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Gwack J, Kim N, Park J. Improving the Yield of Genetic Diagnosis through Additional Genetic Panel Testing in Hereditary Ophthalmic Diseases. Curr Issues Mol Biol 2024; 46:5010-5022. [PMID: 38785568 PMCID: PMC11119902 DOI: 10.3390/cimb46050300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024] Open
Abstract
Numerous hereditary ophthalmic diseases display significant genetic diversity. Consequently, the utilization of gene panel sequencing allows a greater number of patients to receive a genetic diagnosis for their clinical manifestations. We investigated how to improve the yield of genetic diagnosis through additional gene panel sequencing in hereditary ophthalmic diseases. A gene panel sequencing consisting of a customized hereditary retinopathy panel or hereditary retinitis pigmentosa (RP) panel was prescribed and referred to a CAP-accredited clinical laboratory. If no significant mutations associated with hereditary retinopathy and RP were detected in either panel, additional gene panel sequencing was requested for research use, utilizing the remaining panel. After additional gene panel sequencing, a total of 16 heterozygous or homozygous variants were identified in 15 different genes associated with hereditary ophthalmic diseases. Of 15 patients carrying any candidate variants, the clinical symptoms could be tentatively accounted for by genetic mutations in seven patients. However, in the remaining eight patients, given the in silico mutation predictive analysis, variant allele frequency in gnomAD, inheritance pattern, and genotype-phenotype correlation, fully elucidating the clinical manifestations with the identified rare variant was challenging. Our study highlights the utility of gene panel sequencing in achieving accurate diagnoses for hereditary ophthalmic diseases and enhancing the diagnostic yield through additional gene panel sequencing. Thus, gene panel sequencing can serve as a primary tool for the genetic diagnosis of hereditary ophthalmic diseases, even in cases where a single genetic cause is suspected. With a deeper comprehension of the genetic mechanisms underlying these diseases, it becomes feasible.
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Affiliation(s)
- Jin Gwack
- Department of Preventive Medicine, Jeonbuk National University Medical School, Jeonju 54907, Republic of Korea;
| | - Namsu Kim
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
| | - Joonhong Park
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
- Department of Laboratory Medicine, Daejeon St. Mary’s Hospital, Daejeon 34943, Republic of Korea
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Cheng YHH, Bohaczuk SC, Stergachis AB. Functional categorization of gene regulatory variants that cause Mendelian conditions. Hum Genet 2024; 143:559-605. [PMID: 38436667 PMCID: PMC11078748 DOI: 10.1007/s00439-023-02639-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 12/30/2023] [Indexed: 03/05/2024]
Abstract
Much of our current understanding of rare human diseases is driven by coding genetic variants. However, non-coding genetic variants play a pivotal role in numerous rare human diseases, resulting in diverse functional impacts ranging from altered gene regulation, splicing, and/or transcript stability. With the increasing use of genome sequencing in clinical practice, it is paramount to have a clear framework for understanding how non-coding genetic variants cause disease. To this end, we have synthesized the literature on hundreds of non-coding genetic variants that cause rare Mendelian conditions via the disruption of gene regulatory patterns and propose a functional classification system. Specifically, we have adapted the functional classification framework used for coding variants (i.e., loss-of-function, gain-of-function, and dominant-negative) to account for features unique to non-coding gene regulatory variants. We identify that non-coding gene regulatory variants can be split into three distinct categories by functional impact: (1) non-modular loss-of-expression (LOE) variants; (2) modular loss-of-expression (mLOE) variants; and (3) gain-of-ectopic-expression (GOE) variants. Whereas LOE variants have a direct corollary with coding loss-of-function variants, mLOE and GOE variants represent disease mechanisms that are largely unique to non-coding variants. These functional classifications aim to provide a unified terminology for categorizing the functional impact of non-coding variants that disrupt gene regulatory patterns in Mendelian conditions.
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Affiliation(s)
- Y H Hank Cheng
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Stephanie C Bohaczuk
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Andrew B Stergachis
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA.
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
- Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.
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3
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Sunny SS, Lachova J, Kasparek P, Palkova M, Spoutil F, Prochazka J, Sedlacek R, Liskova P, Kozmik Z. Ovol2 promoter mutations in mice and human illuminate species-specific phenotypic divergence. Hum Mol Genet 2024; 33:491-500. [PMID: 37971355 DOI: 10.1093/hmg/ddad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/06/2022] [Accepted: 11/09/2023] [Indexed: 11/19/2023] Open
Abstract
Pathogenic variants in the highly conserved OVOL2 promoter region cause posterior polymorphous corneal dystrophy (PPCD) 1 by inducing an ectopic expression of the endothelial OVOL2 mRNA. Here we produced an allelic series of Ovol2 promoter mutations in the mouse model including the heterozygous c.-307T>C variant (RefSeq NM_021220.4) causing PPCD1 in humans. Despite the high evolutionary conservation of the Ovol2 promoter, only some alterations of its sequence had phenotypic consequences in mice. Four independent sequence variants in the distal part of the Ovol2 promoter had no significant effect on endothelial Ovol2 mRNA level or caused any ocular phenotype. In contrast, the mutation c.-307T>C resulted in increased Ovol2 expression in the corneal endothelium. However, only a small fraction of adult mice c.-307T>C heterozygotes developed ocular phenotypes such as irido-corneal adhesions, and corneal opacity. Interestingly, phenotypic penetrance was increased at embryonic stages. Notably, c.-307T>C mutation is located next to the Ovol1/Ovol2 transcription factor binding site. Mice carrying an allele with a deletion encompassing the Ovol2 binding site c.-307_-320del showed significant Ovol2 gene upregulation in the cornea endothelium and exhibited phenotypes similar to the c.-307T>C mutation. In conclusion, although the mutations c.-307T>C and -307_-320del lead to a comparably strong increase in endothelial Ovol2 expression as seen in PPCD1 patients, endothelial dystrophy was not observed in the mouse model, implicating species-specific differences in endothelial cell biology. Nonetheless, the emergence of dominant ocular phenotypes associated with Ovol2 promoter variants in mice implies a potential role of this gene in eye development and disease.
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Affiliation(s)
- Sweetu Susan Sunny
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague 4, Prague, Czech Republic
| | - Jitka Lachova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague 4, Prague, Czech Republic
| | - Petr Kasparek
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, 513 Parnassus Avenue, CA 94158, San Francisco, United States
| | - Marcela Palkova
- Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Prumyslová 595, 252 50, Vestec, Czech Republic
| | - Frantisek Spoutil
- Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Prumyslová 595, 252 50, Vestec, Czech Republic
| | - Jan Prochazka
- Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Prumyslová 595, 252 50, Vestec, Czech Republic
| | - Radislav Sedlacek
- Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Prumyslová 595, 252 50, Vestec, Czech Republic
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 121 08, Prague 2, Prague Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, U Nemocnice 2, 128 08, Prague 2, Prague, Czech Republic
| | - Zbynek Kozmik
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague 4, Prague, Czech Republic
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Jiang Y, Zhang Z. OVOL2: an epithelial lineage determiner with emerging roles in energy homeostasis. Trends Cell Biol 2023; 33:824-833. [PMID: 37336658 PMCID: PMC10524639 DOI: 10.1016/j.tcb.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/21/2023]
Abstract
Ovo like zinc finger 2 (OVOL2) is an evolutionarily conserved regulator of epithelial lineage determination and differentiation during embryogenesis. OVOL2 binds to DNA using zinc-finger domains to suppress epithelial-mesenchymal transition (EMT), which is critical for tumor metastasis. However, recent studies have suggested some noncanonical roles of OVOL2 that do not rely on the DNA binding of zinc-finger domains or regulation of EMT. OVOL2 and EMT regulators have emerging roles in adipogenesis, thermogenesis, and lipid metabolism. Here, we review different roles of OVOL2 from embryo development to adult tissue homeostasis, and discuss how OVOL2 and other EMT regulators orchestrate a regulatory network to control energy homeostasis. Last, we propose potential applications of targeting OVOL2 to reduce human obesity.
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Affiliation(s)
- Yiao Jiang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Zhao Zhang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Heshmatzad K, Naderi N, Maleki M, Abbasi S, Ghasemi S, Ashrafi N, Fazelifar AF, Mahdavi M, Kalayinia S. Role of non-coding variants in cardiovascular disease. J Cell Mol Med 2023; 27:1621-1636. [PMID: 37183561 PMCID: PMC10273088 DOI: 10.1111/jcmm.17762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/29/2023] [Accepted: 04/25/2023] [Indexed: 05/16/2023] Open
Abstract
Cardiovascular diseases (CVDs) constitute one of the significant causes of death worldwide. Different pathological states are linked to CVDs, which despite interventions and treatments, still have poor prognoses. The genetic component, as a beneficial tool in the risk stratification of CVD development, plays a role in the pathogenesis of this group of diseases. The emergence of genome-wide association studies (GWAS) have led to the identification of non-coding parts associated with cardiovascular traits and disorders. Variants located in functional non-coding regions, including promoters/enhancers, introns, miRNAs and 5'/3' UTRs, account for 90% of all identified single-nucleotide polymorphisms associated with CVDs. Here, for the first time, we conducted a comprehensive review on the reported non-coding variants for different CVDs, including hypercholesterolemia, cardiomyopathies, congenital heart diseases, thoracic aortic aneurysms/dissections and coronary artery diseases. Additionally, we present the most commonly reported genes involved in each CVD. In total, 1469 non-coding variants constitute most reports on familial hypercholesterolemia, hypertrophic cardiomyopathy and dilated cardiomyopathy. The application and identification of non-coding variants are beneficial for the genetic diagnosis and better therapeutic management of CVDs.
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Affiliation(s)
- Katayoun Heshmatzad
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Niloofar Naderi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Majid Maleki
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Shiva Abbasi
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Serwa Ghasemi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Nooshin Ashrafi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Amir Farjam Fazelifar
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Mohammad Mahdavi
- Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research CenterIran University of Medical SciencesTehranIran
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Ye M, Lu Q, Zhao D, Zhao B, Zhang S, Liao Y, Liao R. New Endothelial Corneal Dystrophy in a Chinese Family. Cornea 2023; 42:529-535. [PMID: 36796013 PMCID: PMC10060041 DOI: 10.1097/ico.0000000000003209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/26/2022] [Accepted: 11/02/2022] [Indexed: 02/18/2023]
Abstract
PURPOSE The aim of this study was to characterize the clinical presentation of atypical endothelial corneal dystrophy (ECD) and to identify possible associated genetic variants in a Chinese family. METHODS Six affected members, 4 unaffected first-degree relatives, and 3 spouses who were enrolled in this study underwent ophthalmic examinations. Genetic linkage analysis was performed for 4 affected and 2 unaffected members, and whole-exome sequencing (WES) was performed for 2 patients to identify disease-causing variants. Candidate causal variants were verified using Sanger sequencing in family members and 200 healthy controls. RESULTS The mean age at disease onset was 16.5 years. The early phenotype of this atypical ECD was characterized by multiple small white translucent spots located in Descemet membrane of the peripheral cornea. These spots coalesced to form opacities with variable shapes, and eventually merged along the limbus. Subsequently, translucent spots appeared in central Descemet membrane and accumulated, causing diffuse polymorphous opacities over time. Finally, significant endothelial decompensation led to diffuse corneal edema. A heterozygous missense variant in the KIAA1522 gene (c.1331G>A; p.R444Q) was identified by WES, which was present in all 6 patients but was absent in the unaffected members and healthy controls. CONCLUSIONS The clinical features of atypical ECD are unique compared with those of known corneal dystrophies. Moreover, genetic analysis identified the c.1331G>A variant in KIAA1522 , which may be responsible for the pathogenesis of this atypical ECD. Thus, we propose this is a new form of ECD based on our clinical findings.
