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Panel-based genetic diagnostic testing for inherited eye diseases is highly accurate and reproducible, and more sensitive for variant detection, than exome sequencing. Genet Med 2014; 17:253-261. [PMID: 25412400 PMCID: PMC4572572 DOI: 10.1038/gim.2014.172] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/23/2014] [Indexed: 12/16/2022] Open
Abstract
Purpose Next-generation sequencing (NGS) based methods are being adopted broadly for genetic diagnostic testing, but the performance characteristics of these techniques have not been fully defined with regard to test accuracy and reproducibility. Methods We developed a targeted enrichment and NGS approach for genetic diagnostic testing of patients with inherited eye disorders, including inherited retinal degenerations, optic atrophy and glaucoma. In preparation for providing this Genetic Eye Disease (GEDi) test on a CLIA-certified basis, we performed experiments to measure the sensitivity, specificity, reproducibility as well as the clinical sensitivity of the test. Results The GEDi test is highly reproducible and accurate, with sensitivity and specificity for single nucleotide variant detection of 97.9% and 100%, respectively. The sensitivity for variant detection was notably better than the 88.3% achieved by whole exome sequencing (WES) using the same metrics, due to better coverage of targeted genes in the GEDi test compared to commercially available exome capture sets. Prospective testing of 192 patients with IRDs indicated that the clinical sensitivity of the GEDi test is high, with a diagnostic rate of 51%. Conclusion The data suggest that based on quantified performance metrics, selective targeted enrichment is preferable to WES for genetic diagnostic testing.
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102
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Pérez B, Vilageliu L, Grinberg D, Desviat LR. Antisense mediated splicing modulation for inherited metabolic diseases: challenges for delivery. Nucleic Acid Ther 2014; 24:48-56. [PMID: 24506780 DOI: 10.1089/nat.2013.0453] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the past few years, research in targeted mutation therapies has experienced significant advances, especially in the field of rare diseases. In particular, the efficacy of antisense therapy for suppression of normal, pathogenic, or cryptic splice sites has been demonstrated in cellular and animal models and has already reached the clinical trials phase for Duchenne muscular dystrophy. In different inherited metabolic diseases, splice switching oligonucleotides (SSOs) have been used with success in patients' cells to force pseudoexon skipping or to block cryptic splice sites, in both cases recovering normal transcript and protein and correcting the enzyme deficiency. However, future in vivo studies require individual approaches for delivery depending on the gene defect involved, given the different patterns of tissue and organ expression. Herein we review the state of the art of antisense therapy targeting RNA splicing in metabolic diseases, grouped according to their expression patterns-multisystemic, hepatic, or in central nervous system (CNS)-and summarize the recent progress achieved in the field of in vivo delivery of oligonucleotides to each organ or system. Successful body-wide distribution of SSOs and preferential distribution in the liver after systemic administration have been reported in murine models for different diseases, while for CNS limited data are available, although promising results with intratechal injections have been achieved.
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Affiliation(s)
- Belen Pérez
- 1 Centro de Biología Molecular Severo Ochoa, UAM-CSIC, Universidad Autónoma de Madrid , Madrid, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras, Madrid, Spain
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Kousal B, Skalicka P, Valesova L, Fletcher T, Hart-Holden N, O'Grady A, Chakarova CF, Michaelides M, Hardcastle AJ, Liskova P. Severe retinal degeneration in women with a c.2543del mutation in ORF15 of the RPGR gene. Mol Vis 2014; 20:1307-17. [PMID: 25352739 PMCID: PMC4169777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 09/18/2014] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To describe the genotype-phenotype correlation and serial observations in a five-generation Czech family with X-linked retinitis pigmentosa (XLRP) associated with severe visual impairment in women. METHODS Comprehensive ophthalmological examination including spectral domain optical coherence tomography (SD-OCT) was performed. Based on the pedigree structure and women being severely affected, autosomal dominant inheritance was suspected, and screening for known mutations by genotyping microarray was performed. Subsequently, direct sequencing of ORF15 RPGR was undertaken. RESULTS Eighteen family members (nine women and nine men) were examined. A pathogenic variant, c.2543del in ORF15 of RPGR, was found to segregate with disease. The oldest woman and her two sisters had no perception of light in their sixth decade. Four women and five men had signs and symptoms of typical XLRP, including moderate to high myopia. Three other women also had moderate to high myopia and myopic astigmatism but without the presence of bone spicule-like formation. Severe disruption of macular architecture on SD-OCT was equally common in both sexes. Only one 32-year-old female carrier had clinically normal findings. Subfoveal choroidal thickness was decreased in all affected men and in all female carriers, except the only carrier with a normal fundus examination. CONCLUSIONS The c.2543del mutation in ORF15 of RPGR is associated with a severe phenotype in the women in this family. The presence of a significant myopic refractive error, in the absence of male-to-male transmission, may be indicative of X-linked inheritance. Measurements of choroidal thickness may help in clinically identifying carrier status.
