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Sahebjada S, Chan E, Sutton G, Pang CPC, Kerdraon Y, Natarajan S, Meteoukki W, Ang A, Daniell M, Baird PN. Keratoconus International Consortium (KIC)- advancing keratoconus research. BMC Ophthalmol 2023; 23:337. [PMID: 37501133 PMCID: PMC10375634 DOI: 10.1186/s12886-023-03087-w] [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: 09/19/2022] [Accepted: 07/16/2023] [Indexed: 07/29/2023] Open
Abstract
CLINICAL RELEVANCE The Keratoconus International Consortium (KIC) will allow better understanding of keratoconus. BACKGROUND Keratoconus is a disorder characterised by corneal elevation and thinning, leading to reduced vision. The current gaps in understanding of this disease will be discussed and the need for a multi-pronged and multi-centre engagement to enhance our understanding of keratoconus will be highlighted. DESIGN KIC has been established to address the gaps in our understanding of keratoconus with the aim of collecting baseline as well as longitudinal data on several fields. PARTICIPANTS Keratoconus and control (no corneal condition) subjects from different sites globally will be recruited in the study. METHODS KIC collects data using an online, secure database, which enables standardised data collection at member sites. Data fields collected include medical history, clinical features, quality of life and economic burden questionnaires and possible genetic sample collection from patients of different ethnicities across different geographical locations. RESULTS There are currently 40 Australian and international clinics or hospital departments who have joined the KIC. Baseline data has so far been collected on 1130 keratoconus patients and indicates a median age of 29.70 years with 61% being male. A total of 15.3% report a positive family history of keratoconus and 57.7% self-report a history of frequent eye rubbing. CONCLUSION The strength of this consortium is its international, collaborative design and use of a common data collection tool. Inclusion and analyses of cross-sectional and longitudinal data will help answer many questions that remain in keratoconus, including factors affecting progression and treatment outcomes.
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Affiliation(s)
- Srujana Sahebjada
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia.
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia.
| | - Elsie Chan
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Gerard Sutton
- Sydney Medical School, The University of Sydney, Sydney, Australia
- NSW Tissue Banks, Sydney, Australia
| | | | - Yves Kerdraon
- Sydney Medical School, The University of Sydney, Sydney, Australia
- Envision Eye Centre, Sydney, Australia
| | | | - Wafaa Meteoukki
- Molecular and Cellular Genetics Laboratory, Oran University of Science and Technology - Mohamed Boudiaf (USTOMB), Oran, Algeria
| | | | - Mark Daniell
- Centre for Eye Research Australia, Level 7, 32 Gisborne St, East Melbourne, Victoria, 3002, Australia
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Paul N Baird
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, Australia
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Hao XD, Gao H, Xu WH, Shan C, Liu Y, Zhou ZX, Wang K, Li PF. Systematically Displaying the Pathogenesis of Keratoconus via Multi-Level Related Gene Enrichment-Based Review. Front Med (Lausanne) 2022; 8:770138. [PMID: 35141241 PMCID: PMC8818795 DOI: 10.3389/fmed.2021.770138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/31/2021] [Indexed: 01/20/2023] Open
Abstract
Keratoconus (KC) is an etiologically heterogeneous corneal ectatic disorder. To systematically display the pathogenesis of keratoconus (KC), this study reviewed all the reported genes involved in KC, and performed an enrichment analysis of genes identified at the genome, transcription, and protein levels respectively. Combined analysis of multi-level results revealed their shared genes, gene ontology (GO), and pathway terms, to explore the possible pathogenesis of KC. After an initial search, 80 candidate genes, 2,933 transcriptional differential genes, and 947 differential proteins were collected. The candidate genes were significantly enriched in extracellular matrix (ECM) related terms, Wnt signaling pathway and cytokine activities. The enriched GO/pathway terms of transcription and protein levels highlight the importance of ECM, cell adhesion, and inflammatory once again. Combined analysis of multi-levels identified 13 genes, 43 GOs, and 12 pathways. The pathogenic relationships among these overlapping factors maybe as follows. The gene mutations/variants caused insufficient protein dosage or abnormal function, together with environmental stimulation, leading to the related functions and pathways changes in the corneal cells. These included response to the glucocorticoid and reactive oxygen species; regulation of various signaling (P13K-AKT, MAPK and NF-kappaB), apoptosis and aging; upregulation of cytokines and collagen-related enzymes; and downregulation of collagen and other ECM-related proteins. These undoubtedly lead to a reduction of extracellular components and induction of cell apoptosis, resulting in the loosening and thinning of corneal tissue structure. This study, in addition to providing information about the genes involved, also provides an integrated insight into the gene-based etiology and pathogenesis of KC.
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Affiliation(s)
- Xiao-Dan Hao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- *Correspondence: Xiao-Dan Hao
| | - Hua Gao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China
- Shandong Eye Hospital, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Wen-Hua Xu
- Department of Inspection, The Medical Faculty of Qingdao University, Qingdao, China
| | - Chan Shan
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Ying Liu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Zhi-Xia Zhou
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Kun Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Kun Wang
| | - Pei-Feng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Pei-Feng Li
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Ates KM, Estes AJ, Liu Y. Potential underlying genetic associations between keratoconus and diabetes mellitus. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2021; 1:100005. [PMID: 34746916 PMCID: PMC8570550 DOI: 10.1016/j.aopr.2021.100005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/18/2021] [Accepted: 08/29/2021] [Indexed: 12/14/2022]
Abstract
Background Keratoconus (KC) is the most common ectatic corneal disease, characterized by significantly localized thinning of the corneal stroma. Genetic, environmental, hormonal, and metabolic factors contribute to the pathogenesis of KC. Additionally, multiple comorbidities, such as diabetes mellitus, may affect the risk of KC. Main Body Patients with diabetes mellitus (DM) have been reported to have lower risk of developing KC by way of increased endogenous collagen crosslinking in response to chronic hyperglycemia. However, this remains a debated topic as other studies have suggested either a positive association or no association between DM and KC. To gain further insight into the underlying genetic components of these two diseases, we reviewed candidate genes associated with KC and central corneal thickness in the literature. We then explored how these genes may be regulated similarly or differentially under hyperglycemic conditions and the role they play in the systemic complications associated with DM. Conclusion Our comprehensive review of potential genetic factors underlying KC and DM provides a direction for future studies to further determine the genetic etiology of KC and how it is influenced by systemic diseases such as diabetes.
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Affiliation(s)
- Kristin M. Ates
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Amy J. Estes
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
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Tunç U, Yıldırım Y, Çelebi ARC, Kepez Yıldız B. Potential role of ocular surface microbiota in keratoconus etiopathogenesis. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1942844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Uğur Tunç
- University of Health Sciences, Beyoğlu Eye Training and Research Hospital, Ophthalmology, Istanbul, Turkey
| | - Yusuf Yıldırım
- University of Health Sciences, Beyoğlu Eye Training and Research Hospital, Ophthalmology, Istanbul, Turkey
| | | | - Burçin Kepez Yıldız
- University of Health Sciences, Beyoğlu Eye Training and Research Hospital, Ophthalmology, Istanbul, Turkey
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Unlu N, Erzurumluoglu Gokalp E, Arslan S, Cilingir O, Bilgin M, Yildirim E, Gursoy H. Association of eleven single nucleotide polymorphisms with refractive disorders from Eskisehir, Turkey. Int J Ophthalmol 2021; 14:812-817. [PMID: 34150535 DOI: 10.18240/ijo.2021.06.05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 03/05/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate relationship between refractive errors and eleven single nucleotide polymorphisms (SNPs) in HGF, GC, MFN1, GNB4, and VDR genes in Turkish population. METHODS A group of 212 participants with myopia (n=91), hyperopia (n=45), and emmetropia (n=76) were investigated in this study. SNPs in HGF, GC, MFN1, GNB4 and VDR genes were studied by SnapShot technique. RESULTS The patients in this study consists of 47 female/44 male (age: 23.47±4.30) patients with myopia, 20 female/25 male (age: 31.20±8.02) with hyperopia and 33 female/43 male (age: 25.22±6.60) with emmetropia. The genotype distribution of the rs7618348 polymorphism, which was the only statistically significant one between myopia and emmetropia group. The genotype distribution of the rs3819545, rs3735520, rs7041, and rs2239182 polymorphisms, which were statistically significant between hyperopia and emmetropia groups. CONCLUSION The importance of genetic predisposition to refractive errors with respect to etiology of the disease is revealed. It is known that polymorphism studies may differ because of genetic diversity among populations so larger cohort studies are required in different populations to enlighten the etiology of the refractive errors.
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Affiliation(s)
- Nadir Unlu
- Department of Ophthalmology, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Ebru Erzurumluoglu Gokalp
- Department of Medical Genetics, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Serap Arslan
- Department of Medical Genetics, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Oguz Cilingir
- Department of Medical Genetics, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Muzaffer Bilgin
- Department of Biostatistics, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Engin Yildirim
- Department of Pharmacology, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
| | - Huseyin Gursoy
- Department of Ophthalmology, Eskisehir Osmangazi University Medical Faculty, Eskisehir 26040, Turkey
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Hardcastle AJ, Liskova P, Bykhovskaya Y, McComish BJ, Davidson AE, Inglehearn CF, Li X, Choquet H, Habeeb M, Lucas SEM, Sahebjada S, Pontikos N, Lopez KER, Khawaja AP, Ali M, Dudakova L, Skalicka P, Van Dooren BTH, Geerards AJM, Haudum CW, Faro VL, Tenen A, Simcoe MJ, Patasova K, Yarrand D, Yin J, Siddiqui S, Rice A, Farraj LA, Chen YDI, Rahi JS, Krauss RM, Theusch E, Charlesworth JC, Szczotka-Flynn L, Toomes C, Meester-Smoor MA, Richardson AJ, Mitchell PA, Taylor KD, Melles RB, Aldave AJ, Mills RA, Cao K, Chan E, Daniell MD, Wang JJ, Rotter JI, Hewitt AW, MacGregor S, Klaver CCW, Ramdas WD, Craig JE, Iyengar SK, O'Brart D, Jorgenson E, Baird PN, Rabinowitz YS, Burdon KP, Hammond CJ, Tuft SJ, Hysi PG. A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus. Commun Biol 2021; 4:266. [PMID: 33649486 PMCID: PMC7921564 DOI: 10.1038/s42003-021-01784-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease.
