelides
- Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Suárez-Herrera N, Riswick IB, Vázquez-Domínguez I, Duijkers L, Karjosukarso DW, Piccolo D, Bauwens M, De Baere E, Cheetham ME, Garanto A, Collin RWJ. Proof-of-concept for multiple AON delivery by a single U7snRNA vector to restore splicing defects in ABCA4. Mol Ther 2024; 32:837-851. [PMID: 38243599 PMCID: PMC10928313 DOI: 10.1016/j.ymthe.2024.01.019] [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: 09/13/2023] [Revised: 12/13/2023] [Accepted: 01/12/2024] [Indexed: 01/21/2024] Open
Abstract
The high allelic heterogeneity in Stargardt disease (STGD1) complicates the design of intervention strategies. A significant proportion of pathogenic intronic ABCA4 variants alters the pre-mRNA splicing process. Antisense oligonucleotides (AONs) are an attractive yet mutation-specific therapeutic strategy to restore these splicing defects. In this study, we experimentally assessed the potential of a splicing modulation therapy to target multiple intronic ABCA4 variants. AONs were inserted into U7snRNA gene cassettes and tested in midigene-based splice assays. Five potent antisense sequences were selected to generate a multiple U7snRNA cassette construct, and this combination vector showed substantial rescue of all of the splicing defects. Therefore, the combination cassette was used for viral synthesis and assessment in patient-derived photoreceptor precursor cells (PPCs). Simultaneous delivery of several modified U7snRNAs through a single AAV, however, did not show substantial splicing correction, probably due to suboptimal transduction efficiency in PPCs and/or a heterogeneous viral population containing incomplete AAV genomes. Overall, these data demonstrate the potential of the U7snRNA system to rescue multiple splicing defects, but also suggest that AAV-associated challenges are still a limiting step, underscoring the need for further optimization before implementing this strategy as a potential treatment for STGD1.
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Affiliation(s)
- Nuria Suárez-Herrera
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Iris B Riswick
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Irene Vázquez-Domínguez
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Lonneke Duijkers
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | - Dyah W Karjosukarso
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands
| | | | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium; Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium; Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium
| | | | - Alejandro Garanto
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands; Radboud University Medical Center, Amalia Children's Hospital, Department of Pediatrics, Nijmegen 6252GA, the Netherlands
| | - Rob W J Collin
- Radboud University Medical Center, Department of Human Genetics, 6525GA Nijmegen, the Netherlands.
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Villafuerte-de la Cruz RA, Garza-Garza LA, Garza-Leon M, Rodriguez-De la Torre C, Parra-Bernal C, Vazquez-Camas I, Ramos-Gonzalez D, Rangel-Padilla A, Espino Barros-Palau A, Nava-García J, Castillo-Velazquez J, Castillo-De Leon E, Del Valle-Penella A, Valdez-Garcia JE, Rojas-Martinez A. Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico. BMC Ophthalmol 2024; 24:60. [PMID: 38347443 PMCID: PMC10860328 DOI: 10.1186/s12886-023-03276-7] [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: 08/30/2023] [Accepted: 12/26/2023] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Inherited retinal dystrophies are hereditary diseases which have in common the progressive degeneration of photoreceptors. They are a group of diseases with clinical, genetic, and allelic heterogeneity. There is limited information regarding the genetic landscape of inherited retinal diseases in Mexico, therefore, the present study was conducted in the northeast region of the country. METHODS Patients with inherited retinal dystrophies were included. A complete history, full ophthalmological and medical genetics evaluations, and genetic analysis through a targeted NGS panel for inherited retinal dystrophies comprising at least 293 genes were undertaken. RESULTS A total of 126 patients were included. Cases were solved in 74.6% of the study's population. Retinitis pigmentosa accounted for the most found inherited retinal disease. Ninety-nine causal variants were found, being USH2A and ABCA4 the most affected genes (26 and 15 cases, respectively). CONCLUSIONS The present study documents the most prevalent causative genes in IRDs, as USH2A, in northeastern Mexico. This contrasts with previous reports of IRDs in other zones of the country. Further studies, targeting previously unstudied populations in Mexico are important to document the genetic background of inherited retinal dystrophies in the country.
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Affiliation(s)
- Rocio A Villafuerte-de la Cruz
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
- Destellos de Luz, San Pedro Garza García, México
| | | | - Manuel Garza-Leon
- Destellos de Luz, San Pedro Garza García, México
- Clinical Science Department, Health Sciences Division, University of Monterrey, Monterrey, México
| | - Cesar Rodriguez-De la Torre
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Cinthya Parra-Bernal
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Ilse Vazquez-Camas
- Tecnologico de Monterrey, The Institute for Obesity Research, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
- Tecnologico Nacional de Mexico Campus Tuxtla Gutierrez, Tuxtla Gutierrez, Mexico
| | - David Ramos-Gonzalez
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Andrea Rangel-Padilla
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Angelina Espino Barros-Palau
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Jose Nava-García
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | | | | | | | - Jorge E Valdez-Garcia
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico
| | - Augusto Rojas-Martinez
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de La Salud, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico.
- Tecnologico de Monterrey, The Institute for Obesity Research, Ave. Morones Prieto 3000, Col. Los Doctores, Monterrey, CP 64710, Mexico.
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8
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Kaltak M, de Bruijn P, van Leeuwen W, Platenburg G, Cremers FPM, Collin RWJ, Swildens J. QR-1011 restores defective ABCA4 splicing caused by multiple severe ABCA4 variants underlying Stargardt disease. Sci Rep 2024; 14:684. [PMID: 38182646 PMCID: PMC10770117 DOI: 10.1038/s41598-024-51203-7] [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: 10/10/2023] [Accepted: 01/02/2024] [Indexed: 01/07/2024] Open
Abstract
Stargardt disease type 1 (STGD1), the most common form of hereditary macular dystrophy, can be caused by biallelic combinations of over 2200 variants in the ABCA4 gene. This leads to reduced or absent ABCA4 protein activity, resulting in toxic metabolite accumulation in the retina and damage of the retinal pigment epithelium and photoreceptors. Approximately 21% of all ABCA4 variants that contribute to disease influence ABCA4 pre-mRNA splicing. This emphasizes the need for therapies to restore disrupted ABCA4 splicing and halt STGD1 progression. Previously, QR-1011, an antisense oligonucleotide (AON), successfully corrected splicing abnormalities and restored normal ABCA4 protein translation in human retinal organoids carrying the prevalent disease-causing variant c.5461-10T>C in ABCA4. Here, we investigated whether QR-1011 could also correct splicing in four less common non-canonical splice site (NCSS) variants flanking ABCA4 exon 39: c.5461-8T>G, c.5461-6T>C, c.5584+5G>A and c.5584+6T>C. We administered QR-1011 and three other AONs to midigene-transfected cells and demonstrate that QR-1011 had the most pronounced effect on splicing compared to the others. Moreover, QR-1011 significantly increased full-length ABCA4 transcript levels for c.5461-8T>G and c.5584+6T>C. Splicing restoration could not be achieved in the other two variants, suggesting their more severe effect on splicing. Overall, QR-1011, initially developed for a single ABCA4 variant, exhibited potent splice correction capabilities for two additional severe NCSS variants nearby. This suggests the possibility of a broader therapeutic impact of QR-1011 extending beyond its original target and highlights the potential for treating a larger population of STGD1 patients affected by multiple severe ABCA4 variants with a single AON.