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Affiliation(s)
- Bohdan Kousal
- Department of Ophthalmology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic,Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders; First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Ophthalmology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic
| | - Lucie Valesova
- Department of Ophthalmology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic
| | - Tracy Fletcher
- Regional Molecular Genetics Service, St Mary's Hospital, Manchester, United Kingdom
| | - Niki Hart-Holden
- Regional Molecular Genetics Service, St Mary's Hospital, Manchester, United Kingdom
| | - Anna O'Grady
- Regional Molecular Genetics Service, St Mary's Hospital, Manchester, United Kingdom
| | | | - Michel Michaelides
- UCL Institute of Ophthalmology, London, United Kingdom,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | | | - Petra Liskova
- Department of Ophthalmology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic,Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders; First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic,UCL Institute of Ophthalmology, London, United Kingdom
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104
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A sensitive assay system to test antisense oligonucleotides for splice suppression therapy in the mouse liver. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e193. [PMID: 25226162 PMCID: PMC4222650 DOI: 10.1038/mtna.2014.44] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 07/30/2014] [Indexed: 11/22/2022]
Abstract
We have previously demonstrated the efficacy of antisense therapy for splicing defects in cellular models of metabolic diseases, suppressing the use of cryptic splice sites or pseudoexon insertions. To date, no animal models with these defects are available. Here, we propose exon skipping of the phenylalanine hydroxylase (Pah) gene expressed in liver and kidney to generate systemic hyperphenylalaninemia in mice as a sensitive in vivo assay to test splice suppression. Systemic elevation of blood L-Phe can be quantified using tandem MS/MS. Exon 11 and/or 12 skipping for the normal PAH gene was validated in hepatoma cells for comparing two oligonucleotide chemistries, morpholinos and locked nucleic acids. Subsequently, Vivo-morpholinos (VMO) were tested in wild-type and in phenotypically normal Pahenu2/+ heterozygous mice to target exon 11 and/or 12 of the murine Pah gene using different VMO dosing, mode of injection and treatment regimes. Consecutive intravenous injections of VMO resulted in transient hyperphenylalaninemia correlating with complete exon skipping and absence of PAH protein and enzyme activity. Sustained effect required repeated injection of VMOs. Our results provide not only a sensitive in vivo assay to test for splice-modulating antisense oligonucleotides, but also a simple method to generate murine models for genetic liver diseases.
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105
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Bujakowska KM, Zhang Q, Siemiatkowska AM, Liu Q, Place E, Falk MJ, Consugar M, Lancelot ME, Antonio A, Lonjou C, Carpentier W, Mohand-Saïd S, den Hollander AI, Cremers FPM, Leroy BP, Gai X, Sahel JA, van den Born LI, Collin RWJ, Zeitz C, Audo I, Pierce EA. Mutations in IFT172 cause isolated retinal degeneration and Bardet-Biedl syndrome. Hum Mol Genet 2014; 24:230-42. [PMID: 25168386 DOI: 10.1093/hmg/ddu441] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Primary cilia are sensory organelles present on most mammalian cells. The assembly and maintenance of primary cilia are facilitated by intraflagellar transport (IFT), a bidirectional protein trafficking along the cilium. Mutations in genes coding for IFT components have been associated with a group of diseases called ciliopathies. These genetic disorders can affect a variety of organs including the retina. Using whole exome sequencing in three families, we identified mutations in Intraflagellar Transport 172 Homolog [IFT172 (Chlamydomonas)] that underlie an isolated retinal degeneration and Bardet-Biedl syndrome. Extensive functional analyses of the identified mutations in cell culture, rat retina and in zebrafish demonstrated their hypomorphic or null nature. It has recently been reported that mutations in IFT172 cause a severe ciliopathy syndrome involving skeletal, renal, hepatic and retinal abnormalities (Jeune and Mainzer-Saldino syndromes). Here, we report for the first time that mutations in this gene can also lead to an isolated form of retinal degeneration. The functional data for the mutations can partially explain milder phenotypes; however, the involvement of modifying alleles in the IFT172-associated phenotypes cannot be excluded. These findings expand the spectrum of disease associated with mutations in IFT172 and suggest that mutations in genes originally reported to be associated with syndromic ciliopathies should also be considered in subjects with non-syndromic retinal dystrophy.
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Affiliation(s)
- Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France
| | - Qi Zhang
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | | | - Qin Liu
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Emily Place
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Marni J Falk
- Department of Pediatrics, Division of Human Genetics, The Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Mark Consugar
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Marie-Elise Lancelot
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France
| | - Aline Antonio
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France
| | - Christine Lonjou
- Plateforme Post-génomique P3S, Hôpital Pitié Salpêtrière, Paris 75013, France
| | - Wassila Carpentier
- Plateforme Post-génomique P3S, Hôpital Pitié Salpêtrière, Paris 75013, France
| | - Saddek Mohand-Saïd
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France Institut National de la Santé et de la Recherche Médicale and Direction de L'Hospitalisation et de L'Organisation des Soins Centre D'Investigation Clinique 1423, Centre Hospitalier National D'Ophtalmologie des Quinze-Vingts, Paris 75012, France
| | - Anneke I den Hollander
- Department of Human Genetics Radboud Institute for Molecular Life Sciences, and Department of Ophthalmology, Radboud University Medical Center, Nijmegen 6500 HB, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics Radboud Institute for Molecular Life Sciences, and
| | - Bart P Leroy
- Department of Ophthalmology and Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent 9000, Belgium Ophthalmic Genetics and Visual Electrophysiology, Division of Ophthalmology, The Children's Hospital of Philadelphia, PA 19104, USA
| | - Xiaowu Gai
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - José-Alain Sahel
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France Institut National de la Santé et de la Recherche Médicale and Direction de L'Hospitalisation et de L'Organisation des Soins Centre D'Investigation Clinique 1423, Centre Hospitalier National D'Ophtalmologie des Quinze-Vingts, Paris 75012, France Fondation Ophtalmologique Adolphe de Rothschild, Paris 75019, France Academie des Sciences, Institut de France, Paris 75006, France University College London, Institute of Ophthalmology, London EC1V 9EL, UK and
| | | | - Rob W J Collin