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Affiliation(s)
- Minjie Ye
- Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Qinyi Lu
- Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Duran Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Bingying Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Shengquan Zhang
- Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, China; and
| | - Yi Liao
- Eye Institute of Xiamen University, Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, School of Medicine, Xiamen University, Xiamen, China
| | - Rongfeng Liao
- Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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7
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Variant Landscape of 15 Genes Involved in Corneal Dystrophies: Report of 30 Families and Comprehensive Analysis of the Literature. Int J Mol Sci 2023; 24:ijms24055012. [PMID: 36902444 PMCID: PMC10003302 DOI: 10.3390/ijms24055012] [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: 12/26/2022] [Revised: 02/27/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
Corneal dystrophies (CDs) represent a group of inherited diseases characterized by the progressive deposit of abnormal materials in the cornea. This study aimed to describe the variant landscape of 15 genes responsible for CDs based on a cohort of Chinese families and a comparative analysis of literature reports. Families with CDs were recruited from our eye clinic. Their genomic DNA was analyzed using exome sequencing. The detected variants were filtered using multi-step bioinformatics and confirmed using Sanger sequencing. Previously reported variants in the literature were summarized and evaluated based on the gnomAD database and in-house exome data. In 30 of 37 families with CDs, 17 pathogenic or likely pathogenic variants were detected in 4 of the 15 genes, including TGFBI, CHST6, SLC4A11, and ZEB1. A comparative analysis of large datasets revealed that 12 of the 586 reported variants are unlikely causative of CDs in monogenic mode, accounting for 61 of 2933 families in the literature. Of the 15 genes, the gene most frequently implicated in CDs was TGFBI (1823/2902, 62.82% of families), followed by CHST6 (483/2902, 16.64%) and SLC4A11 (201/2902, 6.93%). This study presents, for the first time, the landscape of pathogenic and likely pathogenic variants in the 15 genes responsible for CDs. Awareness of frequently misinterpreted variants, such as c.1501C>A, p.(Pro501Thr) in TGFBI, is crucial in the era of genomic medicine.
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8
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Dias-Teixeira KL, Sharifian Gh M, Romano J, Norouzi F, Laurie GW. Autophagy in the normal and diseased cornea. Exp Eye Res 2022; 225:109274. [PMID: 36252655 PMCID: PMC10083687 DOI: 10.1016/j.exer.2022.109274] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 01/18/2023]
Abstract
The cornea and covering tear film are together the 'objective lens' of the eye through which 80% of light is refracted. Despite exposure to a physically harsh and at times infectious or toxic environment, transparency essential for sight is in most cases maintained. Such resiliency makes the avascular cornea a superb model for the exploration of autophagy in the regulation of homeostasis with relevancy to all organs. Nonetheless, missense mutations and inflammation respectively clog or apparently overwhelm autophagic flux to create dystrophies much like in neurodegenerative diseases or further exacerbate inflammation. Here there is opportunity to generate novel topical therapies towards the restoration of homeostasis with potential broad application.
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Affiliation(s)
| | | | - Jeff Romano
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Fatemeh Norouzi
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Gordon W Laurie
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA; Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA; Department of Ophthalmology, University of Virginia, Charlottesville, VA, USA.
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9
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Downes DJ, Hughes JR. Natural and Experimental Rewiring of Gene Regulatory Regions. Annu Rev Genomics Hum Genet 2022; 23:73-97. [PMID: 35472292 DOI: 10.1146/annurev-genom-112921-010715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The successful development and ongoing functioning of complex organisms depend on the faithful execution of the genetic code. A critical step in this process is the correct spatial and temporal expression of genes. The highly orchestrated transcription of genes is controlled primarily by cis-regulatory elements: promoters, enhancers, and insulators. The medical importance of this key biological process can be seen by the frequency with which mutations and inherited variants that alter cis-regulatory elements lead to monogenic and complex diseases and cancer. Here, we provide an overview of the methods available to characterize and perturb gene regulatory circuits. We then highlight mechanisms through which regulatory rewiring contributes to disease, and conclude with a perspective on how our understanding of gene regulation can be used to improve human health.
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Affiliation(s)
- Damien J Downes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom;
| | - Jim R Hughes
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom;
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom;
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Skalicka P, Jedlickova J, Horinek A, Trkova M, Davidson AE, Tuft SJ, Dudakova L, Liskova P. Snail Track Lesion with Flat Keratometry in Anterior Segment Dysgenesis Caused by a Novel FOXC1 Variant. J Clin Med 2022; 11:jcm11175166. [PMID: 36079096 PMCID: PMC9457150 DOI: 10.3390/jcm11175166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
We report the phenotype of a 15-year-old female patient with anterior segment dysgenesis (ASD) caused by a novel heterozygous loss-of-function FOXC1 variant. The proband underwent an ophthalmic examination as well as a molecular genetic investigation comprising exome sequencing, a single nucleotide polymorphism array to access copy number and Sanger sequencing to exclude non-coding causal variants. There was bilateral mild iris hypoplasia with pupil deformation and iridocorneal adhesions. In addition to these features of ASD, the corneas were flat, with mean keratometry readings of 38.8 diopters in the right eye and 39.5 diopters in the left eye. There was a snail track lesion of the left cornea at the level of the Descemet membrane. The central corneal endothelial cell density was reduced bilaterally at 1964 and 1373 cells/mm2 in the right and left eyes, respectively. Molecular genetic analysis revealed that the proband was a carrier of a novel heterozygous frameshifting variant in FOXC1, c.605del p.(Pro202Argfs*113). Neither parent had this change, suggesting a de novo origin which was supported by paternity testing. We found no possibly pathogenic variants in the other genes associated with posterior corneal dystrophies or ASD. Further studies are warranted to verify whether there is a true association between snail track lesions, corneal flattening, and pathogenic variants in FOXC1.
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Affiliation(s)
- Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Ales Horinek
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | | | | | - Stephen J. Tuft
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Correspondence: ; Tel.: +420-224-967-139
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11
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Kannabiran C, Chaurasia S, Ramappa M, Mootha VV. Update on the genetics of corneal endothelial dystrophies. Indian J Ophthalmol 2022; 70:2239-2248. [PMID: 35791103 PMCID: PMC9426112 DOI: 10.4103/ijo.ijo_992_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Corneal endothelial dystrophies are a heterogeneous group of diseases with different modes of inheritance and genetic basis for each dystrophy. The genes associated with these diseases encode transcription factors, structural components of the stroma and Descemet membrane, cell transport proteins, and others. Congenital hereditary endothelial dystrophy (CHED) is associated with mutations in two genes, OVOL2 and SLC4A11, for dominant and recessive forms of CHED, respectively. Mutations in three genes are known to cause posterior polymorphous corneal dystrophy (PPCD). They are OVOL2 (PPCD1), ZEB1 (PPCD3), and GRHL1 (PPCD4). The PPCD2 locus involving the collagen gene COL8A2 on chromosome 1 is disputed due to insufficient evidence. Mutations in the COL8A2 gene are associated with early-onset Fuchs’ endothelial corneal dystrophy (FECD). Several genes have been associated with the more common, late-onset FECD. Alterations in each of these genes occur in a fraction of patients, and the most prevalent genetic alteration in FECD patients across the world is a triplet repeat expansion in the TCF4 gene. Knowledge of the genetics of corneal endothelial dystrophies has considerably advanced within the last decade and has contributed to better diagnosis of these dystrophies as well as opened up the possibility of novel therapeutic approaches based on the molecular mechanisms involved. The functions of genes identified to date provide insights into the pathogenic mechanisms involved in each disorder.
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Affiliation(s)
- Chitra Kannabiran
- Kallam Anji Reddy Molecular Genetics Laboratory, Prof Brien Holden Eye Research Centre, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sunita Chaurasia
- Centre for Rare Eye Diseases and Ocular Genetics; The Cornea Institute; Jasti V Ramanamma Children's Eye Care Center, L.V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
| | - Muralidhar Ramappa
- Centre for Rare Eye Diseases and Ocular Genetics; The Cornea Institute; Jasti V Ramanamma Children's Eye Care Center, L.V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India
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12
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Muijzer MB, Kroes HY, Hasselt PM, Wisse RPL. Bilateral posterior lamellar corneal transplant surgery in an infant of 17 weeks old: Surgical challenges and the added value of intraoperative optical coherence tomography. Clin Case Rep 2022; 10:e05637. [PMID: 35387289 PMCID: PMC8978779 DOI: 10.1002/ccr3.5637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/04/2022] [Accepted: 03/07/2022] [Indexed: 11/09/2022] Open
Abstract
This study aimed to describe the surgical challenges, management, and value of intraoperative optical coherence tomography in a case of a bilateral Descemet Stripping Automated Endothelial Keratoplasty corneal transplantation at 17 weeks of age for the treatment of severe posterior polymorphous corneal dystrophy resulting from a de novo mutation of the OVOL2‐gene.
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Affiliation(s)
- Marc B. Muijzer
- Department of Ophthalmology University Medical Center Utrecht Utrecht The Netherlands
| | - Hester Y. Kroes
- Department of Clinical Genetics Wilhelmina Children’s Hospital University Medical Center Utrecht Utrecht The Netherlands
| | - Peter M. Hasselt
- Department of Metabolic Diseases Wilhelmina Children’s Hospital University Medical Center Utrecht Utrecht The Netherlands
| | - Robert P. L. Wisse
- Department of Ophthalmology University Medical Center Utrecht Utrecht The Netherlands
- Department of Ophthalmology Wilhelmina Children’s Hospital University Medical Center Utrecht Utrecht The Netherlands
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Liskova P, Hafford‐Tear NJ, Skalicka P, Malinka F, Jedlickova J, Ďuďáková Ľ, Pontikos N, Davidson AE, Tuft S. Posterior corneal vesicles are not associated with the genetic variants that cause posterior polymorphous corneal dystrophy. Acta Ophthalmol 2022; 100:e1426-e1430. [PMID: 35174971 DOI: 10.1111/aos.15114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/04/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE Posterior corneal vesicles (PCVs) have clinical features that are similar to posterior polymorphous corneal dystrophy (PPCD). To help determine whether there is a shared genetic basis, we screened 38 individuals with PCVs for changes in the three genes identified as causative for PPCD. METHODS We prospectively recruited patients for this study. We examined all individuals clinically, with their first-degree relatives when available. We used a combination of Sanger and exome sequencing to screen regulatory regions of OVOL2 and GRHL2, and the entire ZEB1 coding sequence. RESULTS The median age at examination was 37.5 years (range 4.7-84.0 years), 20 (53%) were male and in 19 (50%) the PCVs were unilateral. Most individuals were discharged to optometric review, but five had follow-up for a median of 12 years (range 5-13 years) with no evidence of progression. In cases with unilateral PCVs, there was statistically significant evidence that the change in the affected eye was associated with a lower endothelial cell density (p = 0.0003), greater central corneal thickness (p = 0.0277) and a steeper mean keratometry (p = 0.0034), but not with a higher keratometric astigmatism or a reduced LogMAR visual acuity. First-degree relatives of 13 individuals were available for examination, and in 3 (23%), PCVs were identified. No possibly pathogenic variants were identified in the PPCD-associated genes screened. CONCLUSION We found no evidence that PCVs share the same genetic background as PPCD. In contrast to PPCD, we confirm that PCVs is a mild, non-progressive condition with no requirement for long-term review. However, subsequent cataract surgery can lead to corneal oedema.
