1
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Ansari M, Faour KNW, Shimamura A, Grimes G, Kao EM, Denhoff ER, Blatnik A, Ben-Isvy D, Wang L, Helm BM, Firth H, Breman AM, Bijlsma EK, Iwata-Otsubo A, de Ravel TJL, Fusaro V, Fryer A, Nykamp K, Stühn LG, Haack TB, Korenke GC, Constantinou P, Bujakowska KM, Low KJ, Place E, Humberson J, Napier MP, Hoffman J, Juusola J, Deardorff MA, Shao W, Rockowitz S, Krantz I, Kaur M, Raible S, Dortenzio V, Kliesch S, Singer-Berk M, Groopman E, DiTroia S, Ballal S, Srivastava S, Rothfelder K, Biskup S, Rzasa J, Kerkhof J, McConkey H, Sadikovic B, Hilton S, Banka S, Tüttelmann F, Conrad DF, O'Donnell-Luria A, Talkowski ME, FitzPatrick DR, Boone PM. Heterozygous loss-of-function SMC3 variants are associated with variable growth and developmental features. HGG Adv 2024; 5:100273. [PMID: 38297832 PMCID: PMC10876629 DOI: 10.1016/j.xhgg.2024.100273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/02/2024] Open
Abstract
Heterozygous missense variants and in-frame indels in SMC3 are a cause of Cornelia de Lange syndrome (CdLS), marked by intellectual disability, growth deficiency, and dysmorphism, via an apparent dominant-negative mechanism. However, the spectrum of manifestations associated with SMC3 loss-of-function variants has not been reported, leading to hypotheses of alternative phenotypes or even developmental lethality. We used matchmaking servers, patient registries, and other resources to identify individuals with heterozygous, predicted loss-of-function (pLoF) variants in SMC3, and analyzed population databases to characterize mutational intolerance in this gene. Here, we show that SMC3 behaves as an archetypal haploinsufficient gene: it is highly constrained against pLoF variants, strongly depleted for missense variants, and pLoF variants are associated with a range of developmental phenotypes. Among 14 individuals with SMC3 pLoF variants, phenotypes were variable but coalesced on low growth parameters, developmental delay/intellectual disability, and dysmorphism, reminiscent of atypical CdLS. Comparisons to individuals with SMC3 missense/in-frame indel variants demonstrated an overall milder presentation in pLoF carriers. Furthermore, several individuals harboring pLoF variants in SMC3 were nonpenetrant for growth, developmental, and/or dysmorphic features, and some had alternative symptomatologies with rational biological links to SMC3. Analyses of tumor and model system transcriptomic data and epigenetic data in a subset of cases suggest that SMC3 pLoF variants reduce SMC3 expression but do not strongly support clustering with functional genomic signatures of typical CdLS. Our finding of substantial population-scale LoF intolerance in concert with variable growth and developmental features in subjects with SMC3 pLoF variants expands the scope of cohesinopathies, informs on their allelic architecture, and suggests the existence of additional clearly LoF-constrained genes whose disease links will be confirmed only by multilayered genomic data paired with careful phenotyping.
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Affiliation(s)
- Morad Ansari
- South East Scotland Genetic Service, Western General Hospital, Edinburgh, UK; MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Kamli N W Faour
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, USA
| | - Akiko Shimamura
- Division of Hematology and Oncology, Boston Children's Hospital, Boston, MA, USA
| | - Graeme Grimes
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Emeline M Kao
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, USA
| | - Erica R Denhoff
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, USA
| | - Ana Blatnik
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK; Department of Clinical Cancer Genetics, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Daniel Ben-Isvy
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA; Division of Medical Sciences, Harvard Medical School, Boston, MA, USA
| | - Lily Wang
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA; Division of Medical Sciences, Harvard Medical School, Boston, MA, USA
| | - Benjamin M Helm
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Helen Firth
- Clinical Genetics, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
| | - Amy M Breman
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Aiko Iwata-Otsubo
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Thomy J L de Ravel
- Centre for Human Genetics, UZ Leuven/Leuven University Hospitals, Leuven, Belgium
| | | | - Alan Fryer
- Department of Clinical Genetics, Alder Hey Children's Hospital Liverpool, Liverpool, UK
| | | | - Lara G Stühn
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - G Christoph Korenke
- Department of Neuropaediatric and Metabolic Diseases, University Children's Hospital Oldenburg, Oldenburg, Germany
| | - Panayiotis Constantinou
- West of Scotland Centre for Genomic Medicine, Queen Elizabeth University Hospital, Glasgow, UK
| | | | - Karen J Low
- University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK; University of Bristol, Bristol, UK
| | - Emily Place
- Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | | | | | | | | | - Matthew A Deardorff
- Departments of Pathology and Pediatrics, Children's Hospital Los Angeles and University of Southern California, Los Angeles, CA, USA
| | - Wanqing Shao
- Research Computing, Information Technology, Boston Children's Hospital, Boston, MA, USA
| | - Shira Rockowitz
