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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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52
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Simna SP, Han Z. Prospects Of Non-Coding Elements In Genomic Dna Based Gene Therapy. Curr Gene Ther 2021; 22:89-103. [PMID: 33874871 DOI: 10.2174/1566523221666210419090357] [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: 12/05/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 11/22/2022]
Abstract
Gene therapy has made significant development since the commencement of the first clinical trials a few decades ago and has remained a dynamic area of research regardless of obstacles such as immune response and insertional mutagenesis. Progression in various technologies like next-generation sequencing (NGS) and nanotechnology has established the importance of non-coding segments of a genome, thereby taking gene therapy to the next level. In this review, we have summarized the importance of non-coding elements, highlighting the advantages of using full-length genomic DNA loci (gDNA) compared to complementary DNA (cDNA) or minigene, currently used in gene therapy. The focus of this review is to provide an overview of the advances and the future of potential use of gDNA loci in gene therapy, expanding the therapeutic repertoire in molecular medicine.
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Affiliation(s)
- S P Simna
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC 27599. United States
| | - Zongchao Han
- Department of Ophthalmology, the University of North Carolina at Chapel Hill, Chapel Hill, NC 27599. United States
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53
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Tarilonte M, Ramos P, Moya J, Fernandez-Sanz G, Blanco-Kelly F, Swafiri ST, Villaverde C, Romero R, Tamayo A, Gener B, Calvas P, Ayuso C, Corton M. Activation of cryptic donor splice sites by non-coding and coding PAX6 variants contributes to congenital aniridia. J Med Genet 2021; 59:428-437. [PMID: 33782094 DOI: 10.1136/jmedgenet-2020-106932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 01/22/2021] [Accepted: 02/14/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND The paired-domain transcription factor paired box gene 6 (PAX6) causes a wide spectrum of ocular developmental anomalies, including congenital aniridia, Peters anomaly and microphthalmia. Here, we aimed to functionally assess the involvement of seven potentially non-canonical splicing variants on missplicing of exon 6, which represents the main hotspot region for loss-of-function PAX6 variants. METHODS By locus-specific analysis of PAX6 using Sanger and/or targeted next-generation sequencing, we screened a Spanish cohort of 106 patients with PAX6-related diseases. Functional splicing assays were performed by in vitro minigene approaches or directly in RNA from patient-derived lymphocytes cell line, when available. RESULTS Five out seven variants, including three synonymous changes, one small exonic deletion and one non-canonical splice variant, showed anomalous splicing patterns yielding partial exon skipping and/or elongation. CONCLUSION We describe new spliceogenic mechanisms for PAX6 variants mediated by creating or strengthening five different cryptic donor sites at exon 6. Our work revealed that the activation of cryptic PAX6 splicing sites seems to be a recurrent and underestimated cause of aniridia. Our findings pointed out the importance of functional assessment of apparently silent PAX6 variants to uncover hidden genetic alterations and to improve variant interpretation for genetic counselling in aniridia.
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Affiliation(s)
- Maria Tarilonte
- 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
| | - Patricia Ramos
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Guilermo Fernandez-Sanz
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, Madrid, Spain.,Department of Ophthalmology, Clínica Universidad de Navarra, Madrid, Spain
| | - 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.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Saoud Tahsin Swafiri
- 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
| | - Cristina Villaverde
- 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
| | - Raquel Romero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD-UAM), Madrid, Spain
| | - Alejandra Tamayo
- 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
| | - Blanca Gener
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Department of Genetics, Cruces University Hospital, BioCruces Health Research Institute, Barakaldo, Spain
| | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France.,INSERM U1056, Université Toulouse III, Toulouse, 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
| | - Marta Corton
- 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
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Collobert M, Bocher O, Le Nabec A, Génin E, Férec C, Moisan S. CFTR Cooperative Cis-Regulatory Elements in Intestinal Cells. Int J Mol Sci 2021; 22:ijms22052599. [PMID: 33807548 PMCID: PMC7961337 DOI: 10.3390/ijms22052599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/25/2021] [Accepted: 02/27/2021] [Indexed: 11/16/2022] Open
Abstract
About 8% of the human genome is covered with candidate cis-regulatory elements (cCREs). Disruptions of CREs, described as "cis-ruptions" have been identified as being involved in various genetic diseases. Thanks to the development of chromatin conformation study techniques, several long-range cystic fibrosis transmembrane conductance regulator (CFTR) regulatory elements were identified, but the regulatory mechanisms of the CFTR gene have yet to be fully elucidated. The aim of this work is to improve our knowledge of the CFTR gene regulation, and to identity factors that could impact the CFTR gene expression, and potentially account for the variability of the clinical presentation of cystic fibrosis as well as CFTR-related disorders. Here, we apply the robust GWAS3D score to determine which of the CFTR introns could be involved in gene regulation. This approach highlights four particular CFTR introns of interest. Using reporter gene constructs in intestinal cells, we show that two new introns display strong cooperative effects in intestinal cells. Chromatin immunoprecipitation analyses further demonstrate fixation of transcription factors network. These results provide new insights into our understanding of the CFTR gene regulation and allow us to suggest a 3D CFTR locus structure in intestinal cells. A better understand of regulation mechanisms of the CFTR gene could elucidate cases of patients where the phenotype is not yet explained by the genotype. This would thus help in better diagnosis and therefore better management. These cis-acting regions may be a therapeutic challenge that could lead to the development of specific molecules capable of modulating gene expression in the future.
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Affiliation(s)
- Mégane Collobert
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
- Correspondence: (M.C.); (S.M.); Tel.: +33-298-0165-67 (M.C.)
| | - Ozvan Bocher
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
| | - Anaïs Le Nabec
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
| | - Emmanuelle Génin
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
| | - Claude Férec
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
- Department of Molecular Genetics and Reproduction Biology, CHRU Brest, F-29200 Brest, France
| | - Stéphanie Moisan
- Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (O.B.); (A.L.N.); (E.G.); (C.F.)
- Department of Molecular Genetics and Reproduction Biology, CHRU Brest, F-29200 Brest, France
- Correspondence: (M.C.); (S.M.); Tel.: +33-298-0165-67 (M.C.)
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55
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Irizarry J, Stathopoulos A. Dynamic patterning by morphogens illuminated by cis-regulatory studies. Development 2021; 148:148/2/dev196113. [PMID: 33472851 DOI: 10.1242/dev.196113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Morphogen concentration changes in space as well as over time during development. However, how these dynamics are interpreted by cells to specify fate is not well understood. Here, we focus on two morphogens: the maternal transcription factors Bicoid and Dorsal, which directly regulate target genes to pattern Drosophila embryos. The actions of these factors at enhancers has been thoroughly dissected and provides a rich platform for understanding direct input by morphogens and their changing roles over time. Importantly, Bicoid and Dorsal do not work alone; we also discuss additional inputs that work with morphogens to control spatiotemporal gene expression in embryos.
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Affiliation(s)
- Jihyun Irizarry
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Angelike Stathopoulos
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 East California Blvd., Pasadena, CA 91125, USA
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56
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Korecki AJ, Cueva-Vargas JL, Fornes O, Agostinone J, Farkas RA, Hickmott JW, Lam SL, Mathelier A, Zhou M, Wasserman WW, Di Polo A, Simpson EM. Human MiniPromoters for ocular-rAAV expression in ON bipolar, cone, corneal, endothelial, Müller glial, and PAX6 cells. Gene Ther 2021; 28:351-372. [PMID: 33531684 PMCID: PMC8222000 DOI: 10.1038/s41434-021-00227-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/17/2020] [Accepted: 01/15/2021] [Indexed: 02/06/2023]
Abstract
Small and cell-type restricted promoters are important tools for basic and preclinical research, and clinical delivery of gene therapies. In clinical gene therapy, ophthalmic trials have been leading the field, with over 50% of ocular clinical trials using promoters that restrict expression based on cell type. Here, 19 human DNA MiniPromoters were bioinformatically designed for rAAV, tested by neonatal intravenous delivery in mouse, and successful MiniPromoters went on to be tested by intravitreal, subretinal, intrastromal, and/or intravenous delivery in adult mouse. We present promoter development as an overview for each cell type, but only show results in detail for the recommended MiniPromoters: Ple265 and Ple341 (PCP2) ON bipolar, Ple349 (PDE6H) cone, Ple253 (PITX3) corneal stroma, Ple32 (CLDN5) endothelial cells of the blood-retina barrier, Ple316 (NR2E1) Müller glia, and Ple331 (PAX6) PAX6 positive. Overall, we present a resource of new, redesigned, and improved MiniPromoters for ocular gene therapy that range in size from 784 to 2484 bp, and from weaker, equal, or stronger in strength relative to the ubiquitous control promoter smCBA. All MiniPromoters will be useful for therapies involving small regulatory RNA and DNA, and proteins ranging from 517 to 1084 amino acids, representing 62.9-90.2% of human proteins.
