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Fu M, Duan S, Zhang X, Wang J, Wang S, Chi ZL. A Novel Heterozygous TGFBI c.1613C>A Pathogenic Variant is Associated With Lattice Corneal Dystrophy in a Chinese Family. Am J Ophthalmol 2023; 256:138-145. [PMID: 37567434 DOI: 10.1016/j.ajo.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023]
Abstract
PURPOSE To investigate the gene mutations and relationship of clinical manifestation in a Chinese family with familial lattice corneal dystrophy (LCD). DESIGN Single-family case-control study. METHODS A family with familial LCD was recruited for this study. A total of 10 affected and 13 healthy family members participated in this research. Clinical features were examined by slit-lamp examination and anterior segment optical coherence tomography (AS-OCT). Peripheral blood samples were collected from each participant, and genomic DNA was extracted. Whole-exome sequencing (WES) analysis was performed, and the pathogenic variants of LCD were identified using bioinformatics tools and confirmed by Sanger sequencing. RESULTS Slit-lamp examination revealed diffuse grayish-white punctate, linear, and "lattice-like" opacities in the corneal epithelium and superficial corneal stroma. AS-OCT revealed an irregularly shaped cornea. The corneal epithelium and anterior corneal stroma showed high-reflective deposits and bulges. The clinical appearance of the patients fit the pattern and features of autosomal dominant inheritance of LCD type I (LCD I). A novel pathogenic variant of exon 12 in TGFBI was found by WES analysis, in which cytosine at position 1613 was substituted by adenine (c.1613C>A), and the amino acid was changed from threonine to lysine (p.T538K). Mutated genes and proteins were predicted to be deleterious. CONCLUSION A novel heterozygous pathogenic variant (c.1613C>A) of TGFBI was identified in the Chinese family with LCD I.
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Affiliation(s)
- Mengjun Fu
- From the State Key Laboratory of Ophthalmology (M.F., X.Z., Z-L.C.), Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases (M.F., X.Z., Z-L.C.), Eye Hospital, Wenzhou Medical University, Wenzhou, China; Weifang Eye Institute (M.F., J.W., S.W.), National Key Clinical Specialty, Weifang Eye Hospital, Zhengda Guangming Eye Group, Weifang, China
| | - Shan Duan
- Laboratory of Molecular Medicine (S.D.), Institute of Maternal and Child Medicine, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Shenzhen, China
| | - Xiaobo Zhang
- From the State Key Laboratory of Ophthalmology (M.F., X.Z., Z-L.C.), Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases (M.F., X.Z., Z-L.C.), Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jiahao Wang
- Weifang Eye Institute (M.F., J.W., S.W.), National Key Clinical Specialty, Weifang Eye Hospital, Zhengda Guangming Eye Group, Weifang, China
| | - Sheng Wang
- Weifang Eye Institute (M.F., J.W., S.W.), National Key Clinical Specialty, Weifang Eye Hospital, Zhengda Guangming Eye Group, Weifang, China
| | - Zai-Long Chi
- From the State Key Laboratory of Ophthalmology (M.F., X.Z., Z-L.C.), Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases (M.F., X.Z., Z-L.C.), Eye Hospital, Wenzhou Medical University, Wenzhou, China.
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Li F, He J, Bai H, Huang Y, Wang F, Tian L. An Arg124Cys mutation in transforming growth factor β-induced gene associated with lattice corneal dystrophy type I in a Chinese pedigree. Indian J Ophthalmol 2021; 70:85-89. [PMID: 34937214 PMCID: PMC8917566 DOI: 10.4103/ijo.ijo_33_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose: To identify a clinical and genetic form of a large Chinese family with an autosomal-dominant lattice corneal dystrophy type I (LCD I). Methods: The patients’ eyes were examined on the basis of slit-lamp microscopy, and other clinical records were also collected. Genomic DNA was extracted from peripheral leukocytes of the affected patients and their unaffected family members. Each previous reported mutation of the transforming growth factor β-induced gene (TGFBI) gene was amplified by touch-down polymerase chain reaction and directly sequenced to verify the disease-causing mutation. Results: Typical clinical features of LCD I were found by slit-lamp photography in these affected Chinese pedigrees. A heterozygous single base-pair transition from C to T (c.418 C > T), leading to amino acid substitution Arg124Cys (R124C) in the encoded TGFBI protein, was detected in all of the eighteen affected patients. The same mutation was not found in unaffected family members. Conclusion: The R124C mutation hot spot, which was relatively rare in China, was responsible for LCD I in the large family. Molecular genetic analysis of TGFBI gene can offer an accurate diagnosis of patients with lattice corneal dystrophies in the clinical treatment.
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Affiliation(s)
- Feng Li
- Shanxi Cancer Research Institute, Taiyuan, China
| | - Jiahuan He
- Department of Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Beijing, China
| | - Hua Bai
- C-MER Dennis Lam Eye Hospital, Beijing, China
| | - Yifei Huang
- Department of Ophthalmology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Fang Wang
- Department of Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Beijing, China
| | - Lei Tian
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing, China
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Nielsen NS, Poulsen ET, Lukassen MV, Chao Shern C, Mogensen EH, Weberskov CE, DeDionisio L, Schauser L, Moore TC, Otzen DE, Hjortdal J, Enghild JJ. Biochemical mechanisms of aggregation in TGFBI-linked corneal dystrophies. Prog Retin Eye Res 2020; 77:100843. [DOI: 10.1016/j.preteyeres.2020.100843] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/22/2022]
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Kheir V, Cortés-González V, Zenteno JC, Schorderet DF. Mutation update: TGFBI pathogenic and likely pathogenic variants in corneal dystrophies. Hum Mutat 2019; 40:675-693. [PMID: 30830990 DOI: 10.1002/humu.23737] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 02/26/2019] [Accepted: 02/28/2019] [Indexed: 01/07/2023]
Abstract
Human transforming growth factor β-induced (TGFBI), is a gene responsible for various corneal dystrophies. TGFBI produces a protein called TGFBI, which is involved in cell adhesion and serves as a recognition sequence for integrins. An alteration in cell surface interactions could be the underlying cause for the progressive accumulation of extracellular deposits in different layers of the cornea with the resulting changes of refractive index and transparency. To this date, 69 different pathogenic or likely pathogenic variants in TGFBI have been identified in a heterozygous or homozygous state in various corneal dystrophies, including a novel variant reported here. All disease-associated variants were inherited as autosomal-dominant traits but one; this latter was inherited as an autosomal recessive trait. Most corneal dystrophy-associated variants are located at amino acids Arg124 and Arg555. To keep the list of corneal dystrophy-associated variant current, we generated a locus-specific database for TGFBI (http://databases.lovd.nl/shared/variants/TGFBI) containing all pathogenic and likely pathogenic variants reported so far. Non-disease-associated variants are described in specific databases, like gnomAD and ExAC but are not listed here. This article presents the most recent up-to-date list of disease-associated variants.