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Research Computing, Information Technology, Boston Children's Hospital, Boston, MA, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA
| | - Ian Krantz
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Maninder Kaur
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sarah Raible
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Sabine Kliesch
- Department of Clinical and Surgical Andrology, Centre of Reproductive Medicine and Andrology, University Hospital Münster, Münster, Germany
| | - Moriel Singer-Berk
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Emily Groopman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Stephanie DiTroia
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sonia Ballal
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, USA; Division of Gastroenterology, Boston Children's Hospital, Boston, MA, USA
| | - Siddharth Srivastava
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, USA; Divison of Neurology, Boston Children's Hospital, Boston, MA, USA
| | | | - Saskia Biskup
- Zentrum für Humangenetik, Tübingen, Germany; Center for Genomics and Transcriptomics (CeGaT), Tübingen, Germany
| | - Jessica Rzasa
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, Canada
| | - Jennifer Kerkhof
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, Canada
| | - Haley McConkey
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, Canada
| | - Bekim Sadikovic
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, Canada
| | - Sarah Hilton
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK; Division of Evolution, Infection, and Genomics, School of Biological Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Frank Tüttelmann
- Institute of Reproductive Genetics, University of Münster, Münster, Germany
| | - Donald F Conrad
- Division of Genetics, Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR, USA; Center for Embryonic Cell and Gene Therapy, Oregon Health and Science University, Portland, OR, USA
| | - Anne O'Donnell-Luria
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Michael E Talkowski
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Philip M Boone
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, USA; Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA; Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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2
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Ansari M, Faour KNW, Shimamura A, Grimes G, Kao EM, Denhoff ER, Blatnik A, Ben-Isvy D, Wang L, Helm BM, Firth H, Breman AM, Bijlsma EK, Iwata-Otsubo A, de Ravel TJL, Fusaro V, Fryer A, Nykamp K, Stühn LG, Haack TB, Korenke GC, Constantinou P, Bujakowska KM, Low KJ, Place E, Humberson J, Napier MP, Hoffman J, Juusola J, Deardorff MA, Shao W, Rockowitz S, Krantz I, Kaur M, Raible S, Kliesch S, Singer-Berk M, Groopman E, DiTroia S, Ballal S, Srivastava S, Rothfelder K, Biskup S, Rzasa J, Kerkhof J, McConkey H, O'Donnell-Luria A, Sadikovic B, Hilton S, Banka S, Tüttelmann F, Conrad D, Talkowski ME, FitzPatrick DR, Boone PM. Heterozygous loss-of-function SMC3 variants are associated with variable and incompletely penetrant growth and developmental features. medRxiv 2023:2023.09.27.23294269. [PMID: 37808847 PMCID: PMC10557843 DOI: 10.1101/2023.09.27.23294269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Heterozygous missense variants and in-frame indels in SMC3 are a cause of Cornelia de Lange syndrome (CdLS), marked by intellectual disability, growth deficiency, and dysmorphism, via an apparent dominant-negative mechanism. However, the spectrum of manifestations associated with SMC3 loss-of-function variants has not been reported, leading to hypotheses of alternative phenotypes or even developmental lethality. We used matchmaking servers, patient registries, and other resources to identify individuals with heterozygous, predicted loss-of-function (pLoF) variants in SMC3, and analyzed population databases to characterize mutational intolerance in this gene. Here, we show that SMC3 behaves as an archetypal haploinsufficient gene: it is highly constrained against pLoF variants, strongly depleted for missense variants, and pLoF variants are associated with a range of developmental phenotypes. Among 13 individuals with SMC3 pLoF variants, phenotypes were variable but coalesced on low growth parameters, developmental delay/intellectual disability, and dysmorphism reminiscent of atypical CdLS. Comparisons to individuals with SMC3 missense/in-frame indel variants demonstrated a milder presentation in pLoF carriers. Furthermore, several individuals harboring pLoF variants in SMC3 were nonpenetrant for growth, developmental, and/or dysmorphic features, some instead having intriguing symptomatologies with rational biological links to SMC3 including bone marrow failure, acute myeloid leukemia, and Coats retinal vasculopathy. Analyses of transcriptomic and epigenetic data suggest that SMC3 pLoF variants reduce SMC3 expression but do not result in a blood DNA methylation signature clustering with that of CdLS, and that the global transcriptional signature of SMC3 loss is model-dependent. Our finding of substantial population-scale LoF intolerance in concert with variable penetrance in subjects with SMC3 pLoF variants expands the scope of cohesinopathies, informs on their allelic architecture, and suggests the existence of additional clearly LoF-constrained genes whose disease links will be confirmed only by multi-layered genomic data paired with careful phenotyping.