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Affiliation(s)
- Alison J Hardcastle
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK.
| | - Petra Liskova
- UCL Institute of Ophthalmology, London, UK
- 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
| | - Yelena Bykhovskaya
- The Cornea Eye Institute, Beverly Hills, CA, USA
- Department of Surgery and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Bennet J McComish
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | | | - Chris F Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Xiaohui Li
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Mahmoud Habeeb
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Sionne E M Lucas
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Srujana Sahebjada
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | | | | | - Anthony P Khawaja
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
- NIHR Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, 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
| | - Bart T H Van Dooren
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Amphia Hospital, Breda, The Netherlands
| | | | - Christoph W Haudum
- Division of Endocrinology and Diabetology, Endocrinology Lab Platform, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Valeria Lo Faro
- Department of Ophthalmology, University Medical Center Groningen (UMCG), Groningen, the Netherlands
- Department of Ophthalmology, Academic Medical Center, Amsterdam, The Netherlands
| | - Abi Tenen
- Vision Eye Institute, Melbourne, VIC, Australia
- School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
- Melbourne Stem Cell Centre, Melbourne, VIC, 3800, Australia
| | - Mark J Simcoe
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Karina Patasova
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Darioush Yarrand
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Jie Yin
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Salina Siddiqui
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
- Department of Ophthalmology, St James's University Hospital, Leeds, UK
| | - Aine Rice
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Layal Abi Farraj
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Jugnoo S Rahi
- UCL Great Ormond Street Hospital Institute of Child Health, London, UK
| | | | | | - Jac C Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | | | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, UK
| | - Magda A Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Andrea J Richardson
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Paul A Mitchell
- Centre for Vision Research, Department of Ophthalmology, Westmead Institute for Medical Research, University of Sydney, Westmead, NSW, Australia
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Ronald B Melles
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Anthony J Aldave
- The Jules Stein Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Richard A Mills
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Ke Cao
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Elsie Chan
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Mark D Daniell
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Jie Jin Wang
- Health Services and Systems Research, Duke-NUS Medical School, Singapore, Singapore
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, The Lundquist Institute for Biomedical Innovation (formerly Los Angeles Biomedical Research Institute) at Harbor-UCLA Medical Center; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Vision Eye Institute, Melbourne, VIC, Australia
- School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
- Melbourne Stem Cell Centre, Melbourne, VIC, 3800, Australia
| | - Stuart MacGregor
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Wishal D Ramdas
- Department of Ophthalmology, Erasmus Medical Center GD, Rotterdam, The Netherlands
| | - Jamie E Craig
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Sudha K Iyengar
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH, USA
| | - David O'Brart
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- St Thomas Hospital, Guy's and St. Thomas NHS Trust, London, London, UK
| | - Eric Jorgenson
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Paul N Baird
- Department of Surgery, Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Yaron S Rabinowitz
- The Cornea Eye Institute, Beverly Hills, CA, USA
- Department of Surgery and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Department of Ophthalmology, Flinders University, Adelaide, SA, Australia
| | - Chris J Hammond
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
- St Thomas Hospital, Guy's and St. Thomas NHS Trust, London, London, UK
| | - Stephen J Tuft
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK.
| | - Pirro G Hysi
- Section of Ophthalmology, School of Life Course Sciences, King's College London, London, UK.
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK.
- UCL Great Ormond Street Hospital Institute of Child Health, London, UK.
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Veerappa AM. Cascade of interactions between candidate genes reveals convergent mechanisms in keratoconus disease pathogenesis. Ophthalmic Genet 2021; 42:114-131. [PMID: 33554698 DOI: 10.1080/13816810.2020.1868013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Keratoconus is a progressive thinning, steepening and distortion of the cornea which can lead to loss of vision if left untreated. Keratoconus has a complex multifactorial etiology, with genetic and environmental components contributing to the disease pathophysiology. Studies have observed high concordance between monozygotic twins, discordance between dizygotic twins, and high familial segregation indicating the presence of a very strong genetic component in the pathogenesis of keratoconus. The use of genome-wide linkage studies on families and twins, genome-wide association studies (GWAS) on case-controls, next-generation sequencing (NGS)-based genomic screens on both familial and non-familial cohorts have led to the identification of keratoconus candidate genes with much greater success and increased resproducibility of genetic findings. This review focuses on candidate genes identified till date and attempts to understand their role in biological processes underlying keratoconus pathogenesis. In addition, using these genes I propose molecular pathways that could contribute to keratoconus pathogenesis. The pathways identified the presence of direct cross-talk between known candidate genes of keratoconus and remarkably, 28 known candidate genes have a direct relationship among themselves that involves direct protein-protein binding, regulatory activities such as activation and inhibition, chaperone, transcriptional activation/co-activation, and enzyme catalysis. This review attempts to describe these relationships and cross-talks in the context of keratoconus pathogenesis.
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Affiliation(s)
- Avinash M Veerappa
- Department of Ophthalmology, NYU Langone Medical Center, New York, New York, USA
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8
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Bykhovskaya Y, Rabinowitz YS. Update on the genetics of keratoconus. Exp Eye Res 2020; 202:108398. [PMID: 33316263 DOI: 10.1016/j.exer.2020.108398] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
In the past few years we have seen a great acceleration of discoveries in the field of keratoconus including new treatments, diagnostic tools, genomic and molecular determinants of disease risk. Recent genome-wide association studies (GWAS) of keratoconus cases and population wide studies of variation in central corneal thickness and in corneal biomechanical properties confirmed already identified genes and found many new susceptibility variants and biological pathways. Recent findings in genetic determinants of familial keratoconus revealed functionally important variants and established first mouse model of keratoconus. Latest transcriptomic and expression studies started assessing novel non-coding RNA targets in addition to identifying tissue specific effects of coding genes. First genomic insights into better prediction of treatment outcomes are bringing the advent of genomic medicine into keratoconus clinical practice.
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Affiliation(s)
- Yelena Bykhovskaya
- Cornea Genetic Eye Institute, Department of Surgery and Board of the Governors Regenerative Medicine Institute, Beverly Hills, Cedars-Sinai, Los Angeles, CA, United States.
| | - Yaron S Rabinowitz
- Cornea Genetic Eye Institute, Department of Surgery and Board of the Governors Regenerative Medicine Institute, Beverly Hills, Cedars-Sinai, Los Angeles, CA, United States
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9
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McComish BJ, Sahebjada S, Bykhovskaya Y, Willoughby CE, Richardson AJ, Tenen A, Charlesworth JC, MacGregor S, Mitchell P, Lucas SEM, Mills RA, Mackey DA, Li X, Wang JJ, Jensen RA, Rotter JI, Taylor KD, Hewitt AW, Rabinowitz YS, Baird PN, Craig JE, Burdon KP. Association of Genetic Variation With Keratoconus. JAMA Ophthalmol 2020; 138:174-181. [PMID: 31855235 DOI: 10.1001/jamaophthalmol.2019.5293] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Importance Keratoconus is a condition in which the cornea progressively thins and protrudes in a conical shape, severely affecting refraction and vision. It is a major indication for corneal transplant. To discover new genetic loci associated with keratoconus and better understand the causative mechanism of this disease, we performed a genome-wide association study on patients with keratoconus. Objective To identify genetic susceptibility regions for keratoconus in the human genome. Design, Setting, and Participants This study was conducted with data from eye clinics in Australia, the United States, and Northern Ireland. The discovery cohort of individuals with keratoconus and control participants from Australia was genotyped using the Illumina HumanCoreExome single-nucleotide polymorphism array. After quality control and data cleaning, genotypes were imputed against the 1000 Genomes Project reference panel (phase III; version 5), and association analyses were completed using PLINK version 1.90. Single-nucleotide polymorphisms with P < 1.00 × 10-6 were assessed for replication in 3 additional cohorts. Control participants were drawn from the cohorts of the Blue Mountains Eye Study and a previous study of glaucoma. Replication cohorts were from a previous keratoconus genome-wide association study data set from the United States, a cohort of affected and control participants from Australia and Northern Ireland, and a case-control cohort from Victoria, Australia. Data were collected from January 2006 to March 2019. Main Outcomes and Measures Associations between keratoconus and 6 252 612 genetic variants were estimated using logistic regression after adjusting for ancestry using the first 3 principal components. Results The discovery cohort included 522 affected individuals and 655 control participants, while the replication cohorts included 818 affected individuals (222 from the United States, 331 from Australia and Northern Ireland, and 265 from Victoria, Australia) and 3858 control participants (2927 from the United States, 229 from Australia and Northern Ireland, and 702 from Victoria, Australia). Two novel loci reached genome-wide significance (defined as P < 5.00 × 10-8), with a P value of 7.46 × 10-9 at rs61876744 in patatin-like phospholipase domain-containing 2 gene (PNPLA2) on chromosome 11 and a P value of 6.35 × 10-12 at rs138380, 2.2 kb upstream of casein kinase I isoform epsilon gene (CSNK1E) on chromosome 22. One additional locus was identified with a P value less than 1.00 × 10-6 in mastermind-like transcriptional coactivator 2 (MAML2) on chromosome 11 (P = 3.91 × 10-7). The novel locus in PNPLA2 reached genome-wide significance in an analysis of all 4 cohorts (P = 2.45 × 10-8). Conclusions and Relevance In this relatively large keratoconus genome-wide association study, we identified a genome-wide significant locus for keratoconus in the region of PNPLA2 on chromosome 11.