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Affiliation(s)
- Andrea J. Korecki
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Jorge L. Cueva-Vargas
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Oriol Fornes
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Jessica Agostinone
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Rachelle A. Farkas
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Jack W. Hickmott
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Siu Ling Lam
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Anthony Mathelier
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Michelle Zhou
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada
| | - Wyeth W. Wasserman
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Adriana Di Polo
- grid.14848.310000 0001 2292 3357Department of Neuroscience, University of Montreal Hospital Research Centre, University of Montreal, Montreal, QC Canada
| | - Elizabeth M. Simpson
- grid.17091.3e0000 0001 2288 9830Centre for Molecular Medicine and Therapeutics at BC Children’s Hospital, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
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Ye XC, Roslin NM, Paterson AD, Lyons CJ, Pegado V, Richmond P, Shyr C, Fornes O, Han X, Higginson M, Ross CJ, Giaschi D, Gregory-Evans C, Patel MS, Wasserman WW. Linkage analysis identifies an isolated strabismus locus at 14q12 overlapping with FOXG1 syndrome region. J Med Genet 2020; 59:46-55. [PMID: 33257509 PMCID: PMC8685624 DOI: 10.1136/jmedgenet-2020-107226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/05/2020] [Accepted: 09/29/2020] [Indexed: 11/21/2022]
Abstract
Strabismus is a common condition, affecting 1%–4% of individuals. Isolated strabismus has been studied in families with Mendelian inheritance patterns. Despite the identification of multiple loci via linkage analyses, no specific genes have been identified from these studies. The current study is based on a seven-generation family with isolated strabismus inherited in an autosomal dominant manner. A total of 13 individuals from a common ancestor have been included for linkage analysis. Among these, nine are affected and four are unaffected. A single linkage signal has been identified at an 8.5 Mb region of chromosome 14q12 with a multipoint LOD (logarithm of the odds) score of 4.69. Disruption of this locus is known to cause FOXG1 syndrome (or congenital Rett syndrome; OMIM #613454 and *164874), in which 84% of affected individuals present with strabismus. With the incorporation of next-generation sequencing and in-depth bioinformatic analyses, a 4 bp non-coding deletion was prioritised as the top candidate for the observed strabismus phenotype. The deletion is predicted to disrupt regulation of FOXG1, which encodes a transcription factor of the Forkhead family. Suggestive of an autoregulation effect, the disrupted sequence matches the consensus FOXG1 and Forkhead family transcription factor binding site and has been observed in previous ChIP-seq studies to be bound by Foxg1 in early mouse brain development. Future study of this specific deletion may shed light on the regulation of FOXG1 expression and may enhance our understanding of the mechanisms contributing to strabismus and FOXG1 syndrome.
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Affiliation(s)
- Xin Cynthia Ye
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nicole M Roslin
- The Centre for Applied Genomics, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Andrew D Paterson
- The Centre for Applied Genomics, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada.,Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Divisions of Epidemiology and Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Christopher J Lyons
- BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Victor Pegado
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Phillip Richmond
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Casper Shyr
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Oriol Fornes
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - XiaoHua Han
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michelle Higginson
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin J Ross
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Deborah Giaschi
- BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Cheryl Gregory-Evans
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Millan S Patel
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada .,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada .,Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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Toral-Lopez J, Huerta LMG, Messina-Baas O, Cuevas-Covarrubias SA. Submicroscopic 11p13 deletion including the elongator acetyltransferase complex subunit 4 gene in a girl with language failure, intellectual disability and congenital malformations: A case report. World J Clin Cases 2020; 8:5296-5303. [PMID: 33269262 PMCID: PMC7674752 DOI: 10.12998/wjcc.v8.i21.5296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/08/2020] [Accepted: 09/17/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND We described the main features of an infant diagnosed with facial dysmorphic, language failure, intellectual disability and congenital malformations to strengthen our understanding of the disease. Currently, treatment is only rehabilitation and surgery for cleft lip and palate.
CASE SUMMARY The proband was a 2-years-8-months-old girl. Familial history was negative for congenital malformations or intellectual disability. The patient had microcephaly, upward-slanting palpebral fissures, depressed nasal bridge, bulbous nose and bilateral cleft lip and palate. Brain magnetic resonance imaging showed cortical atrophy and band heterotopia. Her motor and intellectual development is delayed. A submicroscopic deletion in 11p13 involving the elongator acetyltransferase complex subunit 4 gene (ELP4) and a loss of heterozygosity in Xq25-q26.3 were detected.
CONCLUSION There is no treatment for the ELP4 deletion caused by a submicroscopic 11p3 deletion. We describe a second case of deletion of the ELP4 gene without aniridia, which confirms the association between ELP4 gene with several defects and absence of this ocular defect. Additional clinical data in the deletion of the ELP4 gene as cleft palate, facial dysmorphism, and changes at level brain could be associated to this gene or be part of the effect of the recessives genes involved in the loss of heterozygosity region of Xq25-26.3.
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Affiliation(s)
- Jaime Toral-Lopez
- Departamento de Genética Medica, Centro Medico Ecatepec, ISSEMYM, Ecatepec 55000, México
- Programa de Maestría y Doctorado en Ciencias Médicas, Odontológicas y de la Salud/Hospital Infantil de México, Universidad Nacional Autónoma de México, México 06720, México
| | | | - Olga Messina-Baas
- Departamento de Oftalmología, Hospital General de México, Cuauhtémoc 06720, México
| | - Sergio A Cuevas-Covarrubias
- Genetica, Hospital General de México, Cuauhtémoc 06726, Mexico
- Programa de Maestría y Doctorado en Ciencias Médicas, Odontológicas y de la Salud, Universidad Nacional Autónoma de México, México 06720, Mexico
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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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van der Lee R, Correard S, Wasserman WW. Deregulated Regulators: Disease-Causing cis Variants in Transcription Factor Genes. Trends Genet 2020; 36:523-539. [DOI: 10.1016/j.tig.2020.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/12/2022]
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Cassinari K, Rovelet-Lecrux A, Tury S, Quenez O, Richard AC, Charbonnier C, Olaso R, Boland A, Deleuze JF, Besancenot JF, Delpont B, Pouliquen D, Lecoquierre F, Chambon P, Thauvin-Robinet C, Campion D, Frebourg T, Battini JL, Nicolas G. Haploinsufficiency of the Primary Familial Brain Calcification Gene SLC20A2 Mediated by Disruption of a Regulatory Element. Mov Disord 2020; 35:1336-1345. [PMID: 32506582 DOI: 10.1002/mds.28090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/17/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Primary familial brain calcification (PFBC) is a rare cerebral microvascular calcifying disorder with diverse neuropsychiatric expression. Five genes were reported as PFBC causative when carrying pathogenic variants. Haploinsufficiency of SLC20A2, which encodes an inorganic phosphate importer, is a major cause of autosomal-dominant PFBC. However, PFBC remains genetically unexplained in a proportion of patients, suggesting the existence of additional genes or cryptic mutations. We analyzed exome sequencing data of 71 unrelated, genetically unexplained PFBC patients with the aim to detect copy number variations that may disrupt the expression of core PFBC-causing genes. METHODS After the identification of a deletion upstream of SLC20A2, we assessed its consequences on gene function by reverse transcriptase droplet digital polymerase chain reaction (RT-ddPCR), an ex vivo inorganic phosphate uptake assay, and introduced the deletion of a putative SLC20A2 enhancer mapping to this region in human embryonic kidney 293 (HEK293) cells by clustered regularly interspaced short palindromic repeats (CRISPR) - CRISPR-associated protein 9 (Cas9). RESULTS The 8p11.21 deletion, segregating with PFBC in a family, mapped 35 kb upstream of SLC20A2. The deletion carriers/normal controls ratio of relative SLC20A2 mRNA levels was 60.2% (P < 0.001). This was comparable with that of patients carrying an SLC20A2 premature stop codon (63.4%; P < 0.001). The proband exhibited a 39.3% decrease of inorganic phosphate uptake in blood (P = 0.015). In HEK293 cells, we observed a 39.8% decrease in relative SLC20A2 mRNA levels after normalization on DNA copy number (P < 0.001). DISCUSSION We identified a deletion of an enhancer of SLC20A2 expression, with carriers showing haploinsufficiency in similar ranges to loss-of-function alleles, and we observed reduced mRNA levels after deleting this element in a cellular model. We propose a 3-step strategy to identify and easily assess the effect of such events. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Kévin Cassinari