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Affiliation(s)
- Valeria Kheir
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vianney Cortés-González
- Department of Genetics, Hospital "Dr. Luis Sanchez Bulnes", Asociación Para Evitar la Ceguera en México, Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico.,Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico
| | - Daniel F Schorderet
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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García-Castellanos R, Nielsen NS, Runager K, Thøgersen IB, Lukassen MV, Poulsen ET, Goulas T, Enghild JJ, Gomis-Rüth FX. Structural and Functional Implications of Human Transforming Growth Factor β-Induced Protein, TGFBIp, in Corneal Dystrophies. Structure 2017; 25:1740-1750.e2. [PMID: 28988748 DOI: 10.1016/j.str.2017.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/02/2017] [Accepted: 09/01/2017] [Indexed: 12/31/2022]
Abstract
A major cause of visual impairment, corneal dystrophies result from accumulation of protein deposits in the cornea. One of the proteins involved is transforming growth factor β-induced protein (TGFBIp), an extracellular matrix component that interacts with integrins but also produces corneal deposits when mutated. Human TGFBIp is a multi-domain 683-residue protein, which contains one CROPT domain and four FAS1 domains. Its structure spans ∼120 Å and reveals that vicinal domains FAS1-1/FAS1-2 and FAS1-3/FAS1-4 tightly interact in an equivalent manner. The FAS1 domains are sandwiches of two orthogonal four-stranded β sheets decorated with two three-helix insertions. The N-terminal FAS1 dimer forms a compact moiety with the structurally novel CROPT domain, which is a five-stranded all-β cysteine-knot solely found in TGFBIp and periostin. The overall TGFBIp architecture discloses regions for integrin binding and that most dystrophic mutations cluster at both molecule ends, within domains FAS1-1 and FAS1-4.
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Affiliation(s)
- Raquel García-Castellanos
- Proteolysis Laboratory, Structural Biology Unit ("María-de-Maeztu" Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain
| | - Nadia Sukusu Nielsen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - Kasper Runager
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - Ida B Thøgersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - Marie V Lukassen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - Ebbe T Poulsen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - Theodoros Goulas
- Proteolysis Laboratory, Structural Biology Unit ("María-de-Maeztu" Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej, 10, 8000 Aarhus C, Denmark
| | - F Xavier Gomis-Rüth
- Proteolysis Laboratory, Structural Biology Unit ("María-de-Maeztu" Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain.
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Pathogenesis and treatments of TGFBI corneal dystrophies. Prog Retin Eye Res 2015; 50:67-88. [PMID: 26612778 DOI: 10.1016/j.preteyeres.2015.11.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 11/22/2022]
Abstract
Transforming growth factor beta-induced (TGFBI) corneal dystrophies are a group of inherited progressive corneal diseases. Accumulation of transforming growth factor beta-induced protein (TGFBIp) is involved in the pathogenesis of TGFBI corneal dystrophies; however, the exact molecular mechanisms are not fully elucidated. In this review article, we summarize the current knowledge of TGFBI corneal dystrophies including clinical manifestations, epidemiology, most common and recently reported associated mutations for each disease, and treatment modalities. We review our current understanding of the molecular mechanisms of granular corneal dystrophy type 2 (GCD2) and studies of other TGFBI corneal dystrophies. In GCD2 corneal fibroblasts, alterations of morphological characteristics of corneal fibroblasts, increased susceptibility to intracellular oxidative stress, dysfunctional and fragmented mitochondria, defective autophagy, and alterations of cell cycle were observed. Other studies of mutated TGFBIp show changes in conformational structure, stability and proteolytic properties in lattice and granular corneal dystrophies. Future research should be directed toward elucidation of the biochemical mechanism of deposit formation, the relationship between the mutated TGFBIp and the other materials in the extracellular matrix, and the development of gene therapy and pharmaceutical agents.
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Lakshminarayanan R, Chaurasia SS, Anandalakshmi V, Chai SM, Murugan E, Vithana EN, Beuerman RW, Mehta JS. Clinical and genetic aspects of the TGFBI-associated corneal dystrophies. Ocul Surf 2014; 12:234-51. [PMID: 25284770 DOI: 10.1016/j.jtos.2013.12.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 11/16/2022]
Abstract
Corneal dystrophies are a group of inherited disorders localized to various layers of the cornea that affect corneal transparency and visual acuity. The deposition of insoluble protein materials in the form of extracellular deposits or intracellular cysts is pathognomic. Mutations in TGFBI are responsible for superficial and stromal corneal dystrophies. The gene product, transforming growth factor β induced protein (TGFBIp) accumulates as insoluble deposits in various forms. The severity, clinicopathogenic variations, age of the onset, and location of the deposits depend on the type of amino acid alterations in the protein. Until 2006, 38 different pathogenic mutants were reported for the TGFBI-associated corneal dystrophies. This number has increased to 63 mutants, reported in more than 30 countries. There is no effective treatment to prevent, halt, or reverse the deposition of TGFBIp. This review presents a complete mutation update, classification of phenotypes, comprehensive reported incidents of various mutations, and current treatment options and their shortcomings. Future research directions and possible approaches to inhibiting disease progression are discussed.