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Affiliation(s)
- Bennet J McComish
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Srujana Sahebjada
- Centre for Eye Research Australia, Melbourne, Victoria, Australia.,Department of Surgery (Ophthalmology), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Yelena Bykhovskaya
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California.,Cornea Genetic Eye Institute, Beverly Hills, California.,Board of the Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Colin E Willoughby
- Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, United Kingdom.,Belfast Health and Social Care Trust, Belfast, Northern Ireland, United Kingdom
| | | | - Abi Tenen
- Vision Eye Institute, Melbourne, Victoria, Australia.,School of Primary and Allied Health Care, Monash University, Melbourne, Victoria, Australia.,Melbourne Stem Cell Centre, Melbourne, Victoria, Australia
| | - Jac C Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Paul Mitchell
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - Sionne E M Lucas
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Richard A Mills
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - David A Mackey
- Lions Eye Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Xiaohui Li
- Institute for Translational Genomics and Population Science, Los Angeles Biomedical Research Institute, Los Angeles, California.,Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California
| | - Jie Jin Wang
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - Richard A Jensen
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Science, Los Angeles Biomedical Research Institute, Los Angeles, California.,Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California
| | - Kent D Taylor
- Institute for Translational Genomics and Population Science, Los Angeles Biomedical Research Institute, Los Angeles, California.,Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.,Centre for Eye Research Australia, Melbourne, Victoria, Australia
| | - Yaron S Rabinowitz
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California.,Cornea Genetic Eye Institute, Beverly Hills, California.,Board of the Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Paul N Baird
- Centre for Eye Research Australia, Melbourne, Victoria, Australia.,Department of Surgery (Ophthalmology), Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Jamie E Craig
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.,Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.,Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
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10
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Sahebjada S, Chan E, Xie J, Snibson GR, Daniell M, Baird PN. Risk factors and association with severity of keratoconus: the Australian study of Keratoconus. Int Ophthalmol 2020; 41:891-899. [PMID: 33200389 DOI: 10.1007/s10792-020-01644-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/29/2020] [Indexed: 01/12/2023]
Abstract
SIGNIFICANCE Our results show that asthmatic patients tend to have more severe KC and thus close monitoring for disease progression would be advised, and appropriate treatment strategies may be actioned stabilise the condition that may reduce the need for future corneal transplantation. PURPOSE To explore a wide range of risk factors associated with the severity of keratoconus (KC). METHODS A cross-sectional study of KC patients was undertaken in Melbourne, Australia. A questionnaire addressing age, gender, educational background, ocular and medical history, smoking and alcohol consumption, and physical examination comprising anthropometric measurements was collected; eye examination was undertaken. The associations between a range of risk factors and the severity of KC were determined using univariate and multivariable linear regression analyses. RESULTS A total of 260 KC subjects were included in this study. Mean age of subject was 35.5 (SD = 14.8) years and the majority of the subjects were European 171 (68.2%). Initial univariate regression analysis identified the following risk factors at the p < 0.1 level with KC: higher body mass index, smoking cigarettes, diabetes, rheumatoid arthritis and asthma were associated with increased severity of KC, whereas eczema was associated with less severe KC. Following multivariable regression analysis, only asthma remained as a significant risk factor associated with 2.2 diopters (D) steeper average mean keratometry compared to KC subjects having no asthma [p = 0.03; β = 2.18; 95% confidence intervals: 1.22, 4.14]. CONCLUSION Our study describes the comprehensive assessment of all the known risk factors in a large KC cohort recruited in Australia. Our study has reported asthma as the only risk factor found to be significantly associated with the severity of KC. The results of this study allow us to better understand the aetiology of KC and such knowledge could be useful in instigate systemic management of patients to slow or prevent KC.
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Affiliation(s)
- Srujana Sahebjada
- Centre for Eye Research Australia, Melbourne, VIC, Australia. .,The University of Melbourne, Melbourne, VIC, Australia.
| | - Elsie Chan
- Centre for Eye Research Australia, Melbourne, VIC, Australia.,The University of Melbourne, Melbourne, VIC, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Jing Xie
- Centre for Eye Research Australia, Melbourne, VIC, Australia.,Monash University Melbourne, Melbourne, VIC, Australia
| | - Grant R Snibson
- Centre for Eye Research Australia, Melbourne, VIC, Australia.,The University of Melbourne, Melbourne, VIC, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Mark Daniell
- Centre for Eye Research Australia, Melbourne, VIC, Australia.,The University of Melbourne, Melbourne, VIC, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Paul N Baird
- The University of Melbourne, Melbourne, VIC, Australia
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11
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Karolak JA, Ginter-Matuszewska B, Tomela K, Kabza M, Nowak-Malczewska DM, Rydzanicz M, Polakowski P, Szaflik JP, Gajecka M. Further evaluation of differential expression of keratoconus candidate genes in human corneas. PeerJ 2020; 8:e9793. [PMID: 32879808 PMCID: PMC7443321 DOI: 10.7717/peerj.9793] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/31/2020] [Indexed: 12/26/2022] Open
Abstract
Background Keratoconus (KTCN) is a progressive eye disease, characterized by changes in the shape and thickness of the cornea that results in loss of visual acuity. While numerous KTCN candidate genes have been identified, the genetic etiology of the disease remains undetermined. To further investigate and verify the contribution of particular genetic factors to KTCN, we assessed 45 candidate genes previously indicated as involved in KTCN etiology based on transcriptomic and genomic data. Methods The RealTime ready Custom Panel, covering 45 KTCN candidate genes and two reference transcripts, has been designed. Then, the expression profiles have been assessed using the RT-qPCR assay in six KTCN and six non-KTCN human corneas, obtained from individuals undergoing a penetrating keratoplasty procedure. Results In total, 35 genes exhibiting differential expression between KTCN and non-KTCN corneas have been identified. Among these genes were ones linked to the extracellular matrix formation, including collagen synthesis or the TGF-β, Hippo, and Wnt signaling pathways. The most downregulated transcripts in KTCN corneas were CTGF, TGFB3, ZNF469, COL5A2, SMAD7, and SPARC, while TGFBI and SLC4A11 were the most upregulated ones. Hierarchical clustering of expression profiles demonstrated almost clear separation between KTCN and non-KTCN corneas. The gene expression levels determined using RT-qPCR showed a strong correlation with previous RNA sequencing (RNA-Seq) results. Conclusions A strong correlation between RT-qPCR and earlier RNA-Seq data confirms the possible involvement of genes from collagen synthesis and the TGF-β, Hippo, and Wnt signaling pathways in KTCN etiology. Our data also revealed altered expression of several genes, such as LOX, SPARC, and ZNF469, in which single nucleotide variants have been frequently identified in KTCN. These findings further highlight the heterogeneous nature of KTCN.
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Affiliation(s)
- Justyna A Karolak
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Barbara Ginter-Matuszewska
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Katarzyna Tomela
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Michal Kabza
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Dorota M Nowak-Malczewska
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Piotr Polakowski
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Jacek P Szaflik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Marzena Gajecka
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
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12
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Chan E, Baird PN, Vogrin S, Sundararajan V, Daniell MD, Sahebjada S. Economic impact of keratoconus using a health expenditure questionnaire: A patient perspective. Clin Exp Ophthalmol 2020; 48:287-300. [DOI: 10.1111/ceo.13704] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 11/27/2019] [Accepted: 12/14/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Elsie Chan
- Centre for Eye Research Australia Melbourne Victoria Australia
- Division of Ophthalmology, Department of SurgeryThe University of Melbourne Melbourne Victoria Australia
- Royal Victorian Eye and Ear Hospital Melbourne Victoria Australia
| | - Paul N. Baird
- Centre for Eye Research Australia Melbourne Victoria Australia
- Division of Ophthalmology, Department of SurgeryThe University of Melbourne Melbourne Victoria Australia
| | - Sara Vogrin
- Division of Ophthalmology, Department of SurgeryThe University of Melbourne Melbourne Victoria Australia
- St. Vincent's Hospital Melbourne Victoria Australia
| | - Vijaya Sundararajan
- St. Vincent's Hospital Melbourne Victoria Australia
- Department of Public HealthLa Trobe University Melbourne Victoria Australia
| | - Mark D. Daniell
- Centre for Eye Research Australia Melbourne Victoria Australia
- Division of Ophthalmology, Department of SurgeryThe University of Melbourne Melbourne Victoria Australia
- Royal Victorian Eye and Ear Hospital Melbourne Victoria Australia
| | - Srujana Sahebjada
- Centre for Eye Research Australia Melbourne Victoria Australia
- Division of Ophthalmology, Department of SurgeryThe University of Melbourne Melbourne Victoria Australia
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13
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Cao K, Sahebjada S, Richardson AJ, Baird PN. Do age-related macular degeneration genes show association with keratoconus? EYE AND VISION 2019; 6:38. [PMID: 31819893 PMCID: PMC6885317 DOI: 10.1186/s40662-019-0164-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/03/2019] [Indexed: 01/06/2023]
Abstract
Background Keratoconus (KC) is a common corneal condition with an unknown gender predominance. Although numerous studies have investigated the genetic component of KC, no specific genes have yet been attributed to the condition. We recently reported posterior segment changes occurring in the eyes of KC patients. However, it is not clear whether these changes are part of KC pathogenesis or reflect changes in anatomical features of the eye manifested by changes at the cornea. Given retinal changes represent the main characteristics observed in age-related macular degeneration (AMD) and that pleiotropy has been demonstrated between different eye diseases, we wished to assess if known AMD associated genes were also associated with KC. Methods A total of 248 KC subjects and 366 non-KC (control) subjects were recruited from public and private clinics in Melbourne for this analysis. Nineteen single nucleotide polymorphisms (SNPs) previously associated with AMD, including rs10490924 (ARMS2/HTRA1), rs10737680 (CFH), rs13278062 (TNFRSF10A), rs1864163 (CETP), rs2230199 (C3), rs3130783 (IER3/DDR1), rs334353 (TGFBR1), rs3812111 (COL10A1), rs429608 (C2/CFB), rs4420638 (APOE), rs4698775 (CFI), rs5749482 (TIMP3), rs6795735 (ADAMTS9), rs8017304 (RAD51B), rs8135665 (SLC16A8), rs920915 (LIPC), rs943080 (VEGFA), rs9542236 (B3GALTL) and rs13081855 (COL8A1/FILIP1L), were genotyped in this cohort. Logistic regression was applied to evaluate the association between these SNPs and KC on both genders together, as well as each gender separately. Linear regression was also applied to assess the association between SNPs and corneal curvature. Bonferroni correction was applied to adjust for multiple testing. Results Genotyping data were available for 18 SNPs. The SNP, rs6795735 (ADAMTS9) was significantly associated with KC (p = 3.5 × 10- 4) when both genders were assessed, whereas rs5749482 (TIMP3) was only associated in males (p = 7.7 × 10- 4) following Bonferroni multiple correction. However, when the covariates of age and gender were included, the associations became non-significant. In addition, none of the SNPs appeared significant for corneal curvature. Conclusions Our study suggested a potential association of rs6795735 in the ADAMTS9 gene and rs5749482 in the TIMP3 gene in KC and that different associations may be gender specific. Overall, SNPs initially identified as associated with AMD following multiple correction may be further impacted by other factors such as age or gender and further studies are needed to resolve this issue.