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Anne Rovelet-Lecrux
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Sandrine Tury
- Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Olivier Quenez
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Anne-Claire Richard
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Camille Charbonnier
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Robert Olaso
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Jean-François Deleuze
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | | | - Benoit Delpont
- Department of Internal Medicine and Systemic Diseases, Dijon University Hospital, Dijon, France
| | - Dorothée Pouliquen
- Department of Neurology and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - François Lecoquierre
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Pascal Chambon
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Christel Thauvin-Robinet
- Inserm UMR 1231 GAD, Genetics of Developmental Disorders, Université de Bourgogne-Franche Comté, FHU TRANSLAD, Dijon, France
- CHU Dijon Bourgogne, Unité Fonctionnelle "Innovation diagnostique dans les maladies rares," laboratoire de génétique chromosomique et moléculaire, Plateau Technique de Biologie, Dijon, France
- Centre de Référence Maladies Rares "Déficiences Intellectuelles de causes rares," FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
| | - Dominique Campion
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
- Department of Research, Rouvray Psychiatric Hospital, Sotteville-les-Rouen, France
| | - Thierry Frebourg
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Jean-Luc Battini
- Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Gaël Nicolas
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
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Cherry TJ, Yang MG, Harmin DA, Tao P, Timms AE, Bauwens M, Allikmets R, Jones EM, Chen R, De Baere E, Greenberg ME. Mapping the cis-regulatory architecture of the human retina reveals noncoding genetic variation in disease. Proc Natl Acad Sci U S A 2020; 117:9001-9012. [PMID: 32265282 PMCID: PMC7183164 DOI: 10.1073/pnas.1922501117] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The interplay of transcription factors and cis-regulatory elements (CREs) orchestrates the dynamic and diverse genetic programs that assemble the human central nervous system (CNS) during development and maintain its function throughout life. Genetic variation within CREs plays a central role in phenotypic variation in complex traits including the risk of developing disease. We took advantage of the retina, a well-characterized region of the CNS known to be affected by pathogenic variants in CREs, to establish a roadmap for characterizing regulatory variation in the human CNS. This comprehensive analysis of tissue-specific regulatory elements, transcription factor binding, and gene expression programs in three regions of the human visual system (retina, macula, and retinal pigment epithelium/choroid) reveals features of regulatory element evolution that shape tissue-specific gene expression programs and defines regulatory elements with the potential to contribute to Mendelian and complex disorders of human vision.
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Affiliation(s)
- Timothy J Cherry
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98101;
- Department of Ophthalmology, University of Washington School of Medicine, Seattle, WA 98101
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98101
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98101
| | - Marty G Yang
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115
| | - David A Harmin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Peter Tao
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Andrew E Timms
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98101
| | - Miriam Bauwens
- Center for Medical Genetics, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY 10032
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
| | - Evan M Jones
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411
| | - Rui Chen
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium
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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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Li Y, Tao T, Du L, Zhu X. Three-dimensional genome: developmental technologies and applications in precision medicine. J Hum Genet 2020; 65:497-511. [PMID: 32152365 DOI: 10.1038/s10038-020-0737-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/20/2020] [Accepted: 02/22/2020] [Indexed: 12/17/2022]
Abstract
In the 20th century, our familiar structure of DNA was the double helix. Due to technical limitations, we do not have a good way to understand the finer structure of the genome, let alone its transcriptional regulation. Until the advent of 3C technologies, we were no longer blind to this one. Three-dimensional (3D) genomics is a new subject, which mainly studies the 3D structure and transcriptional regulation of eukaryotic genomes. Now, this field mainly has Hi-C series and CHIA-PET series technologies. Through 3D genomics, we can understand the basic structure of DNA, understand the growth and development of organisms and the occurrence of diseases, so as to promote human medical and health undertakings. The review introduces the main research techniques of 3D genomics and their characteristics, the latest development of 3D genome structure, the relationship between diseases and 3D genome structure, the applications of 3D genome in precision medicine, and the development of the 4D nucleome project.
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Affiliation(s)
- Yingqi Li
- Marine Medical Research Institute of Guangdong Zhanjiang (GDZJMMRI), Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang, 524023, China
| | - Tao Tao
- Department of Gastroenterology, Zibo Central Hospital, Zibo, 255000, China
| | - Likun Du
- First Affiliated Hospital, Heilongjiang University of Traditional Chinese Medicine, Harbin, 150040, China.
| | - Xiao Zhu
- Marine Medical Research Institute of Guangdong Zhanjiang (GDZJMMRI), Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang, 524023, China.
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Williamson KA, Hall HN, Owen LJ, Livesey BJ, Hanson IM, Adams GGW, Bodek S, Calvas P, Castle B, Clarke M, Deng AT, Edery P, Fisher R, Gillessen-Kaesbach G, Heon E, Hurst J, Josifova D, Lorenz B, McKee S, Meire F, Moore AT, Parker M, Reiff CM, Self J, Tobias ES, Verheij JBGM, Willems M, Williams D, van Heyningen V, Marsh JA, FitzPatrick DR. Recurrent heterozygous PAX6 missense variants cause severe bilateral microphthalmia via predictable effects on DNA-protein interaction. Genet Med 2020; 22:598-609. [PMID: 31700164 PMCID: PMC7056646 DOI: 10.1038/s41436-019-0685-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Most classical aniridia is caused by PAX6 haploinsufficiency. PAX6 missense variants can be hypomorphic or mimic haploinsufficiency. We hypothesized that missense variants also cause previously undescribed disease by altering the affinity and/or specificity of PAX6 genomic interactions. METHODS We screened PAX6 in 372 individuals with bilateral microphthalmia, anophthalmia, or coloboma (MAC) from the Medical Research Council Human Genetics Unit eye malformation cohort (HGUeye) and reviewed data from the Deciphering Developmental Disorders study. We performed cluster analysis on PAX6-associated ocular phenotypes by variant type and molecular modeling of the structural impact of 86 different PAX6 causative missense variants. RESULTS Eight different PAX6 missense variants were identified in 17 individuals (15 families) with MAC, accounting for 4% (15/372) of our cohort. Seven altered the paired domain (p.[Arg26Gln]x1, p.[Gly36Val]x1, p.[Arg38Trp]x2, p.[Arg38Gln]x1, p.[Gly51Arg]x2, p.[Ser54Arg]x2, p.[Asn124Lys]x5) and one the homeodomain (p.[Asn260Tyr]x1). p.Ser54Arg and p.Asn124Lys were exclusively associated with severe bilateral microphthalmia. MAC-associated variants were predicted to alter but not ablate DNA interaction, consistent with the electrophoretic mobility shifts observed using mutant paired domains with well-characterized PAX6-binding sites. We found no strong evidence for novel PAX6-associated extraocular disease. CONCLUSION Altering the affinity and specificity of PAX6-binding genome-wide provides a plausible mechanism for the worse-than-null effects of MAC-associated missense variants.