- Department of Human Genetics Radboud Institute for Molecular Life Sciences, and
| | - Christina Zeitz
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France
| | - Isabelle Audo
- Institut National de la Santé et de la Recherche Médicale U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France Centre National de la Recherche Scientifique, UMR_7210, Paris 75012, France Institut National de la Santé et de la Recherche Médicale and Direction de L'Hospitalisation et de L'Organisation des Soins Centre D'Investigation Clinique 1423, Centre Hospitalier National D'Ophtalmologie des Quinze-Vingts, Paris 75012, France University College London, Institute of Ophthalmology, London EC1V 9EL, UK and
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
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106
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Siemiatkowska AM, Collin RWJ, den Hollander AI, Cremers FPM. Genomic approaches for the discovery of genes mutated in inherited retinal degeneration. Cold Spring Harb Perspect Med 2014; 4:a017137. [PMID: 24939053 PMCID: PMC4109577 DOI: 10.1101/cshperspect.a017137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In view of their high degree of genetic heterogeneity, inherited retinal diseases (IRDs) pose a significant challenge for identifying novel genetic causes. Thus far, more than 200 genes have been found to be mutated in IRDs, which together contain causal variants in >80% of the cases. Accurate genetic diagnostics is particularly important for isolated cases, in which X-linked and de novo autosomal dominant variants are not uncommon. In addition, new gene- or mutation-specific therapies are emerging, underlining the importance of identifying causative mutations in each individual. Sanger sequencing of selected genes followed by cost-effective targeted next-generation sequencing (NGS) can identify defects in known IRD-associated genes in the majority of the cases. Exome NGS in combination with genetic linkage or homozygosity mapping studies can aid the identification of the remaining causal genes. As these are thought to be mutated in <1% of the cases, validation through functional modeling in, for example, zebrafish and/or replication through the genotyping of large patient cohorts is required. In the near future, whole genome NGS in combination with transcriptome NGS may reveal mutations that are currently hidden in the noncoding regions of the human genome.
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Affiliation(s)
- Anna M Siemiatkowska
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Ran X, Cai WJ, Huang XF, Liu Q, Lu F, Qu J, Wu J, Jin ZB. 'RetinoGenetics': a comprehensive mutation database for genes related to inherited retinal degeneration. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2014; 2014:bau047. [PMID: 24939193 PMCID: PMC4060621 DOI: 10.1093/database/bau047] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Inherited retinal degeneration (IRD), a leading cause of human blindness worldwide, is exceptionally heterogeneous with clinical heterogeneity and genetic variety. During the past decades, tremendous efforts have been made to explore the complex heterogeneity, and massive mutations have been identified in different genes underlying IRD with the significant advancement of sequencing technology. In this study, we developed a comprehensive database, ‘RetinoGenetics’, which contains informative knowledge about all known IRD-related genes and mutations for IRD. ‘RetinoGenetics’ currently contains 4270 mutations in 186 genes, with detailed information associated with 164 phenotypes from 934 publications and various types of functional annotations. Then extensive annotations were performed to each gene using various resources, including Gene Ontology, KEGG pathways, protein–protein interaction, mutational annotations and gene–disease network. Furthermore, by using the search functions, convenient browsing ways and intuitive graphical displays, ‘RetinoGenetics’ could serve as a valuable resource for unveiling the genetic basis of IRD. Taken together, ‘RetinoGenetics’ is an integrative, informative and updatable resource for IRD-related genetic predispositions. Database URL:http://www.retinogenetics.org/.
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Affiliation(s)
- Xia Ran
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Wei-Jun Cai
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, ChinaInstitute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Xiu-Feng Huang
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, ChinaInstitute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Qi Liu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Fan Lu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, ChinaInstitute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Jia Qu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, ChinaInstitute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Jinyu Wu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
| | - Zi-Bing Jin
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, ChinaInstitute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325027, China, Division of Ophthalmic Genetics, Laboratory for Stem Cell and Retinal Regeneration, The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health People's Republic of China, Wenzhou 325027, China
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LI SHIQIANG, GUAN LIPING, FANG SHAOHUA, JIANG HUI, XIAO XUESHAN, YANG JIANHUA, WANG PANFENG, YIN YE, GUO XIANGMING, WANG JUN, ZHANG JIANGUO, ZHANG QINGJIONG. Exome sequencing reveals CHM mutations in six families with atypical choroideremia initially diagnosed as retinitis pigmentosa. Int J Mol Med 2014; 34:573-7. [DOI: 10.3892/ijmm.2014.1797] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/30/2014] [Indexed: 11/06/2022] Open
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109
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Yuste-Checa P, Medrano C, Gámez A, Desviat LR, Matthijs G, Ugarte M, Pérez-Cerdá C, Pérez B. Antisense-mediated therapeutic pseudoexon skipping in TMEM165-CDG. Clin Genet 2014; 87:42-8. [PMID: 24720419 DOI: 10.1111/cge.12402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 01/18/2023]
Abstract
Deficiencies in glycosyltransferases, glycosidases or nucleotide-sugar transporters involved in protein glycosylation lead to congenital disorders of glycosylation (CDG), a group of genetic diseases mostly showing multisystem phenotype. Despite recent advances in the biochemical and molecular knowledge of these diseases, no effective therapy exists for most. Efforts are now being directed toward therapies based on identifying new targets, which would allow to treat specific patients in a personalized way. This work presents proof-of concept for the antisense RNA rescue of the Golgi-resident protein TMEM165, a gene involved in a new type of CDG with a characteristic skeletal phenotype. Using a functional in vitro splicing assay based on minigenes, it was found that the deep intronic change c.792+182G>A is responsible for the insertion of an aberrant exon, corresponding to an intronic sequence. Antisense morpholino oligonucleotide therapy targeted toward TMEM165 mRNA recovered normal protein levels in the Golgi apparatus of patient-derived fibroblasts. This work expands the application of antisense oligonucleotide-mediated pseudoexon skipping to the treatment of a Golgi-resident protein, and opens up a promising treatment option for this specific TMEM165-CDG.