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Affiliation(s)
- Melita Kaltak
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Petra de Bruijn
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Willemijn van Leeuwen
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Gerard Platenburg
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, The Netherlands
| | - Jim Swildens
- R&D Department, ProQR Therapeutics, Zernikedreef 9, 2333 CK, Leiden, The Netherlands.
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9
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Kaltak M, Corradi Z, Collin RWJ, Swildens J, Cremers FPM. Stargardt disease-associated missense and synonymous ABCA4 variants result in aberrant splicing. Hum Mol Genet 2023; 32:3078-3089. [PMID: 37555651 PMCID: PMC10586196 DOI: 10.1093/hmg/ddad129] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/03/2023] [Accepted: 08/03/2023] [Indexed: 08/10/2023] Open
Abstract
Missense variants in ABCA4 constitute ~50% of causal variants in Stargardt disease (STGD1). Their pathogenicity is attributed to their direct effect on protein function, whilst their potential impact on pre-mRNA splicing disruption remains poorly understood. Interestingly, synonymous ABCA4 variants have previously been classified as 'severe' variants based on in silico analyses. Here, we systemically investigated the role of synonymous and missense variants in ABCA4 splicing by combining computational predictions and experimental assays. To identify variants of interest, we used SpliceAI to ascribe defective splice predictions on a dataset of 5579 biallelic STGD1 probands. We selected those variants with predicted delta scores for acceptor/donor gain > 0.20, and no previous reports on their effect on splicing. Fifteen ABCA4 variants were selected, 4 of which were predicted to create a new splice acceptor site and 11 to create a new splice donor site. In addition, three variants of interest with delta scores < 0.20 were included. The variants were introduced in wild-type midigenes that contained 4-12 kb of ABCA4 genomic sequence, which were subsequently expressed in HEK293T cells. By using RT-PCR and Sanger sequencing, we identified splice aberrations for 16 of 18 analyzed variants. SpliceAI correctly predicted the outcomes for 15 out of 18 variants, illustrating its reliability in predicting the impact of coding ABCA4 variants on splicing. Our findings highlight a causal role for coding ABCA4 variants in splicing aberrations, improving the severity assessment of missense and synonymous ABCA4 variants, and guiding to new treatment strategies for STGD1.
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Affiliation(s)
- Melita Kaltak
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
- R&D Department, ProQR Therapeutics, Leiden, 2333 CK, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
| | - Jim Swildens
- R&D Department, ProQR Therapeutics, Leiden, 2333 CK, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, 6525 GA, The Netherlands
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10
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Corradi Z, Khan M, Hitti-Malin R, Mishra K, Whelan L, Cornelis SS, Hoyng CB, Kämpjärvi K, Klaver CCW, Liskova P, Stöhr H, Weber BHF, Banfi S, Farrar GJ, Sharon D, Zernant J, Allikmets R, Dhaenens CM, Cremers FPM. Targeted sequencing and in vitro splice assays shed light on ABCA4-associated retinopathies missing heritability. HGG ADVANCES 2023; 4:100237. [PMID: 37705246 PMCID: PMC10534262 DOI: 10.1016/j.xhgg.2023.100237] [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: 06/05/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/15/2023] Open
Abstract
The ABCA4 gene is the most frequently mutated Mendelian retinopathy-associated gene. Biallelic variants lead to a variety of phenotypes, however, for thousands of cases the underlying variants remain unknown. Here, we aim to shed further light on the missing heritability of ABCA4-associated retinopathy by analyzing a large cohort of macular dystrophy probands. A total of 858 probands were collected from 26 centers, of whom 722 carried no or one pathogenic ABCA4 variant, while 136 cases carried two ABCA4 alleles, one of which was a frequent mild variant, suggesting that deep-intronic variants (DIVs) or other cis-modifiers might have been missed. After single molecule molecular inversion probes (smMIPs)-based sequencing of the complete 128-kb ABCA4 locus, the effect of putative splice variants was assessed in vitro by midigene splice assays in HEK293T cells. The breakpoints of copy number variants (CNVs) were determined by junction PCR and Sanger sequencing. ABCA4 sequence analysis solved 207 of 520 (39.8%) naive or unsolved cases and 70 of 202 (34.7%) monoallelic cases, while additional causal variants were identified in 54 of 136 (39.7%) probands carrying two variants. Seven novel DIVs and six novel non-canonical splice site variants were detected in a total of 35 alleles and characterized, including the c.6283-321C>G variant leading to a complex splicing defect. Additionally, four novel CNVs were identified and characterized in five alleles. These results confirm that smMIPs-based sequencing of the complete ABCA4 gene provides a cost-effective method to genetically solve retinopathy cases and that several rare structural and splice altering defects remain undiscovered in Stargardt disease cases.
