1
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Hao XL, Chen R, Liu W, Hou BK, Qu LH, Li ZH, Wang DJ, Jin X, Huang HB. Analysis of Phenotypes Associated with Deficiency of PAX6 Haplotypes in Chinese Aniridia Families. Curr Med Sci 2024:10.1007/s11596-024-2903-1. [PMID: 38967890 DOI: 10.1007/s11596-024-2903-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/13/2024] [Indexed: 07/06/2024]
Abstract
OBJECTIVE To examine the clinical phenotype and genetic deficiencies present in Chinese aniridia families with PAX6 haplotype deficiency. METHODS A comprehensive questionnaire and ophthalmological assessments were administered to both affected patients and unaffected relatives. The clinical feature analysis included the evaluation of visual acuity, intraocular pressure, slit-lamp anterior segment examination, fundus photography, and spectral domain optical coherence tomography. To identify the mutation responsible for aniridia, targeted next-generation sequencing was used as a beneficial technique. RESULTS A total of 4 mutations were identified, consisting of two novel frameshift mutations (c.314delA, p.K105Sfs*33 and c.838_845dup AACACACC, p.S283Tfs*85), along with two recurring nonsense mutations (c.307C>T, p.R103X and c.619A>T, p.K207*). Complete iris absence, macular foveal hypoplasia, and nystagmus were consistent in these PAX6 haplotype-deficient Chinese aniridia families, while corneal lesions, cataracts, and glaucoma exhibited heterogeneity both among the families and within the same family. CONCLUSION In our study, two novel PAX6 mutations associated with aniridia were identified in Chinese families, which expanded the phenotypic and genotypic spectrum of PAX6 mutations. We also analyzed the clinical characteristics of PAX6 haplotype deficiency in Chinese aniridia families.
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Affiliation(s)
- Xiao-Lu Hao
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China
| | - Ran Chen
- Bolin Eye Care Group, Beijing, 100098, China
| | - Wei Liu
- Department of Ophthalmology, Hainan Hospital of Chinese PLA General Hospital, Sanya, 572000, China
| | - Bao-Ke Hou
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China
| | - Ling-Hui Qu
- Department of Ophthalmology, the 74th Army Group Hospital, Guangzhou, 510318, China
| | - Zhao-Hui Li
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China
| | - Da-Jiang Wang
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China
| | - Xin Jin
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China.
| | - Hou-Bin Huang
- Senior Department of Opthalmology, the Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China.
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2
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Zucco J, Baldan F, Allegri L, Bregant E, Passon N, Franzoni A, D'Elia AV, Faletra F, Damante G, Mio C. A bird's eye view on the use of whole exome sequencing in rare congenital ophthalmic diseases. J Hum Genet 2024; 69:271-282. [PMID: 38459225 PMCID: PMC11126393 DOI: 10.1038/s10038-024-01237-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/07/2024] [Accepted: 02/22/2024] [Indexed: 03/10/2024]
Abstract
Phenotypic and genotypic heterogeneity in congenital ocular diseases, especially in anterior segment dysgenesis (ASD), have created challenges for proper diagnosis and classification of diseases. Over the last decade, genomic research has indeed boosted our understanding in the molecular basis of ASD and genes associated with both autosomal dominant and recessive patterns of inheritance have been described with a wide range of expressivity. Here we describe the molecular characterization of a cohort of 162 patients displaying isolated or syndromic congenital ocular dysgenesis. Samples were analyzed with diverse techniques, such as direct sequencing, multiplex ligation-dependent probe amplification, and whole exome sequencing (WES), over 20 years. Our data reiterate the notion that PAX6 alterations are primarily associated with ASD, mostly aniridia, since the majority of the cohort (66.7%) has a pathogenic or likely pathogenic variant in the PAX6 locus. Unexpectedly, a high fraction of positive samples (20.3%) displayed deletions involving the 11p13 locus, either partially/totally involving PAX6 coding region or abolishing its critical regulatory region, underlying its significance. Most importantly, the use of WES has allowed us to both assess variants in known ASD genes (i.e., CYP1B1, ITPR1, MAB21L1, PXDN, and PITX2) and to identify rarer phenotypes (i.e., MIDAS, oculogastrointestinal-neurodevelopmental syndrome and Jacobsen syndrome). Our data clearly suggest that WES allows expanding the analytical portfolio of ocular dysgenesis, both isolated and syndromic, and that is pivotal for the differential diagnosis of those conditions in which there may be phenotypic overlaps and in general in ASD.
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Affiliation(s)
- Jessica Zucco
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
| | - Federica Baldan
- Department of Medicine (DMED), University of Udine, Udine, Italy
| | - Lorenzo Allegri
- Department of Medicine (DMED), University of Udine, Udine, Italy
| | - Elisa Bregant
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
| | - Nadia Passon
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
| | - Alessandra Franzoni
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
| | - Angela Valentina D'Elia
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
| | - Flavio Faletra
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy.
| | - Giuseppe Damante
- Institute of Medical Genetics, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy
- Department of Medicine (DMED), University of Udine, Udine, Italy
| | - Catia Mio
- Department of Medicine (DMED), University of Udine, Udine, Italy
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3
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Farris J, Khanna C, Smadbeck JB, Johnson SH, Bothun E, Kaplan T, Hoffman F, Polonis K, Oliver G, Reis LM, Semina EV, Rust L, Hoppman NL, Vasmatzis G, Marcou CA, Schimmenti LA, Klee EW. Complex balanced intrachromosomal rearrangement involving PITX2 identified as a cause of Axenfeld-Rieger Syndrome. Am J Med Genet A 2024; 194:e63542. [PMID: 38234180 PMCID: PMC11003841 DOI: 10.1002/ajmg.a.63542] [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: 08/28/2023] [Revised: 12/15/2023] [Accepted: 01/07/2024] [Indexed: 01/19/2024]
Abstract
Axenfeld-Rieger Syndrome (ARS) type 1 is a rare autosomal dominant condition characterized by anterior chamber anomalies, umbilical defects, dental hypoplasia, and craniofacial anomalies, with Meckel's diverticulum in some individuals. Here, we describe a clinically ascertained female of childbearing age with ARS for whom clinical targeted sequencing and deletion/duplication analysis followed by clinical exome and genome sequencing resulted in no pathogenic variants or variants of unknown significance in PITX2 or FOXC1. Advanced bioinformatic analysis of the genome data identified a complex, balanced rearrangement disrupting PITX2. This case is the first reported intrachromosomal rearrangement leading to ARS, illustrating that for patients with compelling clinical phenotypes but negative genomic testing, additional bioinformatic analysis are essential to identify subtle genomic abnormalities in target genes.
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Affiliation(s)
- Joseph Farris
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Cheryl Khanna
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA
| | - James B Smadbeck
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Sarah H Johnson
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Erick Bothun
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA
| | - Tyler Kaplan
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA
| | - Francis Hoffman
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Katarzyna Polonis
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gavin Oliver
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Laura Rust
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Nicole L Hoppman
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - George Vasmatzis
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Cherisse A Marcou
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Lisa A Schimmenti
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota, USA
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4
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Hall HN, Parry D, Halachev M, Williamson KA, Donnelly K, Campos Parada J, Bhatia S, Joseph J, Holden S, Prescott TE, Bitoun P, Kirk EP, Newbury-Ecob R, Lachlan K, Bernar J, van Heyningen V, FitzPatrick DR, Meynert A. Short-read whole genome sequencing identifies causative variants in most individuals with previously unexplained aniridia. J Med Genet 2024; 61:250-261. [PMID: 38050128 PMCID: PMC7615962 DOI: 10.1136/jmg-2023-109181] [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: 03/12/2023] [Accepted: 09/25/2023] [Indexed: 12/06/2023]
Abstract
BACKGROUND Classic aniridia is a highly penetrant autosomal dominant disorder characterised by congenital absence of the iris, foveal hypoplasia, optic disc anomalies and progressive opacification of the cornea. >90% of cases of classic aniridia are caused by heterozygous, loss-of-function variants affecting the PAX6 locus. METHODS Short-read whole genome sequencing was performed on 51 (39 affected) individuals from 37 different families who had screened negative for mutations in the PAX6 coding region. RESULTS Likely causative mutations were identified in 22 out of 37 (59%) families. In 19 out of 22 families, the causative genomic changes have an interpretable deleterious impact on the PAX6 locus. Of these 19 families, 1 has a novel heterozygous PAX6 frameshift variant missed on previous screens, 4 have single nucleotide variants (SNVs) (one novel) affecting essential splice sites of PAX6 5' non-coding exons and 2 have deep intronic SNV (one novel) resulting in gain of a donor splice site. In 12 out of 19, the causative variants are large-scale structural variants; 5 have partial or whole gene deletions of PAX6, 3 have deletions encompassing critical PAX6 cis-regulatory elements, 2 have balanced inversions with disruptive breakpoints within the PAX6 locus and 2 have complex rearrangements disrupting PAX6. The remaining 3 of 22 families have deletions encompassing FOXC1 (a known cause of atypical aniridia). Seven of the causative variants occurred de novo and one cosegregated with familial aniridia. We were unable to establish inheritance status in the remaining probands. No plausibly causative SNVs were identified in PAX6 cis-regulatory elements. CONCLUSION Whole genome sequencing proves to be an effective diagnostic test in most individuals with previously unexplained aniridia.
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Affiliation(s)
- Hildegard Nikki Hall
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - David Parry
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
- Illumina United Kingdom, Edinburgh, UK
| | - Mihail Halachev
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Kathleen A Williamson
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Kevin Donnelly
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Jose Campos Parada
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Shipra Bhatia
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Jeffrey Joseph
- MRC Human Genetics Unit, The University of Edinburgh, Edinburgh, UK
| | - Simon Holden
- East Anglia Regional Genetics Service, Addenbrooke's Hospital, Cambridge, UK
| | - Trine E Prescott
- Department of Medical Genetics, Telemark Hospital, Skien, Norway
| | - Pierre Bitoun
- Consultations de Génétique médicale, Service de Pédiatrie, CHU Paris-Nord, Hôpital Jean Verdier, Bondy, France
| | - Edwin P Kirk
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Randwick, New South Wales, Australia
| | - Ruth Newbury-Ecob
- Department of Clinical Genetics, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Katherine Lachlan
- University Hospital Southampton, NHS Foundation Trust Wessex Clinical Genetics Service, Southampton, UK
| | - Juan Bernar
- Department of Genetics, Hospital Ruber Internacional, Madrid, Spain
| | - Veronica van Heyningen
- MRC Human Genetics Unit, The University of Edinburgh, Edinburgh, UK
- Institute of Ophthalmology, University College London, London, UK
| | - David R FitzPatrick
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Alison Meynert
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
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5
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Li Y, Chen J, Zheng Y, Chen Z, Wang T, Sun Q, Wan X, Liu H, Sun X. A novel microdeletion of 517 kb downstream of the PAX6 gene in a Chinese family with congenital aniridia. BMC Ophthalmol 2023; 23:393. [PMID: 37752489 PMCID: PMC10523764 DOI: 10.1186/s12886-023-03147-1] [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: 10/11/2022] [Accepted: 09/19/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND To identify the disease-causing gene in a Chinese family affected with congenital aniridia. METHODS Patients underwent systematic ophthalmic examinations such as anterior segment photography, fundus photography, optical coherence tomography, and fundus fluorescein angiography. The proband was screened for pathogenic variants by whole exome sequencing (WES) and copy number variant (CNV) analysis. Real-time quantitative PCR (RT-qPCR) was applied to confirm the CNV results. Breakpoints were identified by long-range PCR followed by Sanger sequencing. RESULTS All seven members of this Chinese family, including four patients and three normal individuals, were recruited for this study. All patients showed bilateral congenital aniridia with nystagmus, except the son of the proband, who presented with bilateral partial coloboma of the iris. A novel heterozygous deletion (chr11:31,139,019-31,655,997) containing the 3' regulatory enhancers of the PAX6 gene was detected in this family. We also reviewed the reported microdeletions downstream of PAX6 in patients with aniridia. CONCLUSIONS We identified a novel microdeletion, 517 kb in size located about 133 kb downstream of the PAX6 gene, responsible for congenital aniridia in this Chinese family, which expands the spectrum of aniridia-associated mutations in PAX6.