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Affiliation(s)
- R Lakshminarayanan
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Shyam S Chaurasia
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Shu-Ming Chai
- Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore
| | | | - Eranga N Vithana
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Roger W Beuerman
- Singapore Eye Research Institute, Singapore; SRP Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore Eye Research Institute, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore National Eye Centre, Singapore; Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
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Daniel E, Nezzar H, Coulangeon LM, Monneyron N, Chiambaretta F. [Case report of Cogan-like dystrophy diagnosed as confirmed type I lattice corneal dystrophy in a 10-year-old child]. J Fr Ophtalmol 2013; 37:e27-31. [PMID: 24176466 DOI: 10.1016/j.jfo.2013.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/03/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
Affiliation(s)
- E Daniel
- Service d'ophtalmologie, pôle médecine interne-ophtalmologie-ORL, CHU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand, France.
| | - H Nezzar
- Service d'ophtalmologie, pôle médecine interne-ophtalmologie-ORL, CHU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand, France
| | - L M Coulangeon
- Service d'ophtalmologie, pôle médecine interne-ophtalmologie-ORL, CHU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand, France
| | - N Monneyron
- Service d'ophtalmologie, pôle médecine interne-ophtalmologie-ORL, CHU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand, France
| | - F Chiambaretta
- Service d'ophtalmologie, pôle médecine interne-ophtalmologie-ORL, CHU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand, France
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Shang D, Liu Y, Yang P, Chen Y, Tian Y. TGFBI-promoted Adhesion, Migration and Invasion of Human Renal Cell Carcinoma Depends on Inactivation of von Hippel-Lindau Tumor Suppressor. Urology 2012; 79:966.e1-7. [DOI: 10.1016/j.urology.2011.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/11/2011] [Accepted: 12/06/2011] [Indexed: 11/29/2022]
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Han YP, Sim AJ, Vora SC, Huang AJW. Unique TGFBI protein in lattice corneal dystrophy. Invest Ophthalmol Vis Sci 2011; 52:8401-6. [PMID: 21948648 DOI: 10.1167/iovs.11-7618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Specific components of transforming growth factor-beta-induced protein (TGFBIp) responsible for amyloid deposits in lattice corneal dystrophy (LCD) have not been delineated. LCD has been associated with various TGFBIp mutations such as R124C, L518P, and L527R. Using recombinant TGFBIp, this study was undertaken to identify TGFBIp components potentially contributing to the protein deposits in LCD. METHODS Recombinant wild-type (WT) TGFBIp and four mutants (R124C, R124H, L518P, and L527R) were generated in HEK293FT cells. WT and mutant TGFBIp were collected from crude cell lysates or purified from culture media. Immunoblot analyses were performed with four different anti-TGFBIp antibodies raised against various regions of TGFBIp. RESULTS Consistent with the authors' previous findings, purified recombinant proteins are more prone to polymerize than crude cell lysates. As expected, all monomers and polymers of TGFBIp WT and mutants were detected by these antibodies. However, the authors noted WT and TGFBIp mutants showed differential reactivities with these antibodies. A 47-kDa band was detected in purified 2-tag proteins of L518P by all four antibodies. A unique 43-kDa band was detected in both 1-tag cell lysates and purified proteins of R124C by the authors' custom-made antibody (KE50) and a commercial anti-TGFBIp. CONCLUSIONS Based on its universal reactivity with various antibodies, the authors surmise that the 47-kDa protein is a ubiquitous TGFBIp fragment derived from the N-terminus of the L518P mutant. The fact that the 43-kDa protein fragment was present primarily in R124C and R124H but not in WT implicates its potential role in the protein deposits of LCD.
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Affiliation(s)
- Yu-Ping Han
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Weiss JS, Møller HU, Lisch W, Kinoshita S, Aldave AJ, Belin MW, Kivelä T, Busin M, Munier FL, Seitz B, Sutphin J, Bredrup C, Mannis MJ, Rapuano CJ, Van Rij G, Kim EK, Klintworth GK. The IC3D classification of the corneal dystrophies. Cornea 2008; 27 Suppl 2:S1-83. [PMID: 19337156 PMCID: PMC2866169 DOI: 10.1097/ico.0b013e31817780fb] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The recent availability of genetic analyses has demonstrated the shortcomings of the current phenotypic method of corneal dystrophy classification. Abnormalities in different genes can cause a single phenotype, whereas different defects in a single gene can cause different phenotypes. Some disorders termed corneal dystrophies do not appear to have a genetic basis. PURPOSE The purpose of this study was to develop a new classification system for corneal dystrophies, integrating up-to-date information on phenotypic description, pathologic examination, and genetic analysis. METHODS The International Committee for Classification of Corneal Dystrophies (IC3D) was created to devise a current and accurate nomenclature. RESULTS This anatomic classification continues to organize dystrophies according to the level chiefly affected. Each dystrophy has a template summarizing genetic, clinical, and pathologic information. A category number from 1 through 4 is assigned, reflecting the level of evidence supporting the existence of a given dystrophy. The most defined dystrophies belong to category 1 (a well-defined corneal dystrophy in which a gene has been mapped and identified and specific mutations are known) and the least defined belong to category 4 (a suspected dystrophy where the clinical and genetic evidence is not yet convincing). The nomenclature may be updated over time as new information regarding the dystrophies becomes available. CONCLUSIONS The IC3D Classification of Corneal Dystrophies is a new classification system that incorporates many aspects of the traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Standardized templates provide key information that includes a level of evidence for there being a corneal dystrophy. The system is user-friendly and upgradeable and can be retrieved on the website www.corneasociety.org/ic3d.
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Affiliation(s)
- Jayne S Weiss
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Gruenauer-Kloevekorn C, Braeutigam S, Froster UG, Duncker GIW. Surgical outcome after phototherapeutic keratectomy in patients with TGFBI-linked corneal dystrophies in relation to molecular genetic findings. Graefes Arch Clin Exp Ophthalmol 2008; 247:93-9. [DOI: 10.1007/s00417-008-0931-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 06/30/2008] [Accepted: 08/01/2008] [Indexed: 10/21/2022] Open
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Aldave AJ, Yellore VS, Sonmez B, Bourla N, Salem AK, Khan MA, Rayner SA, Glasgow BJ. A novel variant of combined granular-lattice corneal dystrophy associated with the Met619Lys mutation in the TGFBI gene. ACTA ACUST UNITED AC 2008; 126:371-7. [PMID: 18332318 DOI: 10.1001/archopht.126.3.371] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To report a novel mutation in TGFBI (GenBank NM_000358), p.Met619Lys, associated with a variant of combined granular-lattice corneal dystrophy. METHODS Slitlamp examination and DNA collection from the proband and affected and unaffected relatives. All 17 exons of TGFBI were amplified and sequenced in the proband. Exon 14 was amplified and sequenced in the proband's family members and in 100 controls. Histopathologic examination of the excised corneal buttons from the proband and 3 family members was also performed. RESULTS Affected individuals demonstrated an age-dependent phenotype, with the progression from central subepithelial needlelike deposits in younger individuals to polymorphic anterior stromal opacities in older family members. Screening of TGFBI in the proband demonstrated a novel mutation, p.Met619Lys, which was also present in all affected family members. Histopathologic examination revealed stromal deposits that stained with the Congo red and Masson trichrome stains as well as an antibody to the protein product of TGFBI. CONCLUSIONS We present a unique corneal dystrophy phenotype associated with the novel p.Met619Lys mutation in TGFBI. Clinical Relevance The atypical and variable phenotype and the demonstration of both hyaline and amyloid stromal deposits indicate that neither clinical nor histopathologic features may be relied on to accurately diagnose and classify the corneal dystrophies.