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Affiliation(s)
- Kathleen A Williamson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - H Nikki Hall
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Liusaidh J Owen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Benjamin J Livesey
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Isabel M Hanson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | | | - Simon Bodek
- Department of Clinical Genetics, St Michael's Hospital, Southwell Street, Bristol, UK
| | - Patrick Calvas
- CHU Toulouse, Service de Génétique Médicale, Hôpital Purpan, Toulouse, France
| | - Bruce Castle
- Peninsula Clinical Genetics, Royal Devon and Exeter Hospitals (Heavitree), Exeter, UK
| | - Michael Clarke
- Newcastle Eye Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Alexander T Deng
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Patrick Edery
- Hospices Civils de Lyon, Genetic Department and National HHT Reference Center, Femme-Mère-Enfants Hospital, Bron, France
| | - Richard Fisher
- Teeside Genetics Unit, The James Cook University Hospital, Middlesbrough, UK
| | | | - Elise Heon
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, ON, Canada
| | - Jane Hurst
- Department of Clinical Genetics, Great Ormond Street Hospital for Children, London, UK
| | - Dragana Josifova
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Shane McKee
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, UK
| | - Francoise Meire
- Department of Ophthalmology, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium
| | | | - Michael Parker
- Department of Clinical Genetics, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Charlotte M Reiff
- Department of Ophthalmology, University of Freiburg, Freiburg, Germany
| | - Jay Self
- University Hospital Southampton, Southampton, UK
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Edward S Tobias
- Academic Medical Genetics and Pathology, University of Glasgow, Queen Elizabeth University Hospital, Glasgow, UK
| | - Joke B G M Verheij
- Department of Genetics, University of Groningen, University Medical Center, Groningen, The Netherlands
| | | | - Denise Williams
- Clinical Genetics Unit, Birmingham Women's Hospital, Birmingham, UK
| | - Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
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Wawrocka A, Walczak-Sztulpa J, Bukowska-Olech E, Jamsheer A, Jaworski M, Jaworski P, Krawczynski MR. Two sisters with microphthalmia and anterior segment dysgenesis secondary to a PAX6 pathogenic variant with clinically healthy parents: a case of gonadal mosaicism? Jpn J Ophthalmol 2020; 64:134-139. [DOI: 10.1007/s10384-020-00715-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/09/2019] [Indexed: 01/19/2023]
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Boese EA, Tollefson MR, Schnieders MJ, Darbro BW, Alward WLM, Fingert JH. Novel Intragenic PAX6 Deletion in a Pedigree with Aniridia, Morbid Obesity, and Diabetes. Curr Eye Res 2020; 45:91-96. [PMID: 31361967 PMCID: PMC10413309 DOI: 10.1080/02713683.2019.1649704] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/18/2019] [Accepted: 07/20/2019] [Indexed: 10/26/2022]
Abstract
Purpose: Aniridia is a rare congenital eye disease, characterized by a constellation of symptoms including hypoplastic irides, foveal hypoplasia, early cataract, corneal stem cell deficiency, and glaucoma. Large chromosomal deletions spanning the PAX6 gene cause WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and intellectual disability [formerly called mental retardation]). We describe clinical and genetic studies of a three-generation pedigree with aniridia along with additional systemic conditions (morbid obesity, diabetes) suggesting the possibility of a contiguous-gene syndrome like WAGR.Methods: Clinical records were obtained and DNA was prepared from blood samples from three of the four patients and tested for mutations in the coding sequences of the PAX6 gene. The index patient also had cardiomyopathy and was tested for known cardiomyopathy genetic mutations using a next-generation DNA sequencing assay.Results: We discovered a novel intragenic PAX6 mutation, a 16 bp heterozygous deletion c.203delCCAGGGCAATCGGTGG, with Sanger sequencing that is the likely cause of autosomal dominant aniridia in this pedigree. This PAX6 deletion causes a frameshift in predicted protein translation and a subsequent premature termination, p.Pro68Leufs*6. The PAX6 deletion was detected in all three available family members with aniridia, the index patient, his mother, and his maternal aunt but was not observed in the Exome Aggregation Consortium (ExAC) database. Targeted sequencing of known cardiomyopathy genes in the index patient identified a second mutation, a 1.7 Mp deletion that spans the MYBPC3 gene.Conclusions: We report a pedigree with aniridia and other systemic abnormalities that were initially suspicious for a contiguous-gene syndrome like WAGR. However, genetic analysis of the pedigree revealed two independent genetic abnormalities on chromosome 11p: 1) a novel PAX6 mutation, and 2) a large chromosome deletion spanning MYBPC3, a known cardiomyopathy gene. It is unclear if morbid obesity and type II diabetes mellitus have a related genetic cause.
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Affiliation(s)
- Erin A Boese
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Mallory R Tollefson
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Michael J Schnieders
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Benjamin W Darbro
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Wallace L M Alward
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - John H Fingert
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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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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Wang H, Zhou L, Meng Z, Su M, Zhang S, Huang P, Jiang F, Liao X, Cao Z, Lu H. Clethodim exposure induced development toxicity and behaviour alteration in early stages of zebrafish life. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113218. [PMID: 31541821 DOI: 10.1016/j.envpol.2019.113218] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 08/27/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
Clethodim is one of the most widely used herbicides in agriculture, however, its potential toxic effects on organisms and the underlying toxicity mechanism are still poorly understood. In this study, zebrafish embryos at 6 h post-fertilization (hpf) were exposed to 10 mg/L, 20 mg/L, and 30 mg/L clethodim for up to 24 hpf, and zebrafish larvae at 6 days post-fertilization (dpf) were exposed to the same density gradient for 24 h. Our results showed that clethodim could cause head and cardiovascular malformations in embryos: blurred brain ventricles, unapparent brain regions, condensation of nucleus and cytoplasm in brain cells, increased intercellular space, developmental malformations of eyes and ears, reduced neonatal neurons, disorder migration of neural ridge cells; morphological aberrations of the vascular ICM, slowing of heart beat and blood flow, reduction of circulating red blood cells, and delayed development of head and tail blood vessels. These defects could be a result of clethodim-induced oxidative stress and decreased acetylcholinesterase (AChE) activity, which in turn affected the expression of neurodevelopmental genes, decreased ATPase activity, and ultimately led to developmental malformations. The swimming behaviour of zebrafish larvae was observed to decrease with increasing concentration of clethodim exposure, but the angular velocity and mobility increased. These could be due to reduced AChE activity and disturbed gene expression of GABA, dopamine and glutamatergic neurotransmitter systems, which thus altered the locomotor behaviour. In summary, we found that clethodim induces developmental toxicity and neurotoxicity in zebrafish embryos and larvae.
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Affiliation(s)
- Honglei Wang
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Liqun Zhou
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Zhen Meng
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Meile Su
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Shouhua Zhang
- Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, 330006, China
| | - Pinzhen Huang
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Fen Jiang
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Xinjun Liao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Zigang Cao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China
| | - Huiqiang Lu
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, 343009, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, 343009, Jiangxi, China.
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70
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McCole RB, Erceg J, Saylor W, Wu CT. Ultraconserved Elements Occupy Specific Arenas of Three-Dimensional Mammalian Genome Organization. Cell Rep 2019; 24:479-488. [PMID: 29996107 DOI: 10.1016/j.celrep.2018.06.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/09/2018] [Accepted: 06/07/2018] [Indexed: 12/23/2022] Open
Abstract
This study explores the relationship between three-dimensional genome organization and ultraconserved elements (UCEs), an enigmatic set of DNA elements that are perfectly conserved between the reference genomes of distantly related species. Examining both human and mouse genomes, we interrogate the relationship of UCEs to three features of chromosome organization derived from Hi-C studies. We find that UCEs are enriched within contact domains and, further, that the subset of UCEs within domains shared across diverse cell types are linked to kidney-related and neuronal processes. In boundaries, UCEs are generally depleted, with those that do overlap boundaries being overrepresented in exonic UCEs. Regarding loop anchors, UCEs are neither overrepresented nor underrepresented, but those present in loop anchors are enriched for splice sites. Finally, as the relationships between UCEs and human Hi-C features are conserved in mouse, our findings suggest that UCEs contribute to interspecies conservation of genome organization and, thus, genome stability.
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Affiliation(s)
- Ruth B McCole
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Jelena Erceg
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Wren Saylor
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Chao-Ting Wu
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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71
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Mann A, Bhatia S. Zebrafish: A Powerful Model for Understanding the Functional Relevance of Noncoding Region Mutations in Human Genetic Diseases. Biomedicines 2019; 7:E71. [PMID: 31527394 PMCID: PMC6784013 DOI: 10.3390/biomedicines7030071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/28/2019] [Accepted: 08/29/2019] [Indexed: 02/06/2023] Open
Abstract
Determining aetiology of genetic disorders caused by damaging mutations in protein-coding genes is well established. However, understanding how mutations in the vast stretches of the noncoding genome contribute to genetic abnormalities remains a huge challenge. Cis-regulatory elements (CREs) or enhancers are an important class of noncoding elements. CREs function as the primary determinants of precise spatial and temporal regulation of their target genes during development by serving as docking sites for tissue-specific transcription factors. Although a large number of potential disease-associated CRE mutations are being identified in patients, lack of robust methods for mechanistically linking these mutations to disease phenotype is currently hampering the understanding of their roles in disease aetiology. Here, we have described the various systems available for testing the CRE potential of stretches of noncoding regions harbouring mutations implicated in human disease. We highlight advances in the field leading to the establishment of zebrafish as a powerful system for robust and cost-effective functional assays of CRE activity, enabling rapid identification of causal variants in regulatory regions and the validation of their role in disruption of appropriate gene expression.