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Affiliation(s)
- Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands
| | - Rebekkah Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ketan Mishra
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Laura Whelan
- The School of Genetics & Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Stéphanie S Cornelis
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Caroline C W Klaver
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands; Institute of Molecular & Clinical Ophthalmology, Basel, Switzerland
| | - Petra Liskova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic; Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Heidi Stöhr
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Institute of Clinical Human Genetics, University Hospital Regensburg, Regensburg, Germany
| | - Sandro Banfi
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples and Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - G Jane Farrar
- The School of Genetics & Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jana Zernant
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY, USA; Department of Pathology & Cell Biology, Columbia University, New York, NY, USA
| | - Claire-Marie Dhaenens
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands; University Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, 59000 Lille, France
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
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11
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Rodríguez-Hidalgo M, de Bruijn SE, Corradi Z, Rodenburg K, Lara-López A, Valverde-Megías A, Ávila-Fernández A, Fernandez-Caballero L, Del Pozo-Valero M, Corominas J, Gilissen C, Irigoyen C, Cremers FPM, Ayuso C, Ruiz-Ederra J, Roosing S. ABCA4 c.6480-35A>G, a novel branchpoint variant associated with Stargardt disease. Front Genet 2023; 14:1234032. [PMID: 37779911 PMCID: PMC10539688 DOI: 10.3389/fgene.2023.1234032] [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: 06/03/2023] [Accepted: 08/15/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction: Inherited retinal dystrophies (IRDs) can be caused by variants in more than 280 genes. The ATP-binding cassette transporter type A4 (ABCA4) gene is one of these genes and has been linked to Stargardt disease type 1 (STGD1), fundus flavimaculatus, cone-rod dystrophy (CRD), and pan-retinal CRD. Approximately 25% of the reported ABCA4 variants affect RNA splicing. In most cases, it is necessary to perform a functional assay to determine the effect of these variants. Methods: Whole genome sequencing (WGS) was performed in one Spanish proband with Stargardt disease. The putative pathogenicity of c.6480-35A>G on splicing was investigated both in silico and in vitro. The in silico approach was based on the deep-learning tool SpliceAI. For the in vitro approach we used a midigene splice assay in HEK293T cells, based on a previously established wild-type midigene (BA29) containing ABCA4 exons 46 to 48. Results: Through the analysis of WGS data, we identified two candidate variants in ABCA4 in one proband: a previously described deletion, c.699_768+342del (p.(Gln234Phefs*5)), and a novel branchpoint variant, c.6480-35A>G. Segregation analysis confirmed that the variants were in trans. For the branchpoint variant, SpliceAI predicted an acceptor gain with a high score (0.47) at position c.6480-47. A midigene splice assay in HEK293T cells revealed the inclusion of the last 47 nucleotides of intron 47 creating a premature stop codon and allowed to categorize the variant as moderately severe. Subsequent analysis revealed the presence of this variant as a second allele besides c.1958G>A p.(Arg653His) in an additional Spanish proband in a large cohort of IRD cases. Conclusion: A splice-altering effect of the branchpoint variant, confirmed by the midigene splice assay, along with the identification of this variant in a second unrelated individual affected with STGD, provides sufficient evidence to classify the variant as likely pathogenic. In addition, this research highlights the importance of studying non-coding regions and performing functional assays to provide a conclusive molecular diagnosis.
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Affiliation(s)
- María Rodríguez-Hidalgo
- Department of Neuroscience, Biodonostia Health Research Institute, Donostia-San Sebastián, Spain
- Department of Genetic, Physical Anthropology and Animal Physiology, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Suzanne E. de Bruijn
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Kim Rodenburg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | - Almudena Ávila-Fernández
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Lidia Fernandez-Caballero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Del Pozo-Valero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Jordi Corominas
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Cristina Irigoyen
- Department of Neuroscience, Biodonostia Health Research Institute, Donostia-San Sebastián, Spain
- Ophthalmology Service, Donostia Universy Hospital, Donostia-San Sebastián, Spain
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Carmen Ayuso
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Javier Ruiz-Ederra
- Department of Neuroscience, Biodonostia Health Research Institute, Donostia-San Sebastián, Spain
- Department of Ophthalmology, University of the Basque Country (UPV/EHU), San Sebastián, Spain
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
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12
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Kaltak M, Blanco-Garavito R, Molday LL, Dhaenens CM, Souied EE, Platenburg G, Swildens J, Molday RS, Cremers FPM. Stargardt disease-associated in-frame ABCA4 exon 17 skipping results in significant ABCA4 function. J Transl Med 2023; 21:546. [PMID: 37587475 PMCID: PMC10428568 DOI: 10.1186/s12967-023-04406-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/01/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND ABCA4, the gene implicated in Stargardt disease (STGD1), contains 50 exons, of which 17 contain multiples of three nucleotides. The impact of in-frame exon skipping is yet to be determined. Antisense oligonucleotides (AONs) have been investigated in Usher syndrome-associated genes to induce skipping of in-frame exons carrying severe variants and mitigate their disease-linked effect. Upon the identification of a STGD1 proband carrying a novel exon 17 canonical splice site variant, the activity of ABCA4 lacking 22 amino acids encoded by exon 17 was examined, followed by design of AONs able to induce exon 17 skipping. METHODS A STGD1 proband was compound heterozygous for the splice variant c.2653+1G>A, that was predicted to result in in-frame skipping of exon 17, and a null variant [c.735T>G, p.(Tyr245*)]. Clinical characteristics of this proband were studied using multi-modal imaging and complete ophthalmological examination. The aberrant splicing of c.2653+1G>A was investigated in vitro in HEK293T cells with wild-type and mutant midigenes. The residual activity of the mutant ABCA4 protein lacking Asp864-Gly885 encoded by exon 17 was analyzed with all-trans-retinal-activated ATPase activity assay, along with its subcellular localization. To induce exon 17 skipping, the effect of 40 AONs was examined in vitro in WT WERI-Rb-1 cells and 3D human retinal organoids. RESULTS Late onset STGD1 in the proband suggests that c.2653+1G>A does not have a fully deleterious effect. The in vitro splice assay confirmed that this variant leads to ABCA4 transcripts without exon 17. ABCA4 Asp864_Gly863del was stable and retained 58% all-trans-retinal-activated ATPase activity compared to WT ABCA4. This sequence is located in an unstructured linker region between transmembrane domain 6 and nucleotide-binding domain-1 of ABCA4. AONs were designed to possibly reduce pathogenicity of severe variants harbored in exon 17. The best AON achieved 59% of exon 17 skipping in retinal organoids. CONCLUSIONS Exon 17 deletion in ABCA4 does not result in the absence of protein activity and does not cause a severe STGD1 phenotype when in trans with a null allele. By applying AONs, the effect of severe variants in exon 17 can potentially be ameliorated by exon skipping, thus generating partial ABCA4 activity in STGD1 patients.