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Affiliation(s)
- P Yuste-Checa
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Campus de Cantoblanco, Universidad Autónoma de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIPaz, Madrid, Spain; Instituto de Investigación Biomedica, IDIPaz, Madrid
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Improving molecular diagnosis in epilepsy by a dedicated high-throughput sequencing platform. Eur J Hum Genet 2014; 23:354-62. [PMID: 24848745 DOI: 10.1038/ejhg.2014.92] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/17/2014] [Accepted: 04/04/2014] [Indexed: 12/22/2022] Open
Abstract
We analyzed by next-generation sequencing (NGS) 67 epilepsy genes in 19 patients with different types of either isolated or syndromic epileptic disorders and in 15 controls to investigate whether a quick and cheap molecular diagnosis could be provided. The average number of nonsynonymous and splice site mutations per subject was similar in the two cohorts indicating that, even with relatively small targeted platforms, finding the disease gene is not an univocal process. Our diagnostic yield was 47% with nine cases in which we identified a very likely causative mutation. In most of them no interpretation would have been possible in absence of detailed phenotype and familial information. Seven out of 19 patients had a phenotype suggesting the involvement of a specific gene. Disease-causing mutations were found in six of these cases. Among the remaining patients, we could find a probably causative mutation only in three. None of the genes affected in the latter cases had been suspected a priori. Our protocol requires 8-10 weeks including the investigation of the parents with a cost per patient comparable to sequencing of 1-2 medium-to-large-sized genes by conventional techniques. The platform we used, although providing much less information than whole-exome or whole-genome sequencing, has the advantage that can also be run on 'benchtop' sequencers combining rapid turnaround times with higher manageability.
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111
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Del Giudice E, Macca M, Imperati F, D'Amico A, Parent P, Pasquier L, Layet V, Lyonnet S, Stamboul-Darmency V, Thauvin-Robinet C, Franco B. CNS involvement in OFD1 syndrome: a clinical, molecular, and neuroimaging study. Orphanet J Rare Dis 2014; 9:74. [PMID: 24884629 PMCID: PMC4113190 DOI: 10.1186/1750-1172-9-74] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 04/29/2014] [Indexed: 01/29/2023] Open
Abstract
Background Oral-facial-digital type 1 syndrome (OFD1; OMIM 311200) belongs to the expanding group of disorders ascribed to ciliary dysfunction. With the aim of contributing to the understanding of the role of primary cilia in the central nervous system (CNS), we performed a thorough characterization of CNS involvement observed in this disorder. Methods A cohort of 117 molecularly diagnosed OFD type I patients was screened for the presence of neurological symptoms and/or cognitive/behavioral abnormalities on the basis of the available information supplied by the collaborating clinicians. Seventy-one cases showing CNS involvement were further investigated through neuroimaging studies and neuropsychological testing. Results Seventeen patients were molecularly diagnosed in the course of this study and five of these represent new mutations never reported before. Among patients displaying neurological symptoms and/or cognitive/behavioral abnormalities, we identified brain structural anomalies in 88.7%, cognitive impairment in 68%, and associated neurological disorders and signs in 53% of cases. The most frequently observed brain structural anomalies included agenesis of the corpus callosum and neuronal migration/organisation disorders as well as intracerebral cysts, porencephaly and cerebellar malformations. Conclusions Our results support recent published findings indicating that CNS involvement in this condition is found in more than 60% of cases. Our findings correlate well with the kind of brain developmental anomalies described in other ciliopathies. Interestingly, we also described specific neuropsychological aspects such as reduced ability in processing verbal information, slow thought process, difficulties in attention and concentration, and notably, long-term memory deficits which may indicate a specific role of OFD1 and/or primary cilia in higher brain functions.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Brunella Franco
- Department of Translational Medical Sciences, Federico II University of Naples, Naples, Italy.
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Davies WI. Challenges using diagnostic next-generation sequencing in the clinical environment for inherited retinal disorders. Per Med 2014; 11:99-111. [PMID: 29751394 DOI: 10.2217/pme.13.95] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Visual impairment, and in particular the inherited retinopathies, is a significant problem worldwide. Many disorders are progressive so their early and accurate detection is crucial to the development and application of appropriate disease management and treatment strategies, some of which are currently being tested in clinical trials. Over the past few decades, the identification of genetic causes that mediate many inherited diseases has largely been based on traditional 'Sanger sequencing' and microchip approaches that are expensive and time consuming. However, with the advent of next-generation sequencing it is now possible to apply high-throughput technologies to the clinical arena and sequence the entire exome or genome of an affected individual. Despite the potential for a paradigm shift in the clinical diagnosis of retinal disease, it may prove difficult to interpret and confirm the pathogenicity of any variants discovered by next-generation sequencing pipelines. In this review, I examine the application of next-generation sequencing to inherited retinal disorders and discuss current limitations and future perspectives.
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Affiliation(s)
- Wayne Il Davies
- School of Animal Biology & University of Western Australia Oceans Institute, University of Western Australia, 35 Stirling Highway, Perth, Western Australia, WA 6009, Australia.