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Affiliation(s)
- Ke Cao
- 1Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,2Department of Surgery, Ophthalmology, The University of Melbourne, 32 Gisborne Street, East Melbourne, VIC 3000 Australia
| | - Srujana Sahebjada
- 1Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,2Department of Surgery, Ophthalmology, The University of Melbourne, 32 Gisborne Street, East Melbourne, VIC 3000 Australia
| | - Andrea J Richardson
- 1Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Paul N Baird
- 2Department of Surgery, Ophthalmology, The University of Melbourne, 32 Gisborne Street, East Melbourne, VIC 3000 Australia
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14
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Kabza M, Karolak JA, Rydzanicz M, Udziela M, Gasperowicz P, Ploski R, Szaflik JP, Gajecka M. Multiple Differentially Methylated Regions Specific to Keratoconus Explain Known Keratoconus Linkage Loci. Invest Ophthalmol Vis Sci 2019; 60:1501-1509. [PMID: 30994860 DOI: 10.1167/iovs.18-25916] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Keratoconus (KTCN) is a complex eye disorder resulting in loss of visual function. Its development is affected by genetic and environmental components. The aim of this study was to unravel the role of epigenetic factors in KTCN. Methods To verify if DNA methylation may play a role in KTCN development, reduced representation bisulfite sequencing of five KTCN and five non-KTCN human corneas was performed. Results Multiple KTCN-specific differentially methylated regions were detected and many of them overlap previously identified KTCN linkage loci (3p14.3, 5q35.2, 13q32.3, 15q24.1, and 20p13) and chromosome arms that have been linked to KTCN (2q, 4q, 5p, 9p, 14q, and 17q). Reanalysis of the previously described RNA sequencing dataset of 25 KTCN and 25 non-KTCN human corneas revealed that 12 genes downregulated in KTCN and 6 upregulated genes overlapped or were located in the near vicinity of the identified differentially methylated regions. Particularly interesting were the DNA methylation changes in WNT3 and WNT5A encoding Wnt ligands, as they provide a potential explanation for the Wnt signaling pathway dysregulation observed in KTCN. Conclusions We presented the results of data analysis from the first study of DNA methylation changes in human KTCN corneas compared to non-KTCN samples. We were able to identify genomic regions with distinct patterns of DNA hypo- and hypermethylation and link them to previously found KTCN susceptibility loci as well as transcriptomic disruption of Wnt signaling pathway observed in KTCN.
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Affiliation(s)
- Michal Kabza
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Justyna A Karolak
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | | | - Monika Udziela
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Gasperowicz
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Rafal Ploski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Jacek P Szaflik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Marzena Gajecka
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
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15
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Skorodumova LO, Belodedova AV, Sharova EI, Malyugin BE. [Search for genetic markers for precise diagnostics of keratoconus]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2019; 65:9-20. [PMID: 30816092 DOI: 10.18097/pbmc20196501009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Keratoconus is a chronic disorder of the cornea, characterized by its progressive thinning, stretching, and conical protrusion. Diagnostics of subclinical keratoconus, as well as its early stages (forme fruste), is a complex problem. The presence of these forms of keratoconus in a patient is one of the reasons for the development of keratectasia after laser refractive surgery. Currently, the role of genetic factors in keratoconus development has been proven. This indicates the possibility of diagnostics of subclinical and forme fruste keratoconus using genetic markers. Knowledge about the patient's genetic susceptibility to keratoconus would allow correcting the tactics of treatment of refractive anomalies and avoiding serious side effects. The studies of causal mutations indicate the genetic heterogeneity of keratoconus, which complicates the development of a diagnostic panel. Selection of candidate variants from the currently known ones based on clear criteria may be one of the approaches for diagnostic markers search. In this review, we have analyzed articles on keratoconus markers in order to form a list of candidate variants for genotyping in the Russian population. The selection criteria took into account the complexes of symptoms in which a marker was found, populations in which a particular marker was investigated, the presence and results of replication studies. The analysis included markers in VSX1, SOD1, ZEB1, LOX, CAST, DOCK9, TGFBI, HGF, MAP3K19, KCND3, COL4A3, COL4A4, COL5A1, FNDC3B, FOXO1, BANP-ZNF469, MPDZ-NF1B, WNT10A genes. Based on the results of the analysis, the following candidate variants were selected for genotyping in the Russian population of patients with keratoconus: rs1536482 and rs7044529 in the COL5A1 gene, rs5745752 and rs2286194 in the HGF gene, rs4954218 in the MAP3K19 gene, rs4839200 near the KCND3 gene, rs2721051 near the FOXO1 gene, rs1324183 between the MPDZ and the NF1B genes, and rs121908120 in the WNT10A gene.
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Affiliation(s)
- L O Skorodumova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - A V Belodedova
- Fyodorov Eye Microsurgery Complex Federal State Institution, Moscow, Russia
| | - E I Sharova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - B E Malyugin
- Fyodorov Eye Microsurgery Complex Federal State Institution, Moscow, Russia
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16
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Volatier TLA, Figueiredo FC, Connon CJ. Keratoconus at a Molecular Level: A Review. Anat Rec (Hoboken) 2019; 303:1680-1688. [DOI: 10.1002/ar.24090] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/19/2018] [Accepted: 11/02/2018] [Indexed: 12/12/2022]
Affiliation(s)
| | | | - Che J. Connon
- Institute of Genetic MedicineNewcastle University Newcastle upon Tyne UK
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17
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Differential epithelial and stromal protein profiles in cone and non-cone regions of keratoconus corneas. Sci Rep 2019; 9:2965. [PMID: 30814630 PMCID: PMC6393548 DOI: 10.1038/s41598-019-39182-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022] Open
Abstract
Keratoconus (KC) is an ectatic corneal disease characterized by progressive thinning and irregular astigmatism, and a leading indication for corneal transplantation. KC-associated changes have been demonstrated for the entire cornea, but the pathological thinning and mechanical weakening is usually localized. We performed quantitative proteomics using Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectrometry (SWATH-MS) to analyze epithelial and stromal changes between the topographically-abnormal cone and topographically-normal non-cone regions of advanced KC corneas, compared to age-matched normal corneas. Expression of 20 epithelial and 14 stromal proteins was significantly altered (≥2 or ≤0.5-fold) between cone and non-cone in all 4 KC samples. Ingenuity pathway analysis illustrated developmental and metabolic disorders for the altered epithelial proteome with mitochondrion as the significant gene ontology (GO) term. The differential stromal proteome was related to cellular assembly, tissue organization and connective tissue disorders with endoplasmic reticulum protein folding as the significant GO term. Validation of selected protein expression was performed on archived KC, non-KC and normal corneal specimens by immunohistochemistry. This is the first time to show that KC-associated proteome changes were not limited to the topographically-thinner and mechanically-weakened cone but also non-cone region with normal topography, indicating a peripheral involvement in KC development.
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18
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HGF-rs12536657 and Ocular Biometric Parameters in Hyperopic Children, Emmetropic Adolescents, and Young Adults: A Multicenter Quantitative Trait Study. J Ophthalmol 2019; 2019:7454250. [PMID: 30863626 PMCID: PMC6378066 DOI: 10.1155/2019/7454250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/14/2018] [Accepted: 12/30/2018] [Indexed: 01/31/2023] Open
Abstract
Introduction Even though ocular refractive state is highly heritable and under strong genetic control, the identification of susceptibility genes remains a challenge. Several HGF (hepatocyte growth factor) gene variants have been associated with ocular refractive errors and corneal pathology. Purpose Here, we assess the association of an HGF gene variant, previously reported as associated with hyperopia, and ocular biometric parameters in a multicenter Spanish cohort. Methods An observational prospective multicenter cross-sectional study was designed, including a total of 403 unrelated subjects comprising 188 hyperopic children (5 to 17 years) and 2 control groups: 52 emmetropic adolescents (13 to 17 years) and 163 emmetropic young adults (18 to 28 years). Each individual underwent a comprehensive eye examination including cycloplegic refraction, and topographic and ocular biometric analysis. Genomic DNA was extracted from oral swabs. HGF single nucleotide polymorphism (SNP) rs12536657 was genotyped. Genotypic, allelic, and logistic regression analyses were performed comparing the different groups. A quantitative trait association test analyzing several biometric parameters was also performed using generalized estimating equations (GEEs) adjusting for age and gender. Results No association between rs12536657 and hyperopia was found through gender-adjusted logistic regression comparing the hyperopic children with either of the two control groups. Significant associations between mean topographic corneal curvature and rs12536657 for G/A (slope = +0.32; CI 95%: 0.04-0.60; p=0.023) and A/A (slope = +0.76; CI 95%: 0.12-1.40; p=0.020) genotypes were observed with the age- and gender-adjusted univariate GEE model. Both flat and steep corneal topographic meridians were also significantly associated with rs12536657 for the G/A and A/A genotypes. No association was found between rs12536657 and any other topographic or biometric measurements. Conclusions Our results support a possible role for HGF gene variant rs12536657 in corneal curvature in our population. To our knowledge, this is the first multicenter quantitative trait association study of HGF genotypes and ocular biometric parameters comprising a pediatric cohort.