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Affiliation(s)
- Yinwen Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jieqiong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Ying Zheng
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Zhixuan Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Tao Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Qian Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xiaoling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
| | - Haiyun Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
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6
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Daruich A, Duncan M, Robert MP, Lagali N, Semina EV, Aberdam D, Ferrari S, Romano V, des Roziers CB, Benkortebi R, De Vergnes N, Polak M, Chiambaretta F, Nischal KK, Behar-Cohen F, Valleix S, Bremond-Gignac D. Congenital aniridia beyond black eyes: From phenotype and novel genetic mechanisms to innovative therapeutic approaches. Prog Retin Eye Res 2023; 95:101133. [PMID: 36280537 PMCID: PMC11062406 DOI: 10.1016/j.preteyeres.2022.101133] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.
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Affiliation(s)
- Alejandra Daruich
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Melinda Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Matthieu P Robert
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; Borelli Centre, UMR 9010, CNRS-SSA-ENS Paris Saclay-Paris Cité University, Paris, France
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, 581 83, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway
| | - Elena V Semina
- Department of Pediatrics, Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Daniel Aberdam
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Stefano Ferrari
- Fondazione Banca degli Occhi del Veneto, Via Paccagnella 11, Venice, Italy
| | - Vito Romano
- Department of Medical and Surgical Specialties, Radiolological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Italy
| | - Cyril Burin des Roziers
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Rabia Benkortebi
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Nathalie De Vergnes
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Michel Polak
- Pediatric Endocrinology, Gynecology and Diabetology, Hôpital Universitaire Necker Enfants Malades, AP-HP, Paris Cité University, INSERM U1016, Institut IMAGINE, France
| | | | - Ken K Nischal
- Division of Pediatric Ophthalmology, Strabismus, and Adult Motility, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Francine Behar-Cohen
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Sophie Valleix
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Dominique Bremond-Gignac
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France.
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7
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Damián A, Núñez-Moreno G, Jubin C, Tamayo A, de Alba MR, Villaverde C, Fund C, Delépine M, Leduc A, Deleuze JF, Mínguez P, Ayuso C, Corton M. Long-read genome sequencing identifies cryptic structural variants in congenital aniridia cases. Hum Genomics 2023; 17:45. [PMID: 37269011 DOI: 10.1186/s40246-023-00490-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/08/2023] [Indexed: 06/04/2023] Open
Abstract
BACKGROUND Haploinsufficiency of the transcription factor PAX6 is the main cause of congenital aniridia, a genetic disorder characterized by iris and foveal hypoplasia. 11p13 microdeletions altering PAX6 or its downstream regulatory region (DRR) are present in about 25% of patients; however, only a few complex rearrangements have been described to date. Here, we performed nanopore-based whole-genome sequencing to assess the presence of cryptic structural variants (SVs) on the only two unsolved "PAX6-negative" cases from a cohort of 110 patients with congenital aniridia after unsuccessfully short-read sequencing approaches. RESULTS Long-read sequencing (LRS) unveiled balanced chromosomal rearrangements affecting the PAX6 locus at 11p13 in these two patients and allowed nucleotide-level breakpoint analysis. First, we identified a cryptic 4.9 Mb de novo inversion disrupting intron 7 of PAX6, further verified by targeted polymerase chain reaction amplification and sequencing and FISH-based cytogenetic analysis. Furthermore, LRS was decisive in correctly mapping a t(6;11) balanced translocation cytogenetically detected in a second proband with congenital aniridia and considered non-causal 15 years ago. LRS resolved that the breakpoint on chromosome 11 was indeed located at 11p13, disrupting the DNase I hypersensitive site 2 enhancer within the DRR of PAX6, 161 Kb from the causal gene. Patient-derived RNA expression analysis demonstrated PAX6 haploinsufficiency, thus supporting that the 11p13 breakpoint led to a positional effect by cleaving crucial enhancers for PAX6 transactivation. LRS analysis was also critical for mapping the exact breakpoint on chromosome 6 to the highly repetitive centromeric region at 6p11.1. CONCLUSIONS In both cases, the LRS-based identified SVs have been deemed the hidden pathogenic cause of congenital aniridia. Our study underscores the limitations of traditional short-read sequencing in uncovering pathogenic SVs affecting low-complexity regions of the genome and the value of LRS in providing insight into hidden sources of variation in rare genetic diseases.
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Affiliation(s)
- Alejandra Damián
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
| | - Claire Jubin
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, 91057, Evry, France
| | - Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871, Alcalá de Henares, Spain
| | - Marta Rodríguez de Alba
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
| | - Cédric Fund
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, 91057, Evry, France
| | - Marc Delépine
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, 91057, Evry, France
| | - Aurélie Leduc
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, 91057, Evry, France
| | - Jean François Deleuze
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, 91057, Evry, France
| | - Pablo Mínguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain.
- Centre for Biomedical Network Research On Rare Diseases (CIBERER), 28029, Madrid, Spain.
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8
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Kuchalska K, Wawrocka A, Krawczynski MR. Novel variants in the PAX6 gene related to isolated aniridia. Congenit Anom (Kyoto) 2023. [PMID: 37191119 DOI: 10.1111/cga.12520] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 04/07/2023] [Accepted: 04/25/2023] [Indexed: 05/17/2023]
Abstract
Aniridia, which is a rare congenital defect of the eye, consists of iris hypoplasia or aplasia, and additional ocular abnormalities. It is most commonly caused by autosomal dominant PAX6 gene mutations. However, in about 30% of cases, it is associated with chromosomal rearrangements in the 11p13 region. The aim of this study was to identify the potential PAX6 gene variants, which could cause the isolated aniridia. Eight patients with isolated aniridia were included in this study. MLPA analysis allowed in the past to exclude large structural rearrangements of the PAX6 and adjacent genes like WT1. Blood samples were collected from the patients (and their families in familial cases) and genomic DNA was extracted from peripheral blood leukocytes and buccal cells. The amplification of the 11 exons of the PAX6 gene was performed. Bidirectional Sanger Sequencing was conducted for the identification of the potentially pathogenic variants, and for the segregation analysis of the identified variant in the family. The results were analyzed with the use of CodonCode Aligner software. In three patients, aniridia was sporadic, whereas in another five cases, the eye defect was familial. The potentially pathogenic variants in the PAX6 gene were found in 6 out of 8 patients with aniridia. We identified four known (c.781C > T, c.607C > T, and c.949C > T twice), and two novel variants (c.258_265del and c.495_496insG). Point mutations in the PAX6 gene are the most frequent cause of aniridia. The investigation of the genetic background of the disease is essential for patients to evaluate recurrence risk in the offspring.
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Affiliation(s)
| | - Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
- Center of Medical Genetics "Genesis", Poznan, Poland
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9
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Reis LM, Maheshwari M, Capasso J, Atilla H, Dudakova L, Thompson S, Zitano L, Lay-Son G, Lowry RB, Black J, Lee J, Shue A, Kremlikova Pourova R, Vaneckova M, Skalicka P, Jedlickova J, Trkova M, Williams B, Richard G, Bachman K, Seeley AH, Costakos D, Glaser TM, Levin AV, Liskova P, Murray JC, Semina EV. Axenfeld-Rieger syndrome: more than meets the eye. J Med Genet 2023; 60:368-379. [PMID: 35882526 PMCID: PMC9912354 DOI: 10.1136/jmg-2022-108646] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/15/2022] [Indexed: 12/11/2022]
Abstract
BACKGROUND Axenfeld-Rieger syndrome (ARS) is characterised by typical anterior segment anomalies, with or without systemic features. The discovery of causative genes identified ARS subtypes with distinct phenotypes, but our understanding is incomplete, complicated by the rarity of the condition. METHODS Genetic and phenotypic characterisation of the largest reported ARS cohort through comprehensive genetic and clinical data analyses. RESULTS 128 individuals with causative variants in PITX2 or FOXC1, including 81 new cases, were investigated. Ocular anomalies showed significant overlap but with broader variability and earlier onset of glaucoma for FOXC1-related ARS. Systemic anomalies were seen in all individuals with PITX2-related ARS and the majority of those with FOXC1-related ARS. PITX2-related ARS demonstrated typical umbilical anomalies and dental microdontia/hypodontia/oligodontia, along with a novel high rate of Meckel diverticulum. FOXC1-related ARS exhibited characteristic hearing loss and congenital heart defects as well as previously unrecognised phenotypes of dental enamel hypoplasia and/or crowding, a range of skeletal and joint anomalies, hypotonia/early delay and feeding disorders with structural oesophageal anomalies in some. Brain imaging revealed highly penetrant white matter hyperintensities, colpocephaly/ventriculomegaly and frequent arachnoid cysts. The expanded phenotype of FOXC1-related ARS identified here was found to fully overlap features of De Hauwere syndrome. The results were used to generate gene-specific management plans for the two types of ARS. CONCLUSION Since clinical features of ARS vary significantly based on the affected gene, it is critical that families are provided with a gene-specific diagnosis, PITX2-related ARS or FOXC1-related ARS. De Hauwere syndrome is proposed to be a FOXC1opathy.