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113
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Wheway G, Parry DA, Johnson CA. The role of primary cilia in the development and disease of the retina. Organogenesis 2014; 10:69-85. [PMID: 24162842 PMCID: PMC4049897 DOI: 10.4161/org.26710] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 02/07/2023] Open
Abstract
The normal development and function of photoreceptors is essential for eye health and visual acuity in vertebrates. Mutations in genes encoding proteins involved in photoreceptor development and function are associated with a suite of inherited retinal dystrophies, often as part of complex multi-organ syndromic conditions. In this review, we focus on the role of the photoreceptor outer segment, a highly modified and specialized primary cilium, in retinal health and disease. We discuss the many defects in the structure and function of the photoreceptor primary cilium that can cause a class of inherited conditions known as ciliopathies, often characterized by retinal dystrophy and degeneration, and highlight the recent insights into disease mechanisms.
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Affiliation(s)
- Gabrielle Wheway
- Section of Ophthalmology and Neurosciences; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
| | - David A Parry
- Section of Genetics; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
| | - Colin A Johnson
- Section of Ophthalmology and Neurosciences; Leeds Institute of Molecular Medicine; The University of Leeds; Leeds, United Kingdom
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Eisenberger T, Neuhaus C, Khan AO, Decker C, Preising MN, Friedburg C, Bieg A, Gliem M, Issa PC, Holz FG, Baig SM, Hellenbroich Y, Galvez A, Platzer K, Wollnik B, Laddach N, Ghaffari SR, Rafati M, Botzenhart E, Tinschert S, Börger D, Bohring A, Schreml J, Körtge-Jung S, Schell-Apacik C, Bakur K, Al-Aama JY, Neuhann T, Herkenrath P, Nürnberg G, Nürnberg P, Davis JS, Gal A, Bergmann C, Lorenz B, Bolz HJ. Increasing the yield in targeted next-generation sequencing by implicating CNV analysis, non-coding exons and the overall variant load: the example of retinal dystrophies. PLoS One 2013; 8:e78496. [PMID: 24265693 PMCID: PMC3827063 DOI: 10.1371/journal.pone.0078496] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 09/12/2013] [Indexed: 01/30/2023] Open
Abstract
Retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are major causes of blindness. They result from mutations in many genes which has long hampered comprehensive genetic analysis. Recently, targeted next-generation sequencing (NGS) has proven useful to overcome this limitation. To uncover “hidden mutations” such as copy number variations (CNVs) and mutations in non-coding regions, we extended the use of NGS data by quantitative readout for the exons of 55 RP and LCA genes in 126 patients, and by including non-coding 5′ exons. We detected several causative CNVs which were key to the diagnosis in hitherto unsolved constellations, e.g. hemizygous point mutations in consanguineous families, and CNVs complemented apparently monoallelic recessive alleles. Mutations of non-coding exon 1 of EYS revealed its contribution to disease. In view of the high carrier frequency for retinal disease gene mutations in the general population, we considered the overall variant load in each patient to assess if a mutation was causative or reflected accidental carriership in patients with mutations in several genes or with single recessive alleles. For example, truncating mutations in RP1, a gene implicated in both recessive and dominant RP, were causative in biallelic constellations, unrelated to disease when heterozygous on a biallelic mutation background of another gene, or even non-pathogenic if close to the C-terminus. Patients with mutations in several loci were common, but without evidence for di- or oligogenic inheritance. Although the number of targeted genes was low compared to previous studies, the mutation detection rate was highest (70%) which likely results from completeness and depth of coverage, and quantitative data analysis. CNV analysis should routinely be applied in targeted NGS, and mutations in non-coding exons give reason to systematically include 5′-UTRs in disease gene or exome panels. Consideration of all variants is indispensable because even truncating mutations may be misleading.
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Affiliation(s)
| | | | - Arif O. Khan
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | | | - Markus N. Preising
- Department of Ophthalmology, Justus-Liebig-University Giessen, University Hospital Giessen and Marburg GmbH, Giessen Campus, Giessen, Germany
| | - Christoph Friedburg
- Department of Ophthalmology, Justus-Liebig-University Giessen, University Hospital Giessen and Marburg GmbH, Giessen Campus, Giessen, Germany
| | - Anika Bieg
- Bioscientia Center for Human Genetics, Ingelheim, Germany
| | - Martin Gliem
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | | | - Frank G. Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Shahid M. Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | | | - Alberto Galvez
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Konrad Platzer
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | | | - Saeed Reza Ghaffari
- Comprehensive Genetic Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Rafati
- Avicenna Biotechnology Research Institute, Tehran, Iran
| | | | - Sigrid Tinschert
- Institute of Clinical Genetics, Technical University Dresden, Dresden, Germany
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | | | - Axel Bohring
- Institute of Human Genetics, Westfälische Wilhelms-University, Münster, Germany
| | - Julia Schreml
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | | | | | - Khadijah Bakur
- Princess Al Jawhara Albrahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jumana Y. Al-Aama
- Princess Al Jawhara Albrahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Peter Herkenrath
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Gudrun Nürnberg
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Cologne Center for Genomics and Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Cologne Center for Genomics and Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - John S. Davis
- Department of Ophthalmology, Zayed Military Hospital, Abu Dhabi, United Arab Emirates
| | - Andreas Gal
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Bergmann
- Bioscientia Center for Human Genetics, Ingelheim, Germany
- Center for Clinical Research, University Hospital of Freiburg, Freiburg, Germany
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, University Hospital Giessen and Marburg GmbH, Giessen Campus, Giessen, Germany
| | - Hanno J. Bolz
- Bioscientia Center for Human Genetics, Ingelheim, Germany
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
- * E-mail:
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Ratnapriya R, Swaroop A. Genetic architecture of retinal and macular degenerative diseases: the promise and challenges of next-generation sequencing. Genome Med 2013; 5:84. [PMID: 24112618 PMCID: PMC4066589 DOI: 10.1186/gm488] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Inherited retinal degenerative diseases (RDDs) display wide variation in their mode of inheritance, underlying genetic defects, age of onset, and phenotypic severity. Molecular mechanisms have not been delineated for many retinal diseases, and treatment options are limited. In most instances, genotype-phenotype correlations have not been elucidated because of extensive clinical and genetic heterogeneity. Next-generation sequencing (NGS) methods, including exome, genome, transcriptome and epigenome sequencing, provide novel avenues towards achieving comprehensive understanding of the genetic architecture of RDDs. Whole-exome sequencing (WES) has already revealed several new RDD genes, whereas RNA-Seq and ChIP-Seq analyses are expected to uncover novel aspects of gene regulation and biological networks that are involved in retinal development, aging and disease. In this review, we focus on the genetic characterization of retinal and macular degeneration using NGS technology and discuss the basic framework for further investigations. We also examine the challenges of NGS application in clinical diagnosis and management.