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Affiliation(s)
- Anita Mann
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
| | - Shipra Bhatia
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
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72
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Pereira Zambalde E, Mathias C, Rodrigues AC, Souza Fonseca Ribeiro EM, Fiori Gradia D, Calin GA, Carvalho de Oliveira J. Highlighting transcribed ultraconserved regions in human diseases. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1567. [DOI: 10.1002/wrna.1567] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/02/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022]
Affiliation(s)
| | - Carolina Mathias
- Department of Genetics Universidade Federal do Paraná Curitiba Brazil
| | | | | | | | - George A. Calin
- Department of Experimental Therapeutics, MD Anderson Cancer Center University of Texas Houston Texas
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73
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Huang J, Jiang Y, Zheng H, Ji X. BAT Hi-C maps global chromatin interactions in an efficient and economical way. Methods 2019; 170:38-47. [PMID: 31442560 DOI: 10.1016/j.ymeth.2019.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 08/15/2019] [Indexed: 11/18/2022] Open
Abstract
Chromosome Conformation Capture (3C)-based technologies, such as Hi-C, have represented a significant breakthrough in investigating the structure and function of higher-order genome architecture. However, the mapping of global chromatin interactions remains challenging across many biological conditions due to high background noise and financial constraints, especially for small laboratories. Here, we describe the Bridge linker-Alul-Tn5 Hi-C (BAT Hi-C) method, which is a simple and efficient method for delineating chromatin conformational features of mouse embryonic stem (mES) cells and uncover DNA loops. This protocol combines Alul fragmentation and biotinylated linker-mediated proximity ligation to obtain kilobase (kb) resolution with a marked increase in the amount of unique read pairs. The protocol also includes chromatin isolation to reduce background noise and Tn5 tagmentation to cut down on preparation time. Importantly, with only one-third sequencing depth, our method revealed the same spectrum of chromatin contacts as in situ Hi-C. BAT Hi-C is an economical (i.e., approximately $40 for library preparation) and straightforward (total hands-on time of 3 days) tool that is ideal for the in-depth analysis of long-range chromatin looping events in a genome-wide fashion.
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Affiliation(s)
- Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| | - Yongpeng Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Haonan Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
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74
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Perenthaler E, Yousefi S, Niggl E, Barakat TS. Beyond the Exome: The Non-coding Genome and Enhancers in Neurodevelopmental Disorders and Malformations of Cortical Development. Front Cell Neurosci 2019; 13:352. [PMID: 31417368 PMCID: PMC6685065 DOI: 10.3389/fncel.2019.00352] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/16/2019] [Indexed: 12/22/2022] Open
Abstract
The development of the human cerebral cortex is a complex and dynamic process, in which neural stem cell proliferation, neuronal migration, and post-migratory neuronal organization need to occur in a well-organized fashion. Alterations at any of these crucial stages can result in malformations of cortical development (MCDs), a group of genetically heterogeneous neurodevelopmental disorders that present with developmental delay, intellectual disability and epilepsy. Recent progress in genetic technologies, such as next generation sequencing, most often focusing on all protein-coding exons (e.g., whole exome sequencing), allowed the discovery of more than a 100 genes associated with various types of MCDs. Although this has considerably increased the diagnostic yield, most MCD cases remain unexplained. As Whole Exome Sequencing investigates only a minor part of the human genome (1–2%), it is likely that patients, in which no disease-causing mutation has been identified, could harbor mutations in genomic regions beyond the exome. Even though functional annotation of non-coding regions is still lagging behind that of protein-coding genes, tremendous progress has been made in the field of gene regulation. One group of non-coding regulatory regions are enhancers, which can be distantly located upstream or downstream of genes and which can mediate temporal and tissue-specific transcriptional control via long-distance interactions with promoter regions. Although some examples exist in literature that link alterations of enhancers to genetic disorders, a widespread appreciation of the putative roles of these sequences in MCDs is still lacking. Here, we summarize the current state of knowledge on cis-regulatory regions and discuss novel technologies such as massively-parallel reporter assay systems, CRISPR-Cas9-based screens and computational approaches that help to further elucidate the emerging role of the non-coding genome in disease. Moreover, we discuss existing literature on mutations or copy number alterations of regulatory regions involved in brain development. We foresee that the future implementation of the knowledge obtained through ongoing gene regulation studies will benefit patients and will provide an explanation to part of the missing heritability of MCDs and other genetic disorders.
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Affiliation(s)
- Elena Perenthaler
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, Netherlands
| | - Soheil Yousefi
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, Netherlands
| | - Eva Niggl
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, Netherlands
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, Netherlands
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Abstract
Structural and quantitative chromosomal rearrangements, collectively referred to as structural variation (SV), contribute to a large extent to the genetic diversity of the human genome and thus are of high relevance for cancer genetics, rare diseases and evolutionary genetics. Recent studies have shown that SVs can not only affect gene dosage but also modulate basic mechanisms of gene regulation. SVs can alter the copy number of regulatory elements or modify the 3D genome by disrupting higher-order chromatin organization such as topologically associating domains. As a result of these position effects, SVs can influence the expression of genes distant from the SV breakpoints, thereby causing disease. The impact of SVs on the 3D genome and on gene expression regulation has to be considered when interpreting the pathogenic potential of these variant types.
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Affiliation(s)
- Malte Spielmann
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Darío G Lupiáñez
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Stefan Mundlos
- Max Planck Institute for Molecular Genetics, RG Development & Disease, Berlin, Germany. .,Institute for Medical and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany.
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76
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Liu L, Kim MH, Hyeon C. Heterogeneous Loop Model to Infer 3D Chromosome Structures from Hi-C. Biophys J 2019; 117:613-625. [PMID: 31337548 DOI: 10.1016/j.bpj.2019.06.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/22/2019] [Accepted: 06/25/2019] [Indexed: 10/26/2022] Open
Abstract
Adapting a well-established formalism in polymer physics, we develop a minimalist approach to infer three-dimensional folding of chromatin from Hi-C data. The three-dimensional chromosome structures generated from our heterogeneous loop model (HLM) are used to visualize chromosome organizations that can substantiate the measurements from fluorescence in situ hybridization, chromatin interaction analysis by paired-end tag sequencing, and RNA-seq signals. We demonstrate the utility of the HLM with several case studies. Specifically, the HLM-generated chromosome structures, which reproduce the spatial distribution of topologically associated domains from fluorescence in situ hybridization measurement, show the phase segregation between two types of topologically associated domains explicitly. We discuss the origin of cell-type-dependent gene-expression level by modeling the chromatin globules of α-globin and SOX2 gene loci for two different cell lines. We also use the HLM to discuss how the chromatin folding and gene-expression level of Pax6 loci, associated with mouse neural development, are modulated by interactions with two enhancers. Finally, HLM-generated structures of chromosome 19 of mouse embryonic stem cells, based on single-cell Hi-C data collected over each cell-cycle phase, visualize changes in chromosome conformation along the cell-cycle. Given a contact frequency map between chromatic loci supplied from Hi-C, HLM is a computationally efficient and versatile modeling tool to generate chromosome structures that can complement interpreting other experimental data.
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Affiliation(s)
- Lei Liu
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea
| | - Min Hyeok Kim
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea
| | - Changbong Hyeon
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea.
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77
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van Heyningen V. Genome sequencing-the dawn of a game-changing era. Heredity (Edinb) 2019; 123:58-66. [PMID: 31189904 PMCID: PMC6781137 DOI: 10.1038/s41437-019-0226-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/16/2019] [Indexed: 01/14/2023] Open
Abstract
The development of genome sequencing technologies has revolutionized the biological sciences in ways which could not have been imagined at the time. This article sets out to document the dawning of the age of genomics and to consider the impact of this revolution on biological investigation, our understanding of life, and the relationship between science and society.
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Affiliation(s)
- Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh, EH4 2XU, UK.
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
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78
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Karnuta JM, Scacheri PC. Enhancers: bridging the gap between gene control and human disease. Hum Mol Genet 2019; 27:R219-R227. [PMID: 29726898 DOI: 10.1093/hmg/ddy167] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/02/2018] [Indexed: 01/21/2023] Open
Abstract
Enhancers are a class of regulatory elements essential for precise spatio-temporal control of gene expression during development and in terminally differentiated cells. This review highlights signature features of enhancer elements as well as new advances that provide mechanistic insights into enhancer-mediated gene control in the context of three-dimensional chromatin. We detail the various ways in which non-coding mutations can instigate aberrant gene control and cause a variety of Mendelian disorders, common diseases and cancer.