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Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
| | - Mohit Maheshwari
- Department of Pediatric Radiology, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
| | - Jenina Capasso
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Golisano Children's Hospital and University of Rochester, Rochester, New York, USA
| | - Huban Atilla
- Department of Ophthalmology, School of Medicine, Ankara University, Ankara, Turkey
| | - Lubica Dudakova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Samuel Thompson
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
| | - Lia Zitano
- Department of Medical Genetics, Spectrum Health, Grand Rapids, Michigan, USA
| | - Guillermo Lay-Son
- Unidad de Genética, División de Pediatría, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - R Brian Lowry
- Department of Clinical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Jennifer Black
- Center for Development, Behavior, and Genetics, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Joseph Lee
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Ann Shue
- Byers Eye Institute, Department of Ophthalmology, Stanford University and Stanford Children's Health, Stanford, California, USA
| | - Radka Kremlikova Pourova
- Department of Biology and Medical Genetics, Second Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Manuela Vaneckova
- Department of Radiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Pavlina Skalicka
- Department of Pediatrics and Inherited Metabolic Disorders, 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
| | - Jana Jedlickova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Marie Trkova
- Gennet, Centre for Fetal Medicine and Reproductive Genetics, Prague, Czech Republic
| | | | | | - Kristine Bachman
- Department of Pediatrics, Geisinger Medical Center, Danville, Pennsylvania, USA
| | - Andrea H Seeley
- Department of Pediatrics, Geisinger Medical Center, Danville, Pennsylvania, USA
| | - Deborah Costakos
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Thomas M Glaser
- Department of Cell Biology and Human Anatomy, UC-Davis School of Medicine, Davis, California, USA
| | - Alex V Levin
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Golisano Children's Hospital and University of Rochester, Rochester, New York, USA
| | - Petra Liskova
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jeffrey C Murray
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, Milwaukee, Wisconsin, USA
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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10
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Tomas-Roca L, Qiu Z, Fransén E, Gokhale R, Bulovaite E, Price DJ, Komiyama NH, Grant SGN. Developmental disruption and restoration of brain synaptome architecture in the murine Pax6 neurodevelopmental disease model. Nat Commun 2022; 13:6836. [PMID: 36369219 PMCID: PMC9652404 DOI: 10.1038/s41467-022-34131-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/14/2022] [Indexed: 11/13/2022] Open
Abstract
Neurodevelopmental disorders of genetic origin delay the acquisition of normal abilities and cause disabling phenotypes. Nevertheless, spontaneous attenuation and even complete amelioration of symptoms in early childhood and adolescence can occur in many disorders, suggesting that brain circuits possess an intrinsic capacity to overcome the deficits arising from some germline mutations. We examined the molecular composition of almost a trillion excitatory synapses on a brain-wide scale between birth and adulthood in mice carrying a mutation in the homeobox transcription factor Pax6, a neurodevelopmental disorder model. Pax6 haploinsufficiency had no impact on total synapse number at any age. By contrast, the molecular composition of excitatory synapses, the postnatal expansion of synapse diversity and the acquisition of normal synaptome architecture were delayed in all brain regions, interfering with networks and electrophysiological simulations of cognitive functions. Specific excitatory synapse types and subtypes were affected in two key developmental age-windows. These phenotypes were reversed within 2-3 weeks of onset, restoring synapse diversity and synaptome architecture to the normal developmental trajectory. Synapse subtypes with rapid protein turnover mediated the synaptome remodeling. This brain-wide capacity for remodeling of synapse molecular composition to recover and maintain the developmental trajectory of synaptome architecture may help confer resilience to neurodevelopmental genetic disorders.
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Affiliation(s)
- Laura Tomas-Roca
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK
| | - Zhen Qiu
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK
| | - Erik Fransén
- grid.5037.10000000121581746Science for Life Laboratory, KTH Royal Institute of Technology, SE-171 65 Solna, Sweden
| | - Ragini Gokhale
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK
| | - Edita Bulovaite
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK
| | - David J. Price
- grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Noboru H. Komiyama
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK
| | - Seth G. N. Grant
- grid.4305.20000 0004 1936 7988Genes to Cognition Program, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB UK ,grid.4305.20000 0004 1936 7988Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH8 9XD UK
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11
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Ferre-Fernández JJ, Muheisen S, Thompson S, Semina EV. CRISPR-Cas9-mediated functional dissection of the foxc1 genomic region in zebrafish identifies critical conserved cis-regulatory elements. Hum Genomics 2022; 16:49. [PMID: 36284357 PMCID: PMC9597995 DOI: 10.1186/s40246-022-00423-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/19/2022] [Indexed: 11/10/2022] Open
Abstract
FOXC1 encodes a forkhead-domain transcription factor associated with several ocular disorders. Correct FOXC1 dosage is critical to normal development, yet the mechanisms controlling its expression remain unknown. Together with FOXQ1 and FOXF2, FOXC1 is part of a cluster of FOX genes conserved in vertebrates. CRISPR-Cas9-mediated dissection of genomic sequences surrounding two zebrafish orthologs of FOXC1 was performed. This included five zebrafish-human conserved regions, three downstream of foxc1a and two remotely upstream of foxf2a/foxc1a or foxf2b/foxc1b clusters, as well as two intergenic regions between foxc1a/b and foxf2a/b lacking sequence conservation but positionally corresponding to the area encompassing a previously reported glaucoma-associated SNP in humans. Removal of downstream sequences altered foxc1a expression; moreover, zebrafish carrying deletions of two or three downstream elements demonstrated abnormal phenotypes including enlargement of the anterior chamber of the eye reminiscent of human congenital glaucoma. Deletions of distant upstream conserved elements influenced the expression of foxf2a/b or foxq1a/b but not foxc1a/b within each cluster. Removal of either intergenic sequence reduced foxc1a or foxc1b expression during late development, suggesting a role in transcriptional regulation despite the lack of conservation at the nucleotide level. Further studies of the identified regions in human patients may explain additional individuals with developmental ocular disorders.
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Affiliation(s)
- Jesús-José Ferre-Fernández
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Sanaa Muheisen
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Samuel Thompson
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA.
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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12
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D’Aurizio R, Catona O, Pitasi M, Li YE, Ren B, Nicolis SK. Bridging between Mouse and Human Enhancer-Promoter Long-Range Interactions in Neural Stem Cells, to Understand Enhancer Function in Neurodevelopmental Disease. Int J Mol Sci 2022; 23:ijms23147964. [PMID: 35887306 PMCID: PMC9322198 DOI: 10.3390/ijms23147964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/08/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022] Open
Abstract
Non-coding variation in complex human disease has been well established by genome-wide association studies, and is thought to involve regulatory elements, such as enhancers, whose variation affects the expression of the gene responsible for the disease. The regulatory elements often lie far from the gene they regulate, or within introns of genes differing from the regulated gene, making it difficult to identify the gene whose function is affected by a given enhancer variation. Enhancers are connected to their target gene promoters via long-range physical interactions (loops). In our study, we re-mapped, onto the human genome, more than 10,000 enhancers connected to promoters via long-range interactions, that we had previously identified in mouse brain-derived neural stem cells by RNApolII-ChIA-PET analysis, coupled to ChIP-seq mapping of DNA/chromatin regions carrying epigenetic enhancer marks. These interactions are thought to be functionally relevant. We discovered, in the human genome, thousands of DNA regions syntenic with the interacting mouse DNA regions (enhancers and connected promoters). We further annotated these human regions regarding their overlap with sequence variants (single nucleotide polymorphisms, SNPs; copy number variants, CNVs), that were previously associated with neurodevelopmental disease in humans. We document various cases in which the genetic variant, associated in humans to neurodevelopmental disease, affects an enhancer involved in long-range interactions: SNPs, previously identified by genome-wide association studies to be associated with schizophrenia, bipolar disorder, and intelligence, are located within our human syntenic enhancers, and alter transcription factor recognition sites. Similarly, CNVs associated to autism spectrum disease and other neurodevelopmental disorders overlap with our human syntenic enhancers. Some of these enhancers are connected (in mice) to homologs of genes already associated to the human disease, strengthening the hypothesis that the gene is indeed involved in the disease. Other enhancers are connected to genes not previously associated with the disease, pointing to their possible pathogenetic involvement. Our observations provide a resource for further exploration of neural disease, in parallel with the now widespread genome-wide identification of DNA variants in patients with neural disease.
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Affiliation(s)
- Romina D’Aurizio
- Institute of Informatics and Telematics (IIT), National Research Council (CNR), 56124 Pisa, Italy;
- Correspondence:
| | - Orazio Catona
- Institute of Informatics and Telematics (IIT), National Research Council (CNR), 56124 Pisa, Italy;
| | - Mattia Pitasi
- Dipartimento di Biotecnologie e Bioscienze, University of Milano-Bicocca, 20126 Milano, Italy; (M.P.); (S.K.N.)
| | - Yang Eric Li
- University of California San Diego, La Jolla, CA 92093, USA; (Y.E.L.); (B.R.)
| | - Bing Ren
- University of California San Diego, La Jolla, CA 92093, USA; (Y.E.L.); (B.R.)
| | - Silvia Kirsten Nicolis
- Dipartimento di Biotecnologie e Bioscienze, University of Milano-Bicocca, 20126 Milano, Italy; (M.P.); (S.K.N.)
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13
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Burgess FR, Hall HN, Megaw R. Emerging Gene Manipulation Strategies for the Treatment of Monogenic Eye Disease. Asia Pac J Ophthalmol (Phila) 2022; 11:380-391. [PMID: 36041151 DOI: 10.1097/apo.0000000000000545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/27/2022] [Indexed: 12/15/2022] Open
Abstract
Genetic eye diseases, representing a wide spectrum of simple and complex conditions, are one of the leading causes of visual loss in children and working adults, and progress in the field has led to changes in disease investigation, diagnosis, and management. The past 15 years have seen the emergence of novel therapies for these previously untreatable conditions to the extent that we now have a licensed therapy for one form of genetic eye disease and many more in clinical trial. This is a systematic review of published and ongoing clinical trials of gene therapies for monogenic eye diseases. Databases of clinical trials and the published literature were searched for interventional studies of gene therapies for eye diseases. Standard methodological procedures were used to assess the relevance of search results. A total of 59 registered clinical trials are referenced, showing the significant level of interest in the potential for translation of these therapies from bench to bedside. The breadth of therapy design is encouraging, providing multiple possible therapeutic mechanisms. Some fundamental questions regarding gene therapy for genetic eye diseases remain, such as optimal dosing, the relative benefits of adeno-associated virus (AAV)-packaging and the potential for a significant inflammatory response to the therapy itself. As a result, despite the promise of the eye as a target, it has proven difficult to deliver clinically effective gene therapies to the eye. Despite setbacks, the licensing of Luxturna (voretigene neparvovec, Novartis) for the treatment of RPE65-mediated Leber congenital amaurosis (LCA) is a major advance in efforts to treat these rare, but devastating, causes of visual loss.
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Affiliation(s)
- Frederick R Burgess
- Princess Alexandra Eye Pavilion, NHS Lothian, UK
- Ophthalmology Department, School of Medicine, University of St Andrews, UK
| | - Hildegard Nikki Hall
- Princess Alexandra Eye Pavilion, NHS Lothian, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, UK
| | - Roly Megaw
- Princess Alexandra Eye Pavilion, NHS Lothian, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, UK
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14
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EPHA2 biallelic disruption causes syndromic complex microphthalmia with iris hypoplasia. Eur J Med Genet 2022; 65:104574. [DOI: 10.1016/j.ejmg.2022.104574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/26/2022] [Accepted: 07/20/2022] [Indexed: 11/23/2022]
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15
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de Souza VS, da Cunha GCR, Versiani BR, de Oliveira CP, Rosa MTAS, de Oliveira SF, Moretti PN, Mazzeu JF, Pic-Taylor A. Characterization of Associated Nonclassical Phenotypes in Patients with Deletion in the WAGR Region Identified by Chromosomal Microarray: New Insights and Literature Review. Mol Syndromol 2022; 13:290-304. [PMID: 36158055 PMCID: PMC9421677 DOI: 10.1159/000518872] [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: 03/16/2021] [Accepted: 08/03/2021] [Indexed: 01/03/2023] Open
Abstract
WAGR syndrome (Wilms' tumor, aniridia, genitourinary changes, and intellectual disability) is a contiguous gene deletion syndrome characterized by the joint deletion of PAX6 and WT1 genes, located in the short arm of chromosome 11. However, most deletions include other genes, leading to multiple associated phenotypes. Therefore, understanding how genes deleted together can contribute to other clinical phenotypes is still considered a challenge. In order to establish genotype-phenotype correlation in patients with interstitial deletions of the short arm of chromosome 11, we selected 17 patients with deletions identified by chromosomal microarray analysis: 4 new subjects and 13 subjects previously described in the literature with detailed clinical data. Through the analysis of deleted regions and the phenotypic changes, it was possible to suggest the contribution of specific genes to several nonclassical phenotypes, contributing to the accuracy of clinical characterization of the syndrome and emphasizing the broad phenotypic spectrum found in the patients. This study reports the first patient with a PAX6 partial deletion who does not present any eye anomaly thus opening a new set of questions about the functional activity of PAX6.