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Affiliation(s)
- Anthony J Aldave
- Jules Stein Eye Institute, University of California, Los Angeles, CA 90095, USA.
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Alavi A, Elahi E, Rahmati-Kamel M, Karimian F, Rezaei-Kanavi M. Mutation screening of TGFBI in two Iranian Avellino corneal dystrophy pedigrees. Clin Exp Ophthalmol 2008; 36:26-30. [PMID: 18290950 DOI: 10.1111/j.1442-9071.2007.01649.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Genetic analysis and phenotypic features of Avellino corneal dystrophy patients from Japan and some European countries have been published. We report for the first time the genetic analysis and phenotypic features of two Avellino corneal dystrophy pedigrees from the Middle East. METHODS Slit-lamp biomicroscope photographs of cornea were obtained, and corneal tissue sections were stained with masson-trichrome and Congo red. DNA was isolated from peripheral blood leucocytes and exons 4 and 12 of TGFBI were screened for mutations by direct sequencing. RESULTS The probands of the pedigrees had phenotypic features consistent with diagnosis of Avellino corneal dystrophy. They were homozygous for the same R124H mutation in TGFBI as previously reported in Avellino patients from Japan and European countries. Heterozygous carriers of the mutation were identified in the pedigree and shown to have symptoms of disease milder than those of the probands. CONCLUSION The finding of R124H in the Middle Eastern (Iranian) population supports the proposal that perhaps only substitution of histidine for arginine at position 124 of tumour growth factor beta induced protein results in the Avellino corneal dystrophy phenotype. As both probands were originally diagnosed with granular corneal dystrophy, and as heterozygous carriers of R124H were unaware of their disease status prior to genetic analysis, the importance of genetic analysis is emphasized.
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Affiliation(s)
- Afagh Alavi
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Atchaneeyasakul LO, Appukuttan B, Pingsuthiwong S, Yenchitsomanus PT, Trinavarat A, Srisawat C. A novel H572R mutation in the transforming growth factor-beta-induced gene in a Thai family with lattice corneal dystrophy type I. Jpn J Ophthalmol 2006; 50:403-408. [PMID: 17013691 DOI: 10.1007/s10384-006-0357-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Accepted: 05/17/2006] [Indexed: 11/28/2022]
Abstract
PURPOSE To describe a large Thai family with lattice corneal dystrophy (LCD) type I and to determine whether this LCD is associated with mutations within the transforming growth factor-beta-induced (TGFBI) gene. METHODS A six-generation family with LCD type I was identified and diagnosed on the basis of clinical and/or histopathologic evaluation. Visual acuity testing and slit-lamp biomicroscopic evaluation were carried out and corneal photography was documented. All 17 exons and flanking intron sequences of the TGFBI gene were sequenced. RESULTS Thirty-three participants demonstrated LCD in both eyes, most of which was symmetrical. Age at onset of decreased vision was the mid- to late twenties. Visual acuity varied from 6/6 to no light perception. Two patients, 74 and 42 years of age, demonstrated a thick yellowish plaque covering the corneal surfaces. DNA sequencing revealed a heterozygous mutation in exon 13 (A1762G), changing histidine to arginine at codon 572 (H572R). Ten of 42 clinically unaffected family members, all under 25 years of age, exhibited the same mutation. CONCLUSIONS This is the first report of a molecular analysis of LCD type I in Thai patients. The novel mutation identified is associated with distinct phenotypes and later onset of the disease compared with the more common R124C mutation.
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Affiliation(s)
| | - Binoy Appukuttan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | | | - Pa-Thai Yenchitsomanus
- Department of Research and Development, Siriraj Hospital Mahidol University, Bangkok, Thailand
| | - Adisak Trinavarat
- Department of Ophthalmology, Siriraj Hospital Mahidol University, Bangkok, Thailand
| | - Chatchawan Srisawat
- Department of Biochemistry, Siriraj Hospital Mahidol University, Bangkok, Thailand
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Abstract
The lattice corneal dystrophies (LCD) and granular corneal dystrophies (GCD) are autosomal dominant disorders of the corneal stroma. They are bilateral, progressive conditions characterized by the formation of opacities arising due to the deposition of insoluble material in the corneal stroma leading to visual impairment. The LCDs and GCDs are distinguished from each other and are divided into subtypes on the basis of the clinical appearance of the opacities, clinical features of the disease, and on histopathological staining properties of the deposits. The GCDs and most types of LCD arise from mutations in the transforming growth factor beta-induced (TGFBI) gene on chromosome 5q31. Over 30 mutations causing LCD and GCD have been identified so far in the TGFBI. There are two mutation hotspots corresponding to arginine residues at positions 124 and 555 of the transforming growth factor beta induced protein (TGFBIp) and they are the most frequent sites of mutation in various populations. Mutations at either of these two hotspots result in specific types of LCD or GCD. The majority of identified mutations involve residues in the fourth fasciclin-like domain of TGFBIp.
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Affiliation(s)
- Chitra Kannabiran
- Kallam Anji Reddy Molecular Genetics Laboratory, L.V. Prasad Eye Institute, Hyderabad, India.