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Affiliation(s)
- Jaret M Karnuta
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.,Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
| | - Peter C Scacheri
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
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79
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Johnson AF, Nguyen HT, Veitia RA. Causes and effects of haploinsufficiency. Biol Rev Camb Philos Soc 2019; 94:1774-1785. [DOI: 10.1111/brv.12527] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Adam F. Johnson
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
| | - Ha T. Nguyen
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
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80
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Schoenfelder S, Fraser P. Long-range enhancer–promoter contacts in gene expression control. Nat Rev Genet 2019; 20:437-455. [DOI: 10.1038/s41576-019-0128-0] [Citation(s) in RCA: 486] [Impact Index Per Article: 97.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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81
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Zhao Y, Zheng D, Cvekl A. Profiling of chromatin accessibility and identification of general cis-regulatory mechanisms that control two ocular lens differentiation pathways. Epigenetics Chromatin 2019; 12:27. [PMID: 31053165 PMCID: PMC6498704 DOI: 10.1186/s13072-019-0272-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/23/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Promoters and enhancers are cis-regulatory DNA sequences that control specificity and quantity of transcription. Both are rich on clusters of cis-acting sites that interact with sequence-specific DNA-binding transcription factors (TFs). At the level of chromatin, these regions display increased nuclease sensitivity, reduced nucleosome density, including nucleosome-free regions, and specific combinations of posttranslational modifications of core histone proteins. Together, "open" and "closed" chromatins represent transcriptionally active and repressed states of individual genes, respectively. Cellular differentiation is marked by changes in local chromatin structure. Lens morphogenesis, regulated by TF Pax6, includes differentiation of epithelial precursor cells into lens fibers in parallel with differentiation of epithelial precursors into the mature lens epithelium. RESULTS Using ATAC-seq, we investigated dynamics of chromatin changes during mouse lens fibers and epithelium differentiation. Tissue-specific features of these processes are demonstrated via comparative studies of embryonic stem cells, forebrain, and liver chromatins. Unbiased analysis reveals cis-regulatory logic of lens differentiation through known (e.g., AP-1, Ets, Hsf4, Maf, and Pax6 sites) and novel (e.g., CTCF, Tead, and NF1) motifs. Twenty-six DNA-binding TFs, recognizing these cis-motifs, are markedly up-regulated in differentiating lens fibers. As specific examples, our ATAC-seq data uncovered both the regulatory regions and TF binding motifs in Foxe3, Prox1, and Mip loci that are consistent with previous, though incomplete, experimental data. A cross-examination of Pax6 binding with ATAC-seq data demonstrated that Pax6 bound to both open (H3K27ac and P300-enriched) and closed chromatin domains in lens and forebrain. CONCLUSIONS Our study has generated the first lens chromatin accessibility maps that support a general model of stage-specific chromatin changes associated with transcriptional activities of batteries of genes required for lens fiber cell formation. Analysis of active (or open) promoters and enhancers reveals important cis-DNA motifs that establish the molecular foundation for temporally and spatially regulated gene expression in lens. Together, our data and models open new avenues for the field to conduct mechanistic studies of transcriptional control regions, reconstruction of gene regulatory networks that govern lens morphogenesis, and identification of cataract-causing mutations in noncoding sequences.
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Affiliation(s)
- Yilin Zhao
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Deyou Zheng
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
- Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Ales Cvekl
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
- Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461 USA
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82
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Wang H, Zhou L, Liao X, Meng Z, Xiao J, Li F, Zhang S, Cao Z, Lu H. Toxic effects of oxine-copper on development and behavior in the embryo-larval stages of zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 210:242-250. [PMID: 30878792 DOI: 10.1016/j.aquatox.2019.02.020] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 02/19/2019] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Oxine-copper (OxCu) is generally used as an agricultural pesticide and induces harmful effects on ecosystems. In this study, zebrafish was used to assess the aquatic toxicity of OxCu. To detect the effects on development, embryos of 6 h post-fertilization (hpf) were exposed to 10 μg/L, 20 μg/L, 40 μg/L OxCu for 18 h; meanwhile, to evaluate the effects on the behavior, larval fish at 6 days post-fertilization (dpf) were exposed to the same concentrations for 24 h. Here, we show that there are embryonic developmental defects, including abnormalities of head and trunk, brain ventricle atrophy, reduced newborn neurons, disordered neurons, increased intercellular space, concentrated cytoplasm, decreased heart beat and blood flow velocity, and developmental delay of the vascular system; in addition, some embryos exposed to the high concentration of OxCu degraded from the tail. We also found that the spontaneous tail coiling frequency and AChE enzyme activity were reduced, while oxidative stress (free radical damage) and cell apoptosis were significantly increased. Moreover, the expression of genes involved in neurodevelopment, vascular development and apoptosis were dysregulated in the OxCu exposed embryos in a concentration-dependent manner. Finally, we found that after exposure to OxCu, larval locomotor activity was decreased and accompanied by Parkinson-like (increased absolute turn angle and sinuosity) and anxiety-like (preferred to the central area) behavior. These results indicate that OxCu induces developmental toxicity and behavioral alterations by affecting AChE enzyme activity and oxidative stress. Our data present new proofs of OxCu toxicity and a warning for its application.
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Affiliation(s)
- Honglei Wang
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Liqun Zhou
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Xinjun Liao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Zhen Meng
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Juhua Xiao
- Department of Ultrasound, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, 330006, China
| | - Fuyan Li
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Shouhua Zhang
- Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang 330006, China
| | - Zigang Cao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Huiqiang Lu
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China.
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83
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Wang H, Meng Z, Zhou L, Cao Z, Liao X, Ye R, Lu H. Effects of acetochlor on neurogenesis and behaviour in zebrafish at early developmental stages. CHEMOSPHERE 2019; 220:954-964. [PMID: 33395817 DOI: 10.1016/j.chemosphere.2018.12.199] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 12/23/2018] [Accepted: 12/30/2018] [Indexed: 06/12/2023]
Abstract
The herbicide acetochlor is used in most parts of the world and is frequently detected in agricultural land and surface water; however, knowledge on the neurotoxicity of acetochlor is limited. Here, to test the effects of acetochlor on zebrafish development and behaviour, zebrafish embryos were exposed to acetochlor from 6 h post-fertilization (hpf) to 24 hpf, and larvae at 6 days post-fertilization (dpf) were exposed to acetochlor for 24 h. Both were exposed to 5, 10, or 20 mg/L acetochlor. We found that acetochlor induced developmental abnormalities, locomotion variations and changes in the physiology and gene expression in the embryos and larvae. The abnormalities included spinal curvature, brain abnormalities, and the decreased formation of newborn neurons. Larval locomotion was decreased with increases in the absolute turn angle and sinuosity. Acetylcholinesterase activity reduced in both embryos and larvae, and the expression of genes that are involved in neurodevelopment and the neurotransmitter system altered. Acetochlor increased the production of ROS and the accumulation of MDA but decreased CAT activity in the embryonic brain. Additionally, acetochlor induced cell death in the brain and tail spinal cord, and the expression of the apoptosis-related genes Bcl2 and caspase 3 were significantly upregulated. Collectively, this is the first study to examine the molecular and physiological effects of acetochlor on neuronal development, and the potential mechanisms appear to be associated with oxidative stress and decreased AChE activity, which disrupt the expression of nervous system genes and apoptosis-related genes and finally lead to apoptosis and morphological malformations.
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Affiliation(s)
- Honglei Wang
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Zhen Meng
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Liqun Zhou
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Zigang Cao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Xinjun Liao
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Rongfang Ye
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China
| | - Huiqiang Lu
- Jiangxi Engineering Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases, Jiangxi Key Laboratory of Developmental Biology of Organs, Ji'an, Jiangxi, China; Center for Developmental Biology of Jinggangshan University, College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, China.