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Affiliation(s)
- Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
- Department of Ophthalmology, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | | | - Pavlina Skalicka
- Department of Ophthalmology, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Frantisek Malinka
- Department of Paediatrics and Inherited Metabolic Disorders First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
- Department of Computer Science Czech Technical University in Prague Prague Czech Republic
| | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | - Ľubica Ďuďáková
- Department of Paediatrics and Inherited Metabolic Disorders First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
| | | | | | - Stephen Tuft
- UCL Institute of Ophthalmology London UK
- Moorfields Eye Hospital London UK
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14
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Sbihi Z, Tanita K, Bachelet C, Bole C, Jabot-Hanin F, Tores F, Le Loch M, Khodr R, Hoshino A, Lenoir C, Oleastro M, Villa M, Spossito L, Prieto E, Danielian S, Brunet E, Picard C, Taga T, Abdrabou SSMA, Isoda T, Yamada M, Palma A, Kanegane H, Latour S. Identification of Germline Non-coding Deletions in XIAP Gene Causing XIAP Deficiency Reveals a Key Promoter Sequence. J Clin Immunol 2022; 42:559-571. [PMID: 35000057 DOI: 10.1007/s10875-021-01188-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/21/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE X-linked inhibitor of apoptosis protein (XIAP) deficiency, also known as the X-linked lymphoproliferative syndrome of type 2 (XLP-2), is a rare immunodeficiency characterized by recurrent hemophagocytic lymphohistiocytosis, splenomegaly, and inflammatory bowel disease. Variants in XIAP including missense, non-sense, frameshift, and deletions of coding exons have been reported to cause XIAP deficiency. We studied three young boys with immunodeficiency displaying XLP-2-like clinical features. No genetic variation in the coding exons of XIAP was identified by whole-exome sequencing (WES), although the patients exhibited a complete loss of XIAP expression. METHODS Targeted next-generation sequencing (NGS) of the entire locus of XIAP was performed on DNA samples from the three patients. Molecular investigations were assessed by gene reporter expression assays in HEK cells and CRISPR-Cas9 genome editing in primary T cells. RESULTS NGS of XIAP identified three distinct non-coding deletions in the patients that were predicted to be driven by repetitive DNA sequences. These deletions share a common region of 839 bp that encompassed the first non-coding exon of XIAP and contained regulatory elements and marks specific of an active promoter. Moreover, we showed that among the 839 bp, the exon was transcriptionally active. Finally, deletion of the exon by CRISPR-Cas9 in primary cells reduced XIAP protein expression. CONCLUSIONS These results identify a key promoter sequence contained in the first non-coding exon of XIAP. Importantly, this study highlights that sequencing of the non-coding exons that are not currently captured by WES should be considered in the genetic diagnosis when no variation is found in coding exons.
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Affiliation(s)
- Zineb Sbihi
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France
| | - Kay Tanita
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Camille Bachelet
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France.,Université de Paris, Paris, France
| | - Christine Bole
- Genomics Core Facility, Institut Imagine-Structure Fédérative de Recherche Necker, INSERM UMR 1163, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | - Fabienne Jabot-Hanin
- Genomics Core Facility, Institut Imagine-Structure Fédérative de Recherche Necker, INSERM UMR 1163, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France.,Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
| | - Frederic Tores
- Genomics Core Facility, Institut Imagine-Structure Fédérative de Recherche Necker, INSERM UMR 1163, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France.,Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
| | - Marc Le Loch
- Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, Paris, France
| | - Radi Khodr
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France
| | - Akihiro Hoshino
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France
| | - Christelle Lenoir
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France
| | - Matias Oleastro
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Mariana Villa
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Lucia Spossito
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Emma Prieto
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Silvia Danielian
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Erika Brunet
- Laboratory of Dynamic of Genome and Immune System, INSERM UMR 1163, Imagine Institute, Paris, France
| | - Capucine Picard
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France.,Université de Paris, Paris, France.,Study Center for Primary Immunodeficiencies, Necker-Enfants Malades Hospital, APHP, Paris, France
| | - Takashi Taga
- Department of Pediatrics, Shiga University of Medical Science, Otsu, Japan
| | | | - Takeshi Isoda
- Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Masafumi Yamada
- Department of Pediatrics, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Alejandro Palma
- Immunology and Rheumatology Division, Hospital de Pediatria S.A.M.I.C. Prof. Dr. Juan P. Garrahan, Buenos Aires, Argentina
| | - Hirokazu Kanegane
- Department of Child Health and Development, Graduate School of Medical and Dental Sciences, TMDU, Tokyo, Japan
| | - Sylvain Latour
- Laboratory of Lymphocyte Activation and Susceptibility to EBV Infection, INSERM UMR 1163, Imagine Institute, Paris, France. .,Université de Paris, Paris, France.
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15
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Overview of Congenital Corneal Opacities: Clinical Diagnosis, Treatment, and Prognosis. Int Ophthalmol Clin 2022; 62:1-13. [PMID: 34965222 DOI: 10.1097/iio.0000000000000395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Dudakova L, Skalicka P, Davidson AE, Sadan AN, Chylova M, Jahnova H, Anteneova N, Tesarova M, Honzik T, Liskova P. Should Patients with Kearns-Sayre Syndrome and Corneal Endothelial Failure Be Genotyped for a TCF4 Trinucleotide Repeat, Commonly Associated with Fuchs Endothelial Corneal Dystrophy? Genes (Basel) 2021; 12:genes12121918. [PMID: 34946867 PMCID: PMC8702069 DOI: 10.3390/genes12121918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/23/2021] [Accepted: 11/28/2021] [Indexed: 11/29/2022] Open
Abstract
The aim of this study was to describe the ocular phenotype in a case with Kearns-Sayre syndrome (KSS) spectrum and to determine if corneal endothelial cell dysfunction could be attributed to other known distinct genetic causes. Herein, genomic DNA was extracted from blood and exome sequencing was performed. Non-coding gene regions implicated in corneal endothelial dystrophies were screened by Sanger sequencing. In addition, a repeat expansion situated within an intron of TCF4 (termed CTG18.1) was genotyped using the short tandem repeat assay. The diagnosis of KSS spectrum was based on the presence of ptosis, chronic progressive external ophthalmoplegia, pigmentary retinopathy, hearing loss, and muscle weakness, which were further supported by the detection of ~6.5 kb mtDNA deletion. At the age of 33 years, the proband’s best corrected visual acuity was reduced to 0.04 in the right eye and 0.2 in the left eye. Rare ocular findings included marked corneal oedema with central corneal thickness of 824 and 844 µm in the right and left eye, respectively. No pathogenic variants in the genes, which are associated with corneal endothelial dystrophies, were identified. Furthermore, the CTG18.1 genotype was 12/33, which exceeds a previously determined critical threshold for toxic RNA foci appearance in corneal endothelial cells.
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Affiliation(s)
- Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Alice E. Davidson
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
- Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Amanda N. Sadan
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
| | - Monika Chylova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Helena Jahnova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Nicole Anteneova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Marketa Tesarova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Tomas Honzik
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (L.D.); (P.S.); (M.C.); (H.J.); (N.A.); (M.T.); (T.H.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.E.D.); (A.N.S.)
- Correspondence: ; Tel.: +420-224-967-139
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17
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Posterior Polymorphous Corneal Dystrophy in a Pediatric Population. Cornea 2021; 41:734-739. [PMID: 34469341 DOI: 10.1097/ico.0000000000002847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/22/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to evaluate the clinical and topographic features of posterior polymorphous corneal dystrophy (PPCD) in children aged 15 years or younger with a long-term follow-up. Retrospective case series. METHODS A retrospective chart review of patients who were diagnosed with PPCD at Boston Children's Hospital from 1999 to 2020 was performed. Data collected included age at the time of diagnosis, slit lamp findings, cycloplegic refraction, best-corrected visual acuity, central corneal thickness, specular microscopy, and corneal topography findings whenever available. RESULTS Twenty-seven eyes of 19 patients were included (11 unilateral and 8 bilateral cases). Ten patients were girls (52.6%). Left eye was affected in 14 eyes. The mean age at the time of diagnosis was 8.5 ± 3.3 years, with a mean follow-up of 5.3 years. In unilateral cases, there was a statistically significant difference in the endothelial cell density (P = 0.01), coefficient variation (P = 0.03), and hexagonality (P = 0.01) between the affected and the contralateral unaffected eyes. The mean best-corrected visual acuity at initial presentation was 0.8 ± 0.2 compared with 0.9 ± 0.08 in unaffected eyes (P = 0.04). The mean astigmatism was higher in the affected eye (+1.7 diopters) compared with (+1.00) the unaffected eye (P = 0.07). At initial presentation, 7 of 27 eyes had amblyopia, which resolved, either partially or completely, in 5 eyes after treatment. CONCLUSIONS PPCD can present early in children with astigmatism and anisometropic amblyopia. A careful slit lamp examination for children presenting with anisoastigmatism is necessary to diagnose PPCD. Contrary to adults, presentation is often unilateral. Such patients should be followed up regularly with cycloplegic retinoscopy to prevent and treat refractive amblyopia if present.
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18
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c.-61G>A in OVOL2 is a Pathogenic 5' Untranslated Region Variant Causing Posterior Polymorphous Corneal Dystrophy 1. Cornea 2021; 41:89-94. [PMID: 34469340 DOI: 10.1097/ico.0000000000002843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 06/07/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this study was to investigate the clinical and genetic features of a man and his daughter with posterior polymorphous corneal dystrophy (PPCD), referred to our clinic for Descemet membrane endothelial keratoplasty. No other known relatives were affected. METHODS Ophthalmic examination and histology, including electron microscopy, were performed. Genetic testing was conducted by means of whole exome sequencing, and variant analysis was achieved by using an internal in silico pipeline. Molecular tests included a dual-luciferase assay. RESULTS Slowly progressive blurred vision was reported from childhood by the daughter. The father's symptoms started at age 55. Best-corrected visual acuity was reduced in both patients (0.2-0.4). Slit-lamp examination in both patients revealed bilateral corneal clouding with gray endothelial lesions; other family members had no ophthalmological signs. Descemet membrane endothelial keratoplasty was performed uneventfully in both patients. Histology showed thickened Descemet membrane and abnormal endothelium resembling epithelial-like cells. Both patients carried the OVOL2 5' untranslated region NM_021220.4.c.-61G>A variant in the heterozygous state. This change was associated with increased promoter activity and was not present in the unaffected members of the family. CONCLUSIONS The 5' untranslated region mutation c.-61G>A in OVOL2 has been previously found in 1 individual with PPCD1 and reported as a variant of unknown significance because of insufficient evidence supporting its pathogenicity. Identification of the second family with 2 individuals affected by PPCD1 carrying this change, together with functional data, provides further proofs that it is disease-causing.
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19
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Roos D, de Boer M. Mutations in cis that affect mRNA synthesis, processing and translation. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166166. [PMID: 33971252 DOI: 10.1016/j.bbadis.2021.166166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022]
Abstract
Genetic mutations that cause hereditary diseases usually affect the composition of the transcribed mRNA and its encoded protein, leading to instability of the mRNA and/or the protein. Sometimes, however, such mutations affect the synthesis, the processing or the translation of the mRNA, with similar disastrous effects. We here present an overview of mRNA synthesis, its posttranscriptional modification and its translation into protein. We then indicate which elements in these processes are known to be affected by pathogenic mutations, but we restrict our review to mutations in cis, in the DNA of the gene that encodes the affected protein. These mutations can be in enhancer or promoter regions of the gene, which act as binding sites for transcription factors involved in pre-mRNA synthesis. We also describe mutations in polyadenylation sequences and in splice site regions, exonic and intronic, involved in intron removal. Finally, we include mutations in the Kozak sequence in mRNA, which is involved in protein synthesis. We provide examples of genetic diseases caused by mutations in these DNA regions and refer to databases to help identify these regions. The over-all knowledge of mRNA synthesis, processing and translation is essential for improvement of the diagnosis of patients with genetic diseases.