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19
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Loukovitis E, Sfakianakis K, Syrmakesi P, Tsotridou E, Orfanidou M, Bakaloudi DR, Stoila M, Kozei A, Koronis S, Zachariadis Z, Tranos P, Kozeis N, Balidis M, Gatzioufas Z, Fiska A, Anogeianakis G. Genetic Aspects of Keratoconus: A Literature Review Exploring Potential Genetic Contributions and Possible Genetic Relationships with Comorbidities. Ophthalmol Ther 2018; 7:263-292. [PMID: 30191404 PMCID: PMC6258591 DOI: 10.1007/s40123-018-0144-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Keratoconus (KC) is a complex, genetically heterogeneous, multifactorial degenerative disorder that is accompanied by corneal ectasia which usually progresses asymmetrically. With an incidence of approximately 1 per 2000 and 2 cases per 100,000 population presenting annually, KC follows an autosomal recessive or dominant pattern of inheritance and is, apparently, associated with genes that interact with environmental, genetic, and/or other factors. This is an important consideration in refractive surgery in the case of familial KC, given the association of KC with other genetic disorders and the imbalance between dizygotic twins. The present review attempts to identify the genetic loci contributing to the different KC clinical presentations and relate them to the common genetically determined comorbidities associated with KC. METHODS The PubMed, MEDLINE, Google Scholar, and GeneCards databases were screened for KC-related articles published in English between January 2006 and November 2017. Keyword combinations of "keratoconus," "risk factor(s)," "genetics," "genes," "genetic association(s)," and "cornea" were used. In total, 217 articles were retrieved and analyzed, with greater weight placed on the more recent literature. Further bibliographic research based on the 217 articles revealed another 124 relevant articles that were included in this review. Using the reviewed literature, an attempt was made to correlate genes and genetic risk factors with KC characteristics and genetically related comorbidities associated with KC based on genome-wide association studies, family-based linkage analysis, and candidate-gene approaches. RESULTS An association matrix between known KC-related genes and KC symptoms and/or clinical signs together with an association matrix between identified KC genes and genetically related KC comorbidities/syndromes were constructed. CONCLUSION Twenty-four genes were identified as potential contributors to KC and 49 KC-related comorbidities/syndromes were found. More than 85% of the known KC-related genes are involved in glaucoma, Down syndrome, connective tissue disorders, endothelial dystrophy, posterior polymorphous corneal dystrophy, and cataract.
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Affiliation(s)
| | - Konstantinos Sfakianakis
- Division of Surgical Anatomy, Laboratory of Anatomy, Medical School, Democritus University of Thrace, University Campus, Alexandroupolis, Greece
| | - Panagiota Syrmakesi
- AHEPA University Hospital, Thessaloníki, Greece
- Ophthalmica Eye Institute, Thessaloníki, Greece
| | - Eleni Tsotridou
- Ophthalmica Eye Institute, Thessaloníki, Greece
- Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Myrsini Orfanidou
- Ophthalmica Eye Institute, Thessaloníki, Greece
- Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Dimitra Rafailia Bakaloudi
- Ophthalmica Eye Institute, Thessaloníki, Greece
- Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Maria Stoila
- Ophthalmica Eye Institute, Thessaloníki, Greece
- Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece
| | - Athina Kozei
- Ophthalmica Eye Institute, Thessaloníki, Greece
- School of Pharmacology, University of Nicosia, Makedonitissis, Nicosia, Cyprus
| | | | | | | | | | | | - Zisis Gatzioufas
- Department of Ophthalmology, Cornea, Cataract and Refractive Surgery, University Hospital Basel, Basel, Switzerland
| | - Aliki Fiska
- Laboratory of Anatomy, Medical School, Democritus University of Thrace, University Campus, Alexandroupolis, Greece
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Roy S, Yadav S, Dasgupta T, Chawla S, Tandon R, Ghosh S. Interplay between hereditary and environmental factors to establish an in vitro disease model of keratoconus. Drug Discov Today 2018; 24:403-416. [PMID: 30408528 DOI: 10.1016/j.drudis.2018.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/03/2018] [Accepted: 10/31/2018] [Indexed: 01/01/2023]
Abstract
Keratoconus (KC) is a bilateral corneal dystrophy and a multifactorial, multigenic disorder with an etiology involving a strong environmental component and complex inheritance patterns. The underlying pathophysiology of KC is poorly understood because of potential crosstalk between genetic-epigenetic variants possibly triggered by the environmental factors. Here, we decode the etiopathological basis of KC using genomic, transcriptomic, proteomic and metabolic approaches. The lack of relevant models that accurately imitate this condition has been particularly limiting in terms of the effective management of KC. Tissue-engineered in vitro models of KC could address this need and generate valuable insights into its etiopathology for the establishment of disease models to accelerate drug discovery.
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Affiliation(s)
- Subhadeep Roy
- Regenerative Engineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi, India
| | - Saumya Yadav
- Cornea & Refractive Surgery Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Tanushree Dasgupta
- Regenerative Engineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi, India
| | - Shikha Chawla
- Regenerative Engineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi, India
| | - Radhika Tandon
- Cornea & Refractive Surgery Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Sourabh Ghosh
- Regenerative Engineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi, India.
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Affiliation(s)
- D Karamichos
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, USA.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
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Lucas SEM, Zhou T, Blackburn NB, Mills RA, Ellis J, Leo P, Souzeau E, Ridge B, Charlesworth JC, Lindsay R, Craig JE, Burdon KP. Rare, potentially pathogenic variants in 21 keratoconus candidate genes are not enriched in cases in a large Australian cohort of European descent. PLoS One 2018; 13:e0199178. [PMID: 29924831 PMCID: PMC6010250 DOI: 10.1371/journal.pone.0199178] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/01/2018] [Indexed: 12/30/2022] Open
Abstract
Many genes have been suggested as candidate genes for keratoconus based on their function, their proximity to associated polymorphisms or due to the identification of putative causative variants within the gene. However, very few of these genes have been assessed for rare variation in keratoconus more broadly. In contrast, VSX1 and SOD1 have been widely assessed, however, the vast majority of studies have been small and the findings conflicting. In a cohort of Australians of European descent, consisting of 385 keratoconus cases and 396 controls, we screened 21 keratoconus candidate genes: BANP, CAST, COL4A3, COL4A4, COL5A1, FOXO1, FNDC3B, HGF, IL1A, IL1B, ILRN, IMMP2L, MPDZ, NFIB, RAB3GAP1, RAD51, RXRA, SLC4A11, SOD1, TF and VSX1. The candidate genes were sequenced in these individuals by either whole exome sequencing or targeted gene sequencing. Variants were filtered to identify rare (minor allele frequency <1%), potentially pathogenic variants. A total of 164 such variants were identified across the two groups with no variants fulfilling these criteria in cases in IL1RN, BANP, IL1B, RAD51 or SOD1. The frequency of variants was compared between cases and controls using chi-square or Fishers' Exact tests for each gene with at least one rare potentially pathogenic variant identified in the case cohort. The number of rare potentially pathogenic variants per gene ranged from three (RXRA) to 102 (MPDZ), however for all genes, there was no difference in the frequency between the cases and controls. We conclude that rare potentially pathogenic variation in the 21 candidate genes assessed do not play a major role in keratoconus susceptibility and pathogenesis.
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Affiliation(s)
- Sionne E. M. Lucas
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Tiger Zhou
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Nicholas B. Blackburn
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
- South Texas Diabetes and Obesity Institute, Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Brownsville, Texas, United States of America
| | - Richard A. Mills
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Jonathan Ellis
- Queensland University of Technology and Translational Research Institute, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Paul Leo
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Bronwyn Ridge
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Jac C. Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Richard Lindsay
- Richard Lindsay and Associates, East Melbourne, Victoria, Australia
| | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Kathryn P. Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
- * E-mail:
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You J, Corley SM, Wen L, Hodge C, Höllhumer R, Madigan MC, Wilkins MR, Sutton G. RNA-Seq analysis and comparison of corneal epithelium in keratoconus and myopia patients. Sci Rep 2018; 8:389. [PMID: 29321650 PMCID: PMC5762683 DOI: 10.1038/s41598-017-18480-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/12/2017] [Indexed: 12/12/2022] Open
Abstract
Keratoconus is a common degenerative corneal disease that can lead to significant visual morbidity, and both genetic and environmental factors have been implicated in its pathogenesis. We compared the transcriptome of keratoconus and control epithelium using RNA-Seq. Epithelial tissues were obtained prior to surgery from keratoconus and myopia control patients, undergoing collagen cross-linking and photorefractive keratectomy, respectively. We identified major differences in keratoconus linked to cell-cell communication, cell signalling and cellular metabolism. The genes associated with the Hedgehog, Wnt and Notch1 signaling pathways were down-regulated in keratoconus. We also identified plasmolipin and Notch1 as being significantly reduced in keratoconus for both gene and protein expression (p < 0.05). Plasmolipin is a novel protein identified in human corneal epithelium, and has been demonstrated to have a key role in epithelial cell differentiation in other tissues. This study shows altered gene and protein expression of these three proteins in keratoconus, and further studies are clearly warranted to confirm the functional role of these proteins in the pathogenesis of keratoconus.
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Affiliation(s)
- Jingjing You
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia.