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Affiliation(s)
- Vanessa Sodré de Souza
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil
| | - Gabriela Corassa Rodrigues da Cunha
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil
| | - Beatriz R. Versiani
- Hospital de Apoio de Brasília, Secretária de Estado de Saúde do Distrito Federal, Brasília, Brazil,Hospital Universitário, Universidade de Brasília, Brasília, Brazil
| | - Claudiner Pereira de Oliveira
- Hospital de Apoio de Brasília, Secretária de Estado de Saúde do Distrito Federal, Brasília, Brazil,Hospital Universitário, Universidade de Brasília, Brasília, Brazil
| | - Maria Teresa Alves Silva Rosa
- Hospital Universitário, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil
| | - Silviene F. de Oliveira
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Patricia N. Moretti
- Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil
| | - Juliana F. Mazzeu
- Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil,Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil,*Juliana F. Mazzeu,
| | - Aline Pic-Taylor
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil,**Aline Pic-Taylor,
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16
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van Heyningen V. A Journey Through Genetics to Biology. Annu Rev Genomics Hum Genet 2022; 23:1-27. [PMID: 35567277 DOI: 10.1146/annurev-genom-010622-095109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although my engagement with human genetics emerged gradually, and sometimes serendipitously, it has held me spellbound for decades. Without my teachers, students, postdocs, colleagues, and collaborators, I would not be writing this review of my scientific adventures. Early gene and disease mapping was a satisfying puzzle-solving exercise, but building biological insight was my main goal. The project trajectory was hugely influenced by the evolutionarily conserved nature of the implicated genes and by the pace of progress in genetic technologies. The rich detail of clinical observations, particularly in eye disease, makes humans an excellent model, especially when complemented by the use of multiple other animal species for experimental validation. The contributions of collaborators and rivals also influenced our approach. We are very fortunate to work in this era of unprecedented progress in genetics and genomics. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Veronica van Heyningen
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
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17
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Wawrocka A, Walczak-Sztulpa J, Socha M, Kuszel L, Sowinska-Seidler A, Budny B, Bukowska-Olech E, Pilas-Pomykalska M, Jamsheer A, Krawczynski MR. Homozygous microdeletion in the 11p13 region in the patient with isolated form of aniridia: New challenges in the genetic diagnostics of aniridia. Am J Med Genet A 2021; 188:642-647. [PMID: 34773354 DOI: 10.1002/ajmg.a.62559] [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: 06/22/2021] [Revised: 10/13/2021] [Accepted: 10/22/2021] [Indexed: 11/09/2022]
Abstract
Aniridia is usually an autosomal dominant, rare disorder characterized by a variable degree of hypoplasia or the absence of iris tissue, with additional ocular abnormalities. Pathogenic variants in the PAX6 gene are associated with aniridia in most patients. However, in up to 30% of individuals, disease results from 11p13 chromosomal rearrangements. Here we present a patient with a clinical diagnosis of partial aniridia born to consanguineous Polish parents. The parents were asymptomatic and ophthalmologically normal. We performed PAX6 sequencing, array comparative genomic hybridization, quantitative real-time PCR, and whole genome sequencing. aCGH revealed a homozygous deletion of the DCDC1 gene fragment in the patient. The same, but heterozygous deletion, was detected in each of the patient's asymptomatic parents and brother. In the presented family, the signs and symptoms of aniridia are observed only in the homozygous proband. Whole genome sequencing analysis was performed to determine other possible causes of the disease and did not detect any additional or alternative potentially pathogenic variant. We report a novel homozygous deletion located in the 11p13 region, which does not include the PAX6 gene or any known PAX6 enhancers. To our best knowledge, this is the first reported case of a patient presented with isolated aniridia carrying a homozygous microdeletion downstream of the PAX6 gene.
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Affiliation(s)
- Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Magdalena Socha
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Lukasz Kuszel
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Anna Sowinska-Seidler
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Bartlomiej Budny
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | | | | | - Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
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18
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Blanco-Kelly F, Tarilonte M, Villamar M, Damián A, Tamayo A, Moreno-Pelayo MA, Ayuso C, Cortón M. Genetics and epidemiology of aniridia: Updated guidelines for genetic study. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2021; 96 Suppl 1:4-14. [PMID: 34836588 DOI: 10.1016/j.oftale.2021.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 02/13/2021] [Indexed: 12/16/2022]
Abstract
Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.
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Affiliation(s)
- F Blanco-Kelly
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - M Tarilonte
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - M Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - A Damián
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - A Tamayo
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - M A Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - C Ayuso
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - M Cortón
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain.
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19
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Muñoz Cardona ML, López Mahecha JM. Gillespie’s Syndrome Phenotype in A Patient with a Homozygous Variant of Uncertain Significance in the ITPR1 Gene. Neuroophthalmology 2021; 46:186-189. [DOI: 10.1080/01658107.2021.1982991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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20
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Latta L, Figueiredo FC, Ashery-Padan R, Collinson JM, Daniels J, Ferrari S, Szentmáry N, Solá S, Shalom-Feuerstein R, Lako M, Xapelli S, Aberdam D, Lagali N. Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions. Ocul Surf 2021; 22:245-266. [PMID: 34520870 DOI: 10.1016/j.jtos.2021.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/19/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022]
Abstract
Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.
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Affiliation(s)
- L Latta
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany; Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - F C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom
| | - R Ashery-Padan
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - J M Collinson
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, United Kingdom
| | - J Daniels
- Cells for Sight, UCL Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - S Ferrari
- The Veneto Eye Bank Foundation, Venice, Italy
| | - N Szentmáry
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - S Solá
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - R Shalom-Feuerstein
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - M Lako
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - S Xapelli
- Instituto Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - D Aberdam
- Centre de Recherche des Cordeliers, INSERM U1138, Team 17, France; Université de Paris, 75006, Paris, France.
| | - N Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
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21
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Ferre-Fernández JJ, Sorokina EA, Thompson S, Collery RF, Nordquist E, Lincoln J, Semina EV. Disruption of foxc1 genes in zebrafish results in dosage-dependent phenotypes overlapping Axenfeld-Rieger syndrome. Hum Mol Genet 2021; 29:2723-2735. [PMID: 32720677 DOI: 10.1093/hmg/ddaa163] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 12/14/2022] Open
Abstract
The Forkhead Box C1 (FOXC1) gene encodes a forkhead/winged helix transcription factor involved in embryonic development. Mutations in this gene cause dysgenesis of the anterior segment of the eye, most commonly Axenfeld-Rieger syndrome (ARS), often with other systemic features. The developmental mechanisms and pathways regulated by FOXC1 remain largely unknown. There are two conserved orthologs of FOXC1 in zebrafish, foxc1a and foxc1b. To further examine the role of FOXC1 in vertebrates, we generated foxc1a and foxc1b single knockout zebrafish lines and bred them to obtain various allelic combinations. Three genotypes demonstrated visible phenotypes: foxc1a-/- single homozygous and foxc1-/- double knockout homozygous embryos presented with similar characteristics comprised of severe global vascular defects and early lethality, as well as microphthalmia, periocular edema and absence of the anterior chamber of the eye; additionally, fish with heterozygous loss of foxc1a combined with homozygosity for foxc1b (foxc1a+/-;foxc1b-/-) demonstrated craniofacial defects, heart anomalies and scoliosis. All other single and combined genotypes appeared normal. Analysis of foxc1 expression detected a significant increase in foxc1a levels in homozygous and heterozygous mutant eyes, suggesting a mechanism for foxc1a upregulation when its function is compromised; interestingly, the expression of another ARS-associated gene, pitx2, was responsive to the estimated level of wild-type Foxc1a, indicating a possible role for this protein in the regulation of pitx2 expression. Altogether, our results support a conserved role for foxc1 in the formation of many organs, consistent with the features observed in human patients, and highlight the importance of correct FOXC1/foxc1 dosage for vertebrate development.
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Affiliation(s)
- Jesús-José Ferre-Fernández
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Elena A Sorokina
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Samuel Thompson
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Ross F Collery
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Emily Nordquist
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Joy Lincoln
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA.,Division of Pediatric Cardiology, Herma Heart Institute, Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
| | - Elena V Semina
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA.,Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA.,Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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22
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Blanco-Kelly F, Tarilonte M, Villamar M, Damián A, Tamayo A, Moreno-Pelayo MA, Ayuso C, Cortón M. Genetics and epidemiology of aniridia: Updated guidelines for genetic study. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2021; 96:S0365-6691(21)00124-6. [PMID: 34243981 DOI: 10.1016/j.oftal.2021.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/09/2021] [Accepted: 02/13/2021] [Indexed: 11/24/2022]
Abstract
Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.
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Affiliation(s)
- F Blanco-Kelly
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - M Tarilonte
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - M Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - A Damián
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - A Tamayo
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - M A Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - C Ayuso
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - M Cortón
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España.
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23
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Jin X, Liu W, Qv LH, X WQ, Huang HB. A novel variant in PAX6 as the cause of aniridia in a Chinese family. BMC Ophthalmol 2021; 21:225. [PMID: 34016071 PMCID: PMC8136215 DOI: 10.1186/s12886-021-01848-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 02/05/2021] [Indexed: 11/25/2022] Open
Abstract
Background Aniridia is a kind of congenital human pan-ocular anomaly, which is related to PAX6 commonly. Methods The ophthalmic examinations including visual acuity, slit lamp and fundoscopy examination were performed in a Chinese aniridia pedigree. The targeted next-generation sequencing of aniridia genes was used to identify the causative mutation. Results A novel heterozygous PAX6 nonsense mutation c.619A > T (p.K207*) was identified in the Chinese autosomal dominant family with aniridia. Phenotype related to the novel mutation included nystagmus, keratopathy, absence of iris, cataract and foveal hypoplasia. Conclusions The novel nonsense variation in PAX6 was the cause of aniridia in this family, which expanded the spectrum of the PAX6 mutation.
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Affiliation(s)
- X Jin
- Department of Ophthalmology, Chinese PLA General Hospital, 100853, Beijing, China
| | - W Liu
- Department of Ophthalmology, Hainan Hospital of Chinese PLA General Hospital, 572000, Sanya, Hainan Province, China
| | - L H Qv
- Department of Ophthalmology, the 74th Army Group Hospital, 510318, Guangzhou, China
| | - W Q X
- Department of Ophthalmology, Chinese PLA General Hospital, 100853, Beijing, China
| | - H B Huang
- Department of Ophthalmology, Chinese PLA General Hospital, 100853, Beijing, China. .,Department of Ophthalmology, Hainan Hospital of Chinese PLA General Hospital, 572000, Sanya, Hainan Province, China. .,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, China.
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24
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Landsend ECS, Lagali N, Utheim TP. Congenital aniridia - A comprehensive review of clinical features and therapeutic approaches. Surv Ophthalmol 2021; 66:1031-1050. [PMID: 33675823 DOI: 10.1016/j.survophthal.2021.02.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/16/2021] [Accepted: 02/23/2021] [Indexed: 12/13/2022]
Abstract
Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, leading to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease.