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84
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Buckle A, Nozawa RS, Kleinjan DA, Gilbert N. Functional characteristics of novel pancreatic Pax6 regulatory elements. Hum Mol Genet 2019; 27:3434-3448. [PMID: 30007277 PMCID: PMC6140780 DOI: 10.1093/hmg/ddy255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/02/2018] [Indexed: 12/28/2022] Open
Abstract
Complex diseases, such as diabetes, are influenced by comprehensive transcriptional networks. Genome-wide association studies have revealed that variants located in regulatory elements for pancreatic transcription factors are linked to diabetes, including those functionally linked to the paired box transcription factor Pax6. Pax6 deletions in adult mice cause rapid onset of classic diabetes, but the full spectrum of pancreatic Pax6 regulators is unknown. Using a regulatory element discovery approach, we identified two novel Pax6 pancreatic cis-regulatory elements in a poorly characterized regulatory desert. Both new elements, Pax6 pancreas cis-regulatory element 3 (PE3) and PE4, are located 50 and 100 kb upstream and interact with different parts of the Pax6 promoter and nearby non-coding RNAs. They drive expression in the developing pancreas and brain and code for multiple pancreas-related transcription factor-binding sites. PE3 binds CCCTC-binding factor (CTCF) and is marked by stem cell identity markers in embryonic stem cells, whilst a common variant located in the PE4 element affects binding of Pax4, a known pancreatic regulator, altering Pax6 gene expression. To determine the ability of these elements to regulate gene expression, synthetic transcriptional activators and repressors were targeted to PE3 and PE4, modulating Pax6 gene expression, as well as influencing neighbouring genes and long non-coding RNAs, implicating the Pax6 locus in pancreas function and diabetes.
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Affiliation(s)
- Adam Buckle
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
| | - Ryu-Suke Nozawa
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
| | - Dirk A Kleinjan
- Centre for Mammalian Synthetic Biology, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
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85
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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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86
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Smith M, Flodman PL. Expanded Insights Into Mechanisms of Gene Expression and Disease Related Disruptions. Front Mol Biosci 2018; 5:101. [PMID: 30542652 PMCID: PMC6277798 DOI: 10.3389/fmolb.2018.00101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 11/02/2018] [Indexed: 12/31/2022] Open
Abstract
Definitive molecular diagnoses in disorders apparently due to genetic or genomic defects are still lacking in a significant number of investigated cases, despite use of studies designed to discover defects in the protein coding regions of the genome. Increasingly studies are being designed to search for defects in the non-protein coding genome, and for alterations in gene expression. Here we review new insights into genomic elements involved in control of gene expression, including methods to analyze chromatin that is accessible for transcription factor binding, enhancers, chromatin looping, transcription, RNA binding proteins, and alternative splicing. We review new studies on levels of genome organization, including the occurrence of transcriptional domains and their boundary elements. Information is presented on specific malformation syndromes that arise due to structural genomic changes that impact the non-protein coding genome and sometimes impact specific transcriptional domains. We also review convergence of genome-wide association with studies of gene expression, discoveries related to expression quantitative trait loci and splicing quantitative trait loci and the relevance of these to specific complex common diseases. Aspects of epigenetic mechanisms and clinical applications of analyses of methylation signatures are also discussed.
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Affiliation(s)
- Moyra Smith
- Department of Pediatrics, University of California, Irvine, Irvine, CA, United States
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87
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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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88
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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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89
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Vasilyeva TA, Voskresenskaya AA, Pozdeyeva NA, Marakhonov AV, Zinchenko RA. PAX6 Gene Characteristic and Causative Role of PAX6 Mutations in Inherited Eye Pathologies. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418090156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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90
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Roux LN, Petit I, Domart R, Concordet JP, Qu J, Zhou H, Joliot A, Ferrigno O, Aberdam D. Modeling of Aniridia-Related Keratopathy by CRISPR/Cas9 Genome Editing of Human Limbal Epithelial Cells and Rescue by Recombinant PAX6 Protein. Stem Cells 2018; 36:1421-1429. [PMID: 29808941 DOI: 10.1002/stem.2858] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/08/2018] [Accepted: 05/14/2018] [Indexed: 12/24/2022]
Abstract
Heterozygous PAX6 gene mutations leading to haploinsufficiency are the main cause of congenital aniridia, a rare and progressive panocular disease characterized by reduced visual acuity. Up to 90% of patients suffer from aniridia-related keratopathy (ARK), caused by a combination of factors including limbal epithelial stem cell (LSC) deficiency, impaired healing response and abnormal differentiation of the corneal epithelium. It usually begins in the first decade of life, resulting in recurrent corneal erosions, sub-epithelial fibrosis, and corneal opacification. Unfortunately, there are currently no efficient treatments available for these patients and no in vitro model for this pathology. We used CRISPR/Cas9 technology to introduce into the PAX6 gene of LSCs a heterozygous nonsense mutation found in ARK patients. Nine clones carrying a p.E109X mutation on one allele were obtained with no off-target mutations. Compared with the parental LSCs, heterozygous mutant LSCs displayed reduced expression of PAX6 and marked slow-down of cell proliferation, migration and detachment. Moreover, addition to the culture medium of recombinant PAX6 protein fused to a cell penetrating peptide was able to activate the endogenous PAX6 gene and to rescue phenotypic defects of mutant LSCs, suggesting that administration of such recombinant PAX6 protein could be a promising therapeutic approach for aniridia-related keratopathy. More generally, our results demonstrate that introduction of disease mutations into LSCs by CRISPR/Cas9 genome editing allows the creation of relevant cellular models of ocular disease that should greatly facilitate screening of novel therapeutic approaches. Stem Cells 2018;36:1421-1429.
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Affiliation(s)
- Lauriane N Roux
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Isabelle Petit
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Romain Domart
- INSERM U1154, CNRS UMR 7196, Museum National d'Histoire Naturelle, Paris, France
| | - Jean-Paul Concordet
- INSERM U1154, CNRS UMR 7196, Museum National d'Histoire Naturelle, Paris, France
| | - Jieqiong Qu
- Department of Human Developmental biology, Radboud University, Nijmegen, The Netherlands.,Faculty of Sciences, Department of Human Genetics, Radboud University Nijmegen, The Netherlands
| | - Huiqing Zhou
- Department of Human Developmental biology, Radboud University, Nijmegen, The Netherlands.,Faculty of Sciences, Department of Human Genetics, Radboud University Nijmegen, The Netherlands
| | - Alain Joliot
- Collège de France CNRS/UMR 7241 - INSERM U1050, Paris, France
| | | | - Daniel Aberdam
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
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91
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Chakraborty A, Ay F. The role of 3D genome organization in disease: From compartments to single nucleotides. Semin Cell Dev Biol 2018; 90:104-113. [PMID: 30017907 DOI: 10.1016/j.semcdb.2018.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/03/2018] [Indexed: 12/26/2022]
Abstract
Since the advent of the chromosome conformation capture technology, our understanding of the human genome 3D organization has grown rapidly and we now know that human interphase chromosomes are folded into multiple layers of hierarchical structures and each layer can play a critical role in transcriptional regulation. Alterations in any one of these finely-tuned layers can lead to unwanted cascade of molecular events and ultimately drive the manifestation of diseases and phenotypes. Here we discuss, starting from chromosome level organization going down to single nucleotide changes, recent studies linking diseases or phenotypes to changes in the 3D genome architecture.
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Affiliation(s)
| | - Ferhat Ay
- La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA; UC San Diego, School of Medicine, La Jolla, 92093, CA, USA.
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92
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Liu X, Wu Y, Miao Z, Zhang H, Gong B, Zhu X, Huang L, Shi Y, Hao F, Ma S, Lin H, Wang L, Yang Z. A novel deletion downstream of the PAX6 gene identified in a Chinese family with congenital aniridia. Ophthalmic Genet 2018; 39:428-436. [PMID: 29902091 DOI: 10.1080/13816810.2018.1466336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- Xiaoqi Liu
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
- School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, China
| | - Yaqi Wu
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Zequn Miao
- Department of Ophthalmology, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Peking University People’s Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
- Center of Optometry, Peking University People’s Hospital, Beijing, China
| | - Houbin Zhang
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Bo Gong
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Xianjun Zhu
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Lulin Huang
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Yi Shi
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Fang Hao
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Shi Ma
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - He Lin
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Lejin Wang
- Department of Ophthalmology, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Peking University People’s Hospital, Beijing, China
- Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
- College of Optometry, Peking University Health Science Center, Beijing, China
- Center of Optometry, Peking University People’s Hospital, Beijing, China
| | - Zhenglin Yang
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Center of Information in Biomedicine, University of Electronic Science and Technology of China, Chengdu, China
- Institute of Chengdu Biology, Chinese Academy of Sciences, Chengdu, China
- Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, China
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93
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Phenotypic Variation in a Four-Generation Family with Aniridia Carrying a Novel PAX6 Mutation. J Ophthalmol 2018; 2018:5978293. [PMID: 29850208 PMCID: PMC5904767 DOI: 10.1155/2018/5978293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/05/2018] [Indexed: 12/14/2022] Open
Abstract
Aniridia is a congenital disease that affects almost all eye structures and is primarily caused by loss-of-function mutations in the PAX6 gene. The degree of vision loss in aniridia varies and is dependent on the extent of foveal, iris, and optic nerve hypoplasia and the presence of glaucoma, cataracts, and corneal opacification. Here, we describe a 4-generation family in which 7 individuals across 2 generations carry a novel disease-causing frameshift mutation (NM_000280.4(PAX6):c.565TC>T) in PAX6. This mutation results in an early stop codon in exon 8, which is predicted to cause nonsense-mediated decay of the truncated mRNA and a functionally null PAX6 allele. Family members with aniridia showed differences in multiple eye phenotypes including iris and optic nerve hypoplasia, congenital and acquired corneal opacification, glaucoma, and strabismus. Visual acuity ranged from 20/100 to less than 20/800. Patients who required surgical intervention for glaucoma or corneal opacification had worse visual outcomes. Our results show that family members carrying a novel PAX6 frameshift mutation have variable expressivity, leading to different ocular comorbidities and visual outcomes.