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Affiliation(s)
- Dirk Roos
- Sanquin Blood Supply Organization, Dept. of Blood Cell Research, Landsteiner Laboratory, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Amsterdam, the Netherlands.
| | - Martin de Boer
- Sanquin Blood Supply Organization, Dept. of Blood Cell Research, Landsteiner Laboratory, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Amsterdam, the Netherlands
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20
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Dudakova L, Stranecky V, Piherova L, Palecek T, Pontikos N, Kmoch S, Skalicka P, Vaneckova M, Davidson AE, Liskova P. Non-Penetrance for Ocular Phenotype in Two Individuals Carrying Heterozygous Loss-of-Function ZEB1 Alleles. Genes (Basel) 2021; 12:genes12050677. [PMID: 33946386 PMCID: PMC8146820 DOI: 10.3390/genes12050677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/13/2021] [Accepted: 04/28/2021] [Indexed: 01/16/2023] Open
Abstract
ZEB1 loss-of-function (LoF) alleles are known to cause a rare autosomal dominant disorder—posterior polymorphous corneal dystrophy type 3 (PPCD3). To date, 50 pathogenic LoF variants have been identified as disease-causing and familial studies have indicated that the PPCD3 phenotype is penetrant in approximately 95% of carriers. In this study, we interrogated in-house exomes (n = 3616) and genomes (n = 88) for the presence of putative heterozygous LoF variants in ZEB1. Next, we performed detailed phenotyping in a father and his son who carried a novel LoF c.1279C>T; p.(Glu427*) variant in ZEB1 (NM_030751.6) absent from the gnomAD v.2.1.1 dataset. Ocular examination of the two subjects did not show any abnormalities characteristic of PPCD3. GnomAD (n = 141,456 subjects) was also interrogated for LoF ZEB1 variants, notably 8 distinct heterozygous changes presumed to lead to ZEB1 haploinsufficiency, not reported to be associated with PPCD3, have been identified. The NM_030751.6 transcript has a pLI score ≥ 0.99, indicating extreme intolerance to haploinsufficiency. In conclusion, ZEB1 LoF variants are present in a general population at an extremely low frequency. As PPCD3 can be asymptomatic, the true penetrance of ZEB1 LoF variants remains currently unknown but is likely to be lower than estimated by the familial led approaches adopted to date.
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Affiliation(s)
- Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
| | - Viktor Stranecky
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
| | - Lenka Piherova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
| | - Tomas Palecek
- Second Department of Medicine—Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, 128 08 Prague, Czech Republic;
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (N.P.); (A.E.D.)
| | - Stanislav Kmoch
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
| | - Pavlina Skalicka
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, 128 08 Prague, Czech Republic
| | - Manuela Vaneckova
- Department of Radiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Katerinska 30, 128 08 Prague, Czech Republic;
| | - Alice E. Davidson
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (N.P.); (A.E.D.)
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08 Prague, Czech Republic; (L.D.); (V.S.); (L.P.); (S.K.); (P.S.)
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (N.P.); (A.E.D.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, 128 08 Prague, Czech Republic
- Correspondence: ; Tel.: +420-22496-7139
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21
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Al Hayek S, Alsawadi A, Kambris Z, Boquete JP, Bohère J, Immarigeon C, Ronsin B, Plaza S, Lemaitre B, Payre F, Osman D. Steroid-dependent switch of OvoL/Shavenbaby controls self-renewal versus differentiation of intestinal stem cells. EMBO J 2021; 40:e104347. [PMID: 33372708 PMCID: PMC7883054 DOI: 10.15252/embj.2019104347] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/27/2022] Open
Abstract
Adult stem cells must continuously fine-tune their behavior to regenerate damaged organs and avoid tumors. While several signaling pathways are well known to regulate somatic stem cells, the underlying mechanisms remain largely unexplored. Here, we demonstrate a cell-intrinsic role for the OvoL family transcription factor, Shavenbaby (Svb), in balancing self-renewal and differentiation of Drosophila intestinal stem cells. We find that svb is a downstream target of Wnt and EGFR pathways, mediating their activity for stem cell survival and proliferation. This requires post-translational processing of Svb into a transcriptional activator, whose upregulation induces tumor-like stem cell hyperproliferation. In contrast, the unprocessed form of Svb acts as a repressor that imposes differentiation into enterocytes, and suppresses tumors induced by altered signaling. We show that the switch between Svb repressor and activator is triggered in response to systemic steroid hormone, which is produced by ovaries. Therefore, the Svb axis allows intrinsic integration of local signaling cues and inter-organ communication to adjust stem cell proliferation versus differentiation, suggesting a broad role of OvoL/Svb in adult and cancer stem cells.
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Affiliation(s)
- Sandy Al Hayek
- Faculty of Sciences III, Lebanese University, Tripoli, Lebanon.,Azm Center for Research in Biotechnology and its Applications, LBA3B, EDST, Lebanese University, Tripoli, Lebanon.,Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Ahmad Alsawadi
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Zakaria Kambris
- Biology Department, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
| | | | - Jérôme Bohère
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Clément Immarigeon
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Brice Ronsin
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Serge Plaza
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, Lausanne, Switzerland
| | - François Payre
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Toulouse, France
| | - Dani Osman
- Faculty of Sciences III, Lebanese University, Tripoli, Lebanon.,Azm Center for Research in Biotechnology and its Applications, LBA3B, EDST, Lebanese University, Tripoli, Lebanon
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22
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Diseases of the corneal endothelium. Exp Eye Res 2021; 205:108495. [PMID: 33596440 DOI: 10.1016/j.exer.2021.108495] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/17/2022]
Abstract
The corneal endothelial monolayer and associated Descemet's membrane (DM) complex is a unique structure that plays an essential role in corneal function. Endothelial cells are neural crest derived cells that rest on a special extracellular matrix and play a major role in maintaining stromal hydration within a narrow physiologic range necessary for clear vision. A number of diseases affect the endothelial cells and DM complex and can impair corneal function and vision. This review addresses different human corneal endothelial diseases characterized by loss of endothelial function including: Fuchs endothelial corneal dystrophy (FECD), posterior polymorphous corneal dystrophy (PPCD), congenital hereditary endothelial dystrophy (CHED), bullous keratopathy, iridocorneal endothelial (ICE) syndrome, post-traumatic fibrous downgrowth, glaucoma and diabetes mellitus.
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23
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Genetics vs chronic corneal mechanical trauma in the etiology of keratoconus. Exp Eye Res 2020; 202:108328. [PMID: 33172608 DOI: 10.1016/j.exer.2020.108328] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/17/2020] [Accepted: 10/20/2020] [Indexed: 12/20/2022]
Abstract
Both genetic and environmental factors have been considered to play a role in the etiology keratoconus. Eye rubbing, and more recently eye compression due to sleeping position, have been identified to be highly related to the condition, and are present in a high percentage of patients. Today, the predominant model is that these factors can provide the "second hit" necessary to generate the condition in a genetically susceptible individual. In addition, the extremely high prevalence in Arab populations, where endogamy could play a role, the high concordance rate in monozygotic twins, and the presence of family history of the condition between 5 and 23% of cases, support a genetic influence. Segregation analysis studies suggest that keratoconus is a complex non-Mendelian disease. Results from linkage analysis, next generation sequencing studies and genome-wide association studies also have suggested that genetic factors are involved in the condition. Recently, it has been proposed that mechanical trauma (i.e. eye rubbing or eye compression at night), is a sine quanon condition for the onset of keratoconus, and quite possibly its only cause. There are various arguments for and against this hypothesis. Indeed, it is possible, as initially suggested around 55 years ago, that the term "keratoconus" include diverse phenotypically similar conditions, which are actually of different etiology.
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24
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Hitti-Malin RJ, Burmeister LM, Ricketts SL, Lewis TW, Pettitt L, Boursnell M, Schofield EC, Sargan D, Mellersh CS. A LINE-1 insertion situated in the promoter of IMPG2 is associated with autosomal recessive progressive retinal atrophy in Lhasa Apso dogs. BMC Genet 2020; 21:100. [PMID: 32894063 PMCID: PMC7487703 DOI: 10.1186/s12863-020-00911-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 08/30/2020] [Indexed: 12/30/2022] Open
Abstract
Background Canine progressive retinal atrophies are a group of hereditary retinal degenerations in dogs characterised by depletion of photoreceptor cells in the retina, which ultimately leads to blindness. PRA in the Lhasa Apso (LA) dog has not previously been clinically characterised or described in the literature, but owners in the UK are advised to have their dog examined through the British Veterinary Association/ Kennel Club/ International Sheep Dog Society (BVA/KC/ISDS) eye scheme annually, and similar schemes that are in operation in other countries. After the exclusion of 25 previously reported canine retinal mutations in LA PRA-affected dogs, we sought to identify the genetic cause of PRA in this breed. Results Analysis of whole-exome sequencing data of three PRA-affected LA and three LA without signs of PRA did not identify any exonic or splice site variants, suggesting the causal variant was non-exonic. We subsequently undertook a genome-wide association study (GWAS), which identified a 1.3 Mb disease-associated region on canine chromosome 33, followed by whole-genome sequencing analysis that revealed a long interspersed element-1 (LINE-1) insertion upstream of the IMPG2 gene. IMPG2 has previously been implicated in human retinal disease; however, until now no canine PRAs have been associated with this gene. The identification of this PRA-associated variant has enabled the development of a DNA test for this form of PRA in the breed, here termed PRA4 to distinguish it from other forms of PRA described in other breeds. This test has been used to determine the genotypes of over 900 LA dogs. A large cohort of genotyped dogs was used to estimate the allele frequency as between 0.07–0.1 in the UK LA population. Conclusions Through the use of GWAS and subsequent sequencing of a PRA case, we have identified a LINE-1 insertion in the retinal candidate gene IMPG2 that is associated with a form of PRA in the LA dog. Validation of this variant in 447 dogs of 123 breeds determined it was private to LA dogs. We envisage that, over time, the developed DNA test will offer breeders the opportunity to avoid producing dogs affected with this form of PRA.
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Affiliation(s)
- Rebekkah J Hitti-Malin
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK. .,Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK.
| | - Louise M Burmeister
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
| | - Sally L Ricketts
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
| | - Thomas W Lewis
- The Kennel Club, London, W1J 8AB, UK.,School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Leicestershire, LE12 5RD, UK
| | - Louise Pettitt
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
| | - Mike Boursnell
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
| | - Ellen C Schofield
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
| | - David Sargan
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK
| | - Cathryn S Mellersh
- Kennel Club Genetics Centre, Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UU, UK
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25
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The Role of Noncoding Variants in Heritable Disease. Trends Genet 2020; 36:880-891. [PMID: 32741549 DOI: 10.1016/j.tig.2020.07.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/26/2022]
Abstract
The genetic basis of disease has largely focused on coding regions. However, it has become clear that a large proportion of the noncoding genome is functional and harbors genetic variants that contribute to disease etiology. Here, we review recent examples of inherited noncoding alterations that are responsible for Mendelian disorders or act to influence complex traits. We explore both rare and common genetic variants and discuss the wide range of mechanisms by which they affect gene regulation to promote disease. We also debate the challenges and progress associated with identifying and interpreting the functional and clinical significance of genetic variation in the context of the noncoding regulatory landscape.
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26
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Fautsch MP, Wieben ED, Baratz KH, Bhattacharyya N, Sadan AN, Hafford-Tear NJ, Tuft SJ, Davidson AE. TCF4-mediated Fuchs endothelial corneal dystrophy: Insights into a common trinucleotide repeat-associated disease. Prog Retin Eye Res 2020; 81:100883. [PMID: 32735996 PMCID: PMC7988464 DOI: 10.1016/j.preteyeres.2020.100883] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/24/2020] [Accepted: 07/04/2020] [Indexed: 12/13/2022]
Abstract
Fuchs endothelial corneal dystrophy (FECD) is a common cause for heritable visual loss in the elderly. Since the first description of an association between FECD and common polymorphisms situated within the transcription factor 4 (TCF4) gene, genetic and molecular studies have implicated an intronic CTG trinucleotide repeat (CTG18.1) expansion as a causal variant in the majority of FECD patients. To date, several non-mutually exclusive mechanisms have been proposed that drive and/or exacerbate the onset of disease. These mechanisms include (i) TCF4 dysregulation; (ii) toxic gain-of-function from TCF4 repeat-containing RNA; (iii) toxic gain-of-function from repeat-associated non-AUG dependent (RAN) translation; and (iv) somatic instability of CTG18.1. However, the relative contribution of these proposed mechanisms in disease pathogenesis is currently unknown. In this review, we summarise research implicating the repeat expansion in disease pathogenesis, define the phenotype-genotype correlations between FECD and CTG18.1 expansion, and provide an update on research tools that are available to study FECD as a trinucleotide repeat expansion disease. Furthermore, ongoing international research efforts to develop novel CTG18.1 expansion-mediated FECD therapeutics are highlighted and we provide a forward-thinking perspective on key unanswered questions that remain in the field. FECD is a common, age-related corneal dystrophy. The majority of cases are associated with expansion of a CTG repeat (CTG18.1). FECD is the most common trinucleotide repeat expansion disease in humans. Evidence supports multiple molecular mechanisms underlying the pathophysiology. Novel CTG18.1-targeted therapeutics are in development.