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Affiliation(s)
- Melita Kaltak
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- ProQR Therapeutics, Leiden, The Netherlands
| | - Rocio Blanco-Garavito
- Department of Ophthalmology, Intercommunal Hospital Center and Henri Mondor Hospital, Paris-Est Créteil University, Creteil, France
| | - Laurie L Molday
- Department of Biochemistry and Molecular Biology, Department of Ophthalmology and Visual Sciences, Centre for Macular Research, University of British Columbia, Vancouver, BC, Canada
| | - Claire-Marie Dhaenens
- University of Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, Lille, France
| | - Eric E Souied
- Department of Ophthalmology, Intercommunal Hospital Center and Henri Mondor Hospital, Paris-Est Créteil University, Creteil, France
| | | | | | - Robert S Molday
- Department of Biochemistry and Molecular Biology, Department of Ophthalmology and Visual Sciences, Centre for Macular Research, University of British Columbia, Vancouver, BC, Canada
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
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13
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Viering DH, Hureaux M, Neveling K, Latta F, Kwint M, Blanchard A, Konrad M, Bindels RJ, Schlingmann KP, Vargas-Poussou R, de Baaij JH. Long-Read Sequencing Identifies Novel Pathogenic Intronic Variants in Gitelman Syndrome. J Am Soc Nephrol 2023; 34:333-345. [PMID: 36302598 PMCID: PMC10103101 DOI: 10.1681/asn.2022050627] [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: 05/30/2022] [Accepted: 10/17/2022] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Gitelman syndrome is a salt-losing tubulopathy characterized by hypokalemic alkalosis and hypomagnesemia. It is caused by homozygous recessive or compound heterozygous pathogenic variants in SLC12A3 , which encodes the Na + -Cl - cotransporter (NCC). In up to 10% of patients with Gitelman syndrome, current genetic techniques detect only one specific pathogenic variant. This study aimed to identify a second pathogenic variant in introns, splice sites, or promoters to increase the diagnostic yield. METHODS Long-read sequencing of SLC12A3 was performed in 67 DNA samples from individuals with suspected Gitelman syndrome in whom a single likely pathogenic or pathogenic variant was previously detected. In addition, we sequenced DNA samples from 28 individuals with one variant of uncertain significance or no candidate variant. Midigene splice assays assessed the pathogenicity of novel intronic variants. RESULTS A second likely pathogenic/pathogenic variant was identified in 45 (67%) patients. Those with two likely pathogenic/pathogenic variants had a more severe electrolyte phenotype than other patients. Of the 45 patients, 16 had intronic variants outside of canonic splice sites (nine variants, mostly deep intronic, six novel), whereas 29 patients had an exonic variant or canonic splice site variant. Midigene splice assays of the previously known c.1670-191C>T variant and intronic candidate variants demonstrated aberrant splicing patterns. CONCLUSION Intronic pathogenic variants explain an important part of the missing heritability in Gitelman syndrome. Long-read sequencing should be considered in diagnostic workflows for Gitelman syndrome.
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Affiliation(s)
- Daan H.H.M. Viering
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marguerite Hureaux
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies Rénales Héréditaires de l’Enfant et de l’Adulte, MARHEA), Paris, France
- Department of Genetics, Hôpital Européen Georges-Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Paris CardioVascular Research Center, Institut National de la Santé et de Recherche Médicale (INSERM) U970, Paris City University, Paris, France
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Femke Latta
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Michael Kwint
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Anne Blanchard
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies Rénales Héréditaires de l’Enfant et de l’Adulte, MARHEA), Paris, France
- Clinical Investigations Center, Hôpital Européen Georges-Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, University of Paris, Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Martin Konrad
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - René J.M. Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - Rosa Vargas-Poussou
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies Rénales Héréditaires de l’Enfant et de l’Adulte, MARHEA), Paris, France
- Department of Genetics, Hôpital Européen Georges-Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
- Clinical Investigations Center, Hôpital Européen Georges-Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Jeroen H.F. de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
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14
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Goyenvalle A, Jimenez-Mallebrera C, van Roon W, Sewing S, Krieg AM, Arechavala-Gomeza V, Andersson P. Considerations in the Preclinical Assessment of the Safety of Antisense Oligonucleotides. Nucleic Acid Ther 2023; 33:1-16. [PMID: 36579950 PMCID: PMC9940817 DOI: 10.1089/nat.2022.0061] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The nucleic acid therapeutics field has made tremendous progress in the past decades. Continuous advances in chemistry and design have led to many successful clinical applications, eliciting even more interest from researchers including both academic groups and drug development companies. Many preclinical studies in the field focus on improving the delivery of antisense oligonucleotide drugs (ONDs) and/or assessing their efficacy in target tissues, often neglecting the evaluation of toxicity, at least in early phases of development. A series of consensus recommendations regarding regulatory considerations and expectations have been generated by the Oligonucleotide Safety Working Group and the Japanese Research Working Group for the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use S6 and Related Issues (WGS6) in several white papers. However, safety aspects should also be kept in sight in earlier phases while screening and designing OND to avoid subsequent failure in the development phase. Experts and members of the network "DARTER," a COST Action funded by the Cooperation in Science and Technology of the EU, have utilized their collective experience working with OND, as well as their insights into OND-mediated toxicities, to generate a series of consensus recommendations to assess OND toxicity in early stages of preclinical research. In the past few years, several publications have described predictive assays, which can be used to assess OND-mediated toxicity in vitro or ex vivo to filter out potential toxic candidates before moving to in vivo phases of preclinical development, that is, animal toxicity studies. These assays also have the potential to provide translational insight since they allow a safety evaluation in human in vitro systems. Yet, small preliminary in vivo studies should also be considered to complement this early assessment. In this study, we summarize the state of the art and provide guidelines and recommendations on the different tests available for these early stage preclinical assessments.
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Affiliation(s)
- Aurélie Goyenvalle
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France.,Address correspondence to: Aurélie Goyenvalle, PhD, Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles 78000, France
| | - Cecilia Jimenez-Mallebrera
- Laboratorio de Investigación Aplicada en Enfermedades Neuromusculares, Unidad de Patología Neuromuscular, Servicio de Neuropediatría, Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain.,Centro de Investigaciones Biomédicas en Red de Enfermedades Raras (CIBERER), Madrid, Spain.,Departamento de Genética, Microbiología y Estadística, Universitat de Barcelona, Barcelona, Spain
| | - Willeke van Roon
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Sabine Sewing
- Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Arthur M. Krieg
- RNA Therapeutics Institute, University of Massachusetts, Worcester, Massachusetts, USA
| | - Virginia Arechavala-Gomeza
- Neuromuscular Disorders, Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Patrik Andersson
- Safety Innovation, Safety Sciences, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Gothenburg, Sweden.,Address correspondence to: Patrik Andersson, PhD, Safety Innovation, Safety Sciences, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Pepparedsleden 1, Mölndal, Gothenburg 431 83, Sweden
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15
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Aartsma-Rus A, Garanto A, van Roon-Mom W, McConnell EM, Suslovitch V, Yan WX, Watts JK, Yu TW. Consensus Guidelines for the Design and In Vitro Preclinical Efficacy Testing N-of-1 Exon Skipping Antisense Oligonucleotides. Nucleic Acid Ther 2023; 33:17-25. [PMID: 36516128 PMCID: PMC9940807 DOI: 10.1089/nat.2022.0060] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Antisense oligonucleotides (ASOs) can modulate pre-mRNA splicing. This offers therapeutic opportunities for numerous genetic diseases, often in a mutation-specific and sometimes even individual-specific manner. Developing therapeutic ASOs for as few as even a single patient has been shown feasible with the development of Milasen for an individual with Batten disease. Efforts to develop individualized ASOs for patients with different genetic diseases are ongoing globally. The N = 1 Collaborative (N1C) is an umbrella organization dedicated to supporting the nascent field of individualized medicine. N1C recently organized a workshop to discuss and advance standards for the rigorous design and testing of splice-switching ASOs. In this study, we present guidelines resulting from that meeting and the key recommendations: (1) dissemination of standardized experimental designs, (2) use of standardized reference ASOs, and (3) a commitment to data sharing and exchange.