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94
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Short PJ, McRae JF, Gallone G, Sifrim A, Won H, Geschwind DH, Wright CF, Firth HV, FitzPatrick DR, Barrett JC, Hurles ME. De novo mutations in regulatory elements in neurodevelopmental disorders. Nature 2018; 555:611-616. [PMID: 29562236 PMCID: PMC5912909 DOI: 10.1038/nature25983] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 01/24/2018] [Indexed: 12/23/2022]
Abstract
We previously estimated that 42% of patients with severe developmental disorders carry pathogenic de novo mutations in coding sequences. The role of de novo mutations in regulatory elements affecting genes associated with developmental disorders, or other genes, has been essentially unexplored. We identified de novo mutations in three classes of putative regulatory elements in almost 8,000 patients with developmental disorders. Here we show that de novo mutations in highly evolutionarily conserved fetal brain-active elements are significantly and specifically enriched in neurodevelopmental disorders. We identified a significant twofold enrichment of recurrently mutated elements. We estimate that, genome-wide, 1-3% of patients without a diagnostic coding variant carry pathogenic de novo mutations in fetal brain-active regulatory elements and that only 0.15% of all possible mutations within highly conserved fetal brain-active elements cause neurodevelopmental disorders with a dominant mechanism. Our findings represent a robust estimate of the contribution of de novo mutations in regulatory elements to this genetically heterogeneous set of disorders, and emphasize the importance of combining functional and evolutionary evidence to identify regulatory causes of genetic disorders.
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Affiliation(s)
- Patrick J Short
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Jeremy F McRae
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Giuseppe Gallone
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Alejandro Sifrim
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Hyejung Won
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Daniel H Geschwind
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- Center for Autism Research and Treatment, Program in Neurobehavioral Genetics, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Caroline F Wright
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, RILD Level 4, Royal Devon & Exeter Hospital, Barrack Road, Exeter EX2 5DW, UK
| | - Helen V Firth
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- East Anglian Medical Genetics Service, Box 134, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - David R FitzPatrick
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
- MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Jeffrey C Barrett
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Matthew E Hurles
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
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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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96
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Abstract
Mutations of the FOXP2 gene cause a severe speech and language disorder, providing a molecular window into the neurobiology of language. Individuals with FOXP2 mutations have structural and functional alterations affecting brain circuits that overlap with sites of FOXP2 expression, including regions of the cortex, striatum, and cerebellum. FOXP2 displays complex patterns of expression in the brain, as well as in non-neuronal tissues, suggesting that sophisticated regulatory mechanisms control its spatio-temporal expression. However, to date, little is known about the regulation of FOXP2 or the genomic elements that control its expression. Using chromatin conformation capture (3C), we mapped the human FOXP2 locus to identify putative enhancer regions that engage in long-range interactions with the promoter of this gene. We demonstrate the ability of the identified enhancer regions to drive gene expression. We also show regulation of the FOXP2 promoter and enhancer regions by candidate regulators - FOXP family and TBR1 transcription factors. These data point to regulatory elements that may contribute to the temporal- or tissue-specific expression patterns of human FOXP2. Understanding the upstream regulatory pathways controlling FOXP2 expression will bring new insight into the molecular networks contributing to human language and related disorders.
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Affiliation(s)
- Martin Becker
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands.,Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands
| | - Paolo Devanna
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands
| | - Simon E Fisher
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands
| | - Sonja C Vernes
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands
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97
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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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98
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Rim JH, Lee ST, Gee HY, Lee BJ, Choi JR, Park HW, Han SH, Han J. Accuracy of Next-Generation Sequencing for Molecular Diagnosis in Patients With Infantile Nystagmus Syndrome. JAMA Ophthalmol 2017; 135:1376-1385. [PMID: 29145603 PMCID: PMC6583550 DOI: 10.1001/jamaophthalmol.2017.4859] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/23/2017] [Indexed: 01/10/2023]
Abstract
Importance Infantile nystagmus syndrome (INS) is a group of disorders presenting with genetic and clinical heterogeneities that have challenged the genetic and clinical diagnoses of INS. Precise molecular diagnosis in early infancy may result in more accurate genetic counseling and improved patient management. Objective To assess the accuracy of genomic data from next-generation sequencing (NGS) and phenotypic data to enhance the definitive diagnosis of INS. Design, Setting, and Participants A single-center retrospective case series was conducted in 48 unrelated, consecutive patients with INS, with or without associated ocular or systemic conditions, who underwent genetic testing between June 1, 2015, and January 31, 2017. Next-generation sequencing analysis was performed using a target panel that included 113 genes associated with INS (n = 47) or a TruSight One sequencing panel that included 4813 genes associated with known human phenotypes (n = 1). Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Patients underwent a detailed ophthalmic examination, including electroretinography and optical coherence tomography, if feasible. Main Outcomes and Measures Diagnostic yield of targeted NGS testing. Results Among the 48 patients (21 female and 27 male; mean [SD] age at genetic testing, 9.2 [10.3] years), 8 had a family history of nystagmus and 40 were simplex. All patients were of a single ethnicity (Korean). Genetic variants that were highly likely to be causative were identified in 28 of the 48 patients, corresponding to a molecular diagnostic yield of 58.3% (95% CI, 44.4%-72.2%). FRMD7, GPR143, and PAX6 mutations appeared to be the major genetic causes of familial INS. A total of 10 patients (21%) were reclassified to a different diagnosis based on results of NGS testing, enabling accurate clinical management. Conclusions and Relevance These findings suggest that NGS is an accurate diagnostic tool to differentiate causes of INS because diagnostic tests, such as electroretinography and optical coherence tomography, are not easily applicable in young infants. Accurate application of NGS using a standardized, stepwise, team-based approach in early childhood not only facilitated early molecular diagnosis but also led to improved personalized management in patients with INS.
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Affiliation(s)
- John Hoon Rim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Heon Yung Gee
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Byung Joo Lee
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hye Won Park
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Sueng-Han Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Jinu Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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99
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Benabdallah NS, Gautier P, Hekimoglu-Balkan B, Lettice LA, Bhatia S, Bickmore WA. SBE6: a novel long-range enhancer involved in driving sonic hedgehog expression in neural progenitor cells. Open Biol 2017; 6:rsob.160197. [PMID: 27852806 PMCID: PMC5133441 DOI: 10.1098/rsob.160197] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022] Open
Abstract
The expression of genes with key roles in development is under very tight spatial and temporal control, mediated by enhancers. A classic example of this is the sonic hedgehog gene (Shh), which plays a pivotal role in the proliferation, differentiation and survival of neural progenitor cells both in vivo and in vitro. Shh expression in the brain is tightly controlled by several known enhancers that have been identified through genetic, genomic and functional assays. Using chromatin profiling during the differentiation of embryonic stem cells to neural progenitor cells, here we report the identification of a novel long-range enhancer for Shh—Shh-brain-enhancer-6 (SBE6)—that is located 100 kb upstream of Shh and that is required for the proper induction of Shh expression during this differentiation programme. This element is capable of driving expression in the vertebrate brain. Our study illustrates how a chromatin-focused approach, coupled to in vivo testing, can be used to identify new cell-type specific cis-regulatory elements, and points to yet further complexity in the control of Shh expression during embryonic brain development.
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Affiliation(s)
- Nezha S Benabdallah
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.,Edinburgh Super Resolution Imaging Consortium (ESRIC), Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Philippe Gautier
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Betul Hekimoglu-Balkan
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Laura A Lettice
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Shipra Bhatia
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
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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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