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17
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Yu P, Gu Y, Yang Y, Yan X, Chen L, Ge Z, Qi M, Si J, Guo L. A clinical and molecular-genetic analysis of Chinese patients with lattice corneal dystrophy and novel Thr538Pro mutation in the TGFBI (BIGH3) gene. J Genet 2006; 85:73-6. [PMID: 16809844 DOI: 10.1007/bf02728974] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Ping Yu
- Department of Medical Genetics, School of Medicine, Zhejiang University, Hangzhou 310006, China
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18
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Sjoberg SA. Genetics of Corneal Disease for the Ocular Surface Clinician. Ocul Surf 2005; 3:155-66. [PMID: 17131020 DOI: 10.1016/s1542-0124(12)70197-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Advances in the understanding of inherited corneal and external diseases may allow interventions that prevent the substantial vision impairment currently caused by these diseases. The observant clinician may first recognize inherited corneal and external diseases based on clinical examination and a careful family history. Researchers using positional cloning and candidate gene techniques have identified several disease-causing genes. Identification of the genes responsible for inherited corneal and external diseases will lead to more definitive diagnoses and represent the first step in development of effective therapies. Future endeavors are directed toward identifying additional inherited corneal and external diseases, the genes that cause them, and possible gene therapies to improve visual outcomes.
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Affiliation(s)
- Stacy A Sjoberg
- Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
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19
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Yoshida S, Yamaji Y, Yoshida A, Noda Y, Kumano Y, Ishibashi T. Rapid genotyping for most common TGFBI mutations with real-time polymerase chain reaction. Hum Genet 2005; 116:518-24. [PMID: 15744520 DOI: 10.1007/s00439-005-1269-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Accepted: 01/05/2005] [Indexed: 01/20/2023]
Abstract
Recent studies of the corneal dystrophies (CDs) have shown that most cases of granular CD, Avellino CD, and lattice CD type I are caused by mutations in the human transforming growth factor beta-induced (TGFBI) gene. The aim of this study was to develop a rapid diagnostic assay to detect mutations in the TGFBI gene. Sixty-six patients from 64 families with TGFBI-associated CD were studied. A primer probe set was designed to examine the genome from exons 4 and 12 of the TGFBI gene in order to identify mutant and wild-type alleles. A region spanning the mutations was amplified by the polymerase chain reaction (PCR) in a commercial cycler. Mutations were then identified by melting curve analysis of the hybrid formed between the PCR product and a specific fluorescent probe. Using this system, we clearly distinguished each CD genotype (homozygous and heterozygous 418G-->A, heterozygous 417C-->T, heterozygous 1710C-->T, and wild-type) of all the patients by means of the clearly distinct melting peaks at different temperatures. One thermal cycling took approximately 54 min, and all results were completely in concordance with the genotypes determined by conventional DNA sequencing. Thus, the technique is accurate and can be used for routine clinical diagnosis. We expect that our new method will help in making precise diagnoses of patients with atypical CDs and aid the revision of the clinical classification of inherited corneal diseases based on the genetic pathogenesis.
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Affiliation(s)
- Shigeo Yoshida
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.
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El-Ashry MF, Abd El-Aziz MM, Ficker LA, Hardcastle AJ, Bhattacharya SS, Ebenezer ND. BIGH3 mutation in a Bangladeshi family with a variable phenotype of LCDI. Eye (Lond) 2004; 18:723-8. [PMID: 15017378 DOI: 10.1038/sj.eye.6701313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
AIMS To report a Bangladeshi family displaying intrafamilial phenotypic heterogeneity of lattice corneal dystrophy type I (LCDI) and to identify the causative mutation. METHODS Molecular genetic analysis was performed on DNA extracted from all members of the family. Exons of BIGH3 gene were amplified by polymerase chain reaction. Gene mutation and polymorphisms were identified by heteroduplex and sequence analyses. Segregation of the mutation in the family was confirmed by restriction digestion of amplified gene fragments. RESULTS A heterozygous C --> T transition at the first nucleotide position of codon 124 of the BIGH3 gene was detected in the three affected members and not in the unaffected members of the family. CONCLUSIONS This is the first report of BIGH3 gene mutation in a Bangladeshi family with phenotypic heterogeneity. This study confirms that BIGH3 gene screening should be undertaken for proper classification of corneal dystrophy, especially in the absence of histopathological examination.
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Affiliation(s)
- M F El-Ashry
- Department of Molecular Genetics, Institute of Ophthalmology, London, UK. m_el_ashry@hotmailcom
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21
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Warren JF, Abbott RL, Yoon MK, Crawford JB, Spencer WH, Margolis TP. A new mutation (Leu569Arg) within exon 13 of the TGFBI (BIGH3) gene causes lattice corneal dystrophy type I. Am J Ophthalmol 2003; 136:872-8. [PMID: 14597039 DOI: 10.1016/s0002-9394(03)00541-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe an American family with lattice corneal dystrophy type I, which associates with a novel mutation, Leu569Arg, of the TGFBI (BIGH3) gene. DESIGN Experimental study. METHODS Genomic DNA was extracted from buccal epithelial cells of four affected members of an American family with lattice corneal dystrophy type I. All 17 exons of the TGFBI gene were evaluated by PCR amplification and direct sequencing. Clinical and histologic data were also collected. RESULTS Three generations of this family have been positively diagnosed with lattice corneal dystrophy, indicating autosomal dominant inheritance. We identified a heterozygous point mutation that associates with the disease phenotype. The single base-pair substitution (T1753G) results in an amino acid substitution (Leu569Arg) in exon 13 of the TGFBI gene. CONCLUSIONS Substitution of arginine for leucine at position 569 of the TGFBI gene results in a form of lattice corneal dystrophy that is phenotypically similar to other genetically distinct forms of type I disease. This is the first report of disease correlated with changes in exon 13 of the TGFBI gene.
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Affiliation(s)
- John F Warren
- Francis I. Proctor Foundation and the Department of Ophthalmology, University of California, San Francisco, San Francisco, California 94143, USA.