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Affiliation(s)
- Michael P Fautsch
- Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Eric D Wieben
- Department of Biochemistry and Molecular Biology, 200 1st St SW, Mayo Clinic, Rochester, MN, USA.
| | - Keith H Baratz
- Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA.
| | | | - Amanda N Sadan
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK.
| | | | - Stephen J Tuft
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK; Moorfields Eye Hospital, London, EC1V 2PD, UK.
| | - Alice E Davidson
- University College London Institute of Ophthalmology, London, ECIV 9EL, UK.
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27
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Soh YQ, Kocaba V, Weiss JS, Jurkunas UV, Kinoshita S, Aldave AJ, Mehta JS. Corneal dystrophies. Nat Rev Dis Primers 2020; 6:46. [PMID: 32528047 DOI: 10.1038/s41572-020-0178-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/24/2020] [Indexed: 12/21/2022]
Abstract
Corneal dystrophies are broadly defined as inherited disorders that affect any layer of the cornea and are usually progressive, bilateral conditions that do not have systemic effects. The 2015 International Classification of Corneal Dystrophies classifies corneal dystrophies into four classes: epithelial and subepithelial dystrophies, epithelial-stromal TGFBI dystrophies, stromal dystrophies and endothelial dystrophies. Whereas some corneal dystrophies may result in few or mild symptoms and morbidity throughout a patient's lifetime, others may progress and eventually result in substantial visual and ocular disturbances that require medical or surgical intervention. Corneal transplantation, either with full-thickness or partial-thickness donor tissue, may be indicated for patients with advanced corneal dystrophies. Although corneal transplantation techniques have improved considerably over the past two decades, these surgeries are still associated with postoperative risks of disease recurrence, graft failure and other complications that may result in blindness. In addition, a global shortage of cadaveric corneal graft tissue critically limits accessibility to corneal transplantation in some parts of the world. Ongoing advances in gene therapy, regenerative therapy and cell augmentation therapy may eventually result in the development of alternative, novel treatments for corneal dystrophies, which may substantially improve the quality of life of patients with these disorders.
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Affiliation(s)
- Yu Qiang Soh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Viridiana Kocaba
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands
| | - Jayne S Weiss
- Department of Ophthalmology, Pathology and Pharmacology, Louisiana State University, School of Medicine, New Orleans, USA
| | - Ula V Jurkunas
- Cornea and Refractive Surgery Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.,Schepens Eye Research Institute, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shigeru Kinoshita
- Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Anthony J Aldave
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore. .,Singapore National Eye Centre, Singapore, Singapore. .,Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore, Singapore. .,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
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28
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Nicklason E, Mack H, Beltz J, Jacob J, Farahani M, Colville D, Savige J. Corneal endothelial cell abnormalities in X-linked Alport syndrome. Ophthalmic Genet 2020; 41:13-19. [PMID: 32159412 DOI: 10.1080/13816810.2019.1709126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background: X-linked Alport syndrome results from the effect of COL4A5 mutations on basement membranes in the kidney, ear and eye. This study investigated individuals with X-linked Alport syndrome for corneal abnormalities.Patients and Methods: Six men and four women from 8 families with genetically-diagnosed X-linked Alport syndrome underwent ophthalmological examination including slit lamp examination and corneal endothelial specular microscopy. Results for corneal microscopy for men and women with X-linked disease were compared separately with the mean values for age- matched normals using the student's t test.Results: Five of the 6 men had end-stage kidney failure, all 6 had a hearing loss, three had lenticonus, and three had a central fleck retinopathy. Two men had a history of recurrent corneal erosions but no evidence of posterior polymorphous corneal dystrophy. None of the four women had kidney failure, but two had a hearing loss, and two had a central fleck retinopathy. One woman, whose son had recurrent corneal erosions, also had erosions, but no features of a posterior polymorphous corneal dystrophy.Corneal specular microscopy demonstrated abnormalities in affected men and women, with larger endothelial cells (p = .0001 in men, p = .004 in women) fewer 6-sided cells (p = .0001, p = .001 respectively) and reduced cell density (p = .03, p = .02 respectively) than normal.Conclusions: Recurrent corneal erosions are common in men and women with X-linked Alport syndrome, but posterior polymorphous corneal dystrophy is rare. The abnormal corneal endothelial cells in affected men and women are consistent with an abnormal Descemet membrane, and the reduced cell density resembles the reduced podocyte numbers found in the Alport glomerulus.
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Affiliation(s)
- Eleanor Nicklason
- Department of Medicine (Melbourne Health), The University of Melbourne, Parkville, Australia
| | - Heather Mack
- Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Australia
| | - Jacqueline Beltz
- Department of Ophthalmology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Julie Jacob
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | - Mina Farahani
- Department of Ophthalmology, University of California, Irvine, California, USA
| | - Deb Colville
- Department of Medicine (Melbourne Health), The University of Melbourne, Parkville, Australia
| | - Judy Savige
- Department of Medicine (Melbourne Health), The University of Melbourne, Parkville, Australia
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Direct Reprogramming Into Corneal Epithelial Cells Using a Transcriptional Network Comprising PAX6, OVOL2, and KLF4. Cornea 2019; 38 Suppl 1:S34-S41. [PMID: 31403532 DOI: 10.1097/ico.0000000000002074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In its early stages, an embryo polarizes to form cell subpopulations that subsequently produce specific organ cell types. These cell subpopulations are defined by transcription factors (TFs) that activate or repress specific genes. Although an embryo comprises thousands of TFs, surprisingly few are needed to determine the fate of a given cell. The ectoderm divides into the neuroectoderm and surface ectoderm, the latter of which gives rise to epidermal keratinocytes and corneal epithelial cells (CECs). Meanwhile, neuroectoderm cells give rise to other parts of the eye such as the corneal endothelium and retina. To investigate the regulatory role of TFs in CECs, we overexpressed the "core TFs" (PAX6, OVOL2, and KLF4) in human fibroblasts and found that the cells adopted a CEC-like quality. OVOL2 overexpression was even able to directly induce cells with a neuroectoderm fate toward a surface ectoderm fate, designated "direct reprogramming." Conversely, suppression of OVOL2 or PAX6 expression induced CECs to show qualities consistent with neural lineage cells or epidermal keratinocytes, respectively. This suggests that these core TFs can maintain the CEC phenotype through reciprocal gene regulation. Direct reprogramming has important implications for cell therapies. The potential benefits of cells derived by direct reprogramming compared with induced pluripotent stem cells include the fact that it requires less time than reprogramming a cell back to the pluripotent state and then to another cell type. Further understanding of the reciprocally repressive mechanism of action for core TFs could lead to alternative treatments for regenerative medicine not requiring cell transplantation.
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30
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Alterations in GRHL2-OVOL2-ZEB1 axis and aberrant activation of Wnt signaling lead to altered gene transcription in posterior polymorphous corneal dystrophy. Exp Eye Res 2019; 188:107696. [DOI: 10.1016/j.exer.2019.107696] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/02/2019] [Accepted: 06/11/2019] [Indexed: 12/11/2022]
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31
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Kim Y, You HJ, Park SH, Kim MS, Chae H, Park J, Jekarl DW, Kim J, Kwon A, Choi H, Kim Y, Paek AR, Lee A, Kim JM, Park SY, Kim Y, Joo K, Jung J, Chung SH, Mok JW, Kim M. A Mutation in ZNF143 as a Novel Candidate Gene for Endothelial Corneal Dystrophy. J Clin Med 2019; 8:jcm8081174. [PMID: 31390831 PMCID: PMC6723187 DOI: 10.3390/jcm8081174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/02/2019] [Accepted: 08/04/2019] [Indexed: 02/06/2023] Open
Abstract
Corneal dystrophies (CDs) are a diverse group of inherited disorders with a heterogeneous genetic background. Here, we report the identification of a novel ZNF143 heterozygous missense mutation in three individuals of the same family with clinical and pathological features that are consistent with endothelial CD. Ophthalmologic examination revealed diffuse corneal clouding and edema with decreased endothelial cell density. Pathological findings showed increased corneal thickness due to edema of basal epithelial cells and stroma, and abnormal metaplastic endothelium with stratified epithelium-like changes. Patients’ metaplastic corneal endothelial cells expressed predominantly cytokerain 7, cytokeratin 19, and E-cadherin. Although Sanger sequencing did not detect any mutation associated with endothelial CDs, whole exome sequencing identified the ZNF143 c.937G>C p.(Asp313His) mutation as a candidate gene for our patients’ endothelial CD. In-vitro functional studies demonstrated that mutant ZNF143 promoted the mesenchymal-to-epithelial transition; it upregulated the expression of genes associated with epithelialization in human corneal endothelial cells. Additionally, proinflammatory cytokine responsive genes were significantly enriched after mutant ZNF143 transfection, which may contribute to the severe phenotype of the three patients. These findings link a mutation in ZNF143 with endothelial CD for the first time.
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Affiliation(s)
- Yonggoo Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Hye Jin You
- Cancer Cell and Molecular Biology Branch, Division of Cancer Biology, National Cancer Center, Gyeonggi-do 10408, Korea
| | - Shin Hae Park
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Man Soo Kim
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Hyojin Chae
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Joonhong Park
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Dong Wook Jekarl
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Jiyeon Kim
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Ahlm Kwon
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Hayoung Choi
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Yeojae Kim
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - A Rome Paek
- Cancer Cell and Molecular Biology Branch, Division of Cancer Biology, National Cancer Center, Gyeonggi-do 10408, Korea
| | - Ahwon Lee
- Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | | | - Seon Young Park
- Department of Life Systems, Sookmyung Women's University, Seoul 04312, Korea
| | - Yonghwan Kim
- Department of Life Systems, Sookmyung Women's University, Seoul 04312, Korea
| | - Keehyoung Joo
- Center for in Silico Protein Science, Korea Institute for Advanced Study, Seoul 02455, Korea
- Center for Advanced Computation, Korea Institute for Advanced Study, Seoul 02455, Korea
- Center for Advanced Computation, Korea Institute for Advanced Study, Seoul 02455, Korea
| | | | - So-Hyang Chung
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Institutes of Visual Science, The Catholic University of Korea, Seoul 06591, Korea
| | - Jee Won Mok
- Catholic Institutes of Visual Science, The Catholic University of Korea, Seoul 06591, Korea
| | - Myungshin Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.
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32
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Clinical and genetic update of corneal dystrophies. Exp Eye Res 2019; 186:107715. [PMID: 31301286 DOI: 10.1016/j.exer.2019.107715] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/06/2019] [Accepted: 06/27/2019] [Indexed: 11/23/2022]
Abstract
The International Committee for Classification of Corneal Dystrophies (IC3D) distinguishes between 22 distinct forms of corneal dystrophy which are predominantly autosomal dominant, although autosomal recessive and X-chromosomal dominant patterns do exist. Before any genetic examination, there should be documentation of a detailed corneal exam of as many affected and unaffected family members as possible, because detailed phenotypic description is essential for accurate diagnosis. Corneal documentation should be performed in direct and indirect illumination at the slit lamp with the pharmacologically dilated pupil. For the majority of the corneal dystrophies, a phenotype-genotype correlation has not been demonstrated. However, for the dystrophies associated with mutations in the transforming growth factor, ß-induced gene (TGFBI) a general phenotype-genotype correlation is evident. The discovery of collagen, type XVII, alpha 1 mutation (COL17A1), causative in the called epithelial recurrent erosion dystrophy (ERED) was a very important step in the accurate diagnosis of corneal dystrophies. This led to the subsequent discovery that the entity previously called 10q Thiel-Behnke corneal dystrophy, was in reality actually COL17A1 ERED, and not Thiel-Behnke corneal dystrophy. In addition to the phenotypic landmarks, we describe the current genotype of the individual corneal dystrophies. Differential diagnosis can be aided by information on histopathology, optical coherence tomography (OCT), and confocal microscopy.