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Affiliation(s)
- Rinki Ratnapriya
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Siemiatkowska AM, van den Born LI, van Hagen PM, Stoffels M, Neveling K, Henkes A, Kipping-Geertsema M, Hoefsloot LH, Hoyng CB, Simon A, den Hollander AI, Cremers FPM, Collin RWJ. Mutations in the mevalonate kinase (MVK) gene cause nonsyndromic retinitis pigmentosa. Ophthalmology 2013; 120:2697-2705. [PMID: 24084495 DOI: 10.1016/j.ophtha.2013.07.052] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/29/2013] [Accepted: 07/31/2013] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous disorder characterized by night blindness and peripheral vision loss, and in many cases leads to blindness. Despite extensive knowledge about genes involved in the pathogenesis of RP, the genetic cause remains elusive in many patients. In this study, we aimed to identify novel genes that are involved in the cause of RP. DESIGN We present a case series with mutations in the mevalonate kinase (MVK) gene. PARTICIPANTS A total of 769 patients with nonsyndromic RP and 174 Dutch control individuals participated in this study. METHODS Exome sequencing analysis was performed in a proband of Dutch origin who was initially diagnosed with nonsyndromic autosomal recessive RP. Mutations in MVK were identified and subsequently tested for segregation within the patient's family and screened in a large cohort of patients with genetically unsolved RP. Patients with mutations underwent extensive clinical reexamination. MAIN OUTCOME MEASURES Digital fundus photography, spectral-domain optical coherence tomography (OCT), and fundus autofluorescence analysis were performed in patients with MVK mutations. Mevalonate kinase (MK) enzyme activity was analyzed in cultured lymphoblastoid cells, and mevalonic acid levels were measured in urine samples. RESULTS Exome variant filtering and prioritization led to the identification of compound heterozygous mutations in MVK (p.I268T and p.A334T) in the proband and her affected brother. Screening of our nonsyndromic RP patient cohort revealed an additional individual who was homozygous for the p.A334T alteration. Clinical reevaluation of all 3 patients showed a classic form of RP with variable extraocular symptoms, such as history of recurrent childhood febrile crises in 2 patients, mild ataxia in 1, and renal failure in 1. All 3 affected individuals showed a significantly decreased MK activity and highly elevated levels of urinary mevalonic acid. CONCLUSIONS Although the MK activity in cells and mevalonic acid concentrations in urine are strongly aberrant and comparable to that in patients with systemic mevalonate kinase deficiency (MKD), only mild clinical symptoms related to this syndrome were observed in our patients. In the current article, we add another phenotype to the spectrum of diverging disorders associated with mutations in MVK.
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Affiliation(s)
- Anna M Siemiatkowska
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - P Martin van Hagen
- Department of Immunology, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Monique Stoffels
- Department of General Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Infection, Inflammation and Immunity (N4i), Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands; Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Arjen Henkes
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Lies H Hoefsloot
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Anna Simon
- Department of General Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Infection, Inflammation and Immunity (N4i), Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands; Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands; Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands; Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands; Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands.
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117
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Role of pseudoexons and pseudointrons in human cancer. Int J Cell Biol 2013; 2013:810572. [PMID: 24204383 PMCID: PMC3800588 DOI: 10.1155/2013/810572] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 08/09/2013] [Indexed: 11/18/2022] Open
Abstract
In all eukaryotic organisms, pre-mRNA splicing and alternative splicing processes play an essential role in regulating the flow of information required to drive complex developmental and metabolic pathways. As a result, eukaryotic cells have developed a very efficient macromolecular machinery, called the spliceosome, to correctly recognize the pre-mRNA sequences that need to be inserted in a mature mRNA (exons) from those that should be removed (introns). In healthy individuals, alternative and constitutive splicing processes function with a high degree of precision and fidelity in order to ensure the correct working of this machinery. In recent years, however, medical research has shown that alterations at the splicing level play an increasingly important role in many human hereditary diseases, neurodegenerative processes, and especially in cancer origin and progression. In this minireview, we will focus on several genes whose association with cancer has been well established in previous studies, such as ATM, BRCA1/A2, and NF1. In particular, our objective will be to provide an overview of the known mechanisms underlying activation/repression of pseudoexons and pseudointrons; the possible utilization of these events as biomarkers of tumor staging/grading; and finally, the treatment options for reversing pathologic splicing events.