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22
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Chau HM, Ha NT, Cung LX, Thanh TK, Fujiki K, Murakami A, Kanai A. H626R and R124C mutations of the TGFBI (BIGH3) gene caused lattice corneal dystrophy in Vietnamese people. Br J Ophthalmol 2003; 87:686-9. [PMID: 12770961 PMCID: PMC1771727 DOI: 10.1136/bjo.87.6.686] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIMS Mutations of the human transforming growth factor beta induced gene (TGFBI) were reported to cause lattice corneal dystrophy (LCD) in various nationalities. This study analysed the TGFBI gene in Vietnamese people with LCD. METHODS 13 unrelated families, including 34 patients and 21 unaffected members were examined. 50 normal Vietnamese people served as controls. Blood samples were collected. Genomic DNA was extracted from leucocytes. Analysis of TGFBI gene was performed using the polymerase chain reaction and direct sequencing. Corneal buttons were studied histopathologically. RESULTS Two clinically distinguishable forms of LCD were revealed: one was typical of LCDI; the other was characterised by the late onset, thick lattice lines, and asymmetry between two eyes. Sequencing of the TGFBI gene revealed R124C mutation in three families and H626R mutation in 10 families. Congo red staining of the H626R-LCD cornea showed amyloid deposits in the subepithelial and stromal layers. CONCLUSIONS R124C and H626R mutations of TGFBI gene caused LCD in Vietnamese people. R124C, a common cause of LCDI in many nationalities, was relatively rare, whereas H626R reported in several white people but not yet in Asians was most common (>75%) in Vietnamese people. Since the phenotype caused by H626R represents a new variant intermediate between LCDI and LCDIIIA, we proposed to consider it as LCD type IIIB.
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Affiliation(s)
- H M Chau
- National Institute of Ophthalmology, Hanoi, Vietnam
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Schmitt-Bernard CF, Chavanieu A, Herrada G, Subra G, Arnaud B, Demaille JG, Calas B, Argilés A. BIGH3 (TGFBI) Arg124 mutations influence the amyloid conversion of related peptides in vitro. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:5149-56. [PMID: 12392546 DOI: 10.1046/j.1432-1033.2002.03205.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Amyloid deposits with Arg124 mutated TGFBI protein have been identified in autosomal dominant blinding corneal dystrophies. We assessed in vitro the mechanisms determining TGFBI protein amyloid transformation involving mutations of Arg124. Eight peptides synthesized following the TGFBI protein sequence, centered on codon Arg124 holding the previously reported amyloidogenic mutations and the respective controls were studied. Cys124 and His124 mutated peptide preparations contained significantly higher amounts of amyloid than the native peptide. Blocking the SH group of Cys124 and deleting the first four NH2-terminal amino acids including Val112-Val113 resulted in a decrease in amyloid fibril formation while deletion of the nine CONH2-terminal residues increased amyloid fibril concentration. Fourrier transformed-infrared spectroscopy analysis of the different peptide solutions showed an increase in beta-pleated sheet structures in those with enhanced amyloid yielding. We designed a peptide (BB1) likely to counteract the role of Val112-Val113 in amyloid fibril formation. Incubation of Cys124 peptide with BB1 indeed resulted in a 35% inhibition of amyloid fibril formation. Our results are in keeping with the clinical observations of Arg124 mutation-linked amyloidosis and show the importance of Val112-Val113, disulfide and hydrogen bonding in increasing the beta-pleated conformation and amyloid formation. These findings shed new light on the molecular mechanisms of TGFBI protein amyloidogenesis and encourage further research on the use of specifically designed peptides as putative therapeutic agents for these disabling diseases.
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Schmitt-Bernard CF, Schneider C, Argilés A. Clinical, histopathologic, and ultrastructural characteristics of BIGH3(TGFBI) amyloid corneal dystrophies are supportive of the existence of a new type of LCD: the LCDi. Cornea 2002; 21:463-8. [PMID: 12072720 DOI: 10.1097/00003226-200207000-00006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess the morphologic differences of three types of lattice corneal dystrophies (LCDs) from histologic, immunohistochemical, and ultrastructural studies. METHODS Corneas from three patients, one LCD1, one His626Arg-LCD, and one LCD3A were processed for Congo red, betaig-h3(541-564) antibodies immunostaining, and electron transmission microscopy studies. Control tissues were submitted to identical analyses and consisted of one cornea from a patient not having LCD and one skin biopsy from the patient suffering from LCD1. RESULTS The three corneas displayed birefringent congophilic deposits under polarized light, confirming their amyloid nature. The deposits differed regarding their shape and location in each of the corneas. A strong immunoreactivity for betaig-h3 was shown in the LCD1 and His626Arg-LCD deposits, which was faint for the LCD3A deposits. Ultrastructural analysis confirmed the dissimilarity of the deposits among the different types of LCD. No amyloid deposits were observed in the skin from the LCD1 patient, whereas immunostaining showed the presence of high amounts of betaig-h3. CONCLUSION Our results show that betaig-h3 is involved in amyloid deposition in all the LCDs included in the study (LCD1, His626Arg-LCD, and LCD3A). These three forms of LCD, clinically different, were also distinguishable histologically, confirming that they belong to distinctive groups of LCDs. The absence of amyloid deposition in skin from the LCD1 patient supports cornea-specific amyloid formation. In light of the present clinical, histologic, and ultrastructural data, His626Arg and related LCDs constitute a separate group of LCD that could be considered as of intermediate type on clinical grounds.
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Affiliation(s)
- Clair-Florent Schmitt-Bernard
- Institut de Génétique Humaine, CNRS UPR 1142, Antigone Ophtalmologie, 141 Rue de la Cardonille, 34396 Montpellier Cedex 5, France.
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Kim HS, Yoon SK, Cho BJ, Kim EK, Joo CK. BIGH3 gene mutations and rapid detection in Korean patients with corneal dystrophy. Cornea 2001; 20:844-9. [PMID: 11685063 DOI: 10.1097/00003226-200111000-00013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Mutations in the BIGH3 gene on chromosome 5q31 cause four distinct autosomal dominant corneal dystrophies. We sought to determine whether the BIGH3 gene mutation was responsible for corneal dystrophy in Korean patients. METHODS Polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) analysis was performed with the DNA from patients and healthy individuals. We sequenced the PCR products with the aberrant SSCP pattern to identify the mutation. Mutant-specific reverse primers were used to screen genomic DNA for the identified mutations. RESULTS We identified mutations R124C in the CDL1 family and R124H in four families with a granular dystrophy. We identified our granular dystrophy to be Avellino corneal dystrophy (ACD). Eighteen of 20 patients with a granular dystrophy contained the same R124H mutation, indicating that mutation R124H was very common in Korean patients with ACD. During this study, we identified a new polymorphism (T1667C, F540F). CONCLUSIONS This is the first report of mutations found in the BIGH3 gene in Korean families with corneal dystrophy. We report that the majority (90%) of ACD patients in Korea carry the R124H mutation. Mutant-specific reverse primers can be used to screen efficiently for CDL1 and ACD.