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Affiliation(s)
| | - Neil Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tor P Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
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25
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Pedersen HR, Baraas RC, Landsend ECS, Utheim ØA, Utheim TP, Gilson SJ, Neitz M. PAX6 Genotypic and Retinal Phenotypic Characterization in Congenital Aniridia. Invest Ophthalmol Vis Sci 2020; 61:14. [PMID: 32396632 PMCID: PMC7405610 DOI: 10.1167/iovs.61.5.14] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose To investigate the association between PAX6 genotype and macular morphology in congenital aniridia. Methods The study included 37 participants (15 males) with congenital aniridia (aged 10–72 years) and 58 age-matched normal controls (18 males). DNA was isolated from saliva samples. PAX6 exons, intron/exon junctions, and known regulatory regions were amplified in PCR and sequenced. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect larger deletions or duplications in PAX6 or known cis-regulatory regions. Spectral-domain optical coherence tomography images were acquired and segmented semiautomatically. Mean thicknesses were calculated for inner and outer retinal layers within the macula along nasal and temporal meridians. Results Mutations in PAX6 or regulatory regions were found in 97% of the participants with aniridia. Foveal hypoplasia was observed in all who had a mutation within the PAX6 gene. Aniridic eyes had thinner outer retinal layers than controls, but with large between-individual variation (mean ± SD, 156.3 ± 32.3 µm vs 210.8 ± 12.3 µm, P < 0.001). Parafoveal and perifoveal inner and outer retinal layers were thinner in aniridia. Participants with mutations in noncoding PAX6 regions had thicker foveal outer retinal layers than those with mutations in the PAX6 coding regions (P = 0.04) and showed signs of postnatal development and maturation. Mutations outside the PAX6 gene were associated with the mildest retinal phenotypes. Conclusions PAX6 mutations are associated with significant thinning of macular inner and outer retinal layers, consistent with misdirected retinal development resulting in abnormal foveal formation and reduced number of neurons in the macula, with mutations in PAX6 coding regions giving the worst outcome.
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26
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Cross E, Duncan-Flavell PJ, Howarth RJ, Crooks RO, Thomas NS, Bunyan DJ. Screening of a large PAX6 cohort identified many novel variants and emphasises the importance of the paired and homeobox domains. Eur J Med Genet 2020; 63:103940. [DOI: 10.1016/j.ejmg.2020.103940] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/20/2019] [Accepted: 04/23/2020] [Indexed: 12/21/2022]
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27
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You B, Zhang X, Xu K, Xie Y, Ye H, Li Y. Mutation spectrum of PAX6 and clinical findings in 95 Chinese patients with aniridia. Mol Vis 2020; 26:226-234. [PMID: 32214788 PMCID: PMC7093334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 03/24/2020] [Indexed: 11/03/2022] Open
Abstract
Purpose Aniridia is a rare congenital panocular disease caused by mutations in PAX6. The purposes of this study were to clarify the mutation features of PAX6 in a cohort of Chinese patients with aniridia and to describe their clinical characteristics. Methods We recruited 95 patients from 65 unrelated families clinically diagnosed with aniridia. All patients underwent ophthalmic examinations. Sanger sequencing and multiplex ligation probe amplification of PAX6 were performed to detect intragenic variants and copy number variations (CNVs). Results We identified 58 disease-causing mutations in PAX6 in 63 families; the detection rate was 96.9%. The 58 mutations included frameshift indels (27.6%), splice site changes (25.9%), nonsense mutations (20.7%), CNVs (19.0%), missense mutations (3.4%), run-on mutations (1.7%), and a synonymous mutation (1.7%). Clinical examinations revealed that 71 patients had complete or almost complete iris loss, 16 patients showed partial iris loss, and six patients had a full iris but with an abnormal structure. Conclusions The results confirmed that mutations in PAX6 are the predominant cause of aniridia, and the majority are loss-of-function mutations that usually result in classical aniridia. In contrast, missense mutations, run-on mutations, and small numbers of splicing mutations mostly lead to atypical aniridia and an intrafamilial phenotypic variability of iris hypoplasia.
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28
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Lima Cunha D, Arno G, Corton M, Moosajee M. The Spectrum of PAX6 Mutations and Genotype-Phenotype Correlations in the Eye. Genes (Basel) 2019; 10:genes10121050. [PMID: 31861090 PMCID: PMC6947179 DOI: 10.3390/genes10121050] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022] Open
Abstract
The transcription factor PAX6 is essential in ocular development in vertebrates, being considered the master regulator of the eye. During eye development, it is essential for the correct patterning and formation of the multi-layered optic cup and it is involved in the developing lens and corneal epithelium. In adulthood, it is mostly expressed in cornea, iris, and lens. PAX6 is a dosage-sensitive gene and it is highly regulated by several elements located upstream, downstream, and within the gene. There are more than 500 different mutations described to affect PAX6 and its regulatory regions, the majority of which lead to PAX6 haploinsufficiency, causing several ocular and systemic abnormalities. Aniridia is an autosomal dominant disorder that is marked by the complete or partial absence of the iris, foveal hypoplasia, and nystagmus, and is caused by heterozygous PAX6 mutations. Other ocular abnormalities have also been associated with PAX6 changes, and genotype-phenotype correlations are emerging. This review will cover recent advancements in PAX6 regulation, particularly the role of several enhancers that are known to regulate PAX6 during eye development and disease. We will also present an updated overview of the mutation spectrum, where an increasing number of mutations in the non-coding regions have been reported. Novel genotype-phenotype correlations will also be discussed.
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Affiliation(s)
| | - Gavin Arno
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital—Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28029 Madrid, Spain
| | - Mariya Moosajee
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Correspondence:
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Genetics of anophthalmia and microphthalmia. Part 1: Non-syndromic anophthalmia/microphthalmia. Hum Genet 2019; 138:799-830. [PMID: 30762128 DOI: 10.1007/s00439-019-01977-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/30/2019] [Indexed: 12/22/2022]
Abstract
Eye formation is the result of coordinated induction and differentiation processes during embryogenesis. Disruption of any one of these events has the potential to cause ocular growth and structural defects, such as anophthalmia and microphthalmia (A/M). A/M can be isolated or occur with systemic anomalies, when they may form part of a recognizable syndrome. Their etiology includes genetic and environmental factors; several hundred genes involved in ocular development have been identified in humans or animal models. In humans, around 30 genes have been repeatedly implicated in A/M families, although many other genes have been described in single cases or families, and some genetic syndromes include eye anomalies occasionally as part of a wider phenotype. As a result of this broad genetic heterogeneity, with one or two notable exceptions, each gene explains only a small percentage of cases. Given the overlapping phenotypes, these genes can be most efficiently tested on panels or by whole exome/genome sequencing for the purposes of molecular diagnosis. However, despite whole exome/genome testing more than half of patients currently remain without a molecular diagnosis. The proportion of undiagnosed cases is even higher in those individuals with unilateral or milder phenotypes. Furthermore, even when a strong gene candidate is available for a patient, issues of incomplete penetrance and germinal mosaicism make diagnosis and genetic counseling challenging. In this review, we present the main genes implicated in non-syndromic human A/M phenotypes and, for practical purposes, classify them according to the most frequent or predominant phenotype each is associated with. Our intention is that this will allow clinicians to rank and prioritize their molecular analyses and interpretations according to the phenotypes of their patients.
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30
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Pedersen HR, Hagen LA, Landsend ECS, Gilson SJ, Utheim ØA, Utheim TP, Neitz M, Baraas RC. Color Vision in Aniridia. Invest Ophthalmol Vis Sci 2019; 59:2142-2152. [PMID: 29801149 PMCID: PMC6110168 DOI: 10.1167/iovs.17-23047] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Purpose To assess color vision and its association with retinal structure in persons with congenital aniridia. Methods We included 36 persons with congenital aniridia (10–66 years), and 52 healthy, normal trichromatic controls (10–74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0–4). Results Five participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology. Conclusions Arrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.
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Affiliation(s)
- Hilde R Pedersen
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University College of Southeast Norway, Kongsberg, Norway
| | - Lene A Hagen
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University College of Southeast Norway, Kongsberg, Norway
| | | | - Stuart J Gilson
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University College of Southeast Norway, Kongsberg, Norway
| | - Øygunn A Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Tor P Utheim
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University College of Southeast Norway, Kongsberg, Norway.,Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.,Department of Ophthalmology, Drammen Hospital, Drammen, Norway
| | - Maureen Neitz
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Rigmor C Baraas
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University College of Southeast Norway, Kongsberg, Norway
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31
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De novo truncating variants in PHF21A cause intellectual disability and craniofacial anomalies. Eur J Hum Genet 2018; 27:378-383. [PMID: 30487643 DOI: 10.1038/s41431-018-0289-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/26/2018] [Accepted: 09/28/2018] [Indexed: 11/09/2022] Open
Abstract
Potocki-Shaffer syndrome (PSS) is a contiguous gene syndrome caused by 11p11.2 deletions. PSS is clinically characterized by intellectual disability, craniofacial anomalies, enlarged parietal foramina, and multiple exostoses. PSS occasionally shows autism spectrum disorder, epilepsy, and overgrowth. Some of the clinical features are thought to be associated with haploinsufficiency of two genes in the 11p11.2 region; variants affecting the function of ALX4 cause enlarged parietal foramina and EXT2 lead to multiple exostoses. However, the remaining clinical features were still yet to be linked to specific genetic alterations. In this study, we identified de novo truncating variants in an 11p11.2 gene, PHF21A, in three cases with intellectual disability and craniofacial anomalies. Among these three cases, autism spectrum disorder was recognized in one case, epilepsy in one case, and overgrowth in two cases. This study shows that PHF21A haploinsufficiency results in intellectual disability and craniofacial anomalies and possibly contributes to susceptibility to autism spectrum disorder, epilepsy, and overgrowth, all of which are PSS features.
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32
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Tarilonte M, Morín M, Ramos P, Galdós M, Blanco-Kelly F, Villaverde C, Rey-Zamora D, Rebolleda G, Muñoz-Negrete FJ, Tahsin-Swafiri S, Gener B, Moreno-Pelayo MA, Ayuso C, Villamar M, Corton M. Parental Mosaicism in PAX6 Causes Intra-Familial Variability: Implications for Genetic Counseling of Congenital Aniridia and Microphthalmia. Front Genet 2018; 9:479. [PMID: 30386378 PMCID: PMC6199369 DOI: 10.3389/fgene.2018.00479] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/26/2018] [Indexed: 11/17/2022] Open
Abstract
Mutations in PAX6 are involved in several developmental eye disorders. These disorders have considerable phenotypic variability, ranging from panocular forms of congenital aniridia and microphthalmia to isolated anomalies of the anterior or posterior segment. Here, we describe 3 families with variable inter-generational ocular expression of aniridia, iris coloboma, or microphthalmia, and an unusual transmission of PAX6 mutations from an unaffected or mildly affected parent; all of which raised suspicion of gonosomal mosaicism. We first identified two previously known nonsense mutations and one novel likely pathogenic missense variant in PAX6 in probands by means of targeted NGS. The subsequent segregation analysis by Sanger sequencing evidenced the presence of highly probable mosaic events in paternal blood samples. Mosaicism was further confirmed by droplet digital PCR analysis in several somatic tissues of mosaic fathers. Quantification of the mutant allele fraction in parental samples showed a marked deviation from 50%, with a range between 12 and 29% depending on cell type. Gonosomal mosaicsm was definitively confirmed in one of the families thanks to the availability of a sperm sample from the mosaic father. Thus, the recurrence risk in this family was estimated to be about one-third. This is the first report confirming parental PAX6 mosaicism as a cause of disease recurrence in aniridia and other related phenotypes. In addition, we demonstrated that post-zygotic mosaicism is a frequent and underestimated pathogenic mechanism in aniridia, explaining intra-familial phenotypic variability in many cases. Our findings may have substantial implications for genetic counseling in congenital aniridia. Thus, we also highlight the importance of comprehensive genetic screening of parents for new sporadic cases with aniridia or related developmental eye disease to more accurately assess recurrence risk. In conclusion, somatic and/or gonosomal mosaicism should be taken into consideration as a genetic factor to explain not only families with unaffected parents despite multiple affected children but also variable expressivity, apparent de novo cases, and even uncharacterized cases of aniridia and related developmental eye disorders, apparently lacking PAX6 mutations.