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118
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Li L, Khan N, Hurd T, Ghosh AK, Cheng C, Molday R, Heckenlively JR, Swaroop A, Khanna H. Ablation of the X-linked retinitis pigmentosa 2 (Rp2) gene in mice results in opsin mislocalization and photoreceptor degeneration. Invest Ophthalmol Vis Sci 2013; 54:4503-11. [PMID: 23745007 DOI: 10.1167/iovs.13-12140] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Mutations in the RP2 gene are associated with 10% to 15% of X-linked retinitis pigmentosa (XLRP), a debilitating disorder characterized by the degeneration of retinal rod and cone photoreceptors. The molecular mechanism of pathogenesis of photoreceptor degeneration in XLRP-RP2 has not been elucidated, and no treatment is currently available. This study was undertaken to investigate the pathogenesis of RP2-associated retinal degeneration. METHODS We introduced loxP sites that flank exon 2, a mutational hotspot in XLRP-RP2, in the mouse Rp2 gene. We then produced Rp2-null allele using transgenic mice that expressed Cre-recombinase under control of the ubiquitous CAG promoter. Electroretinography (ERG), histology, light microscopy, transmission electron microscopy, and immunofluorescence microscopy were performed to ascertain the effect of ablation of Rp2 on photoreceptor development, function, and protein trafficking. RESULTS Although no gross abnormalities were detected in the Rp2(null) mice, photopic (cone) and scotopic (rod) function as measured by ERG showed a gradual decline starting as early as 1 month of age. We also detected slow progressive degeneration of the photoreceptor membrane discs in the mutant retina. These defects were associated with mislocalization of cone opsins to the nuclear and synaptic layers and reduced rhodopsin content in the outer segment of mutant retina prior to the onset of photoreceptor degeneration. CONCLUSIONS Our studies suggest that RP2 contributes to the maintenance of photoreceptor function and that cone opsin mislocalization represents an early step in XLRP caused by RP2 mutations. The Rp2(null) mice should serve as a useful preclinical model for testing gene- and cell-based therapies.
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Affiliation(s)
- Linjing Li
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Detailed clinical, genetic and neuroimaging characterization of OFD VI syndrome. Eur J Med Genet 2013; 56:301-8. [PMID: 23523602 DOI: 10.1016/j.ejmg.2013.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/03/2013] [Indexed: 12/16/2022]
Abstract
Oral-facial-digital syndrome type VI (OFD VI) is characterized by the association of malformations of the face, oral cavity and extremities, distinguished from the 12 other OFD syndromes by cerebellar and metacarpal abnormalities. Cerebellar malformations in OFD VI have been described as a molar tooth sign (MTS), thus, including OFD VI among the "Joubert syndrome related disorders" (JSRD). OFD VI diagnostic criteria have recently been suggested: MTS and one or more of the following: 1) tongue hamartoma(s) and/or additional frenula and/or upper lip notch; 2) mesoaxial polydactyly of hands or feet; 3) hypothalamic hamartoma. In order to further delineate this rare entity, we present the neurological and radiological data of 6 additional OFD VI patients. All patients presented oral malformations, facial dysmorphism and distal abnormalities including frequent polydactyly (66%), as well as neurological symptoms with moderate to severe mental retardation. Contrary to historically reported patients, mesoaxial polydactyly did not appear to be a predominant clinical feature in OFD VI. Sequencing analyzes of the 14 genes implicated in JSRD up to 2011 revealed only an OFD1 frameshift mutation in one female OFD VI patient, strengthening the link between these two oral-facial-digital syndromes and JSRD.
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Vladan B, Biljana SP, Mandusic V, Zorana M, Zivkovic L. Instability in X chromosome inactivation patterns in AMD: a new risk factor? MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2013; 2:74-82. [PMID: 24600647 PMCID: PMC3939760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Years ago, it was thought that a genetic component was the fundamental cause of a number retinopathy diseases including age related macular degeneration (AMD). Since then, information has emerged about novel genes that contribute to various forms of AMD and other retinopathies that have been eluding researchers for years. In the genetic sense, only the APOE 2 and 4 genes have been found to be a risk factor for sporadic AMD. But, a recent Genome wide association study (GWAS) revealed that an alteration of five SNIPs on the X chromosome in a gene named DIAPH2 may be a susceptibility gene for AMD. Furthermore, the gene DIAPH2 showed to have a polygenic pleiotropy for premature ovarian failure (POF) and AMD in a cohort of women. POF is highly associated with X chromosome skewing, an epigenetic alteration of the inactivation process of the X chromosome. These findings suggest a hypothesis that an epigenetic alteration on the inactivation centres of the X chromosome (or skewing) relates not only to aging, but might be a novel property that affects women with AMD more often than men.
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Affiliation(s)
- Bajic Vladan
- Institute of Pharmaceutical Research and Development, University of Belgrade and Galenika a.d
| | | | - Vesna Mandusic
- Institute for Nuclear Sciences’’ Vinca’’, Department of Molecular Biology and Endocrinology, Belgrade, Serbia
| | - Milicevic Zorana
- Institute for Nuclear Sciences’’ Vinca’’, Department of Molecular Biology and Endocrinology, Belgrade, Serbia
| | - Lada Zivkovic
- Department of Physiology, Faculty of Pharmacy, University of Belgrade
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Branham K, Othman M, Brumm M, Karoukis AJ, Atmaca-Sonmez P, Yashar BM, Schwartz SB, Stover NB, Trzupek K, Wheaton D, Jennings B, Ciccarelli ML, Jayasundera KT, Lewis RA, Birch D, Bennett J, Sieving PA, Andreasson S, Duncan JL, Fishman GA, Iannaccone A, Weleber RG, Jacobson SG, Heckenlively JR, Swaroop A. Mutations in RPGR and RP2 account for 15% of males with simplex retinal degenerative disease. Invest Ophthalmol Vis Sci 2012; 53:8232-7. [PMID: 23150612 DOI: 10.1167/iovs.12-11025] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To determine the proportion of male patients presenting simplex retinal degenerative disease (RD: retinitis pigmentosa [RP] or cone/cone-rod dystrophy [COD/CORD]) with mutations in the X-linked retinal degeneration genes RPGR and RP2. METHODS Simplex males were defined as patients with no known affected family members. Patients were excluded if they had a family history of parental consanguinity. Blood samples from a total of 214 simplex males with a diagnosis of retinal degeneration were collected for genetic analysis. The patients were screened for mutations in RPGR and RP2 by direct sequencing of PCR-amplified genomic DNA. RESULTS We identified pathogenic mutations in 32 of the 214 patients screened (15%). Of the 29 patients with a diagnosis of COD/CORD, four mutations were identified in the ORF15 mutational hotspot of the RPGR gene. Of the 185 RP patients, three patients had mutations in RP2 and 25 had RPGR mutations (including 12 in the ORF15 region). CONCLUSIONS This study represents mutation screening of RPGR and RP2 in the largest cohort, to date, of simplex males affected with RP or COD/CORD. Our results demonstrate a substantial contribution of RPGR mutations to retinal degenerations, and in particular, to simplex RP. Based on our findings, we suggest that RPGR should be considered as a first tier gene for screening isolated males with retinal degeneration.