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Affiliation(s)
- H S Kim
- Laboratory of Ophthalmology and Visual Science, Catholic Research Institutes of Medical Science, Catholic University Medical College, Seoul, Korea
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26
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Kinoshita S, Adachi W, Sotozono C, Nishida K, Yokoi N, Quantock AJ, Okubo K. Characteristics of the human ocular surface epithelium. Prog Retin Eye Res 2001; 20:639-73. [PMID: 11470454 DOI: 10.1016/s1350-9462(01)00007-6] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An appreciation of the biological characteristics of the human ocular surface epithelium affords us a great insight into the physiology of the human ocular surface in health and disease. Here, we review five important aspects of the human ocular surface epithelium. First, we recognize the discovery of corneal epithelial stem cells, and note how the palisades of Vogt have been suggested as a clinical marker of their presence. Second, we introduce the concept of the gene expression profile of the ocular surface epithelium as arrived at using a new strategy for the systematic analysis of active genes. We also provide a summary of several genes abundantly or uniquely expressed in the human corneal epithelium, namely clusterin, keratin 3, keratin 12, aldehyde dehydrogenase 3 (ALDH3), troponin-I fast-twitch isoform, ssig-h3, cathepsin L2 (cathepsin V), uroplakin Ib, and Ca(2+)-activated chloride channel. Genes related to limbal and conjunctival epithelia are also described. Third, we touch upon the genetic abnormalities thought to be involved with epithelial dysfunction in Meesmann's dystrophy, gelatinous drop-like corneal dystrophy, and the ssig-h3-mutated corneal dystrophies. Fourth, we provide an update regarding the current state of knowledge of the role of cytokines, growth factors and apoptosis in relation to ocular surface homeostasis and tissue reconstruction; the main factors being epidermal growth factor (EGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), transforming growth factor-ss (TGF-ss), and some inflammatory cytokines. Fifth, corneal epithelial barrier function and dysfunction as measured by fluorophotometry is remarked upon, with an explanation of the FL-500 fluorophotometer and its ability to detect corneal epithelial dysfunction at a subclinical level. The research described in this review has undoubtedly generated a complete understanding of corneal epithelial pathophysiology-an understanding that, directly or indirectly, has helped advance the development of new therapeutic modalities for ocular surface reconstruction.
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Affiliation(s)
- S Kinoshita
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, 645 Kajii-cho, Hirokoji Kawaramachi, Kamigyo-ku, Kyoto 602-0841, Japan.
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Hirano K, Hotta Y, Nakamura M, Fujiki K, Kanai A, Yamamoto N. Late-onset form of lattice corneal dystrophy caused by leu527Arg mutation of the TGFBI gene. Cornea 2001; 20:525-9. [PMID: 11413411 DOI: 10.1097/00003226-200107000-00017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report two Japanese patients who were clinically diagnosed with late-onset and sporadic lattice corneal dystrophy (LCD) in whom a Leu527Arg mutation in the TGFBI gene was found. METHODS Molecular genetic analysis was performed on DNA extracted from peripheral leukocytes from the patients. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and directly sequenced. Histopathologic study was performed on the corneal tissue obtained during deep lamellar keratoplasty (DLK) from one of the patients. RESULTS Patient 1 was a 74-year-old man who noticed a visual disturbance at the age of 72 years. Deep stromal opacities with nodular deposits and thick lattice lines were observed only in the right cornea, and DLK was performed. Patient 2 was an 82-year-old man who had LCD (similar in appearance to that in patient 1) in both eyes without visual disturbance. Neither of the patients had a family history of corneal problems and had no episode of corneal erosion. A heterozygous single base-pair transition (CTG to CGG, leucine to arginin) was detected in codon 527 of the TGFBI gene in both patients. No mutation was found in codons 124, 501, 518, 546, or 555. Histopathologically, relatively large amyloid deposits in the deep corneal stroma and ribbons of amyloid deposits just beneath the Bowman's layer were observed in the corneal tissue of patient 1. CONCLUSIONS Clinical features and pathologic findings of the late-onset form of LCD with an L527R mutation in the TGFBI gene were made clear.
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Affiliation(s)
- K Hirano
- Department of Ophthalmology, Nagoya University School of Medicine, Nagoya, Japan.
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28
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Dighiero P, Niel F, Ellies P, D'Hermies F, Savoldelli M, Renard G, Delpech M, Valleix S. Histologic phenotype-genotype correlation of corneal dystrophies associated with eight distinct mutations in the TGFBI gene. Ophthalmology 2001; 108:818-23. [PMID: 11297504 DOI: 10.1016/s0161-6420(00)00662-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To establish a phenotype-genotype correlation of various autosomal-dominant corneal dystrophies among French subjects. DESIGN Retrospective molecular genetic study and clinicopathologic correlation. PARTICIPANTS Forty-four subjects from 26 unrelated French families were included in this study, and 60 corneal buttons could be examined at the histologic and ultrastructural levels. METHODS Light microscopy and transmission electron microscopy were performed on corneal specimens obtained during keratoplasty. Blood samples were collected for DNA analysis. MAIN OUTCOME MEASURES After genomic DNA extraction from peripheral blood leukocytes of each family member, exons of the TGFBI gene were amplified by polymerase chain reaction (PCR), and the PCR products were directly sequenced on both strands. RESULTS Four different mutations were found to be responsible for dystrophy of granular type (R555W, R124L, R124H, and R124L+delT125-delE126), three other different mutations produced a lattice type (R124C, H626R, and A546T), and the last mutation identified was associated with the honeycomb-shaped dystrophy (R555Q). Each subtype of dystrophy showed, histologically and ultrastructurally, specific characteristics that are easily recognizable. However, besides these stereotyped forms, differential histologic diagnosis of atypical forms remains difficult, and these forms could be misdiagnosed. CONCLUSIONS The characteristic biomicroscopic appearance and histopathologic features of each "classic" dystrophy present a significant degree of specificity and generally provide an accurate diagnosis. However, atypical forms in which clinical and histologic data alone could be misleading, are unequivocally diagnosed after DNA analysis.