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Australia.
| | - Susan M Corley
- School of Biotechnology and Biomolecular Science, NSW System Biology Initiative, University of New South Wales, New South Wales, Australia
| | - Li Wen
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Chris Hodge
- Lions NSW Eye Bank, Sydney, Australia
- Vision Eye Institute, Chatswood, New South Wales, Australia
| | - Roland Höllhumer
- University of the Witwatersrand, Johannesburg, South Africa
- The Cornea Foundation, Johannesburg, South Africa
| | - Michele C Madigan
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Science, NSW System Biology Initiative, University of New South Wales, New South Wales, Australia
| | - Gerard Sutton
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- Lions NSW Eye Bank, Sydney, Australia
- Vision Eye Institute, Chatswood, New South Wales, Australia
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Yuksel Elgin C, Iskeleli G, Aydin O. Effects of the rigid gas permeable contact lense use on tear and ocular surface among keratoconus patients. Cont Lens Anterior Eye 2017; 41:273-276. [PMID: 29223651 DOI: 10.1016/j.clae.2017.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 12/03/2017] [Accepted: 12/05/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate changes in tear and ocular surface of patients with keratoconus using rigid gas permeable contact lenses (RGPCL) and compare them against keratoconus patients who were not using lenses as well as a control group of healthy subjects. METHODS 24 keratoconus patients using RGPCL (Group 1) 22 patients who were not using lenses (Group 3) and 21 healthy subjects (Group 3) were included in the study. Subjective complaints about the subjects' eyes have been investigated using the ocular-surface disease index (OSDI). After the control of best-corrected visual acuity, anterior chamber and fundus examinations were performed. RESULTS Schirmer (p-value=0.01) and tear break up mean comparison tests (p-value=0.002) revealed significant differences across different groups but tear osmolarity analysis did not (p-value >0.05). Oxford and OSDI scores were compatible with Schirmer and tear break up test comparisons. (for both p-value=0.001) Moreover, no statistical differences were seen in impression cytology measures between groups. (p-value >0.05) CONCLUSIONS: The erosion in the tear film stability is in line with the erosion in the ocular surface epithelium. Taking into account the statistical indifference between the impression cytology measures across groups, the break up time differences may be attributed to the collagen destruction in tear.
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Affiliation(s)
| | - Guzin Iskeleli
- Istanbul University Cerrahpasa, School of Medicine, Department of Opthalmology, Turkey.
| | - Ovgu Aydin
- Istanbul University, Cerrahpasa School of Medicine, Department of Pathology, Turkey.
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25
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Moussa S, Grabner G, Ruckhofer J, Dietrich M, Reitsamer H. Genetics in Keratoconus - What is New? Open Ophthalmol J 2017; 11:201-210. [PMID: 28932336 PMCID: PMC5585456 DOI: 10.2174/1874364101711010201] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 04/01/2017] [Accepted: 06/14/2017] [Indexed: 11/22/2022] Open
Abstract
Background: Keratoconus is characterized as a bilateral, progressive, non-inflammatory thinning of the cornea resulting in blurred vision due to irregular astigmatism. Keratoconus has a multifactorial etiology, with multiple genetic and environmental components contributing to the disease pathophysiology. Several genomic loci and genes have been identified that highlight the complex molecular etiology of this disease. Conclusion: The review focuses on current knowledge of these genetic risk factors associated with keratoconus.
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Affiliation(s)
- Sarah Moussa
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria
| | - Günther Grabner
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria
| | - Josef Ruckhofer
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria
| | - Marie Dietrich
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria
| | - Herbert Reitsamer
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria
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26
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Rong SS, Ma STU, Yu XT, Ma L, Chu WK, Chan TCY, Wang YM, Young AL, Pang CP, Jhanji V, Chen LJ. Genetic associations for keratoconus: a systematic review and meta-analysis. Sci Rep 2017; 7:4620. [PMID: 28676647 PMCID: PMC5496893 DOI: 10.1038/s41598-017-04393-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/15/2017] [Indexed: 12/21/2022] Open
Abstract
Genetic associations for keratoconus could be useful for understanding disease pathogenesis and discovering biomarkers for early detection of the disease. We conducted a systematic review and meta-analysis to summarize all reported genetic associations for the disease. We searched in the MEDLINE, Embase, Web of Science, and HuGENET databases for genetic studies of keratoconus published from 1950 to June 2016. The summary odds ratio and 95% confidence intervals of all polymorphisms were estimated using the random-effect model. Among 639 reports that were retrieved, 24 fulfilled required criteria as eligible studies for meta-analysis, involving a total of 53 polymorphisms in 28 genes/loci. Results of our meta-analysis lead to the prioritization of 8 single-nucleotide polymorphisms (SNPs) in 6 genes/loci for keratoconus in Whites. Of them 5 genes/loci were originally detected in genome-wide association studies, including FOXO1 (rs2721051, P = 5.6 × 10-11), RXRA-COL5A1 (rs1536482, P = 2.5 × 10-9), FNDC3B (rs4894535, P = 1.4 × 10-8), IMMP2L (rs757219, P = 6.1 × 10-7; rs214884, P = 2.3 × 10-5), and BANP-ZNF469 (rs9938149, P = 1.3 × 10-5). The gene COL4A4 (rs2229813, P = 1.3 × 10-12; rs2228557, P = 4.5 × 10-7) was identified in previous candidate gene studies. We also found SNPs in 10 genes/loci that had a summary P value < 0.05. Sensitivity analysis indicated that the results were robust. Replication studies and understanding the roles of these genes in keratoconus are warranted.
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Affiliation(s)
- Shi Song Rong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Sarah Tsz Ue Ma
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xin Ting Yu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Department of Gastroenterology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Li Ma
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Tommy Chung Yan Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Yu Meng Wang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Alvin L Young
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Vishal Jhanji
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
- Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China.
- UPMC Eye Centre, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
- Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China.
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Joseph R, Srivastava OP, Pfister RR. Modeling Keratoconus Using Induced Pluripotent Stem Cells. Invest Ophthalmol Vis Sci 2017; 57:3685-97. [PMID: 27403997 PMCID: PMC5996875 DOI: 10.1167/iovs.16-19105] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
PURPOSE To model keratoconus (KC) using induced pluripotent stem cells (iPSC) generated from fibroblasts of both KC and normal human corneal stroma by a viral method. METHODS Both normal and KC corneal fibroblasts from four human donors were reprogramed directly by delivering reprogramming factors in a single virus using 2A "self-cleaving" peptides, using a single polycistronic lentiviral vector coexpressing four transcription factors (Oct 4, Sox2, Klf4, and Myc) to yield iPSC. These iPS cells were characterized by immunofluorescence detection using of stem cell markers (SSEA4, Oct4, and Sox2). The mRNA sequencing was performed and the datasets were analyzed using ingenuity pathways analysis (IPA) software. RESULTS The generated stem cell-like clones expressed the pluripotency markers, SSEA4, Oct4, Sox2, Tra-1-60, and also expressed pax6. Our transcriptome analysis showed 4300 genes, which had 2-fold change and 870 genes with a q-value of <0.05 in keratoconus iPSC compared to normal iPSC. One of the genes that showed difference in KC iPSC was FGFR2 (down-regulated by 2.4 fold), an upstream target of Pi3-Kinase pathway, was further validated in keratoconus corneal sections and also KC iPSC-derived keratocytes (down regulated by 2.0-fold). Both normal and KC-derived keratocytes expressed keratocan, signature marker for keratocytes. KC iPSC-derived keratocytes showed adverse growth and proliferation and was further confirmed by using Ly2924002, a PI3k inhibitor, which severely affected the growth and differentiation in normal iPSC. CONCLUSIONS Based on our result, we propose a model for KC in which inhibition FGFR2-Pi3-Kinase pathway affects the AKT phosphorylation, and thus affecting the keratocytes survival signals. This inhibition of the survival signals could be a potential mechanism for the KC-specific decreased cell survival and apoptosis of keratocytes.
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Affiliation(s)
- Roy Joseph
- Department of Optometry and Vision Science University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Om P Srivastava
- Department of Optometry and Vision Science University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Roswell R Pfister
- Eye Research Laboratory, Eye Research Foundation, Birmingham, Alabama, United States
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Bikbov MM, Usubov EL, Oganisyan KK, Lobov SL, Khasanova RR, Dzhemileva LU, Khusnutdinova EK. Genetic aspects of keratoconus development. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417040020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Correlation between the COL4A3, MMP-9, and TIMP-1 polymorphisms and risk of keratoconus. Jpn J Ophthalmol 2017; 61:218-222. [PMID: 28197741 DOI: 10.1007/s10384-017-0503-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/30/2016] [Indexed: 12/17/2022]
Abstract
PURPOSE Keratoconus (KC) is thinning of the central cornea. Its etiology is unknown, but it may result from degrading of collagen type IV. The major protein in the cornea is collagen. Matrix metalloproteinase-9 (MMP-9) is able to degrade collagen type IV from the basement membrane and extracellular matrix (ECM). MMP-9 enzymatic activity is inhibited by the tissue inhibitor of metalloproteinase-1 (TIMP-1). In the present study, we sought to investigate and evaluate the effects of single nucleotide polymorphisms in COL4A3, MMP-9, and TIMP-1 on the risk of KC in an Iranian population sample. METHODS This case-control study was performed on 140 KC patients and 150 healthy controls. Genotyping of the COL4A3 rs55703767, MMP-9 rs17576, and TIMP-1 rs6609533 polymorphisms was done using amplification refractory mutation system polymerase chain reaction (ARMS-PCR). RESULTS Our findings showed that the rs55703767G/T polymorphism decreased the risk of KC (OR = 0.26, 95% CI = 0.08-0.82, P = 0.022). rs17576A/G, associated with KC and the A allele, was significantly overrepresented in healthy individuals. rs6609533A/G (X-chromosome) increased the risk of KC in females (OR = 2.27, 95% CI = 1.06-4.76, P = 0.036). In males, the allele frequency was not associated with KC risk/protection. CONCLUSIONS This study indicates that in our population, the COL4A3 rs55703767 polymorphism decreased the risk of KC. However, the TIMP-1 rs6609533 polymorphism was associated with an increased risk of KC.