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Affiliation(s)
- Kari Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105, USA
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Thauvin-Robinet C, Thomas S, Sinico M, Aral B, Burglen L, Gigot N, Dollfus H, Rossignol S, Raynaud M, Philippe C, Badens C, Touraine R, Gomes C, Franco B, Lopez E, Elkhartoufi N, Faivre L, Munnich A, Boddaert N, Van Maldergem L, Encha-Razavi F, Lyonnet S, Vekemans M, Escudier E, Attié-Bitach T. OFD1 mutations in males: phenotypic spectrum and ciliary basal body docking impairment. Clin Genet 2012; 84:86-90. [PMID: 23036093 DOI: 10.1111/cge.12013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 08/22/2012] [Accepted: 09/04/2012] [Indexed: 12/30/2022]
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Di Gioia SA, Letteboer SJF, Kostic C, Bandah-Rozenfeld D, Hetterschijt L, Sharon D, Arsenijevic Y, Roepman R, Rivolta C. FAM161A, associated with retinitis pigmentosa, is a component of the cilia-basal body complex and interacts with proteins involved in ciliopathies. Hum Mol Genet 2012; 21:5174-84. [PMID: 22940612 DOI: 10.1093/hmg/dds368] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Retinitis pigmentosa (RP) is a retinal degenerative disease characterized by the progressive loss of photoreceptors. We have previously demonstrated that RP can be caused by recessive mutations in the human FAM161A gene, encoding a protein with unknown function that contains a conserved region shared only with a distant paralog, FAM161B. In this study, we show that FAM161A localizes at the base of the photoreceptor connecting cilium in human, mouse and rat. Furthermore, it is also present at the ciliary basal body in ciliated mammalian cells, both in native conditions and upon the expression of recombinant tagged proteins. Yeast two-hybrid analysis of binary interactions between FAM161A and an array of ciliary and ciliopathy-associated proteins reveals direct interaction with lebercilin, CEP290, OFD1 and SDCCAG8, all involved in hereditary retinal degeneration. These interactions are mediated by the C-terminal moiety of FAM161A, as demonstrated by pull-down experiments in cultured cell lines and in bovine retinal extracts. As other ciliary proteins, FAM161A can also interact with the microtubules and organize itself into microtubule-dependent intracellular networks. Moreover, small interfering RNA-mediated depletion of FAM161A transcripts in cultured cells causes the reduction in assembled primary cilia. Taken together, these data indicate that FAM161A-associated RP can be considered as a novel retinal ciliopathy and that its molecular pathogenesis may be related to other ciliopathies.
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Estrada-Cuzcano A, Roepman R, Cremers FPM, den Hollander AI, Mans DA. Non-syndromic retinal ciliopathies: translating gene discovery into therapy. Hum Mol Genet 2012; 21:R111-24. [PMID: 22843501 DOI: 10.1093/hmg/dds298] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Homozygosity mapping and exome sequencing have accelerated the discovery of gene mutations and modifier alleles implicated in inherited retinal degeneration in humans. To date, 158 genes have been found to be mutated in individuals with retinal dystrophies. Approximately one-third of the gene defects underlying retinal degeneration affect the structure and/or function of the 'connecting cilium' in photoreceptors. This structure corresponds to the transition zone of a prototypic cilium, a region with increasing relevance for ciliary homeostasis. The connecting cilium connects the inner and outer segments of the photoreceptor, mediating bi-directional transport of phototransducing proteins required for vision. In fact, the outer segment, connecting cilium and associated basal body, forms a highly specialized sensory cilium, fully dedicated to photoreception and subsequent signal transduction to the brain. At least 21 genes that encode ciliary proteins are implicated in non-syndromic retinal dystrophies such as cone dystrophy, cone-rod dystrophy, Leber congenital amaurosis (LCA), macular degeneration or retinitis pigmentosa (RP). The generation and characterization of vertebrate retinal ciliopathy animal models have revealed insights into the molecular disease mechanism which are indispensable for the development and evaluation of therapeutic strategies. Gene augmentation therapy has proven to be safe and successful in restoring long-term sight in mice, dogs and humans suffering from LCA or RP. Here, we present a comprehensive overview of the genes, mutations and modifier alleles involved in non-syndromic retinal ciliopathies, review the progress in dissecting the associated retinal disease mechanisms and evaluate gene augmentation approaches to antagonize retinal degeneration in these ciliopathies.
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