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Affiliation(s)
- Morad Ansari
- South East Scotland Genetic Service, Western General Hospital, Edinburgh, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- These authors contributed equally
| | - Kamli N W Faour
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, US
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, US
- These authors contributed equally
| | - Akiko Shimamura
- Division of Hematology and Oncology, Boston Children's Hospital, Boston, MA, US
| | - Graeme Grimes
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Emeline M Kao
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, US
| | - Erica R Denhoff
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, US
| | - Ana Blatnik
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- Department of Clinical Cancer Genetics, Institute of Oncology Ljubljana, Ljubljana, SI
| | - Daniel Ben-Isvy
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, US
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
- Division of Medical Sciences, Harvard Medical School, Boston, MA, US
| | - Lily Wang
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, US
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
- Division of Medical Sciences, Harvard Medical School, Boston, MA, US
| | - Benjamin M Helm
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, US
| | - Helen Firth
- Clinical Genetics, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
| | - Amy M Breman
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, US
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, NL
| | - Aiko Iwata-Otsubo
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, US
| | - Thomy J L de Ravel
- Centre for Human Genetics, UZ Leuven/ Leuven University Hospitals, Leuven, BE
| | | | - Alan Fryer
- Department of Clinical Genetics, Alder Hey Children's Hospital Liverpool, Liverpool, UK
| | | | - Lara G Stühn
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, DE
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, DE
| | - G Christoph Korenke
- University Children's Hospital Oldenburg, Department of Neuropaediatric and Metabolic Diseases, University Children's Hospital Oldenburg, Oldenburg, DE
| | - Panayiotis Constantinou
- West of Scotland Centre for Genomic Medicine, Queen Elizabeth University Hospital, Glasgow, UK
| | | | - Karen J Low
- University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
- University of Bristol, Bristol, UK
| | - Emily Place
- Massachusetts Eye and Ear Infirmary, Boston, MA, US
| | | | | | | | | | - Matthew A Deardorff
- Departments of Pathology and Pediatrics, Children's Hospital Los Angeles and University of Southern California, Los Angeles, CA, US
| | - Wanqing Shao
- Research Computing, Information Technology, Boston Children's Hospital, Boston, MA, US
| | - Shira Rockowitz
- Research Computing, Information Technology, Boston Children's Hospital, Boston, MA, US
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, US
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, US
| | - Ian Krantz
- Children's Hospital of Philadelphia, Philadelphia, PA, US
| | - Maninder Kaur
- Children's Hospital of Philadelphia, Philadelphia, PA, US
| | - Sarah Raible
- Children's Hospital of Philadelphia, Philadelphia, PA, US
| | - Sabine Kliesch
- Department of Clinical and Surgical Andrology, Centre of Reproductive Medicine and Andrology, University Hospital Münster, Münster, DE
| | - Moriel Singer-Berk
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
| | - Emily Groopman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, US
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
| | - Stephanie DiTroia
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
| | - Sonia Ballal
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, US
- Division of Gastroenterology, Boston Children's Hospital, Boston, MA, US
| | - Siddharth Srivastava
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, US
- Divison of Neurology, Boston Children's Hospital, Boston, MA, US
| | | | - Saskia Biskup
- Zentrum für Humangenetik, Tübingen, DE
- Center for Genomics and Transcriptomics (CeGaT), Tübingen, DE
| | - Jessica Rzasa
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, LHSC, London, CA
| | - Jennifer Kerkhof
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, LHSC, London, CA
| | - Haley McConkey
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, LHSC, London, CA
| | - Anne O'Donnell-Luria
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, US
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, US
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
| | - Bekim Sadikovic
- Molecular Diagnostics Program and Verspeeten Clinical Genome Centre, LHSC, London, CA
| | | | | | - Frank Tüttelmann
- Institute of Reproductive Genetics, University of Münster, Münster, DE
| | - Donald Conrad
- Division of Genetics, Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR, US
- Center for Embryonic Cell and Gene Therapy, Oregon Health and Science University, Portland, OR, US
| | - Michael E Talkowski
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, US
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- These authors contributed equally
| | - Philip M Boone
- Cornelia de Lange Syndrome and Related Disorders Clinic, Boston Children's Hospital, Boston, MA, US
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, US
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, US
- Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, US
- These authors contributed equally
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3
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Solaki M, Baumann B, Reuter P, Andreasson S, Audo I, Ayuso C, Balousha G, Benedicenti F, Birch D, Bitoun P, Blain D, Bocquet B, Branham K, Català-Mora J, De Baere E, Dollfus H, Falana M, Giorda R, Golovleva I, Gottlob I, Heckenlively JR, Jacobson SG, Jones K, Jägle H, Janecke AR, Kellner U, Liskova P, Lorenz B, Martorell-Sampol L, Messias A, Meunier I, Belga Ottoni Porto F, Papageorgiou E, Plomp AS, de Ravel TJL, Reiff CM, Renner AB, Rosenberg T, Rudolph G, Salati R, Sener EC, Sieving PA, Stanzial F, Traboulsi EI, Tsang SH, Varsanyi B, Weleber RG, Zobor D, Stingl K, Wissinger B, Kohl S. Comprehensive variant spectrum of the CNGA3 gene in patients affected by achromatopsia. Hum Mutat 2022; 43:832-858. [PMID: 35332618 DOI: 10.1002/humu.24371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/23/2022] [Accepted: 03/22/2022] [Indexed: 11/06/2022]
Abstract
Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by impaired color discrimination, low visual acuity, photosensitivity, and nystagmus. To date, six genes have been associated with ACHM (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6), the majority of these being implicated in the cone phototransduction cascade. CNGA3 encodes the CNGA3 subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors and is one of the major disease-associated genes for ACHM. Herein, we provide a comprehensive overview of the CNGA3 variant spectrum in a cohort of 1060 genetically confirmed ACHM patients, 385 (36.3%) of these carrying "likely disease-causing" variants in CNGA3. Compiling our own genetic data with those reported in the literature and in public databases, we further extend the CNGA3 variant spectrum to a total of 316 variants, 244 of which we interpreted as "likely disease-causing" according to ACMG/AMP criteria. We report 48 novel "likely disease-causing" variants, 24 of which are missense substitutions underlining the predominant role of this mutation class in the CNGA3 variant spectrum. In addition, we provide extensive in silico analyses and summarize reported functional data of previously analyzed missense, nonsense and splicing variants to further advance the pathogenicity assessment of the identified variants.