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Affiliation(s)
- P Dighiero
- Department of Ophthalmology, Hôtel-Dieu Hospital, Paris, France
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29
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Konishi M, Yamada M, Nakamura Y, Mashima Y. Immunohistology of kerato-epithelin in corneal stromal dystrophies associated with R124 mutations of the BIGH3 gene. Curr Eye Res 2000; 21:891-6. [PMID: 11262611 DOI: 10.1076/ceyr.21.5.891.5536] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To investigate corneal deposits associated with kerato-epithelin (KE) in three corneal dystrophies harboring mutations at Arg-124 in the BIGH3 gene. METHODS Six patients with Avellino corneal dystrophy (ACD) associated with R124H, one patient with superficial granular corneal dystrophy (SGCD) associated with R124L, and seven patients with lattice corneal dystrophy type 1 (CDL1) associated with R124C were examined. Corneal buttons obtained during keratoplasties were stained with Masson's trichrome and with Congo red, and immunostained with antibodies specific for N-terminal and C-terminal portions of KE (KE-15 and KE-2, respectively). RESULTS In all corneas with ACD, subepithelial to midstromal deposits of granular material stained with KE-2 and KE-15. However, deep stromal deposits containing amyloid reacted with KE-2, but not KE-15. Granular deposits in the subepithelial layer observed in SGCD stained intensely with KE-2 and KE-15. In all corneas with CDL1, subepithelial and midstromal amyloid deposits stained with KE-2; these deposits did not stain with KE-15. Deposits between the epithelial layer and Bowman's layer stained with Masson's trichrome but not with Congo red in five of the seven corneas; these deposits were stained with both KE-2 and KE-15. CONCLUSIONS Deposits in corneal buttons involved by ACD, SGCD, and CDL1 included forms of the BIGH3 gene product, KE. An N-terminal sequence of KE may be related to formation of amyloid associated with R124 mutations.
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Affiliation(s)
- M Konishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
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30
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Fujiki K, Hotta Y, Nakayasu K, Yamaguchi T, Kato T, Uesugi Y, Ha NT, Endo S, Ishida N, Lu WN, Kanai A. Six different mutations of TGFBI (betaig-h3, keratoepithelin) gene found in Japanese corneal dystrophies. Cornea 2000; 19:842-5. [PMID: 11095060 DOI: 10.1097/00003226-200011000-00015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate mutations of the human transforming growth factor beta-induced gene (TGFBI), transforming growth factor-beta-induced gene product (betaig-h3, keratoepithelin), in Japanese patients with Avellino corneal dystrophy (ACD), lattice corneal dystrophy (LCD), granular corneal dystrophy (GCD), and Reis-Bücklers corneal dystrophy (RBCD). METHODS Genomic DNA was extracted from the peripheral blood of 75 patients and 7 unaffected relatives from 60 families with ACD, 34 patients and 8 unaffected relatives from 21 families with LCD, 4 patients and 4 unaffected relatives from 4 families with GCD, and 4 patients and an unaffected relative from 3 families with RBCD. Fifty normal volunteers served as controls. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and were directly sequenced. RESULTS Six different heterozygous missense mutations were detected in codons R124, L518, L527, and R555 of the TGFBI gene in the 117 patients from 88 families. A R124H mutation was detected in the patients with ACD. A R124C mutation was detected in the patients with LCD type 1 (LCD1), L518P was in atypical LCDI, and L527R in LCD with opacities deep in stroma. A R555W mutation was detected in the patients with GCD. A R555Q mutation was detected in the patients with RBCD. CONCLUSIONS We conclude that codons R124 and R555 of the TGFBI gene are also hot spots in Japanese patients with ACD, LCD, GCD, and RBCD. Many Japanese patients with CD had ACD with R124H mutation. GCD with R555W mutation was rare.
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Affiliation(s)
- K Fujiki
- Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan
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Abstract
PURPOSE To indicate important changes in our understanding of the corneal dystrophies. METHODS A review of the literature of the last quarter of a century. RESULTS The earliest clinical classifications of the corneal dystrophies were based on the application of clinical, biological, histochemical, and ultrastructural methods. Since then, the first great impetus to our understanding has come from the application of techniques to map disorders to specific chromosome loci, using polymorphic markers. More recently, using candidate gene and related approaches, it has been possible to identify genes causing several of the corneal dystrophies and the mutations responsible for their phenotypic variation. A notable success has been to show that several important "stromal" dystrophies result from mutations in the gene beta ig-h3, which encodes for the protein keratoepithelin (beta ig-h3). CONCLUSIONS For the corneal dystrophies, as with other inherited disorders, there is room for two sorts of classification system, one based mainly on clinical presentation and the other on an up-to-date understanding of the genetic mechanisms. They are not mutually exclusive. Some developmental corneal disorders are also discussed.
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Affiliation(s)
- A J Bron
- Nuffield Laboratory of Ophthalmology, University of Oxford, UK
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Hirano K, Hotta Y, Fujiki K, Kanai A. Corneal amyloidosis caused by Leu518Pro mutation of betaig-h3 gene. Br J Ophthalmol 2000; 84:583-5. [PMID: 10837380 PMCID: PMC1723504 DOI: 10.1136/bjo.84.6.583] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To report a Japanese family diagnosed clinically as having lattice corneal dystrophy type I (LCDI) in which a Leu518Pro mutation in the betaig-h3 gene and not the R124C mutation reported previously was found. METHODS Molecular genetic analysis was performed on DNA extracted from peripheral leucocytes from four members (three affected and one unaffected) of a family. Exon 4 of the betaig-h3 gene was amplified by PCR and directly sequenced. Histopathological study was performed on the corneal tissue from the proband obtained during deep lamellar keratoplasty. RESULTS All the affected members were clinically diagnosed as having LCDI, and the pedigree indicated an autosomal dominant inheritance. A heterozygous single base pair transition (CTG to CCG, leucine to proline) was detected in codon 518 of the betaig-h3 gene in the three affected members, and not in the unaffected member. No mutation was found in codon 124. Amyloid deposits were observed between the collagen bundles of the corneal stroma and were seen to extend deep into the stroma. CONCLUSION The Leu518Pro mutated betaig-h3 forms amyloidogeneic intermediates which precipitate in the cornea and gives rise to a clinical appearance of LCDI.
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Affiliation(s)
- K Hirano
- Department of Ophthalmology, Nagoya University School of Medicine, Aichi, Japan.
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