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Affiliation(s)
- Annemieke Aartsma-Rus
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.,N = 1 Collaborative
| | - Alejandro Garanto
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Pediatrics and Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Willeke van Roon-Mom
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Victoria Suslovitch
- N = 1 Collaborative.,Department of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Jonathan K Watts
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Timothy W Yu
- N = 1 Collaborative.,Department of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Division of Genetics and Genomics, Boston, Massachusetts, USA
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16
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The Diagnostic Yield of Next Generation Sequencing in Inherited Retinal Diseases: A Systematic Review and Meta-analysis. Am J Ophthalmol 2022; 249:57-73. [PMID: 36592879 DOI: 10.1016/j.ajo.2022.12.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023]
Abstract
PURPOSE Accurate genotyping of individuals with inherited retinal diseases (IRD) is essential for patient management and identifying suitable candidates for gene therapies. This study evaluated the diagnostic yield of next generation sequencing (NGS) in IRDs. DESIGN Systematic review and meta-analysis. METHODS This systematic review was prospectively registered (CRD42021293619). Ovid MEDLINE and Ovid Embase were searched on 6 June 2022. Clinical studies evaluating the diagnostic yield of NGS in individuals with IRDs were eligible for inclusion. Risk of bias assessment was performed. Studies were pooled using a random...effects inverse variance model. Sources of heterogeneity were explored using stratified analysis, meta-regression, and sensitivity analysis. RESULTS This study included 105 publications from 28 countries. Most studies (90 studies) used targeted gene panels. The diagnostic yield of NGS was 61.3% (95% confidence interval: 57.8-64.7%; 51 studies) in mixed IRD phenotypes, 58.2% (51.6-64.6%; 41 studies) in rod-cone dystrophies, 57.7% (46.8-68.3%; eight studies) in macular and cone/cone-rod dystrophies, and 47.6% (95% CI: 41.0-54.3%; four studies) in familial exudative vitreoretinopathy. For mixed IRD phenotypes, a higher diagnostic yield was achieved pooling studies published between 2018-2022 (64.2% [59.5-68.7%]), studies using exome sequencing (73.5% [58.9-86.1%]), and studies using the American College of Medical Genetics variant interpretation standards (65.6% [60.8-70.4%]). CONCLUSION The current diagnostic yield of NGS in IRDs is between 52-74%. The certainty of the evidence was judged as low or very low. A key limitation of the current evidence is the significant heterogeneity between studies. Adoption of standardized reporting guidelines could improve confidence in future meta-analyses.
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17
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Tomkiewicz TZ, Nieuwenhuis SE, Cremers FPM, Garanto A, Collin RWJ. Correction of the Splicing Defect Caused by a Recurrent Variant in ABCA4 (c.769-784C>T) That Underlies Stargardt Disease. Cells 2022; 11:3947. [PMID: 36552712 PMCID: PMC9777113 DOI: 10.3390/cells11243947] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/13/2022] Open
Abstract
Stargardt disease is an inherited retinal disease caused by biallelic mutations in the ABCA4 gene, many of which affect ABCA4 splicing. In this study, nine antisense oligonucleotides (AONs) were designed to correct pseudoexon (PE) inclusion caused by a recurrent deep-intronic variant in ABCA4 (c.769-784C>T). First, the ability of AONs to skip the PE from the final ABCA4 mRNA transcript was assessed in two cellular models carrying the c.769-784C>T variant: a midigene assay using HEK293T cells and patient-derived fibroblasts. Based on the splicing-correcting ability of each individual AON, the three most efficacious AONs targeting independent regions of the PE were selected for a final assessment in photoreceptor precursor cells (PPCs). The final analysis in the PPC model confirmed high efficacy of AON2, -5, and -7 in promoting PE exclusion. Among the three AONs, AON2 is chosen as the lead candidate for further optimization, hereby showcasing the high potential of AONs to correct aberrant splicing events driven by deep-intronic variants.
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Affiliation(s)
- Tomasz Z. Tomkiewicz
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Sara E. Nieuwenhuis
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Alejandro Garanto
- Departments of Pediatrics, Amalia Children’s Hospital, Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Rob W. J. Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
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18
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Affiliation(s)
- Tamar Ben-Yosef
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
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19
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Zheng Y, Zhou C, Zheng B, Hu G, Wang C, Zhou W, Lu Y, Zhang Z, Lin Q, Guo H, Jin Y, Liu Z, Tang W. Antisense oligonucleotides rescue an intronic splicing variant in the ABCB11 gene that causes progressive familial intrahepatic cholestasis type 2. Dig Liver Dis 2022; 54:1541-1547. [PMID: 35490150 DOI: 10.1016/j.dld.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/21/2022] [Accepted: 04/04/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a rare disorder caused by variants in the ABCB11 gene encoding the bile salt export pump (BSEP). We investigated the molecular defect in a PFIC2 infant and rescued the splicing defect with antisense oligonucleotides (ASOs). METHODS Whole-exome sequencing (WES) revealed compound heterozygous variants in the ABCB11 gene in a PFIC2 patient. Liver biopsy was immunostained for BSEP. The splicing effect of the candidate variants was investigated by minigene assay. ASOs were designed to rescue aberrant splicing. RESULTS A Chinese girl of two nonconsanguineous healthy parents suffered from low glutamyl transpeptidase cholestasis and showed no response to the ursodeoxycholic acid. WES revealed that the patient was compound heterozygous for two novel variants in the ABCB11 gene: c.76+29T>G and c.390-2A>G. Liver immunohistochemistry showed the absence of BSEP. The variant c.76+29T>G was confirmed to retain 42 bp in the mature mRNA. The variant c.390-2A>G was confirmed to cause exon 6 skipping. We designed two ASOs and identified one of them that efficiently induced pseudoexon exclusion. CONCLUSION We reported two novel variants of the ABCB11 gene, c.76+29T>G and c.390-2A>G, in a PFIC2 infant, thereby expanding the genotype of PFIC2. Our findings provide evidence for ASOs as a therapeutic approach for PFIC2 patients carrying intronic variants.