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Affiliation(s)
- Maria Solaki
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Britta Baumann
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Peggy Reuter
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Sten Andreasson
- Department of Ophthalmology, University Hospital Lund, Lund, Sweden
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, Centre de Référence Maladies Rares REFERET, and INSERM-DGOS CIC1423, Paris, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Ghassan Balousha
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Francesco Benedicenti
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - David Birch
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Pierre Bitoun
- Genetique Medicale, CHU Paris Nord, Hopital Jean Verdier, Bondy Cedex, France
| | | | - Beatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Kari Branham
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Jaume Català-Mora
- Unitat de Distròfies Hereditàries de Retina Hospital Sant Joan de Déu, Barcelona, Esplugues de Llobregat, Spain
| | - Elfride De Baere
- Department of Biomolecular Medicine, Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Helene Dollfus
- CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- U-1112, Inserm, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Mohammed Falana
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Roberto Giorda
- Molecular Biology Laboratory, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Irina Golovleva
- Department of Medical Biosciences/Medical and Clinical Genetics, University of Umea, Umea, Sweden
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, UK
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kaylie Jones
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Herbert Jägle
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Andreas R Janecke
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Ulrich Kellner
- Zentrum für Seltene Netzhauterkrankungen, AugenZentrum Siegburg, MVZ Augenärztliches Diagnostik- und Therapiecentrum Siegburg GmbH, Siegburg, Germany
- RetinaScience, Bonn, 53192, Germany
| | - Petra Liskova
- Department of Paediatrics 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
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
- Department of Ophthalmology, Universitaetsklinikum Bonn, Bonn, Germany
| | | | - André Messias
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, Montpellier University Hospital, University of Montpellier, Montpellier, France
- Sensgene Care Network, France
| | | | - Eleni Papageorgiou
- Department of Ophthalmology, University Hospital of Larissa, Mezourlo, Larissa, Greece
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomy J L de Ravel
- Centre for Medical Genetics, University Hospital Brussels, Brussels, Belgium
| | | | | | - Thomas Rosenberg
- Department of Ophthalmology, National Eye Clinic, Glostrup Hospital, Glostrup, Denmark
| | - Günther Rudolph
- University Eye Hospital, Ludwig Maximilians University, Munich, Germany
| | - Roberto Salati
- Scientific Institute, IRCCS Eugenio Medea, Pediatric Ophthalmology Unit, Bosisio Parini, Lecco, Italy
| | - E Cumhur Sener
- Strabismus and Pediatric Ophthalmology, Private Practice, Ankara, Turkey
| | - Paul A Sieving
- Center for Ocular Regenerative Therapy, School of Medicine, University of California Davis, Sacramento, USA
| | - Franco Stanzial
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - Elias I Traboulsi
- Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Pathology and Cell Biology, College of Physicians and Surgeons, Columbia Stem Cell Initiative, Columbia University, New York City, New York, USA
| | - Balázs Varsanyi
- Department of Ophthalmology, Medical School, University of Pécs and Ganglion Medical Center, Pécs, Pécs, Hungary
| | - Richard G Weleber
- Oregon Health & Science University, Ophthalmic Genetics Service of the Casey Eye Institute, 515 SW Campus Drive, 97239, Portland, Oregon, USA
| | - Ditta Zobor
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Hospital Tübingen, Tübingen, Germany
- Department of Ophthalmology, Semmelweis University Budapest, Budapest, Hungary
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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Ripamonti C, Henning GB, Robbie SJ, Sundaram V, van den Born LI, Casteels I, de Ravel TJL, Moore AT, Smith AJ, Bainbridge JW, Ali RR, Stockman A. Spectral sensitivity measurements reveal partial success in restoring missing rod function with gene therapy. J Vis 2016; 15:20. [PMID: 26605849 DOI: 10.1167/15.15.20] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Restored rod visual function after gene therapy can be established unequivocally by demonstrating that, after dark adaptation, spectral sensitivity has the shape characteristic of rods and that this shape collapses to a cone-like shape before rods have recovered after an intense bleach. We used these tests to assess retinal function in eight young adults and children with early-onset severe retinal dystrophy from Phase II of a clinical gene-therapy trial for RPE65 deficiency that involved the subretinal delivery of a recombinant adeno-associated viral vector carrying RPE65. We found substantial improvements in rod sensitivity in two participants: dark-adapted spectral sensitivity was rod-like after treatment and was cone-like before rods had recovered after a bleach. After 40 min of dark adaptation, one participant showed up to 1,000-fold sensitivity improvements 4 months after treatment and the second up to 100-fold improvements 6 months after treatment. The dark-adapted spectral sensitivities of the other six participants remained cone-like and showed little improvement in sensitivity.