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Chen HY, Chen YM, Wu J, Yang FC, Lv Z, Qian YG, Zheng SS. Effects of HGF gene polymorphisms and protein expression on transhepatic arterial chemotherapeutic embolism efficacy and prognosis in patients with primary liver cancer. Onco Targets Ther 2017; 10:803-810. [PMID: 28243116 PMCID: PMC5315352 DOI: 10.2147/ott.s115035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Objective To investigate the correlations of two hepatocyte growth factor (HGF) gene polymorphisms (rs5745652 and rs2074725) and their protein expression levels with the efficacy of transhepatic arterial chemotherapeutic embolism (TACE) and prognosis in patients with primary liver cancer (PLC). Methods From March 2011 to June 2012, 109 PLC patients (the case group) who chose TACE as primary treatment and 80 healthy people (the control group) who had undergone physical examination in The First Affiliated Hospital, Zhejiang University were selected during the same period. Gene polymorphisms of HGF rs5745652 and HGF rs2074725 were detected. Serum HGF level, treating efficacy, survival quality, and 3-year survival rate for PLC patients who received TACE were observed. Results There were significant differences in genotype and allele frequencies of HGF rs5745652 and HGF rs2074725, between the case and control groups (all P<0.05). Compared with CT+TT genotype of HGF rs5745652, patients carrying CC genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate (all P<0.05). In rs2074725, patients carrying CA+AA genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate compared with patients carrying rs2074725 CC genotype (all P<0.05). Gene polymorphisms of HGF rs5745652 and HGF rs2074725, tumor size, and Barcelona Clinic Liver Cancer stage were independent prognostic factors for PLC (P<0.05). Conclusion Our results indicated that HGF gene polymorphisms affect TACE efficacy and survival quality of PLC patients. Patients with HGF CC genotype of rs5745652 and CA+AA genotype of rs2074725 had decreased HGF level, better curative effect, high survival quality, and a good prognosis after TACE treatment.
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Affiliation(s)
- Hai-Yong Chen
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
| | - Yao-Min Chen
- Department of Breast Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Jian Wu
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
| | - Fu-Chun Yang
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
| | - Zhen Lv
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
| | - Yi-Gang Qian
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
| | - Shu-Sen Zheng
- Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases
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Karolak JA, Gajecka M. Genomic strategies to understand causes of keratoconus. Mol Genet Genomics 2016; 292:251-269. [PMID: 28032277 PMCID: PMC5357269 DOI: 10.1007/s00438-016-1283-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 12/19/2016] [Indexed: 12/12/2022]
Abstract
Keratoconus (KTCN) is a degenerative disorder of the eye characterized by the conical shape and thinning of the cornea. The abnormal structure of KTCN-affected cornea results in loss of visual acuity. While many studies examine how environmental factors influence disease development, finding the genetic triggers has been a major emphasis of KTCN research. This paper focuses on genomic strategies that were implemented for finding candidate genes, including linkage and association studies, and presents different approaches of mutation screening. The advantages and limitations of particular tools are discussed based on literature and personal experience. Since etiology underlying KTCN is complex, numerous findings indicating heterogeneity of genetic factors involved KTCN etiology are presented.
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Affiliation(s)
- Justyna A Karolak
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Swiecickiego 4, Poznan, 60-781, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska 32, Poznan, 60-479, Poland
| | - Marzena Gajecka
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Swiecickiego 4, Poznan, 60-781, Poland. .,Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska 32, Poznan, 60-479, Poland.
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Bykhovskaya Y, Margines B, Rabinowitz YS. Genetics in Keratoconus: where are we? EYE AND VISION 2016; 3:16. [PMID: 27350955 PMCID: PMC4922054 DOI: 10.1186/s40662-016-0047-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/03/2016] [Indexed: 01/06/2023]
Abstract
Keratoconus (KC) is a non-inflammatory thinning and protrusion of the cornea in which the cornea assumes a conical shape. Complex etiology of this condition at present remains an enigma. Although environmental factors have been involved in KC pathogenesis, strong underlining genetic susceptibility has been proven. The lack of consistent findings among early genetic studies suggested a heterogeneity and complex nature of the genetic contribution to the development of KC. Recently, genome-wide linkage studies (GWLS) and genome-wide association studies (GWAS) were undertaken. Next-generation sequencing (NGS)-based genomic screens are also currently being carried out. Application of these recently developed comprehensive genetic tools led to a much greater success and increased reproducibility of genetic findings in KC. Involvement of the LOX gene identified through GWLS has been confirmed in multiple cohorts of KC patients around the world. KC susceptibility region located at the 2q21.3 chromosomal region near the RAB3GAP1 gene identified through GWAS was independently replicated. Rare variants in the ZNF469 gene (mutated in corneal dystrophy Brittle Cornea Syndrome) and in the TGFBI gene (mutated in multiple corneal epithelial–stromal TGFBI dystrophies) have been repeatedly identified in familial and sporadic KC patients of different ethnicities. Additional comprehensive strategies using quantitative endophenotypes have been successfully employed to bring further understanding to the genetics of KC. Additional genetic determinants including the COL5A1 gene have been identified in the GWAS of KC-related trait central corneal thickness. These recent discoveries confirmed the importance of the endophenotype approach for studying complex genetic diseases such as KC and showed that different connective tissue disorders may have the same genetic determinants.
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Affiliation(s)
- Yelena Bykhovskaya
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, USA ; Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA
| | - Benjamin Margines
- Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA
| | - Yaron S Rabinowitz
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, USA ; Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA ; The Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, USA
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Rong SS, Tang FY, Chu WK, Ma L, Yam JCS, Tang SM, Li J, Gu H, Young AL, Tham CC, Pang CP, Chen LJ. Genetic Associations of Primary Angle-Closure Disease: A Systematic Review and Meta-analysis. Ophthalmology 2016; 123:1211-21. [PMID: 26854036 DOI: 10.1016/j.ophtha.2015.12.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 12/01/2015] [Accepted: 12/16/2015] [Indexed: 02/04/2023] Open
Abstract
TOPIC Systematic review and meta-analysis of the genetic associations of primary angle-closure disease (PACD). CLINICAL RELEVANCE To confirm the genetic biomarkers for PACD, including primary angle-closure glaucoma (PACG) and related phenotypes. METHODS We searched in the MEDLINE and EMBASE databases for genetic studies of PACG or other PACD published from the start dates of the databases to May 11, 2015. We estimated the summary odds ratios (ORs) and 95% confidence intervals (CIs) for each polymorphism in PACG, primary angle-closure suspect (PACS), and primary angle-closure (PAC) using fixed- or random-effect models. We also performed sensitivity analysis to test the robustness of the results. RESULTS Our literature search yielded 6463 reports. Among them, we identified 24 studies that fulfilled the eligibility criteria for meta-analysis, involving 28 polymorphisms in 11 genes/loci. We affirmed the association of PACG and combined PACS/PAC/PACG with 10 polymorphisms in 8 genes/loci, including COL11A1 (rs3753841-G, OR, 1.22; P = 0.00046), HGF (rs17427817-C, OR, 2.02; P = 6.9E-07; rs5745718-A, OR, 2.11; P = 9.9E-07), HSP70 (rs1043618, GG+GC, OR, 0.52; P = 0.0010), MFRP (rs2510143-C, OR, 0.66; P = 0.012; rs3814762-G, OR, 1.40; P = 0.0090), MMP9 (rs3918249-C, OR, 1.35; P = 0.034), NOS3 (rs7830-A, OR, 0.80; P = 0.036), PLEKHA7 (rs11024102-G, OR, 1.24; P = 8.3E-05), and PCMTD1-ST18 (rs1015213-A, OR, 1.59; P = 0.00013). Sensitivity analysis indicated that the results were robust. CONCLUSIONS In this study, we confirmed multiple polymorphisms in 8 genes/loci as genetic biomarkers for PACD, among which 3 were identified in a genome-wide association study (COL11A1, PLEKHA7, and PCMTD1-ST18), and 5 were identified in candidate gene studies (HGF, HSP70, MFRP, MMP9, and NOS3).
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Affiliation(s)
- Shi Song Rong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Fang Yao Tang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Li Ma
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jason C S Yam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China; Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Shu Min Tang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jian Li
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Hong Gu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Alvin L Young
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
| | - Clement C Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China; Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China.
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Expression of HGF and c-Met Proteins in Human Keratoconus Corneas. J Ophthalmol 2015; 2015:852986. [PMID: 26697215 PMCID: PMC4677219 DOI: 10.1155/2015/852986] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/30/2015] [Accepted: 11/12/2015] [Indexed: 11/21/2022] Open
Abstract
Keratoconus (KC) is a progressive degenerative inflammatory-related disease of the human cornea leading to decreased visual function. The pathogenesis of KC remains to be understood. Recent genetic studies indicate that gene variants of an inflammation-related molecule, hepatocyte growth factor (HGF), are associated with an increased susceptibility for developing KC. However HGF protein expression in KC has not been explored. In this initial study, we investigated late-stage KC and control corneas for the expression of HGF and its receptor mesenchymal-epithelial transition factor (c-Met/Met). KC buttons (~8 mm diameter) (n = 10) and whole control corneas (n = 6) were fixed in 10% formalin or 2% paraformaldehyde, paraffin embedded and sectioned. Sections were immunolabelled with HGF and c-Met antibodies, visualised using immunofluorescence, and examined with scanning laser confocal microscopy. Semiquantitative grading was used to compare HGF and c-Met immunostaining in KC and control corneas. Overall, KC corneas showed increased HGF and c-Met immunostaining compared to controls. KC corneal epithelium displayed heterogeneous moderate-to-strong immunoreactivity for HGF and c-Met, particularly in the basal epithelium adjacent to the cone area. Taken together with the recent genetic studies, our results further support a possible role for HGF/c-Met in the pathogenesis of KC.
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Wang Y, Wei W, Zhang C, Zhang X, Liu M, Zhu X, Xu K. Association of Interleukin-1 Gene Single Nucleotide Polymorphisms with Keratoconus in Chinese Han Population. Curr Eye Res 2015. [DOI: 10.3109/02713683.2015.1045083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nowak DM, Gajecka M. Nonrandom Distribution of miRNAs Genes and Single Nucleotide Variants in Keratoconus Loci. PLoS One 2015; 10:e0132143. [PMID: 26176855 PMCID: PMC4503774 DOI: 10.1371/journal.pone.0132143] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/10/2015] [Indexed: 12/14/2022] Open
Abstract
Despite numerous studies, the causes of both development and progression of keratoconus remain elusive. Previous studies of this disorder focused mainly on one or two genetic factors only. However, in the analysis of such complex diseases all potential factors should be taken into consideration. The purpose of this study was a comprehensive analysis of known keratoconus loci to uncover genetic factors involved in this disease causation in the general population, which could be omitted in the original studies. In this investigation genomic data available in various databases and experimental own data were assessed. The lists of single nucleotide variants and miRNA genes localized in reported keratoconus loci were obtained from Ensembl and miRBase, respectively. The potential impact of nonsynonymous amino acid substitutions on protein structure and function was assessed with PolyPhen-2 and SIFT. For selected protein genes the ranking was made to choose those most promising for keratoconus development. Ranking results were based on topological features in the protein-protein interaction network. High specificity for the populations in which the causative sequence variants have been identified was found. In addition, the possibility of links between previously analyzed keratoconus loci was confirmed including miRNA-gene interactions. Identified number of genes associated with oxidative stress and inflammatory agents corroborated the hypothesis of their effect on the disease etiology. Distribution of the numerous sequences variants within both exons and mature miRNA which forces you to search for a broader look at the determinants of keratoconus. Our findings highlight the complexity of the keratoconus genetics.