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Affiliation(s)
- Yucan Zheng
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Chunlei Zhou
- Department of Pathology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Bixia Zheng
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Guorui Hu
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Chunli Wang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Zhou
- Department of Pathology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yan Lu
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhihua Zhang
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Qian Lin
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Hongmei Guo
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yu Jin
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhifeng Liu
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, China.
| | - Weibing Tang
- Department of Pediatric Surgery, Children's Hospital of Nanjing Medical University, Nanjing, China.
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20
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Iosifidis C, Liu J, Gale T, Ellingford JM, Campbell C, Ingram S, Chandler K, Parry NRA, Black GC, Sergouniotis PI. Clinical and genetic findings in TRPM1-related congenital stationary night blindness. Acta Ophthalmol 2022; 100:e1332-e1339. [PMID: 35633130 DOI: 10.1111/aos.15186] [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: 11/25/2021] [Accepted: 05/05/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE Congenital stationary night blindness (CSNB) is a heterogeneous group of Mendelian retinal disorders that present in childhood. Biallelic variants altering the protein-coding region of the TRPM1 gene are one of the commonest causes of CSNB. Here, we report the clinical and genetic findings in 10 unrelated individuals with TRPM1-retinopathy. METHODS Study subjects were recruited through a tertiary clinical ophthalmic genetic service at Manchester, UK. All participants underwent visual electrodiagnostic testing and panel-based genetic analysis. RESULTS Study subjects had a median age of 8 years (range: 3-20 years). All probands were myopic and had electroretinographic findings in keeping with complete CSNB. Notably, three probands reported no night vision problems. Fourteen different disease-associated TRPM1 variants were detected. One individual was homozygous for the NM_001252024.2 (TRPM1):c.965 + 29G>A variant and a mini-gene assay highlighted that this change results in mis-splicing and premature protein termination. Additionally, two unrelated probands who had CSNB and mild neurodevelopmental abnormalities were found to carry a 15q13.3 microdeletion. This copy number variant encompasses seven genes, including TRPM1, and was encountered in the heterozygous state and in trans with a missense TRPM1 variant in each case. CONCLUSION Our findings highlight the importance of comprehensive genomic analysis, beyond the exons and protein-coding regions of genes, for individuals with CSNB. When this characteristic retinal phenotype is accompanied by extraocular findings (including learning and/or behavioural difficulties), a 15q13.3 microdeletion should be suspected. Focused analysis (e.g. microarray testing) is recommended to look for large-scale deletions encompassing TRPM1 in patients with CSNB and neurodevelopmental abnormalities.
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Affiliation(s)
- Christos Iosifidis
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
- Manchester Royal Eye Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Jingshu Liu
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
| | - Theodora Gale
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Jamie M. Ellingford
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Christopher Campbell
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Stuart Ingram
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Kate Chandler
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Neil R. A. Parry
- Manchester Royal Eye Hospital Manchester University NHS Foundation Trust Manchester UK
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
| | - Graeme C. Black
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
| | - Panagiotis I. Sergouniotis
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicines and Health University of Manchester Manchester UK
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital Manchester University NHS Foundation Trust Manchester UK
- Manchester Royal Eye Hospital Manchester University NHS Foundation Trust Manchester UK
- Institute of Biochemistry and Molecular Genetics, Faculty of Medicine University of Ljubljana Ljubljana Slovenia
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21
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Poncet AF, Grunewald O, Vaclavik V, Meunier I, Drumare I, Pelletier V, Bocquet B, Todorova MG, Le Moing AG, Devos A, Schorderet DF, Jobic F, Defoort-Dhellemmes S, Dollfus H, Smirnov VM, Dhaenens CM. Contribution of Whole-Genome Sequencing and Transcript Analysis to Decipher Retinal Diseases Associated with MFSD8 Variants. Int J Mol Sci 2022; 23:ijms23084294. [PMID: 35457110 PMCID: PMC9032189 DOI: 10.3390/ijms23084294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/25/2022] [Accepted: 04/11/2022] [Indexed: 01/01/2023] Open
Abstract
Biallelic gene defects in MFSD8 are not only a cause of the late-infantile form of neuronal ceroid lipofuscinosis, but also of rare isolated retinal degeneration. We report clinical and genetic data of seven patients compound heterozygous or homozygous for variants in MFSD8, issued from a French cohort with inherited retinal degeneration, and two additional patients retrieved from a Swiss cohort. Next-generation sequencing of large panels combined with whole-genome sequencing allowed for the identification of twelve variants from which seven were novel. Among them were one deep intronic variant c.998+1669A>G, one large deletion encompassing exon 9 and 10, and a silent change c.750A>G. Transcript analysis performed on patients’ lymphoblastoid cell lines revealed the creation of a donor splice site by c.998+1669A>G, resulting in a 140 bp pseudoexon insertion in intron 10. Variant c.750A>G produced exon 8 skipping. In silico and in cellulo studies of these variants allowed us to assign the pathogenic effect, and showed that the combination of at least one severe variant with a moderate one leads to isolated retinal dystrophy, whereas the combination in trans of two severe variants is responsible for early onset severe retinal dystrophy in the context of late-infantile neuronal ceroid lipofuscinosis.
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Affiliation(s)
- Anaïs F. Poncet
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Olivier Grunewald
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Veronika Vaclavik
- University of Lausanne, Jules-Gonin Eye Hospital, 1004 Lausanne, Switzerland;
- Cantonal Hospital, Department of Ophthalmology, 1700 Fribourg, Switzerland
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, F-34000 Montpellier, France; (I.M.); (B.B.)
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, F-34000 Montpellier, France
| | - Isabelle Drumare
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
| | - Valérie Pelletier
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologiques, Hopitaux Universitaires de Strasbourg, F-67000 Strasbourg, France; (V.P.); (H.D.)
| | - Béatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, F-34000 Montpellier, France; (I.M.); (B.B.)