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Bainbridge JWB, Mehat MS, Sundaram V, Robbie SJ, Barker SE, Ripamonti C, Georgiadis A, Mowat FM, Beattie SG, Gardner PJ, Feathers KL, Luong VA, Yzer S, Balaggan K, Viswanathan A, de Ravel TJL, Casteels I, Holder GE, Tyler N, Fitzke FW, Weleber RG, Nardini M, Moore AT, Thompson DA, Petersen-Jones SM, Michaelides M, van den Born LI, Stockman A, Smith AJ, Rubin G, Ali RR. Long-term effect of gene therapy on Leber's congenital amaurosis. N Engl J Med 2015; 372:1887-97. [PMID: 25938638 PMCID: PMC4497809 DOI: 10.1056/nejmoa1414221] [Citation(s) in RCA: 508] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Mutations in RPE65 cause Leber's congenital amaurosis, a progressive retinal degenerative disease that severely impairs sight in children. Gene therapy can result in modest improvements in night vision, but knowledge of its efficacy in humans is limited. METHODS We performed a phase 1-2 open-label trial involving 12 participants to evaluate the safety and efficacy of gene therapy with a recombinant adeno-associated virus 2/2 (rAAV2/2) vector carrying the RPE65 complementary DNA, and measured visual function over the course of 3 years. Four participants were administered a lower dose of the vector, and 8 were administered a higher dose. In a parallel study in dogs, we investigated the relationship among vector dose, visual function, and electroretinography (ERG) findings. RESULTS Improvements in retinal sensitivity were evident, to varying extents, in six participants for up to 3 years, peaking at 6 to 12 months after treatment and then declining. No associated improvement in retinal function was detected by means of ERG. Three participants had intraocular inflammation, and two had clinically significant deterioration of visual acuity. The reduction in central retinal thickness varied among participants. In dogs, RPE65 gene therapy with the same vector at lower doses improved vision-guided behavior, but only higher doses resulted in improvements in retinal function that were detectable with the use of ERG. CONCLUSIONS Gene therapy with rAAV2/2 RPE65 vector improved retinal sensitivity, albeit modestly and temporarily. Comparison with the results obtained in the dog model indicates that there is a species difference in the amount of RPE65 required to drive the visual cycle and that the demand for RPE65 in affected persons was not met to the extent required for a durable, robust effect. (Funded by the National Institute for Health Research and others; ClinicalTrials.gov number, NCT00643747.).
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Affiliation(s)
- James W B Bainbridge
- From the UCL (University College London) Institute of Ophthalmology (J.W.B.B., M.S.M., V.S., S.J.R., S.E.B., C.R., A.G., F.M.M., S.G.B., P.J.G., V.A.L., K.B., A.V., G.E.H., F.W.F., M.N., A.T.M., M.M., A.S., A.J.S., G.R., R.R.A.) and the Department of Civil, Environmental, and Geomatic Engineering (N.T.), UCL, and Moorfields Eye Hospital (J.W.B.B., M.S.M., V.S., S.J.R., A.G., K.B., G.H., A.M., M.M.), London, and the Department of Psychology, Durham University, Durham (M.N.) - all in the United Kingdom; the College of Veterinary Medicine, Michigan State University, East Lansing (F.M.M., S.M.P.-J.), and the Kellogg Eye Center, University of Michigan Medical School, Ann Arbor (K.L.F., D.A.T., R.R.A.); the Center for Human Genetics, KU Leuven (T.J.L.R.), and the Department of Ophthalmology, UZ Leuven, Campus Sint-Rafaël (I.C.) - both in Leuven, Belgium; Rotterdam Eye Hospital, Rotterdam, the Netherlands (S.Y., L.I.B.); and the Oregon Retinal Degeneration Center, Ophthalmic Genetics Service, Casey Eye Institute, Oregon Health and Science University, Portland (R.G.W.)
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6
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Schlögel MJ, Mendola A, Fastré E, Vasudevan P, Devriendt K, de Ravel TJL, Van Esch H, Casteels I, Arroyo Carrera I, Cristofoli F, Fieggen K, Jones K, Lipson M, Balikova I, Singer A, Soller M, Mercedes Villanueva M, Revencu N, Boon LM, Brouillard P, Vikkula M. No evidence of locus heterogeneity in familial microcephaly with or without chorioretinopathy, lymphedema, or mental retardation syndrome. Orphanet J Rare Dis 2015; 10:52. [PMID: 25934493 PMCID: PMC4464120 DOI: 10.1186/s13023-015-0271-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/20/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Microcephaly with or without chorioretinopathy, lymphedema, or mental retardation syndrome (MCLMR) is a rare autosomal dominant disorder with variable expressivity. It is characterized by mild-to-severe microcephaly, often associated with intellectual disability, ocular defects and lymphedema. It can be sporadic or inherited. Eighty-seven patients have been described to carry a mutation in KIF11, which encodes a homotetrameric motor kinesin, EG5. METHODS We tested 23 unreported MCLMR index patients for KIF11. We also reviewed the clinical phenotypes of all our patients as well as of those described in previously published studies. RESULTS We identified 14 mutations, 12 of which are novel. We detected mutations in 12 affected individuals, from 6 out of 6 familial cases, and in 8 out of 17 sporadic patients. Phenotypic evaluation of patients (our 26 + 61 earlier published = 87) revealed microcephaly in 91%, eye anomalies in 72%, intellectual disability in 67% and lymphedema in 47% of the patients. Unaffected carriers were rare (4 out of 87: 5%). Family history is not a requisite for diagnosis; 31% (16 out of 52) were de novo cases. CONCLUSIONS All inherited cases, and 50% of sporadic cases of MCLMR are due to germline KIF11 mutations. It is possible that mosaic KIF11 mutations cause the remainder of sporadic cases, which the methods employed here were not designed to detect. On the other hand, some of them might have another mimicking disorder and genetic defect, as microcephaly is highly heterogeneous. In aggregate, KIF11 mutations likely cause the majority, if not all, of MCLMR.