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Affiliation(s)
- María Tarilonte
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Matías Morín
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Patricia Ramos
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Galdós
- Department of Ophthalmology, Cruces University Hospital, Bilbao, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Dolores Rey-Zamora
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Gema Rebolleda
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Francisco J Muñoz-Negrete
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Saoud Tahsin-Swafiri
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Blanca Gener
- Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics, BioCruces Health Research Institute, Cruces University Hospital, Bilbao, Spain
| | - Miguel-Angel Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Manuela Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Corton
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
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33
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Plaisancié J, Tarilonte M, Ramos P, Jeanton-Scaramouche C, Gaston V, Dollfus H, Aguilera D, Kaplan J, Fares-Taie L, Blanco-Kelly F, Villaverde C, Francannet C, Goldenberg A, Arroyo I, Rozet JM, Ayuso C, Chassaing N, Calvas P, Corton M. Implication of non-coding PAX6 mutations in aniridia. Hum Genet 2018; 137:831-846. [PMID: 30291432 DOI: 10.1007/s00439-018-1940-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/23/2018] [Indexed: 01/14/2023]
Abstract
There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.
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Affiliation(s)
- Julie Plaisancié
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France.
- INSERM U1056, Université Toulouse III, Toulouse, France.
| | - M Tarilonte
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - P Ramos
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Jeanton-Scaramouche
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - V Gaston
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - H Dollfus
- Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - D Aguilera
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - J Kaplan
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - L Fares-Taie
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - F Blanco-Kelly
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Villaverde
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Francannet
- Service de Génétique Médicale, CHU Estaing, Clermont-Ferrand, France
| | - A Goldenberg
- Service de Génétique, CHU de Rouen, Centre Normand de Génomique Médicale et Médecine Personnalisée, Rouen, France
| | - I Arroyo
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetics, Hospital of Cáceres, Cáceres, Spain
| | - J M Rozet
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - C Ayuso
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - N Chassaing
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - P Calvas
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - M Corton
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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The genetic architecture of aniridia and Gillespie syndrome. Hum Genet 2018; 138:881-898. [PMID: 30242502 PMCID: PMC6710220 DOI: 10.1007/s00439-018-1934-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 09/06/2018] [Indexed: 12/13/2022]
Abstract
Absence of part or all of the iris, aniridia, is a feature of several genetically distinct conditions. This review focuses on iris development and then the clinical features and molecular genetics of these iris malformations. Classical aniridia, a panocular eye malformation including foveal hypoplasia, is the archetypal phenotype associated with heterozygous PAX6 loss-of-function mutations. Since this was identified in 1991, many genetic mechanisms of PAX6 inactivation have been elucidated, the commonest alleles being intragenic mutations causing premature stop codons, followed by those causing C-terminal extensions. Rarely, aniridia cases are associated with FOXC1, PITX2 and/or their regulatory regions. Aniridia can also occur as a component of many severe global eye malformations. Gillespie syndrome—a triad of partial aniridia, non-progressive cerebellar ataxia and intellectual disability—is phenotypically and genotypically distinct from classical aniridia. The causative gene has recently been identified as ITPR1. The same characteristic Gillespie syndrome-like iris, with aplasia of the pupillary sphincter and a scalloped margin, is seen in ACTA2-related multisystemic smooth muscle dysfunction syndrome. WAGR syndrome (Wilms tumour, aniridia, genitourinary anomalies and mental retardation/intellectual disability), is caused by contiguous deletion of PAX6 and WT1 on chromosome 11p. Deletions encompassing BDNF have been causally implicated in the obesity and intellectual disability associated with the condition. Lastly, we outline a genetic investigation strategy for aniridia in light of recent developments, suggesting an approach based principally on chromosomal array and gene panel testing. This strategy aims to test all known aniridia loci—including the rarer, life-limiting causes—whilst remaining simple and practical.
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35
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Syrimis A, Nicolaou N, Alexandrou A, Papaevripidou I, Nicolaou M, Loukianou E, Sismani C, Malas S, Christophidou-Anastasiadou V, Tanteles GA. Molecular analysis of Cypriot families with aniridia reveals a novel PAX6 mutation. Mol Med Rep 2018; 18:1623-1627. [PMID: 29901133 PMCID: PMC6072148 DOI: 10.3892/mmr.2018.9126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022] Open
Abstract
The present study investigated the clinical and mutational spectrum of aniridia in a cohort of 17 affected individuals from six families from Cyprus. Each proband was initially evaluated for copy number variants at the PAX6 locus and subsequently underwent PAX6 mutation screening. Sequence analysis of FOXC1 and PITX2 was performed in patients who did not carry a PAX6 mutation. The most common clinical features in the group of aniridia patients associated with aniridia were nystagmus, cataracts and glaucoma. PAX6 pathogenic mutations were identified in five out of six families (a diagnostic yield of 84%). Previously reported pathogenic mutations in PAX6 were identified in four families, which comprise p.R203*, p.R240* and p.R317*. In addition, a novel pathogenic variant (p.E220Gfs*23) was identified in a single family. No pathogenic mutations were detected in PAX6, FOXC1 or PITX2 in the only patient with a sporadic form of aniridia‑like phenotype, confirming the genetic heterogeneity associated with this disease. To the best of our knowledge this is the first report on the mutational spectrum of PAX6 in aniridia patients of Cypriot ancestry. Mutational screening of PAX6 serves a crucial role in distinguishing isolated from syndromic forms of aniridia, and it may therefore eliminate the need for renal ultrasound scan surveillance, delineate the phenotype and improve genetic counseling.
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Affiliation(s)
- Andreas Syrimis
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Nayia Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Michael Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Eleni Loukianou
- Department of Ophthalmology, Nicosia General Hospital, 2029 Nicosia, Cyprus
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Stavros Malas
- Department of Developmental and Functional Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Violetta Christophidou-Anastasiadou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
- Department of Clinical Genetics, Archbishop Makarios III Hospital, 2012 Nicosia, Cyprus
| | - George A. Tanteles
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
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36
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Syrimis A, Nicolaou N, Alexandrou A, Papaevripidou I, Nicolaou M, Loukianou E, Christophidou-Anastasiadou V, Malas S, Sismani C, Tanteles GA. Aniridia due to a novel microdeletion affecting PAX6 regulatory enhancers: case report and review of the literature. J Genet 2018; 97:555-562. [PMID: 29932076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Aniridia is a rare congenital ocular malformation that follows an autosomal dominant mode of inheritance. Most patients carry pathogenic point mutations in the paired box 6 gene (PAX6), but some carry deletions involving the 11p13 region, encompassing partly or completely PAX6 or the region downstream. We identified a novel deletion, ~564 kb in size located about 46.5 kb downstream of PAX6 in a family with bilateral aniridia and foveal hypoplasia using array-CGH and multiplex ligation-dependent probe amplification. We also reviewall of the reported deletions downstream of PAX6 in patients with aniridia and/or other congenital malformations and define the overlapping region that leads to aniridia when deleted.
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Affiliation(s)
- Andreas Syrimis
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus.
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37
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Aniridia due to a novel microdeletion affecting
$$\textit{PAX6}$$
PAX
6
regulatory enhancers: case report and review of the literature. J Genet 2018. [DOI: 10.1007/s12041-018-0925-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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38
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Paganini L, Pesenti C, Milani D, Fontana L, Motta S, Sirchia SM, Scuvera G, Marchisio P, Esposito S, Cinnante CM, Tabano SM, Miozzo MR. A novel splice site variant in ITPR1
gene underlying recessive Gillespie syndrome. Am J Med Genet A 2018; 176:1427-1431. [DOI: 10.1002/ajmg.a.38704] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/06/2018] [Accepted: 03/15/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Leda Paganini
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Chiara Pesenti
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Donatella Milani
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Laura Fontana
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Silvia Motta
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Silvia Maria Sirchia
- Medical Genetics, Department of Health Sciences; Università degli Studi di Milano; Italy
| | - Giulietta Scuvera
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Paola Marchisio
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences; Università degli Studi di Perugia; Italy
| | - Claudia Maria Cinnante
- Neuroradiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Silvia Maria Tabano
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Monica Rosa Miozzo
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
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PAX6 molecular analysis and genotype-phenotype correlations in families with aniridia from Australasia and Southeast Asia. Mol Vis 2018; 24:261-273. [PMID: 29618921 PMCID: PMC5873721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/26/2018] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Aniridia is a congenital disorder caused by variants in the PAX6 gene. In this study, we assessed the involvement of PAX6 in patients with aniridia from Australasia and Southeast Asia. METHODS Twenty-nine individuals with aniridia from 18 families originating from Australia, New Caledonia, Cambodia, Sri Lanka, and Bhutan were included. The PAX6 gene was investigated for sequence variants and analyzed for deletions with multiplex ligation-dependent probe amplification. RESULTS We identified 11 sequence variants and six chromosomal deletions, including one in mosaic. Four deleterious sequence variants were novel: p.(Pro81HisfsTer12), p.(Gln274Ter), p.(Ile29Thr), and p.(Met1?). Ocular complications were associated with a progressive loss of visual function as shown by a visual acuity ≤ 1.00 logMAR reported in 65% of eyes. The prevalence of keratopathy was statistically significantly higher in the Australasian cohort (78.6%) compared with the Southeast Asian cohort (9.1%, p=0.002). Variants resulting in protein truncating codons displayed limited genotype-phenotype correlations compared with other variants. CONCLUSIONS PAX6 variants and deletions were identified in 94% of patients with aniridia from Australasia and Southeast Asia. This study is the first report of aniridia and variations in PAX6 in individuals from Cambodia, Sri Lanka, Bhutan, and New Caledonia, and the largest cohort from Australia.
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Wawrocka A, Krawczynski MR. The genetics of aniridia - simple things become complicated. J Appl Genet 2018; 59:151-159. [PMID: 29460221 PMCID: PMC5895662 DOI: 10.1007/s13353-017-0426-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/21/2017] [Accepted: 12/21/2017] [Indexed: 12/26/2022]
Abstract
Aniridia is a rare, panocular disorder characterized by a variable degree of hypoplasia or the absence of iris tissue associated with additional ocular abnormalities. It is inherited in an autosomal dominant manner, with high penetrance and variable expression even within the same family. In most cases the disease is caused by haploinsufficiency truncating mutations in the PAX6 gene; however, in up to 30% of aniridia patients, disease results from chromosomal rearrangements at the 11p13 region. The aim of this review is to present the clinical and genetic aspects of the disease. Furthermore, we present a molecular diagnostic strategy in the aniridia patients. Recent improvement in the genetic diagnostic approach will precisely diagnosis aniridia patients, which is essential especially for children with aniridia in order to determine the risk of developing a Wilms tumor or neurodevelopmental disorder. Finally, based on the previous studies we describe the current knowledge and latest research findings in the topic of pathogenesis of aniridia and possible future treatment.