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, F-34000 Montpellier, France
| | - Margarita G. Todorova
- Department of Ophthalmology, Cantonal Hospital, 9007 St. Gallen, Switzerland;
- Department of Ophthalmology, University of Zürich, 8091 Zürich, Switzerland
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland
| | - Anne-Gaëlle Le Moing
- Department of Child Neurology, Amiens-Picardy University Hospital, F-80000 Amiens, France;
| | - Aurore Devos
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
| | - Daniel F. Schorderet
- Faculty of Biology and Medicine, University of Lausanne and Faculty of Life Sciences, Ecole Polytechnique Fédérale of Lausanne, 1004 Lausanne, Switzerland;
| | - Florence Jobic
- Unité de Génétique Médicale et Oncogénétique, Centre Hospitalier Universitaire Amiens Picardie, F-80000 Amiens, France;
| | - Sabine Defoort-Dhellemmes
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
| | - Hélène Dollfus
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologiques, Hopitaux Universitaires de Strasbourg, F-67000 Strasbourg, France; (V.P.); (H.D.)
| | - Vasily M. Smirnov
- Exploration de la Vision et Neuro-Ophtalmology, CHU de Lille, F-59000 Lille, France; (I.D.); (S.D.-D.); (V.M.S.)
- Université de Lille, Faculté de Médecine, F-59000 Lille, France
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, F-59000 Lille, France; (A.F.P.); (O.G.); (A.D.)
- Correspondence: ; Tel.: +33-320444953
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22
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Corradi Z, Salameh M, Khan M, Héon E, Mishra K, Hitti-Malin RJ, AlSwaiti Y, Aslanian A, Banin E, Brooks BP, Zein WM, Hufnagel RB, Roosing S, Dhaenens C, Sharon D, Cremers FPM, AlTalbishi A. ABCA4 c.859-25A>G, a Frequent Palestinian Founder Mutation Affecting the Intron 7 Branchpoint, Is Associated With Early-Onset Stargardt Disease. Invest Ophthalmol Vis Sci 2022; 63:20. [PMID: 35475888 PMCID: PMC9055564 DOI: 10.1167/iovs.63.4.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/02/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose The effect of noncoding variants is often unknown in the absence of functional assays. Here, we characterized an ABCA4 intron 7 variant, c.859-25A>G, identified in Palestinian probands with Stargardt disease (STGD) or cone-rod dystrophy (CRD). We investigated the effect of this variant on the ABCA4 mRNA and retinal phenotype, and its prevalence in Palestine. Methods The ABCA4 gene was sequenced completely or partially in 1998 cases with STGD or CRD. The effect of c.859-25A>G on splicing was investigated in silico using SpliceAI and in vitro using splice assays. Homozygosity mapping was performed for 16 affected individuals homozygous for c.859-25A>G. The clinical phenotype was assessed using functional and structural analyses including visual acuity, full-field electroretinography, and multimodal imaging. Results The smMIPs-based ABCA4 sequencing revealed c.859-25A>G in 10 Palestinian probands from Hebron and Jerusalem. SpliceAI predicted a significant effect of this putative branchpoint-inactivating variant on the nearby intron 7 splice acceptor site. Splice assays revealed exon 8 skipping and two partial inclusions of intron 7, each having a deleterious effect. Additional genotyping revealed another 46 affected homozygous or compound heterozygous individuals carrying variant c.859-25A>G. Homozygotes shared a genomic segment of 59.6 to 87.9 kb and showed severe retinal defects on ophthalmoscopic evaluation. Conclusions The ABCA4 variant c.859-25A>G disrupts a predicted branchpoint, resulting in protein truncation because of different splice defects, and is associated with early-onset STGD1 when present in homozygosity. This variant was found in 25/525 Palestinian inherited retinal dystrophy probands, representing one of the most frequent inherited retinal disease-causing variants in West-Bank Palestine.
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Affiliation(s)
- Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Manar Salameh
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Palestine
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ketan Mishra
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rebekkah J. Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yahya AlSwaiti
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Palestine
| | - Alice Aslanian
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Palestine
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Brian P. Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institutes, National Institutes of Health, Bethesda, Maryland, United States
| | - Wadih M. Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institutes, National Institutes of Health, Bethesda, Maryland, United States
| | - Robert B. Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institutes, National Institutes of Health, Bethesda, Maryland, United States
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claire‐Marie Dhaenens
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille, France
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alaa AlTalbishi
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Palestine
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23
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Stingl K, Hoyng C, Kempf M, Kohl S, Jung R, Righetti G, Kühlewein L, Pohl L, Kortüm F, Kelbsch C, Wilhelm B, Peters T, Stingl K. Evaluation of Local Rod and Cone Function in Stargardt Disease. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 35262734 PMCID: PMC8934563 DOI: 10.1167/iovs.63.3.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Purpose In this study, chromatic pupil campimetry (CPC) was used to map local functional degenerative changes of cones and rods in Stargardt disease (STGD1). Methods 19 patients (age 36 ± 8 years; 12 males) with genetically confirmed ABCA4 mutations and a clinical diagnosis of STGD1 and 12 age-matched controls (age 37 ± 11 years; 2 males) underwent scotopic (rod-favoring) and photopic (cone-favoring) CPC. CPC evaluates the local retinal function in the central 30° visual field via analysis of the pupil constriction to local stimuli in a gaze-corrected manner. Results Scotopic CPC revealed that the rod function of patients with STGD1 inside the 30° visual field was not impaired when compared with age-matched controls. However, a statistically significant faster pupil response onset time (∼ 40 ms) was observed in the measured area. Photopic CPC showed a significant reduction of the central cone function up to 6°, with a minor, non-significant reduction beyond this eccentricity. The time dynamic of the pupillary response in photopic CPC did not reveal differences between STGD1 and controls. Conclusions The functional analysis of the macular region in STGD1 disease indicates reduced central cone function, corresponding to photoreceptor degeneration. In contrast, the rod function in the central area was not affected. Nevertheless, some alteration of the time dynamics in the rod system was observed indicating a complex effect of cone degeneration on the functional performance of the rod system. Our results should be considered when interpreting safety and efficacy in interventional trials of STGD1.