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Affiliation(s)
- Matthieu J Schlögel
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium.
| | - Antonella Mendola
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium.
| | - Elodie Fastré
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium.
| | - Pradeep Vasudevan
- Department of Clinical Genetics, University Hospitals of Leicester, Leicester Royal Infirmary, Leicester, LE1 5WW, UK.
| | - Koen Devriendt
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, 3000, Leuven, Belgium.
| | - Thomy J L de Ravel
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, 3000, Leuven, Belgium.
| | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, 3000, Leuven, Belgium.
| | - Ingele Casteels
- Department of Ophthalmology, St Rafael University Hospitals, 3000, Leuven, Belgium.
| | | | - Francesca Cristofoli
- Center for Human Genetics, University Hospitals Leuven, KU Leuven, 3000, Leuven, Belgium.
| | - Karen Fieggen
- Division of Human Genetics, University of Cape Town, 7700, Cape Town, South Africa.
| | - Katheryn Jones
- Medical Genetics, Kaiser Permanente, Sacramento, CA, 95815, USA.
| | - Mark Lipson
- Medical Genetics, Kaiser Permanente, Sacramento, CA, 95815, USA.
| | - Irina Balikova
- Department of Ophthalmology, Queen Fabiola Children's University Hospital (HUDERF), 1020, Brussels, Belgium.
| | - Ami Singer
- Pediatrics and Medical Genetics, Barzilai Medical Center, 78306, Ashkelon, Israel.
| | - Maria Soller
- Department of Clinical Genetics, Lund University Hospital, 221 85, Lund, Sweden.
| | - María Mercedes Villanueva
- General Hospital of Florencio Varela, Children's Hospital Dr. Pedro Elizalde and Foundation for Neurological Diseases of Childhood (FLENI), C1270AAN, Buenos Aires, Capital Federal, Argentina.
| | - Nicole Revencu
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium. .,Center for Human Genetics, Cliniques universitaires Saint-Luc, Université catholique de Louvain, 1200, Brussels, Belgium.
| | - Laurence M Boon
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium. .,Center for Vascular Anomalies, Cliniques universitaires Saint-Luc, Université catholique de Louvain, 1200, Brussels, Belgium.
| | - Pascal Brouillard
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium.
| | - Miikka Vikkula
- Laboratory of Human Molecular Genetics, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 74, bte B1.74.06, B-1200, Brussels, Belgium. .,Center for Vascular Anomalies, Cliniques universitaires Saint-Luc, Université catholique de Louvain, 1200, Brussels, Belgium. .,Walloon Excellence in Lifesciences and Biotechnology (WELBIO), Université catholique de Louvain, 1200, Brussels, Belgium.
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7
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Ripamonti C, Henning GB, Ali RR, Bainbridge JW, Robbie SJ, Sundaram V, Luong VA, van den Born LI, Casteels I, de Ravel TJL, Moore AT, Stockman A. Nature of the visual loss in observers with Leber's congenital amaurosis caused by specific mutations in RPE65. Invest Ophthalmol Vis Sci 2014; 55:6817-28. [PMID: 25257057 DOI: 10.1167/iovs.14-14923] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize visual losses associated with genetic mutations in the RPE65 gene that cause defects in the RPE-specific isomerase, RPE65. RPE65 is an important component of the retinoid cycle that restores 11-cis-retinal after its photoisomerization to its all-trans form. The defects investigated here cause Leber's congenital amaurosis (LCA2), an autosomal, recessively-inherited, severe, congenital-onset rod-cone dystrophy. METHODS Vision was assessed in nine patients and 10 normal controls by measuring: (1) long-wavelength sensitive (L-) cone temporal acuity (critical flicker fusion frequency or cff) as a function of target illuminance, and (2) L-cone temporal contrast sensitivity as a function of temporal frequency at a fixed-target illuminance. Measurements were made by modulating either a 650-nm light superimposed on a 480-nm background or the red phosphor of a color monitor on a background produced by the monitor's blue phosphor. RESULTS RPE65-mutant observers have severely reduced cffs with shallower cff versus log illuminance functions that rise with a mean slope of 4.53 Hz per decade of illuminance compared with 8.69 Hz in normal controls. Consistent with the cff differences, RPE65-mutant observers show losses in temporal contrast sensitivity that increase rapidly with temporal frequency. CONCLUSIONS All RPE65-mutant observers have consistent and substantial losses in temporal acuity and sensitivity compared with normal observers. The losses can be characterized by the addition of two sluggish filters within the mutant visual pathway, both filters with a time constant of 29.5 ms (i.e., low-pass filters with cut-off frequencies of 5.40 Hz).
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Affiliation(s)
- Caterina Ripamonti
- UCL Institute of Ophthalmology, University College London, London, England
| | - G Bruce Henning
- UCL Institute of Ophthalmology, University College London, London, England
| | - Robin R Ali
- UCL Institute of Ophthalmology, University College London, London, England
| | - James W Bainbridge
- UCL Institute of Ophthalmology, University College London, London, England
| | - Scott J Robbie
- UCL Institute of Ophthalmology, University College London, London, England
| | - Venki Sundaram
- UCL Institute of Ophthalmology, University College London, London, England
| | - Vy A Luong
- UCL Institute of Ophthalmology, University College London, London, England
| | | | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | | | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London, England
| | - Andrew Stockman
- UCL Institute of Ophthalmology, University College London, London, England
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8
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de Ravel TJL, Devriendt K, Fryns JP, Vermeesch JR. What's new in karyotyping? The move towards array comparative genomic hybridisation (CGH). Eur J Pediatr 2007; 166:637-43. [PMID: 17372759 DOI: 10.1007/s00431-007-0463-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Accepted: 02/27/2007] [Indexed: 12/16/2022]
Abstract
Molecular karyotyping by array comparative genomic hybridisation (array CGH) has doubled the detection rate of pathogenic chromosomal imbalances in patients. This has been possible by increasing the resolution level from the 5 Mb obtained using the conventional karyotype to as low as 100 kb by array technology. Moreover, the technology revealed that over 12% of the human genome includes sub-microscopic benign copy number variable regions. These new findings have implications in genetic counselling and patient management.