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Affiliation(s)
- Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Rokietnicka 8, 60-806, Poznan, Poland.
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Rokietnicka 8, 60-806, Poznan, Poland
- Centers for Medical Genetics GENESIS, Poznan, Poland
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Landsend ES, Utheim ØA, Pedersen HR, Lagali N, Baraas RC, Utheim TP. The genetics of congenital aniridia—a guide for the ophthalmologist. Surv Ophthalmol 2018; 63:105-113. [DOI: 10.1016/j.survophthal.2017.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 01/10/2023]
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Bertsch M, Floyd M, Kehoe T, Pfeifer W, Drack AV. The clinical evaluation of infantile nystagmus: What to do first and why. Ophthalmic Genet 2017; 38:22-33. [PMID: 28177849 DOI: 10.1080/13816810.2016.1266667] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Infantile nystagmus has many causes, some life threatening. We determined the most common diagnoses in order to develop a testing algorithm. METHODS Retrospective chart review. Exclusion criteria were no nystagmus, acquired after 6 months, or lack of examination. DATA COLLECTED pediatric eye examination findings, ancillary testing, order of testing, referral, and final diagnoses. Final diagnosis was defined as meeting published clinical criteria and/or confirmed by diagnostic testing. Patients with a diagnosis not meeting the definition were "unknown." Patients with incomplete testing were "incomplete." Patients with multiple plausible etiologies were "multifactorial." Patients with negative complete workup were "motor." RESULTS A total of 284 charts were identified; 202 met inclusion criteria. The three most common causes were Albinism (19%), Leber Congenital Amaurosis (LCA; 14%), and Non-LCA retinal dystrophy (13%). Anatomic retinal disorders comprised 10%, motor another 10%. The most common first test was MRI (74/202) with a diagnostic yield of 16%. For 28 MRI-first patients, nystagmus alone was the indication; for 46 MRI-first patients other neurologic signs were present. 0/28 nystagmus-only patients had a diagnostic MRI while 14/46 (30%) with neurologic signs did. The yield of ERG as first test was 56%, OCT 55%, and molecular genetic testing 47%. Overall, 90% of patients had an etiology identified. CONCLUSION The most common causes of infantile nystagmus were retinal disorders (56%), however the most common first test was brain MRI. For patients without other neurologic stigmata complete pediatric eye examination, ERG, OCT, and molecular genetic testing had a higher yield than MRI scan. If MRI is not diagnostic, a complete ophthalmologic workup should be pursued.
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Affiliation(s)
- Morgan Bertsch
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
| | - Michael Floyd
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA.,b HealthPartners , Minneapolis , Minnesota , USA
| | - Taylor Kehoe
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA.,c Physician Assistant Program , University of Iowa , Iowa City , Iowa , USA
| | - Wanda Pfeifer
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
| | - Arlene V Drack
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
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Protas ME, Weh E, Footz T, Kasberger J, Baraban SC, Levin AV, Katz LJ, Ritch R, Walter MA, Semina EV, Gould DB. Mutations of conserved non-coding elements of PITX2 in patients with ocular dysgenesis and developmental glaucoma. Hum Mol Genet 2017; 26:3630-3638. [PMID: 28911203 PMCID: PMC5886142 DOI: 10.1093/hmg/ddx251] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/09/2017] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
Mutations in FOXC1 and PITX2 constitute the most common causes of ocular anterior segment dysgenesis (ASD), and confer a high risk for secondary glaucoma. The genetic causes underlying ASD in approximately half of patients remain unknown, despite many of them being screened by whole exome sequencing. Here, we performed whole genome sequencing on DNA from two affected individuals from a family with dominantly inherited ASD and glaucoma to identify a 748-kb deletion in a gene desert that contains conserved putative PITX2 regulatory elements. We used CRISPR/Cas9 to delete the orthologous region in zebrafish in order to test the pathogenicity of this structural variant. Deletion in zebrafish reduced pitx2 expression during development and resulted in shallow anterior chambers. We screened additional patients for copy number variation of the putative regulatory elements and found an overlapping deletion in a second family and in a potentially-ancestrally-related index patient with ASD and glaucoma. These data suggest that mutations affecting conserved non-coding elements of PITX2 may constitute an important class of mutations in patients with ASD for whom the molecular cause of their disease have not yet been identified. Improved functional annotation of the human genome and transition to sequencing of patient genomes instead of exomes will be required before the magnitude of this class of mutations is fully understood.
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Affiliation(s)
- Meredith E. Protas
- Departments of Ophthalmology and Anatomy and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
| | - Eric Weh
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Tim Footz
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jay Kasberger
- Celgene Quanticel Research, San Francisco, CA 94158, USA
| | - Scott C. Baraban
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Alex V. Levin
- Pediatric Ophthalmology and Ocular Genetics, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - L. Jay Katz
- Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Robert Ritch
- Einhorn Clinical Research Center, The New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
| | - Michael A. Walter
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Elena V. Semina
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
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Abstract
PURPOSE OF REVIEW Aniridia is a rare and panocular disorder affecting most of the ocular structures which may have significant impact on vision. The purpose of this review is to describe the clinical features, genetics, and therapeutic options for this disease and to provide an update of current knowledge and latest research findings. RECENT FINDINGS Aside from the ocular features, a variety of associated systemic abnormalities, including hormonal, metabolic, gastrointestinal, genitourinary, and neurologic pathologies have been reported in children with aniridia. Although mutations in PAX6 are a major cause of aniridia, genetic defects in nearby genes, such as TRIM44 or ELP4, have also been reported to cause aniridia. Recent improvement in genetic testing technique will help more rapid and precise diagnosis for aniridia. A promising therapeutic approach called nonsense suppression therapy has been introduced and successfully used in an animal model. SUMMARY Aniridia is a challenging disease. The progressive nature of this condition and its potential complications require continuous and life-long ophthalmologic care. Genetic diagnosis for aniridia is important for establishing definitive molecular characterization as well as identifying individuals at high risk for Wilms tumor. Recent advancement in understanding the genetic pathogenesis of this disease offers promise for the approaches to treatment.
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Dentici ML, Barresi S, Nardella M, Bellacchio E, Alfieri P, Bruselles A, Pantaleoni F, Danieli A, Iarossi G, Cappa M, Bertini E, Tartaglia M, Zanni G. Identification of novel and hotspot mutations in the channel domain of ITPR1 in two patients with Gillespie syndrome. Gene 2017; 628:141-145. [PMID: 28698159 PMCID: PMC5607352 DOI: 10.1016/j.gene.2017.07.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/03/2017] [Accepted: 07/07/2017] [Indexed: 11/24/2022]
Abstract
ITPR1 encodes an intracellular receptor for inositol 1,4,5-trisphosphate (InsP3) which is highly expressed in the cerebellum and is involved in the regulation of Ca2 + homeostasis. Missense mutations in the InsP3-binding domain (IRBIT) of ITPR1 are frequently associated with early onset cerebellar atrophy. Gillespie syndrome is characterized by congenital ataxia, mild to moderate intellectual disability and iris hypoplasia. Dominant or recessive ITPR1 mutations have been recently associated with this form of syndromic ataxia. We performed next generation sequencing in two simplex families with Gillespie syndrome and identified de novo pathological mutations localized in the C-terminal channel domain of ITPR1 in both patients: a recurrent deletion (p.Lys2596del) and a novel missense mutation (p.Asn2576Ile) close to a point of constriction in the Ca2 + pore. Our study expands the mutational spectrum of ITPR1 and confirms that ITPR1 screening should be implemented in patients with congenital cerebellar ataxia with or without iris hypoplasia. De novo ITPR1 mutations were identified in two patients with Gillespie syndrome. The Asn2576Ile mutation is located close to a point of constriction in the Ca2 + pore. ITPR1 is frequently involved in congenital ataxias with or without iris hypoplasia.
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Affiliation(s)
- Maria Lisa Dentici
- Medical Genetics, Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Sabina Barresi
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marta Nardella
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Paolo Alfieri
- Child Neuropsychiatry, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alessandro Bruselles
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Pantaleoni
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alberto Danieli
- Unit of Epilepsy and Clinical Neurophysiology, IRCCS E. Medea-Conegliano, Italy
| | - Giancarlo Iarossi
- Ophthalmology Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marco Cappa
- Endocrinology, Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
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Sannan NS, Gregory-Evans CY, Lyons CJ, Lehman AM, Langlois S, Warner SJ, Zakrzewski H, Gregory-Evans K. Correlation of novel PAX6 gene abnormalities in aniridia and clinical presentation. Can J Ophthalmol 2017; 52:570-577. [PMID: 29217025 DOI: 10.1016/j.jcjo.2017.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/24/2017] [Accepted: 04/05/2017] [Indexed: 01/12/2023]
Abstract
OBJECTIVE To describe the clinical presentation and genotype of subjects with aniridia with a particular focus on foveal hypoplasia. DESIGN Prospective cohort study. PARTICIPANTS Thirty-three Canadian participants with aniridia and of various ethnic backgrounds residing in British Columbia. METHODS Full ophthalmic examinations and posterior segment spectral domain-optical coherence tomography (SD-OCT) imaging were performed. Foveal hypoplasia was graded independently by 2 staff ophthalmologists. PAX6 sequencing was performed and chromosomal 11p anomalies investigated. Candidate gene and single-nucleotide polymorphism sequencing in genes functionally related to PAX6 were also studied. RESULTS Best corrected visual acuities in the cohort ranged from 0.0 logMAR to no light perception. Total absence of iris tissue was seen in the majority (42 of 66 eyes). In those in whom SD-OCT was possible, foveal hypoplasia was seen in the majority (45 of 56 eyes, 80%). Molecular genetic defects involving PAX6 were identified in 30 participants (91%), including 4 novel PAX6 mutations (Gly18Val; Ser65ProfsX14; Met337ArgfsX18; Ser321CysfsX34) and 4 novel chromosome 11p deletions inclusive of PAX6 or a known PAX6 regulatory region. CONCLUSIONS The number of PAX6 mutations associated with aniridia continues to increase. Variable foveal architecture despite nearly identical anterior segment disease in 4 participants with an Ex9 ELP4-Ex4 DCDC1 deletion suggested that molecular cues causing variation in disease in the posterior segment differ from those at play in the anterior segment. Results in 3 patients without identifiable PAX6 mutations and a review of the literature suggest that such cases be described as phenocopies rather than actual cases of the syndrome of aniridia.
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Affiliation(s)
- Naif S Sannan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Cheryl Y Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Christopher J Lyons
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C; Department of Ophthalmology, BC Children's Hospital, Vancouver, B.C
| | - Anna M Lehman
- Department of Medical Genetics, University of British Columbia, Vancouver, B.C
| | - Sylvie Langlois
- Department of Medical Genetics, University of British Columbia, Vancouver, B.C
| | - Simon J Warner
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Helen Zakrzewski
- Cumming School of Medicine, University of Calgary, Calgary, Alta
| | - Kevin Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C.