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Affiliation(s)
- Krunoslav Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany
| | - Carel Hoyng
- Department of Ophthalmology, Radboud University Medical Centre, 6500HB Nijmegen, the Netherlands
| | - Melanie Kempf
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Ronja Jung
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Giulia Righetti
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Laura Kühlewein
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Lisa Pohl
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Friederike Kortüm
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Carina Kelbsch
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Pupil research group, University of Tuebingen, Tuebingen, Germany
| | - Barbara Wilhelm
- Pupil research group, University of Tuebingen, Tuebingen, Germany.,STZ eyetrial at the Center for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Tobias Peters
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Pupil research group, University of Tuebingen, Tuebingen, Germany.,STZ eyetrial at the Center for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.,Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany
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Antisense RNA Therapeutics: A Brief Overview. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2434:33-49. [PMID: 35213008 DOI: 10.1007/978-1-0716-2010-6_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nucleic acid therapeutics is a growing field aiming to treat human conditions that has gained special attention due to the successful development of mRNA vaccines against SARS-CoV-2. Another type of nucleic acid therapeutics is antisense oligonucleotides, versatile tools that can be used in multiple ways to target pre-mRNA and mRNA. While some years ago these molecules were just considered a useful research tool and a curiosity in the clinical market, this has rapidly changed. These molecules are promising strategies for personalized treatments for rare genetic diseases and they are in development for very common disorders too. In this chapter, we provide a brief description of the different mechanisms of action of these RNA therapeutic molecules, with clear examples at preclinical and clinical stages.
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Abstract
RNA-based therapeutics have entered the mainstream with seemingly limitless possibilities to treat all categories of neurological disease. Here, common RNA-based drug modalities such as antisense oligonucleotides, small interfering RNAs, RNA aptamers, RNA-based vaccines and mRNA drugs are reviewed highlighting their current and potential applications. Rapid progress has been made across rare genetic diseases and neurodegenerative disorders, but safe and effective delivery to the brain remains a significant challenge for many applications. The advent of individualized RNA-based therapies for ultra-rare diseases is discussed against the backdrop of the emergence of this field into more common conditions such as Alzheimer's disease and ischaemic stroke. There remains significant untapped potential in the use of RNA-based therapeutics for behavioural disorders and tumours of the central nervous system; coupled with the accelerated development expected over the next decade, the true potential of RNA-based therapeutics to transform the therapeutic landscape in neurology remains to be uncovered.
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Affiliation(s)
- Karen Anthony
- Centre for Physical Activity and Life Sciences, University of Northampton, Northampton, UK
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26
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Suárez-Herrera N, Tomkiewicz TZ, Garanto A, Collin RWJ. Development and Use of Cellular Systems to Assess and Correct Splicing Defects. Methods Mol Biol 2022; 2434:145-165. [PMID: 35213015 PMCID: PMC9703848 DOI: 10.1007/978-1-0716-2010-6_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A significant proportion of mutations underlying genetic disorders affect pre-mRNA splicing, generally causing partial or total skipping of exons, and/or inclusion of pseudoexons. These changes often lead to the formation of aberrant transcripts that can induce nonsense-mediated decay, and a subsequent lack of functional protein. For some genetic disorders, including inherited retinal diseases (IRDs), reproducing splicing dynamics in vitro is a challenge due to the specific environment provided by, e.g. the retinal tissue, cells of which cannot be easily obtained and/or cultured. Here, we describe how to engineer splicing vectors, validate the reliability and reproducibility of alternative cellular systems, assess pre-mRNA splicing defects involved in IRD, and finally correct those by using antisense oligonucleotide-based strategies.
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Affiliation(s)
- Nuria Suárez-Herrera
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tomasz Z Tomkiewicz
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alejandro Garanto
- Department of Pediatrics, Amalia Children's Hospital, Nijmegen, The Netherlands
- Department of Human Genetics and Radboud Institute of Molecular Life Sciences (RIMLS), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
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27
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Molday RS, Garces FA, Scortecci JF, Molday LL. Structure and function of ABCA4 and its role in the visual cycle and Stargardt macular degeneration. Prog Retin Eye Res 2021; 89:101036. [PMID: 34954332 DOI: 10.1016/j.preteyeres.2021.101036] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/07/2021] [Accepted: 12/13/2021] [Indexed: 12/17/2022]
Abstract
ABCA4 is a member of the superfamily of ATP-binding cassette (ABC) transporters that is preferentially localized along the rim region of rod and cone photoreceptor outer segment disc membranes. It uses the energy from ATP binding and hydrolysis to transport N-retinylidene-phosphatidylethanolamine (N-Ret-PE), the Schiff base adduct of retinal and phosphatidylethanolamine, from the lumen to the cytoplasmic leaflet of disc membranes. This ensures that all-trans-retinal and excess 11-cis-retinal are efficiently cleared from photoreceptor cells thereby preventing the accumulation of toxic retinoid compounds. Loss-of-function mutations in the gene encoding ABCA4 cause autosomal recessive Stargardt macular degeneration, also known as Stargardt disease (STGD1), and related autosomal recessive retinopathies characterized by impaired central vision and an accumulation of lipofuscin and bis-retinoid compounds. High resolution structures of ABCA4 in its substrate and nucleotide free state and containing bound N-Ret-PE or ATP have been determined by cryo-electron microscopy providing insight into the molecular architecture of ABCA4 and mechanisms underlying substrate recognition and conformational changes induced by ATP binding. The expression and functional characterization of a large number of disease-causing missense ABCA4 variants have been determined. These studies have shed light into the molecular mechanisms underlying Stargardt disease and a classification that reliably predicts the effect of a specific missense mutation on the severity of the disease. They also provide a framework for developing rational therapeutic treatments for ABCA4-associated diseases.
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Affiliation(s)
- Robert S Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada; Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, B.C., Canada.
| | - Fabian A Garces
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
| | | | - Laurie L Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
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Piotter E, McClements ME, MacLaren RE. Therapy Approaches for Stargardt Disease. Biomolecules 2021; 11:1179. [PMID: 34439845 PMCID: PMC8393614 DOI: 10.3390/biom11081179] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/14/2022] Open
Abstract
Despite being the most prevalent cause of inherited blindness in children, Stargardt disease is yet to achieve the same clinical trial success as has been achieved for other inherited retinal diseases. With an early age of onset and continual progression of disease over the life course of an individual, Stargardt disease appears to lend itself to therapeutic intervention. However, the aetiology provides issues not encountered with the likes of choroideremia and X-linked retinitis pigmentosa and this has led to a spectrum of treatment strategies that approach the problem from different aspects. These include therapeutics ranging from small molecules and anti-sense oligonucleotides to viral gene supplementation and cell replacement. The advancing development of CRISPR-based molecular tools is also likely to contribute to future therapies by way of genome editing. In this we review, we consider the most recent pre-clinical and clinical trial data relating to the different strategies being applied to the problem of generating a treatment for the large cohort of Stargardt disease patients worldwide.
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Affiliation(s)
- Elena Piotter
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; (E.P.); (M.E.M.)
- Oxford University Hospitals NHS Foundation Trust NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
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