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Affiliation(s)
- Thomy J L de Ravel
- Centre for Human Genetics, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
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9
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Stoetzel C, Muller J, Laurier V, Davis EE, Zaghloul NA, Vicaire S, Jacquelin C, Plewniak F, Leitch CC, Sarda P, Hamel C, de Ravel TJL, Lewis RA, Friederich E, Thibault C, Danse JM, Verloes A, Bonneau D, Katsanis N, Poch O, Mandel JL, Dollfus H. Identification of a novel BBS gene (BBS12) highlights the major role of a vertebrate-specific branch of chaperonin-related proteins in Bardet-Biedl syndrome. Am J Hum Genet 2007; 80:1-11. [PMID: 17160889 PMCID: PMC1785304 DOI: 10.1086/510256] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Accepted: 10/17/2006] [Indexed: 11/03/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is primarily an autosomal recessive ciliopathy characterized by progressive retinal degeneration, obesity, cognitive impairment, polydactyly, and kidney anomalies. The disorder is genetically heterogeneous, with 11 BBS genes identified to date, which account for ~70% of affected families. We have combined single-nucleotide-polymorphism array homozygosity mapping with in silico analysis to identify a new BBS gene, BBS12. Patients from two Gypsy families were homozygous and haploidentical in a 6-Mb region of chromosome 4q27. FLJ35630 was selected as a candidate gene, because it was predicted to encode a protein with similarity to members of the type II chaperonin superfamily, which includes BBS6 and BBS10. We found pathogenic mutations in both Gypsy families, as well as in 14 other families of various ethnic backgrounds, indicating that BBS12 accounts for approximately 5% of all BBS cases. BBS12 is vertebrate specific and, together with BBS6 and BBS10, defines a novel branch of the type II chaperonin superfamily. These three genes are characterized by unusually rapid evolution and are likely to perform ciliary functions specific to vertebrates that are important in the pathophysiology of the syndrome, and together they account for about one-third of the total BBS mutational load. Consistent with this notion, suppression of each family member in zebrafish yielded gastrulation-movement defects characteristic of other BBS morphants, whereas simultaneous suppression of all three members resulted in severely affected embryos, possibly hinting at partial functional redundancy within this protein family.
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Affiliation(s)
- Corinne Stoetzel
- Laboratoire de Genetique Medicale, Faculte de Medecine, Hopitaux Universitaires de Strasbourg, Strasbourg, France
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10
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Stoetzel C, Laurier V, Davis EE, Muller J, Rix S, Badano JL, Leitch CC, Salem N, Chouery E, Corbani S, Jalk N, Vicaire S, Sarda P, Hamel C, Lacombe D, Holder M, Odent S, Holder S, Brooks AS, Elcioglu NH, Silva ED, Rossillion B, Sigaudy S, de Ravel TJL, Lewis RA, Leheup B, Verloes A, Amati-Bonneau P, Mégarbané A, Poch O, Bonneau D, Beales PL, Mandel JL, Katsanis N, Dollfus H. Corrigendum: BBS10 encodes a vertebrate-specific chaperonin-like protein and is a major BBS locus. Nat Genet 2006. [DOI: 10.1038/ng0606-721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Stoetzel C, Laurier V, Davis EE, Muller J, Rix S, Badano JL, Leitch CC, Salem N, Chouery E, Corbani S, Jalk N, Vicaire S, Sarda P, Hamel C, Lacombe D, Holder M, Odent S, Holder S, Brooks AS, Elcioglu NH, Silva ED, Da Silva E, Rossillion B, Sigaudy S, de Ravel TJL, Lewis RA, Leheup B, Verloes A, Amati-Bonneau P, Mégarbané A, Poch O, Bonneau D, Beales PL, Mandel JL, Katsanis N, Dollfus H. BBS10 encodes a vertebrate-specific chaperonin-like protein and is a major BBS locus. Nat Genet 2006; 38:521-4. [PMID: 16582908 DOI: 10.1038/ng1771] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Accepted: 03/01/2006] [Indexed: 11/08/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a genetically heterogeneous ciliopathy. Although nine BBS genes have been cloned, they explain only 40-50% of the total mutational load. Here we report a major new BBS locus, BBS10, that encodes a previously unknown, rapidly evolving vertebrate-specific chaperonin-like protein. We found BBS10 to be mutated in about 20% of an unselected cohort of families of various ethnic origins, including some families with mutations in other BBS genes, consistent with oligogenic inheritance. In zebrafish, mild suppression of bbs10 exacerbated the phenotypes of other bbs morphants.