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47
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Pérez-Solórzano S, Chacón-Camacho OF, Astiazarán MC, Ledesma-Gil G, Zenteno JC. PAX6 allelic heterogeneity in Mexican congenital aniridia patients: expanding the mutational spectrum with seven novel pathogenic variants. Clin Exp Ophthalmol 2017; 45:875-883. [PMID: 28488383 DOI: 10.1111/ceo.12982] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/24/2017] [Accepted: 05/02/2017] [Indexed: 02/04/2023]
Abstract
IMPORTANCE The importance of the study was to describe the clinical characteristics and mutational analysis of Mexican patients with aniridia. BACKGROUND Aniridia is a panocular hereditary eye disease caused by mutations in the PAX6 transcription factor. Mutation detection rate is highly variable ranging from 30% to 90% in different populations. Very few studies have been published about the PAX6 mutational analysis in aniridia patients from Mexico. In order to establish a more representative PAX6 mutational frequency in the country, a cohort of 22 Mexican unrelated aniridia probands were analysed in this study. DESIGN Case series. PARTICIPANTS A total of 22 Mexican probands with bilateral isolated aniridia and their available relatives were included. METHODS Sanger sequencing was used for the mutational analysis of all coding exons and flanking intronic regions of PAX6. MAIN OUTCOME MEASURES Clinical characteristics and results of PAX6 mutational analysis in probands with aniridia and available family members. RESULTS Molecular analysis of PAX6 in 22 index cases with aniridia allowed the identification of a total of 16 different mutations. Seven of these pathogenic variants are novel, including c.183C>G, p.(Y61*); c.718delC, p.(R240Efs*3); c.1149_1152delTCAG, p.(P385Wfs*139); c.257_266delAAATAGCCCA, p.(K86Sfs*35); c.836_843dupGCAACACA p.(P282Afs*86); c.1032+2_1032+3insT; and c.141+2T>A. Inter and intrafamilial phenotypic heterogeneity was found. CONCLUSIONS AND RELEVANCE The mutational diagnostic rate in this series was 77%, which is comparable with reports from other populations. Importantly, no founder mutations were identified in this case series. Our results add 7 novel PAX6 pathogenic variants to the aniridia-related mutational spectrum and reveal considerable PAX6 allelic heterogeneity in this population.
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Affiliation(s)
- Sofía Pérez-Solórzano
- Genetics Department, Institute of Ophthalmology 'Conde de Valenciana', Mexico City, Mexico
| | - Oscar F Chacón-Camacho
- Genetics Department, Institute of Ophthalmology 'Conde de Valenciana', Mexico City, Mexico
| | - Mirena C Astiazarán
- Genetics Department, Institute of Ophthalmology 'Conde de Valenciana', Mexico City, Mexico
| | - Gerardo Ledesma-Gil
- Retina Department, Institute of Ophthalmology 'Conde de Valenciana', Mexico City, Mexico
| | - Juan Carlos Zenteno
- Genetics Department, Institute of Ophthalmology 'Conde de Valenciana', Mexico City, Mexico.,Department of Biochemistry, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
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Blanco-Kelly F, Palomares M, Vallespín E, Villaverde C, Martín-Arenas R, Vélez-Monsalve C, Lorda-Sánchez I, Nevado J, Trujillo-Tiebas MJ, Lapunzina P, Ayuso C, Corton M. Improving molecular diagnosis of aniridia and WAGR syndrome using customized targeted array-based CGH. PLoS One 2017; 12:e0172363. [PMID: 28231309 PMCID: PMC5322952 DOI: 10.1371/journal.pone.0172363] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/04/2017] [Indexed: 11/18/2022] Open
Abstract
Chromosomal deletions at 11p13 are a frequent cause of congenital Aniridia, a rare pan-ocular genetic disease, and of WAGR syndrome, accounting up to 30% of cases. First-tier genetic testing for newborn with aniridia, to detect 11p13 rearrangements, includes Multiplex Ligation-dependent Probe Amplification (MLPA) and karyotyping. However, neither of these approaches allow obtaining a complete picture of the high complexity of chromosomal deletions and breakpoints in aniridia. Here, we report the development and validation of a customized targeted array-based comparative genomic hybridization, so called WAGR-array, for comprehensive high-resolution analysis of CNV in the WAGR locus. Our approach increased the detection rate in a Spanish cohort of 38 patients with aniridia, WAGR syndrome and other related ocular malformations, allowing to characterize four undiagnosed aniridia cases, and to confirm MLPA findings in four additional patients. For all patients, breakpoints were accurately established and a contiguous deletion syndrome, involving a large number of genes, was identified in three patients. Moreover, we identified novel microdeletions affecting 3' PAX6 regulatory regions in three families with isolated aniridia. This tool represents a good strategy for the genetic diagnosis of aniridia and associated syndromes, allowing for a more accurate CNVs detection, as well as a better delineation of breakpoints. Our results underline the clinical importance of performing exhaustive and accurate analysis of chromosomal rearrangements for patients with aniridia, especially newborns and those without defects in PAX6 after diagnostic screening.
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Affiliation(s)
- Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - María Palomares
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Elena Vallespín
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Rubén Martín-Arenas
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Camilo Vélez-Monsalve
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Isabel Lorda-Sánchez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Julián Nevado
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - María José Trujillo-Tiebas
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Pablo Lapunzina
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- * E-mail: (CA); (MC)
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- * E-mail: (CA); (MC)
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McEntagart M, Williamson KA, Rainger JK, Wheeler A, Seawright A, De Baere E, Verdin H, Bergendahl LT, Quigley A, Rainger J, Dixit A, Sarkar A, López Laso E, Sanchez-Carpintero R, Barrio J, Bitoun P, Prescott T, Riise R, McKee S, Cook J, McKie L, Ceulemans B, Meire F, Temple IK, Prieur F, Williams J, Clouston P, Németh AH, Banka S, Bengani H, Handley M, Freyer E, Ross A, van Heyningen V, Marsh JA, Elmslie F, FitzPatrick DR. A Restricted Repertoire of De Novo Mutations in ITPR1 Cause Gillespie Syndrome with Evidence for Dominant-Negative Effect. Am J Hum Genet 2016; 98:981-992. [PMID: 27108798 PMCID: PMC4863663 DOI: 10.1016/j.ajhg.2016.03.018] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/16/2016] [Indexed: 12/19/2022] Open
Abstract
Gillespie syndrome (GS) is characterized by bilateral iris hypoplasia, congenital hypotonia, non-progressive ataxia, and progressive cerebellar atrophy. Trio-based exome sequencing identified de novo mutations in ITPR1 in three unrelated individuals with GS recruited to the Deciphering Developmental Disorders study. Whole-exome or targeted sequence analysis identified plausible disease-causing ITPR1 mutations in 10/10 additional GS-affected individuals. These ultra-rare protein-altering variants affected only three residues in ITPR1: Glu2094 missense (one de novo, one co-segregating), Gly2539 missense (five de novo, one inheritance uncertain), and Lys2596 in-frame deletion (four de novo). No clinical or radiological differences were evident between individuals with different mutations. ITPR1 encodes an inositol 1,4,5-triphosphate-responsive calcium channel. The homo-tetrameric structure has been solved by cryoelectron microscopy. Using estimations of the degree of structural change induced by known recessive- and dominant-negative mutations in other disease-associated multimeric channels, we developed a generalizable computational approach to indicate the likely mutational mechanism. This analysis supports a dominant-negative mechanism for GS variants in ITPR1. In GS-derived lymphoblastoid cell lines (LCLs), the proportion of ITPR1-positive cells using immunofluorescence was significantly higher in mutant than control LCLs, consistent with an abnormality of nuclear calcium signaling feedback control. Super-resolution imaging supports the existence of an ITPR1-lined nucleoplasmic reticulum. Mice with Itpr1 heterozygous null mutations showed no major iris defects. Purkinje cells of the cerebellum appear to be the most sensitive to impaired ITPR1 function in humans. Iris hypoplasia is likely to result from either complete loss of ITPR1 activity or structure-specific disruption of multimeric interactions.
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Affiliation(s)
- Meriel McEntagart
- Medical Genetics, St George's University Hospitals NHS Foundation Trust, Cranmer Terrace, London SW17 0RE, UK
| | - Kathleen A Williamson
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Jacqueline K Rainger
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Ann Wheeler
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Anne Seawright
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Elfride De Baere
- Center for Medical Genetics Ghent (CMGG), Ghent University Hospital, Medical Research Building (MRB), 1st Floor, Room 110.029, De Pintelaan 185, 9000 Ghent, Belgium
| | - Hannah Verdin
- Center for Medical Genetics Ghent (CMGG), Ghent University Hospital, Medical Research Building (MRB), 1st Floor, Room 110.029, De Pintelaan 185, 9000 Ghent, Belgium
| | - L Therese Bergendahl
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Alan Quigley
- Department of Radiology, Royal Hospital for Sick Children, Edinburgh EH9 1LF, UK
| | - Joe Rainger
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK; Roslin Institute, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Abhijit Dixit
- Clinical Genetics, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK
| | - Ajoy Sarkar
- Clinical Genetics, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK
| | - Eduardo López Laso
- Pediatric Neurology Unit, Department of Pediatrics, Reina Sofia University Hospital, Av. Menéndez Pidal s/n, 14004 Córdoba, Spain
| | - Rocio Sanchez-Carpintero
- Paediatric Neurology Unit, Department of Paediatrics, Clinica Universidad de Navarra, 31008 Pamplona, Spain
| | - Jesus Barrio
- Department of Ophthalmology, Clinica Universidad de Navarra, 31008 Pamplona, Spain
| | - Pierre Bitoun
- Service de pédiatrie, CHU Paris Seine-Saint-Denis - Hôpital Jean Verdier Avenue du 14 juillet, 93140 Bondy, France
| | - Trine Prescott
- Department of Medical Genetics, Oslo University Hospital, 0424 Oslo, Norway
| | - Ruth Riise
- Department of Ophthalmology, Innland Hospital, 2418 Elverum, Norway
| | - Shane McKee
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast BT9 7AB, UK
| | - Jackie Cook
- Sheffield Clinical Genetics Service, Sheffield Children's Hospital, Western Bank, Sheffield S10 2TH, UK
| | - Lisa McKie
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Berten Ceulemans
- Department of Neurology-Pediatric Neurology, University and University Hospital Antwerp, Antwerp 2650, Belgium
| | - Françoise Meire
- Department of Ophthalmology, Queen Fabiola Children's University Hospital, 1020 Brussels, Belgium
| | - I Karen Temple
- Human Development and Health Academic Unit, University Hospital Southampton, Tremona Road, University of Southampton, Southampton SO16 6YD, UK
| | - Fabienne Prieur
- Service Génétique, Plateau de biologie, CHU Saint Etienne, 42055 Saint Etienne cedex 2, France
| | - Jonathan Williams
- Oxford University Hospitals NHS Trust, Oxford Medical Genetics Laboratories, The Churchill Hospital, Old Road, Headington, Oxford OX3 7LE, UK
| | - Penny Clouston
- Oxford University Hospitals NHS Trust, Oxford Medical Genetics Laboratories, The Churchill Hospital, Old Road, Headington, Oxford OX3 7LE, UK
| | - Andrea H Németh
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 7LJ, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, University of Manchester, St. Mary's Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Hemant Bengani
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Mark Handley
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Elisabeth Freyer
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Allyson Ross
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Veronica van Heyningen
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Joseph A Marsh
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Frances Elmslie
- Medical Genetics, St George's University Hospitals NHS Foundation Trust, Cranmer Terrace, London SW17 0RE, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK.
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