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Affiliation(s)
- Dorota M. Nowak
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Marzena Gajecka
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
- * E-mail:
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Galvis V, Sherwin T, Tello A, Merayo J, Barrera R, Acera A. Keratoconus: an inflammatory disorder? Eye (Lond) 2015; 29:843-59. [PMID: 25931166 PMCID: PMC4506344 DOI: 10.1038/eye.2015.63] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 03/08/2015] [Indexed: 02/06/2023] Open
Abstract
Keratoconus has been classically defined as a progressive, non-inflammatory condition, which produces a thinning and steepening of the cornea. Its pathophysiological mechanisms have been investigated for a long time. Both genetic and environmental factors have been associated with the disease. Recent studies have shown a significant role of proteolytic enzymes, cytokines, and free radicals; therefore, although keratoconus does not meet all the classic criteria for an inflammatory disease, the lack of inflammation has been questioned. The majority of studies in the tears of patients with keratoconus have found increased levels of interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α), and matrix metalloproteinase (MMP)-9. Eye rubbing, a proven risk factor for keratoconus, has been also shown recently to increase the tear levels of MMP-13, IL-6, and TNF-α. In the tear fluid of patients with ocular rosacea, IL-1α and MMP-9 have been reported to be significantly elevated, and cases of inferior corneal thinning, resembling keratoconus, have been reported. We performed a literature review of published biochemical changes in keratoconus that would support that this could be, at least in part, an inflammatory condition.
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Affiliation(s)
- V Galvis
- Centro Oftalmologico Virgilio Galvis, Floridablanca, Colombia
- Faculty of Health Sciences, Universidad Autonoma de Bucaramanga, Floridablanca, Colombia
| | - T Sherwin
- Faculty of Medical and Health Sciences, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - A Tello
- Centro Oftalmologico Virgilio Galvis, Floridablanca, Colombia
- Faculty of Health Sciences, Universidad Autonoma de Bucaramanga, Floridablanca, Colombia
| | - J Merayo
- Instituto Oftalmologico Fernandez-Vega, Oviedo, Spain
| | - R Barrera
- Centro Oftalmologico Virgilio Galvis, Floridablanca, Colombia
| | - A Acera
- Bioftalmik Applied Research, Derio, Spain
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Abu-Amero KK, Helwa I, Al-Muammar A, Strickland S, Hauser MA, Allingham RR, Liu Y. Case-control association between CCT-associated variants and keratoconus in a Saudi Arabian population. J Negat Results Biomed 2015; 14:10. [PMID: 26040312 PMCID: PMC4461978 DOI: 10.1186/s12952-015-0029-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/26/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Keratoconus (KC) is the most common primary ectatic disease of the cornea and a major indication for corneal transplant. To date, limited KC-associated-risk loci have been identified. Association has recently been suggested between KC and 8 single nucleotide polymorphisms (SNPs) in the genomic regions of FNDC3B, COL4A3, MPDZ-NF1B, RXRA-COL5A1, LCN12-PTGDS, FOXO1, and BANP-ZNF469. These SNPs are associated with central corneal thickness (CCT), a known risk factor to KC. We are questioning whether these SNPs are significantly associated with KC in a Saudi Arabian population. The study included 108 unrelated KC cases and 300 controls. Patients were diagnosed with KC according to the Schimpff-flow based elevation map of the cornea. DNA genotyping was done using probe-based allelic discrimination TaqMan assays. Allele frequencies were compared between the cases and controls. RESULTS All SNPs were successfully genotyped with high efficiency (>95 %). The SNPs had no significant deviation in cases or controls from Hardy-Weinberg Equilibrium (HWE, p value > 0.05). None of the selected SNPs were significantly associated with KC in the Saudi Arabian population. However, we replicated the same trend of minor allele frequency (MAF) between cases and controls reported by a recent GWAS regarding the 5 SNPs rs4894535 (FNDC3B, chr3: 171995605), rs1536482 (RXRA-COL5A1, chr9: 137440528), rs7044529 (COL5A1, chr9: 137568051), rs11145951 (LCN12-PTGDS, chr9: 139860264), and rs2721051 (FOXO1, chr13: 41110884). CONCLUSIONS This is the first study investigating the association of these SNPs with KC in a population from Saudi Arabia. We replicated the same trend of MAF alteration of the association between the SNPs rs4894535 (FNDC3B, chr3: 171995605), rs7044529 (COL5A1, chr9: 137568051), rs11145951 (LCN12-PTGDS, chr9: 139860264) and rs2721051 (FOXO1, chr13: 41110884) and KC-risk as reported by a recently published GWAS. Consistently replicated population-based studies are necessary to identify and/or confirm genetic susceptibility for certain diseases. We acknowledge that the lack of significance in our study is due to our small sample size and insufficient statistical power; however our data still add to the body of evidence of potential KC-candidate SNPs. This report aims at supporting the possible association between CCT-associated SNPs and KC susceptibility.
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Affiliation(s)
- Khaled K Abu-Amero
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
| | - Inas Helwa
- Department of Cellular Biology and Anatomy, The Medical College of Georgia, Georgia Regents University, Augusta, GA, USA.
| | - Abdulrahman Al-Muammar
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
| | - Shelby Strickland
- Departments of Medicine, Duke University Medical Center, Durham, NC, USA.
| | - Michael A Hauser
- Departments of Medicine, Duke University Medical Center, Durham, NC, USA.
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, The Medical College of Georgia, Georgia Regents University, Augusta, GA, USA.
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The genetic and environmental factors for keratoconus. BIOMED RESEARCH INTERNATIONAL 2015; 2015:795738. [PMID: 26075261 PMCID: PMC4449900 DOI: 10.1155/2015/795738] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 12/22/2022]
Abstract
Keratoconus (KC) is the most common cornea ectatic disorder. It is characterized by a cone-shaped thin cornea leading to myopia, irregular astigmatism, and vision impairment. It affects all ethnic groups and both genders. Both environmental and genetic factors may contribute to its pathogenesis. This review is to summarize the current research development in KC epidemiology and genetic etiology. Environmental factors include but are not limited to eye rubbing, atopy, sun exposure, and geography. Genetic discoveries have been reviewed with evidence from family-based linkage analysis and fine mapping in linkage region, genome-wide association studies, and candidate genes analyses. A number of genes have been discovered at a relatively rapid pace. The detailed molecular mechanism underlying KC pathogenesis will significantly advance our understanding of KC and promote the development of potential therapies.
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Assessment of Macular Parameter Changes in Patients with Keratoconus Using Optical Coherence Tomography. J Ophthalmol 2015; 2015:245953. [PMID: 26064670 PMCID: PMC4443881 DOI: 10.1155/2015/245953] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 04/24/2015] [Indexed: 11/28/2022] Open
Abstract
Keratoconus is typically diagnosed through changes at the anterior ocular surface. However, we wished to assess if macular parameter changes might also occur in these patients. We assessed posterior changes through the use of optical coherence tomography and compared to a nonkeratoconus patient group. All subjects underwent clinical examination including macular thickness measurements. The generalized estimation equation model was used to estimate the means and compare the differences in various measurements between keratoconus and nonkeratoconus patients. A total of 129 keratoconus eyes of 67 cases and 174 nonkeratoconus eyes of 87 controls were analysed. Keratoconus individuals presented with a significantly greater mean retinal thickness in the central fovea, inner, and outer macula compared to the nonkeratoconus group (p < 0.05). In addition, individuals presenting with the early signs of keratoconus had significantly greater inner and outer macular volume compared to the nonkeratoconus group (p < 0.05). This study indicates the retina appears to thicken at the fovea and macula and had increased macular volume in keratoconus individuals compared to nonkeratoconus individuals. Thus we posit that structural retinal changes exist in keratoconus eyes that are additional to those typically seen in the anterior segment.
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Validation of rs2956540:G>C and rs3735520:G>A association with keratoconus in a population of European descent. Eur J Hum Genet 2015; 23:1581-3. [PMID: 25735481 DOI: 10.1038/ejhg.2015.28] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 01/21/2015] [Accepted: 01/27/2015] [Indexed: 11/08/2022] Open
Abstract
Corneal ectasias, among which keratoconus (KC) is the single most common entity, are one of the most frequent reasons for corneal grafting in developed countries and a threatening complication of laser in situ keratomileusis. Genome-wide association studies have previously found lysyl oxidase (LOX) and hepatocyte growth factor (HGF) associated with susceptibility to KC development. The aim of our study was to validate the effects of seven single-nucleotide polymorphisms (SNPs) within LOX and HGF over KC. Unrelated Czech cases with KC of European descent (108 males and 57 females, 165 cases in total) and 193 population and gender-matched controls were genotyped using Kompetitive Allele Specific PCR assays. Fisher's exact tests were used to assess the strength of associations. Evidence for association was found for both of the tested loci. It was strongest for rs3735520:G>A near HGF (allelic test odds ratio (OR)=1.45; 95% confidence interval (CI), 1.06-1.98; P=0.018) with A allele being a risk factor and rs2956540:G>C (OR=0.69; 95% CI, 0.50-0.96; P=0.024) within LOX with C allele having a protective effect. This first independent association validation of rs2956540:G>C and rs3735520:G>A suggests that these SNPs may serve as genetic risk markers for KC in individuals of European descent.
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