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Affiliation(s)
- Corinne Stoetzel
- Laboratoire de Génétique Médicale EA 3949, Faculté de Médecine de Strasbourg, Université Louis Pasteur, 67085 Strasbourg, France
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12
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de Ravel TJL, Taylor IB, Van Oostveldt AJT, Fryns JP, Wilkie AOM. A further mutation of the FGFR2 tyrosine kinase domain in mild Crouzon syndrome. Eur J Hum Genet 2005; 13:503-5. [PMID: 15523492 DOI: 10.1038/sj.ejhg.5201325] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We report a family heterozygous for a newly identified mutation in the tyrosine kinase I domain of the FGFR2 gene (1576A > G, encoding the missense substitution Lys526Glu), associated with variable expressivity of Crouzon syndrome, including clinical nonpenetrance. Our observations expand both the clinical and molecular spectrum of this unusual subset of FGFR2 mutations.
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13
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Rossenbacker T, Carroll SJ, Liu H, Kuipéri C, de Ravel TJL, Devriendt K, Carmeliet P, Kass RS, Heidbüchel H. Novel pore mutation in SCN5A manifests as a spectrum of phenotypes ranging from atrial flutter, conduction disease, and Brugada syndrome to sudden cardiac death. Heart Rhythm 2005; 1:610-5. [PMID: 15851228 DOI: 10.1016/j.hrthm.2004.07.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Accepted: 07/07/2004] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The purpose of this study was to determine the clinical and biophysical characteristics of a novel SCN5A mutation. BACKGROUND Brugada syndrome and isolated cardiac conduction defect have been linked to SCN5A mutations. METHODS Eleven members of a western European family underwent electrophysiologic investigations and mutation analysis of the SCN5A gene. Wild-type and mutant SCN5A channels were expressed in HEK293 cells, and whole cell currents were studied using patch clamp procedures. RESULTS A novel mutation, R376H, in the first pore segment of SCN5A variably causes Brugada syndrome and/or conduction disease in a single family. Biophysical analysis demonstrated a significant current reduction for the mutant, a pathophysiologic profile consistent with Brugada syndrome and isolated cardiac conduction defect. Among 11 family members, 9 were carriers of the mutation. The proband's initial presentation was a saddleback Brugada ECG, atrial flutter, and diffuse conduction disturbances. He had no inducible ventricular arrhythmias but experienced sudden cardiac death. His brother was affected by atrial flutter and had a clear conduction disorder, but he did not display baseline or evocable ECG signs of Brugada syndrome. He received an implantable cardioverter-defibrillator that delivered one appropriate shock after 1 year of follow-up. The phenotype in the family members was highly variable and ranged from noninducible and inducible asymptomatic carriers of the mutations to isolated conduction disease and to symptomatic Brugada syndrome. CONCLUSIONS We describe the functional characterization of a novel SCN5A pore mutation, R376H, with variable clinical expression in the same family. Differentiating between electrophysiologic entities (Brugada syndrome-isolated cardiac conduction defect) is more challenging. Recognition of factors modifying the clinical presentation may be important for clinical decision making.
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Affiliation(s)
- Tom Rossenbacker
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversitary Institute for Biotechnology, KULeuven, Belgium
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14
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Abstract
The 18p- syndrome has been known for over 40 years, the first report being by de Grouchy et al. [Comptes Rendus Hebdomadaires Séances l'Acad Sci 256 (1963) 1028]. Mental retardation of varying severity is the most constant feature. Over 100 cases have been reported. The eldest patients have been 50 years [Hum Genet 63 (1983) 139; Clin Genet 2 (1971) 338]. Follow-up of two adult patients, then 22 and 42 years [Ann Génét 29 (1986) 107], now 42 and 62 years of age, is reported. Further case reports are required in order to better define the evolution of adult patients with the 18p- syndrome.
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Affiliation(s)
- Thomy J L de Ravel
- Center for Human Genetics, UZ Gasthuisberg, 49 Herestraat, 3000 Leuven, Belgium.
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15
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de Ravel TJL, Keymolen K, van Assche E, Wittevronghel I, Moerman P, Salden I, Matthijs G, Fryns JP, Vermeesch JR. Post-zygotic origin of isochromosome 12p. Prenat Diagn 2004; 24:984-8. [PMID: 15614858 DOI: 10.1002/pd.956] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE Advance knowledge about the mechanism of isochromosome formation. METHODS Echographic examination of the foetus. G- and/or T-banded chromosome and FISH analysis using chromosome 12p subtelomeric probes on short- and long-term CVS cultures, amniocytes and foetal fibroblasts. Polymorphic CA repeat analysis on DNA from the foetus and both parents. RESULTS Short-term CVS cultures showed a 46,XX karyotype, whilst long-term CVS cultures showed a 47,XX,+12 karyotype. FISH on amniocytes indicated 2, 3 and 4 signals. Foetal fibroblasts showed both 47,XX,+12 and 47,XX,+i(12)(p10) karyotypes. DNA analysis revealed the isochromosome to be paternal in origin, whilst the other two foetal chromosomes 12 were maternal, part iso- and part heterodisomy. CONCLUSION The cytogenetic and DNA constitution of the foetus indicated the isochromosome 12p to be of paternal origin, and implied post-zygotic formation of the isochromosome 12p in the Pallister-Killian syndrome.
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Affiliation(s)
- Thomy J L de Ravel
- Centre for Human Genetics, UZ Gasthuisberg, Katholieke Universiteit Leuven, Herestraat 49, B-3000 Leuven, Belgium.
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