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Coincidental Occurrence of Schnyder Corneal Dystrophy and Posterior Polymorphous Corneal Dystrophy Type 3. Cornea 2019; 38:758-760. [PMID: 30950897 DOI: 10.1097/ico.0000000000001930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE To report a simultaneous occurrence of 2 rare corneal dystrophies. METHODS A 30-year-old man with a family history of posterior polymorphous corneal dystrophy type 3 (PPCD3) was invited for ophthalmic examination. Sanger sequencing of the coding regions and intron/exon boundaries of disease-associated genes, ZEB1 and UBIAD1, was performed. RESULTS The clinical findings suggested co-occurrence of PPCD3 and Schnyder corneal dystrophy in the proband. This dual diagnosis was supported by genetic findings. He was identified to carry a previously reported heterozygous nonsense mutation in ZEB1: c.2157C>G; p.(Tyr719*), and a novel heterozygous missense mutation in UBIAD1: c.569T>C; p.(Ile190Thr). The mother of the proband only carried c.2157C>G in ZEB1, and slit-lamp examination of her corneas showed endothelial lesions characteristic of PPCD3. The sister of the proband carried c.569T>C in UBIAD1 and had corneal crystal deposition in her anterior stroma consistent with the diagnosis of Schnyder corneal dystrophy. CONCLUSIONS This case illustrates the coincidental occurrence of 2 rare and genetically distinct corneal dystrophies in a single patient. Furthermore, it highlights the need to perform comprehensive phenotyping in combination with appropriate genetic diagnostic testing to achieve an accurate diagnosis.
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Davidson AE, Hafford-Tear NJ, Dudakova L, Sadan AN, Pontikos N, Hardcastle AJ, Tuft SJ, Liskova P. CUGC for posterior polymorphous corneal dystrophy (PPCD). Eur J Hum Genet 2019; 28:126-131. [PMID: 31201376 DOI: 10.1038/s41431-019-0448-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/23/2019] [Accepted: 05/31/2019] [Indexed: 11/09/2022] Open
Abstract
Name of the disease (synonyms) CUGC for posterior polymorphous corneal dystrophy (PPCD).OMIM# of the disease 122000; 609141; 618031.Name of the analysed genes or DNA/chromosome segments OVOL2 (PPCD1); ZEB1 (PPCD3); GRHL2 (PPCD4).OMIM# of the gene(s) 616441; 189909; 608576. Review of the analytical and clinical validity as well as of the clinical utility of DNA-based testing for variants in theOVOL2, ZEB1andGRHL2gene(s) in a diagnostic setting, predictive and parental settings and for risk assesment in relatives.
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Affiliation(s)
| | | | - Lubica Dudakova
- First Faculty of Medicine, Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08, Prague 2, Czech Republic
| | | | | | | | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Petra Liskova
- First Faculty of Medicine, Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, 128 08, Prague 2, Czech Republic
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ZEB1 insufficiency causes corneal endothelial cell state transition and altered cellular processing. PLoS One 2019; 14:e0218279. [PMID: 31194824 PMCID: PMC6564028 DOI: 10.1371/journal.pone.0218279] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022] Open
Abstract
The zinc finger e-box binding homeobox 1 (ZEB1) transcription factor is a master regulator of the epithelial to mesenchymal transition (EMT), and of the reverse mesenchymal to epithelial transition (MET) processes. ZEB1 plays an integral role in mediating cell state transitions during cell lineage specification, wound healing and disease. EMT/MET are characterized by distinct changes in molecular and cellular phenotype that are generally context-independent. Posterior polymorphous corneal dystrophy (PPCD), associated with ZEB1 insufficiency, provides a new biological context in which to understand and evaluate the classic EMT/MET paradigm. PPCD is characterized by a cadherin-switch and transition to an epithelial-like transcriptomic and cellular phenotype, which we study in a cell-based model of PPCD generated using CRISPR-Cas9-mediated ZEB1 knockout in corneal endothelial cells (CEnCs). Transcriptomic and functional studies support the hypothesis that CEnC undergo a MET-like transition in PPCD, termed endothelial to epithelial transition (EnET), and lead to the conclusion that EnET may be considered a corollary to the classic EMT/MET paradigm.
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Litke AM, Samuelson S, Delaney KR, Sauvé Y, Chow RL. Investigating the Pathogenicity of VSX1 Missense Mutations and Their Association With Corneal Disease. Invest Ophthalmol Vis Sci 2019; 59:5824-5835. [PMID: 30535423 DOI: 10.1167/iovs.18-25490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Despite numerous studies associating Visual System Homeobox 1 (VSX1), with posterior polymorphous corneal dystrophy and keratoconus, its role in these diseases is unclear. Here we examine the pathogenicity of VSX1 missense mutations in vitro and in a mouse genetic model. Methods Vsx1 transcriptional repressor activity, protein stability, and subcellular localization activity, was examined using luciferase reporter-based assays, western blotting and immunolabeling, respectively, in transfected human embryonic kidney 293T cells. A genetic model for VSX1 p.P247R was generated to investigate pathogenicity of the mutation, in vivo. A wholemount confocal imaging approach on unfixed intact eyes was developed to examine corneal morphology, curvature, and thickness. Immunolabeling and electroretinography was used to examine retinal phenotype. Results A mutation corresponding to human VSX1 p.P247R led to enhanced transcriptional repressor activity, in vitro. A mouse model for VSX1 p.P247R did not have any observable corneal defect, but did exhibit an abnormal electroretinogram response characterized by a more prominent ON as opposed to OFF panretinal responsiveness. In vitro analysis of additional VSX1 missense mutations showed that they either enhanced repressor activity or did not alter activity. Conclusions Our results indicate that although VSX1 sequence variants can alter transcriptional activity, in the context of a mouse genetic model, at least one of these changes does not lead to corneal abnormalities. While we cannot exclude a role for VSX1 as a risk factor for corneal disease, on its own, it does not appear to play a major causative role.
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Affiliation(s)
| | - Sarah Samuelson
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kerry R Delaney
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Yves Sauvé
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Robert L Chow
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
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Fine-mapping and transcriptome analysis of BoGL-3, a wax-less gene in cabbage (Brassica oleracea L. var. capitata). Mol Genet Genomics 2019; 294:1231-1239. [PMID: 31098741 DOI: 10.1007/s00438-019-01577-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 05/08/2019] [Indexed: 01/27/2023]
Abstract
The great majority of terrestrial plants produce epicuticular wax that is used to protect plants from a variety of biotic and abiotic stresses. Cabbage epicuticular wax is a white crystalline compound of various lipids. Wax-less cabbage has the characteristics of lustrous green leaves and beautiful exterior, which facilitates the brilliant green cabbage breeding. CGL-3 is a spontaneous wax-less mutant identified from cabbage. Genetic analysis indicated that the waxy deficiency of the mutant was controlled by a single dominant gene. To clarify the mechanism of the waxy deficiency, fine-mapping and transcriptome analysis of the wax-less gene, BoGL-3, were carried out in this study. The result of fine mapping showed that the wax-less gene, BoGL-3, was delimited in a 33.5-kb interval which is between the flanking marker C08-98 and the end of chromosome 8. Two cDNA libraries, constructed with wax-less cabbage CGL-3 and the wild-type cabbage WT, were sequenced for screening of the target gene BoGL-3. A total of 8340 genes were identified with significant differential expression between CGL-3 and WT. Among these genes, 3187 were up-regulated and 5153 were down-regulated in CGL-3. With homologous analysis, four differential expressed genes related to wax metabolism were obtained. Among these four genes, only Bol018504 is located within the region of fine-mapping. Bol08504 is homologous to CER1, which encodes fatty acid hydroxylase and plays an important role in wax synthesis in Arabidopsis. However, there was no difference of Bol08504 sequence between CGL-3 and WT. We suggested that Bol018504 was regulated by BoGL-3. The suppression of Bol018504 leads to the reduction of wax. These findings will be helpful to reveal the mechanism of the wax metabolism in cabbage and develop lustrous green cabbage germplasm material.
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The utility of massively parallel sequencing for posterior polymorphous corneal dystrophy type 3 molecular diagnosis. Exp Eye Res 2019; 182:160-166. [PMID: 30851240 DOI: 10.1016/j.exer.2019.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/05/2019] [Accepted: 03/02/2019] [Indexed: 02/06/2023]
Abstract
The aim of this study was to identify the molecular genetic cause of disease in posterior polymorphous corneal dystrophy (PPCD) probands of diverse origin and to assess the utility of massively parallel sequencing in the detection of ZEB1 mutations. We investigated a total of 12 families (five British, four Czech, one Slovak and two Swiss). Ten novel and two recurrent disease-causing mutations in ZEB1, were identified in probands by Sanger (n = 5), exome (n = 4) and genome (n = 3) sequencing. Sanger sequencing was used to confirm the mutations detected by massively parallel sequencing, and to perform segregation analysis. Genome sequencing revealed that one proband harboured a novel ∼0.34 Mb heterozygous de novo deletion spanning exons 1-7 and part of exon 8. Transcript analysis confirmed that the ZEB1 transcript is detectable in blood-derived RNA samples and that the disease-associated variant c.482-2A>G leads to aberrant pre-mRNA splicing. De novo mutations, which are a feature of PPCD3, were found in the current study with an incidence rate of at least 16.6%. In general, massively parallel sequencing is a time-efficient way to detect PPCD3-associated mutations and, importantly, genome sequencing enables the identification of full or partial heterozygous ZEB1 deletions that can evade detection by both Sanger and exome sequencing. These findings contribute to our understanding of PPCD3, for which currently, 49 pathogenic variants have been identified, all of which are predicted to be null alleles.
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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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Han S, Yang H, Han Y, Zhang H. Genes and transcription factors related to the adverse effects of maternal type I diabetes mellitus on fetal development. Mol Cell Probes 2018; 43:64-71. [PMID: 30447278 DOI: 10.1016/j.mcp.2018.11.003] [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: 07/03/2018] [Revised: 10/15/2018] [Accepted: 11/13/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE Maternal type I diabetes mellitus (T1DM) increases the risk of adverse pregnancy outcomes, but the corresponding mechanism is unclear. This study aims to investigate the mechanism underlying the adverse pregnancy outcomes of maternal T1DM. METHODS Gene expression microarray (GSE51546) was down-loaded from the Gene Expression Omnibus. This dataset included 12 umbilical cord samples from the newborns of T1DM mothers (T1DM group, N = six) and non-diabetic mothers (control group, N = six). RESULTS Consequently, 1051 differentially expressed genes (DEGs) were found between the two groups. The up-regulated DEGs enriched in 30 KEGG pathways. HLA-DPA1, HLA-DMA, HLA-DMB, HLA-DQA1, HLA-DQA2 and HLA-DRA enriched in "Type I diabetes mellitus". This pathway was strongly related to 14 pathways, most of which were associated with diseases. Then, a protein-protein interaction network was constructed, and 45 potential key DEGs were identified. The 45 DEGs enriched in pathways such as "Rheumatoid arthritis", "Chemokine signaling pathway" and "Cytokine-cytokine receptor interaction" (e.g. CXCL12 and CCL5). Transcription factors (TFs) of key DEGs were predicted, and a TF-DEG regulatory network was constructed. CONCLUSIONS Some genes (e.g. CXCL12 and CCL5) and their TFs were significantly and abnormally regulated in the umbilical cord tissue from the pregnancies of T1DM mothers compared to that from non-T1DM mothers.
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Affiliation(s)
- Shuyi Han
- Department of Clinical Laboratory, Ji'nan Central Hospital Affiliated to Shandong University, Ji'nan, 250013, China
| | - Huili Yang
- Department of Obstetrics, Ji'nan Central Hospital Affiliated to Shandong University, Ji'nan, 250013, China.
| | - Yunhui Han
- Department of Obstetrics, Ji'nan Central Hospital Affiliated to Shandong University, Ji'nan, 250013, China
| | - Hongzhi Zhang
- Department of Gynecology, Ji'nan Central Hospital Affiliated to Shandong University, Ji'nan, 250013, China
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Esapa CT, Piret SE, Nesbit MA, Thomas GP, Coulton LA, Gallagher OM, Simon MM, Kumar S, Mallon AM, Bellantuono I, Brown MA, Croucher PI, Potter PK, Brown SD, Cox RD, Thakker RV. An N-Ethyl- N-Nitrosourea (ENU) Mutagenized Mouse Model for Autosomal Dominant Nonsyndromic Kyphoscoliosis Due to Vertebral Fusion. JBMR Plus 2018; 2:154-163. [PMID: 30283900 PMCID: PMC6124210 DOI: 10.1002/jbm4.10033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/01/2018] [Accepted: 01/14/2018] [Indexed: 02/06/2023] Open
Abstract
Kyphosis and scoliosis are common spinal disorders that occur as part of complex syndromes or as nonsyndromic, idiopathic diseases. Familial and twin studies implicate genetic involvement, although the causative genes for idiopathic kyphoscoliosis remain to be identified. To facilitate these studies, we investigated progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) and assessed them for morphological and radiographic abnormalities. This identified a mouse with kyphoscoliosis due to fused lumbar vertebrae, which was inherited as an autosomal dominant trait; the phenotype was designated as hereditary vertebral fusion (HVF) and the locus as Hvf. Micro-computed tomography (μCT) analysis confirmed the occurrence of nonsyndromic kyphoscoliosis due to fusion of lumbar vertebrae in HVF mice, consistent with a pattern of blocked vertebrae due to failure of segmentation. μCT scans also showed the lumbar vertebral column of HVF mice to have generalized disc narrowing, displacement with compression of the neural spine, and distorted transverse processes. Histology of lumbar vertebrae revealed HVF mice to have irregularly shaped vertebral bodies and displacement of intervertebral discs and ossification centers. Genetic mapping using a panel of single nucleotide polymorphic (SNP) loci arranged in chromosome sets and DNA samples from 23 HVF (eight males and 15 females) mice, localized Hvf to chromosome 4A3 and within a 5-megabase (Mb) region containing nine protein coding genes, two processed transcripts, three microRNAs, five small nuclear RNAs, three large intergenic noncoding RNAs, and 24 pseudogenes. However, genome sequence analysis in this interval did not identify any abnormalities in the coding exons, or exon-intron boundaries of any of these genes. Thus, our studies have established a mouse model for a monogenic form of nonsyndromic kyphoscoliosis due to fusion of lumbar vertebrae, and further identification of the underlying genetic defect will help elucidate the molecular mechanisms involved in kyphoscoliosis. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Christopher T Esapa
- Academic Endocrine Unit Radcliffe Department of Medicine University of Oxford Oxford Centre for Diabetes, Endocrinology and Metabolism Churchill Hospital Headington UK.,MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Sian E Piret
- Academic Endocrine Unit Radcliffe Department of Medicine University of Oxford Oxford Centre for Diabetes, Endocrinology and Metabolism Churchill Hospital Headington UK
| | - M Andrew Nesbit
- Academic Endocrine Unit Radcliffe Department of Medicine University of Oxford Oxford Centre for Diabetes, Endocrinology and Metabolism Churchill Hospital Headington UK.,School of Biomedical Sciences Ulster University Coleraine UK
| | - Gethin P Thomas
- Institute of Health and Biomedical Innovation Queensland University of Technology Translational Research Institute Princess Alexandra Hospital Brisbane Australia.,Charles Sturt University Boorooma Street Wagga Wagga Australia
| | - Leslie A Coulton
- The Mellanby Centre for Bone Research University of Sheffield Sheffield UK
| | - Orla M Gallagher
- The Mellanby Centre for Bone Research University of Sheffield Sheffield UK
| | - Michelle M Simon
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Saumya Kumar
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK.,Instituto de Medicina Molecular (IMM) Faculdade de Medicina de Universidade de Lisboa Lisboa Portugal
| | - Ann-Marie Mallon
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Ilaria Bellantuono
- The Mellanby Centre for Bone Research University of Sheffield Sheffield UK
| | - Matthew A Brown
- Institute of Health and Biomedical Innovation Queensland University of Technology Translational Research Institute Princess Alexandra Hospital Brisbane Australia
| | - Peter I Croucher
- The Mellanby Centre for Bone Research University of Sheffield Sheffield UK.,Garvan Institute for Medical Research Sydney Australia
| | - Paul K Potter
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Steve Dm Brown
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Roger D Cox
- MRC Mammalian Genetics Unit and Mary Lyon Centre MRC Harwell Institute Harwell Science and Innovation Campus Harwell UK
| | - Rajesh V Thakker
- Academic Endocrine Unit Radcliffe Department of Medicine University of Oxford Oxford Centre for Diabetes, Endocrinology and Metabolism Churchill Hospital Headington UK
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Effect of Posterior Corneal Vesicles on Corneal Endothelial Cell Density and Anisometropic Amblyopia. Cornea 2018; 37:813-817. [PMID: 29757851 DOI: 10.1097/ico.0000000000001612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To evaluate the effect of corneal vesicles in patients with posterior corneal vesicles (PCV) on corneal endothelial cell (CEC) density and the acquisition of amblyopia. METHODS In this retrospective study of patients with PCV (18 eyes of 14 patients), CEC density was examined by noncontact specular microscopy during each follow-up examination. Best-corrected visual acuity and the objective refractive error were also examined. RESULTS Of the 14 total patients, 10 were diagnosed with PCV and 4 were diagnosed with bilateral suspected PCV or posterior polymorphous corneal dystrophy (PPCD), and in all patients, no ocular abnormality other than corneal vesicles was observed. In patients with PCV and patients with bilateral suspected PCV or PPCD, mean CEC density was 1131 ± 338 and 1095 ± 492 cells/mm, respectively. In both PCV group and the bilateral suspected PCV or PPCD-group patients who were followed for 164.2 ± 25.4 months (range: 123-186 months), CEC density tended not to decrease. In patients with PCV, the mean best-corrected visual acuity of the unaffected eyes was significantly higher than that of the affected eyes with corneal vesicles (-0.10 ± 0.06 and 0.05 ± 0.13, respectively, P = 0.012). Four of 9 affected eyes (1 eye was excluded because of retinal atrophy) exhibited amblyopia, and all 4 eyes had astigmatism higher than 2 diopters. CONCLUSIONS Although CEC density of patients with PCV in this study was found to be stable over a long-term follow-up period, strict attention should be given to the possibility of amblyopia in eyes with PCV.
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Qi XK, Han HQ, Zhang HJ, Xu M, Li L, Chen L, Xiang T, Feng QS, Kang T, Qian CN, Cai MY, Tao Q, Zeng YX, Feng L. OVOL2 links stemness and metastasis via fine-tuning epithelial-mesenchymal transition in nasopharyngeal carcinoma. Am J Cancer Res 2018; 8:2202-2216. [PMID: 29721073 PMCID: PMC5928881 DOI: 10.7150/thno.24003] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/13/2018] [Indexed: 01/06/2023] Open
Abstract
Rationale: Metastasis is the leading cause of disease-related death among patients with nasopharyngeal carcinoma (NPC). Mounting evidence suggest that epithelial-mesenchymal transition (EMT) is crucial for cancer cells to acquire metastatic ability. In this study, we aim to clarify the extent to which EMT is involved in various cancer properties and identify novel markers for predicting the prognosis of NPC patients. Methods: Two cellular models derived from the same NPC cell line with distinct metastasis ability were used for microarray analysis to identify key transcriptional factors that drive metastasis. Cell migration and invasion were analyzed by wound healing and Transwell analysis. Lung metatasis was determined by tail vein injection assay. Cancer stemness was analyzed using colony formation and xenograft assay. The EMT extent was evaluated using immunoblotting, RT-qPCR and immunofluorescence of EMT markers. The value of OVOL2 in prognosis was determined by immunohistochemistry in NPC biopsies. Results: OVOL2 was the most significantly down-regulated EMT transcription factor (EMT-TF) in cellular models of NPC metatasis. Low levels of OVOL2 were associated with poor overall survival of NPC patients and the reduced expression is partly due to promoter methylation and epithelial dedifferentiation. Knockout of OVOL2 in epithelial-like NPC cells partially activates EMT program and significantly promotes cancer stemness and metastatic phenotypes. Conversely, ectopically expression of OVOL2 in mesenchymal-like cells leads to a partial transition to an epithelial phenotype and reduced malignancy. Reversing EMT by depleting ZEB1, a major target of OVOL2, does not eliminate the stemness advantage of OVOL2-deficient cells but does reduce their invasion capacity. A comparison of subpopulations at different stages of EMT revealed that the extent of EMT is positively correlated with metastasis and drug resistance; however, only the intermediate EMT state is associated with cancer stemness. Conclusion: Distinct from other canonical EMT-TFs, OVOL2 only exhibits modest effect on EMT but has a strong impact on both metastasis and tumorigenesis. Therefore, OVOL2 could serve as a prognostic indicator for cancer patients.
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Liskova P, Dudakova L, Evans CJ, Rojas Lopez KE, Pontikos N, Athanasiou D, Jama H, Sach J, Skalicka P, Stranecky V, Kmoch S, Thaung C, Filipec M, Cheetham ME, Davidson AE, Tuft SJ, Hardcastle AJ. Ectopic GRHL2 Expression Due to Non-coding Mutations Promotes Cell State Transition and Causes Posterior Polymorphous Corneal Dystrophy 4. Am J Hum Genet 2018; 102:447-459. [PMID: 29499165 PMCID: PMC5985340 DOI: 10.1016/j.ajhg.2018.02.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 02/02/2018] [Indexed: 12/11/2022] Open
Abstract
In a large family of Czech origin, we mapped a locus for an autosomal-dominant corneal endothelial dystrophy, posterior polymorphous corneal dystrophy 4 (PPCD4), to 8q22.3-q24.12. Whole-genome sequencing identified a unique variant (c.20+544G>T) in this locus, within an intronic regulatory region of GRHL2. Targeted sequencing identified the same variant in three additional previously unsolved PPCD-affected families, including a de novo occurrence that suggests this is a recurrent mutation. Two further unique variants were identified in intron 1 of GRHL2 (c.20+257delT and c.20+133delA) in unrelated PPCD-affected families. GRHL2 is a transcription factor that suppresses epithelial-to-mesenchymal transition (EMT) and is a direct transcriptional repressor of ZEB1. ZEB1 mutations leading to haploinsufficiency cause PPCD3. We previously identified promoter mutations in OVOL2, a gene not normally expressed in the corneal endothelium, as the cause of PPCD1. OVOL2 drives mesenchymal-to-epithelial transition (MET) by directly inhibiting EMT-inducing transcription factors, such as ZEB1. Here, we demonstrate that the GRHL2 regulatory variants identified in PPCD4-affected individuals induce increased transcriptional activity in vitro. Furthermore, although GRHL2 is not expressed in corneal endothelial cells in control tissue, we detected GRHL2 in the corneal "endothelium" in PPCD4 tissue. These cells were also positive for epithelial markers E-Cadherin and Cytokeratin 7, indicating they have transitioned to an epithelial-like cell type. We suggest that mutations inducing MET within the corneal endothelium are a convergent pathogenic mechanism leading to dysfunction of the endothelial barrier and disease.
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Affiliation(s)
- Petra Liskova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic; Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, Prague 128 08, Czech Republic; UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.
| | - Lubica Dudakova
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic
| | - Cerys J Evans
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Karla E Rojas Lopez
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Dimitra Athanasiou
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Hodan Jama
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Josef Sach
- Institute of Pathology, Third Faculty of Medicine, Charles University, Faculty Hospital Kralovske Vinohrady, Srobarova 50, Prague 100 34, Czech Republic
| | - Pavlina Skalicka
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic; Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, Prague 128 08, Czech Republic
| | - Viktor Stranecky
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic
| | - Stanislav Kmoch
- Research Unit for Rare Diseases, Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Ke Karlovu 2, Prague 128 08, Czech Republic
| | - Caroline Thaung
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK
| | - Martin Filipec
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, U Nemocnice 2, Prague 128 08, Czech Republic
| | - Michael E Cheetham
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Alice E Davidson
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | | | - Alison J Hardcastle
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK; Moorfields Eye Hospital, London EC1V 2PD, UK.
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Zakharevich M, Kattan JM, Chen JL, Lin BR, Cervantes AE, Chung DD, Frausto RF, Aldave AJ. Elucidating the molecular basis of PPCD: Effects of decreased ZEB1 expression on corneal endothelial cell function. Mol Vis 2017; 23:740-752. [PMID: 29046608 PMCID: PMC5644665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 10/12/2017] [Indexed: 11/01/2022] Open
Abstract
PURPOSE To investigate the functional role that the zinc e-box binding homeobox 1 (ZEB1) gene, which underlies the genetic basis of posterior polymorphous corneal dystrophy 3 (PPCD3), plays in corneal endothelial cell proliferation, apoptosis, migration, and barrier function. METHODS A human corneal endothelial cell line (HCEnC-21T) was transfected with siRNA targeting ZEB1 mRNA. Cell proliferation, apoptosis, migration, and barrier assays were performed: Cell proliferation was assessed with cell counting using a hemocytometer; cell apoptosis, induced by either ultraviolet C (UVC) radiation or doxorubicin treatment, was quantified by measuring cleaved caspase 3 (cCASP3) protein levels; and cell migration and barrier function were monitored with electric cell-substrate impedance sensing (ECIS). RESULTS ZEB1 knockdown in HCEnC-21T cells transfected with siRNA targeting ZEB1 did not result in a significant difference in cell proliferation when compared with control. Although knockdown of ZEB1 in HCEnC-21T cells sensitized the cells to UV-induced apoptosis, ZEB1 knockdown did not alter the cells' susceptibility to doxorubicin-induced apoptosis, as measured with cCASP3 protein levels, compared with controls. Similarly, no difference was observed in cell migration following ZEB1 knockdown. However, cell barrier function increased significantly following ZEB1 knockdown. CONCLUSIONS The corneal endothelium in PPCD3 is characterized by morphologic, anatomic, and molecular features that are more consistent with an epithelial-like rather than an endothelial-like phenotype. Although these characteristics have been well documented, we demonstrate for the first time that susceptibility to UV-induced apoptosis and cell barrier function are significantly altered in the setting of reduced ZEB1. The significance of an altered cellular response to apoptotic stimuli and increased cell barrier function in the pathobiology of PPCD remains to be fully elucidated.
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Quinodoz M, Royer-Bertrand B, Cisarova K, Di Gioia SA, Superti-Furga A, Rivolta C. DOMINO: Using Machine Learning to Predict Genes Associated with Dominant Disorders. Am J Hum Genet 2017; 101:623-629. [PMID: 28985496 DOI: 10.1016/j.ajhg.2017.09.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 09/01/2017] [Indexed: 10/18/2022] Open
Abstract
In contrast to recessive conditions with biallelic inheritance, identification of dominant (monoallelic) mutations for Mendelian disorders is more difficult, because of the abundance of benign heterozygous variants that act as massive background noise (typically, in a 400:1 excess ratio). To reduce this overflow of false positives in next-generation sequencing (NGS) screens, we developed DOMINO, a tool assessing the likelihood for a gene to harbor dominant changes. Unlike commonly-used predictors of pathogenicity, DOMINO takes into consideration features that are the properties of genes, rather than of variants. It uses a machine-learning approach to extract discriminant information from a broad array of features (N = 432), including: genomic data, intra-, and interspecies conservation, gene expression, protein-protein interactions, protein structure, etc. DOMINO's iterative architecture includes a training process on 985 genes with well-established inheritance patterns for Mendelian conditions, and repeated cross-validation that optimizes its discriminant power. When validated on 99 newly-discovered genes with pathogenic mutations, the algorithm displays an excellent final performance, with an area under the curve (AUC) of 0.92. Furthermore, unsupervised analysis by DOMINO of real sets of NGS data from individuals with intellectual disability or epilepsy correctly recognizes known genes and predicts 9 new candidates, with very high confidence. In summary, DOMINO is a robust and reliable tool that can infer dominance of candidate genes with high sensitivity and specificity, making it a useful complement to any NGS pipeline dealing with the analysis of the morbid human genome.
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Shen AL, Moran SM, Glover EA, Teixeira LB, Bradfield CA. Retinal pathology in the PPCD1 mouse. PLoS One 2017; 12:e0185094. [PMID: 28981549 PMCID: PMC5628829 DOI: 10.1371/journal.pone.0185094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 09/06/2017] [Indexed: 12/30/2022] Open
Abstract
Retinal phenotypes of the PPCD1 mouse, a mouse model of posterior polymorphous corneal dystrophy, have been characterized. PPCD1 mice on the DBA/2J background (D2.Ppcd1) have previously been reported to develop an enlarged anterior chamber due to epithelialization and proliferation of the corneal endothelium and subsequent blockage of the iridocorneal angle. Results presented here show that D2.Ppcd1 mice develop increased intraocular pressure (IOP), with measurements at three months of age revealing significant increases in IOP. Significant retinal ganglion cell layer cell loss is observed at five months of age. D2.Ppcd1 animals also exhibit marked degeneration of the outer nuclear layer in association with hyperplasia of the retinal pigment epithelium. Evidence of retinal detachment is present as early as three weeks of age. By 3.5 months of age, focal areas of outer nuclear layer loss are observed. Although the GpnmbR150X mutation leads to increased IOP and glaucoma in DBA/2J mice, development of anterior segment and retinal defects in D2.Ppcd1 animals does not depend upon presence of the GpnmbR150X mutation.
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Affiliation(s)
- Anna L. Shen
- The McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail: (CAB); (ALS)
| | - Susan M. Moran
- The McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Edward A. Glover
- The McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Leandro B. Teixeira
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Christopher A. Bradfield
- The McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail: (CAB); (ALS)
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Chung DD, Frausto RF, Lin BR, Hanser EM, Cohen Z, Aldave AJ. Transcriptomic Profiling of Posterior Polymorphous Corneal Dystrophy. Invest Ophthalmol Vis Sci 2017; 58:3202-3214. [PMID: 28654985 PMCID: PMC5488878 DOI: 10.1167/iovs.17-21423] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose To investigate the molecular basis of posterior polymorphous corneal dystrophy (PPCD) by examining the PPCD transcriptome and the effect of decreased ZEB1 expression on corneal endothelial cell (CEnC) gene expression. Methods Next-generation RNA sequencing (RNA-seq) analyses of corneal endothelium from two PPCD-affected individuals (one with PPCD3 and one of unknown genetic cause) compared with two age-matched controls, and primary human CEnC (pHCEnC) transfected with siRNA-mediated ZEB1 knockdown. The expression of selected differentially expressed genes was validated by quantitative polymerase chain reaction (qPCR) and/or assessed by in situ hybridization in the corneal endothelium of four independent cases of PPCD (one with PPCD3 and three of unknown genetic cause). Results Expression of 16% and 46% of the 104 protein-coding genes specific to ex vivo corneal endothelium was lost in the endothelium of two individuals with PPCD. Thirty-two genes associated with ZEB1 and 3 genes (BMP4, CCND1, ZEB1) associated with OVOL2 were differentially expressed in the same direction in both individuals with PPCD. Immunohistochemistry staining and RNA-seq analyses demonstrated variable expression of type IV collagens in PPCD corneas. Decreasing ZEB1 expression in pHCEnC altered expression of 711 protein-coding genes, many of which are associated with canonical pathways regulating various cellular processes. Conclusions Identification of the altered transcriptome in PPCD and in a cell-based model of PPCD provided insight into the molecular alterations characterizing PPCD. Further study of the differentially expressed genes associated with ZEB1 and OVOL2 is expected to identify candidate genes for individuals with PPCD and without a ZEB1 or OVOL2 mutation.
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Affiliation(s)
- Doug D Chung
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
| | - Ricardo F Frausto
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
| | - Benjamin R Lin
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
| | - Evelyn M Hanser
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
| | - Zack Cohen
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
| | - Anthony J Aldave
- Stein Eye Institute, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California, United States
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Abstract
Degenerative or hereditary corneal diseases are sometimes difficult to discriminate. Corneal dystrophies affect approximately 0.09 % of the population. They are identified by the IC3D classification based on their phenotype, genotype and evidence gathered for their diagnosis. Practically, the ophthalmologist manages functional symptoms, such as recurrent erosions, visual loss and amblyopia, photophobia, foreign body sensation, and sometimes pain and aesthetic concerns. Medical treatments consist of drops to promote healing, ointments, hyperosmotic agents and bandage contact lenses. Less invasive surgical treatments are used as second line therapy (phototherapeutic keratectomy, lamellar keratectomy). More invasive procedures may eventually be utilized (lamellar or penetrating keratoplasty). Anterior lamellar or endothelial keratoplasty are now preferred to penetrating keratoplasty, although the latter still remains the only possible option in some cases. Some rare dystrophies require coordinated and comprehensive medical care.
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Affiliation(s)
- J-L Bourges
- Université Paris Descartes, Sorbonne Paris Cité, 15, rue École-de-Médecine, 75006 Paris, France; Unité d'ophtalmologie de l'Hôtel-Dieu, service d'ophtalmologie, hôpitaux universitaires Paris Centre, Assistance publique-Hôpitaux de Paris, 1, place du Parvis-Notre-Dame, 75004 Paris, France; Équipe 17, Inserm UMRS 1138, centre de recherche des Cordeliers, 15, rue de l'École-de-Médecine, 75006 Paris, France.
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50
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Bourges JL. Corneal dystrophies. J Fr Ophtalmol 2017; 40:e177-e192. [PMID: 28583694 DOI: 10.1016/j.jfo.2017.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/04/2017] [Accepted: 05/05/2017] [Indexed: 10/19/2022]
Abstract
Degenerative or hereditary corneal diseases are sometimes difficult to discriminate. Corneal dystrophies affect approximately 0.09% of the population. They are identified by the IC3D classification based on their phenotype, genotype and evidence gathered for their diagnosis. In practice, the ophthalmologist manages functional symptoms such as recurrent erosions, visual loss and amblyopia, photophobia, foreign body sensation, and sometimes pain and aesthetic concerns. Medical treatments consist of drops to promote healing, ointments, hyperosmotic agents and bandage contact lenses. Less invasive surgical treatments are used as second line therapy (phototherapeutic keratectomy, lamellar keratectomy). More invasive procedures may eventually be utilized (lamellar or penetrating keratoplasty). Anterior lamellar or endothelial keratoplasty are now preferred to penetrating keratoplasty, although the latter still remains the only possible option in some cases. Some rare dystrophies require coordinated and comprehensive medical care.
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Affiliation(s)
- J-L Bourges
- Université Paris Descartes, Sorbonne Paris Cité, 15, rue de l'École-de-Médecine, 75006 Paris, France; Ophthalmology Unit, Ophthalmology Service, Hôtel-Dieu, Hôpitaux Universitaires Paris Centre, Assistance publique-Hôpitaux de Paris, 1, place du Parvis-Notre-Dame, 75004 Paris, France; Équipe 17, Inserm UMRS 1138, Centre de Recherche des Cordeliers, 15, rue de l'École-de-Médecine, 75006 Paris, France.
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