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Serpen JY, Presley W, Beil A, Armenti ST, Johnson K, Mian SI, Innis JW, Prasov L. A Novel 13q12 Microdeletion Associated with Familial Syndromic Corneal Opacification. Genes (Basel) 2023; 14:1034. [PMID: 37239394 PMCID: PMC10218699 DOI: 10.3390/genes14051034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023] Open
Abstract
Progressive corneal opacification can result from multiple etiologies, including corneal dystrophies or systemic and genetic diseases. We describe a novel syndrome featuring progressive epithelial and anterior stromal opacification in a brother and sister and their mildly affected father, with all three family members having sensorineural hearing loss and two also with tracheomalacia/laryngomalacia. All carried a 1.2 Mb deletion at chromosome 13q12.11, with no other noteworthy co-segregating variants identified on clinical exome or chromosomal microarray. RNAseq analysis from an affected corneal epithelial sample from the proband's brother revealed downregulation of XPO4, IFT88, ZDHHC20, LATS2, SAP18, and EEF1AKMT1 within the microdeletion interval, with no notable effect on the expression of nearby genes. Pathway analysis showed upregulation of collagen metabolism and extracellular matrix (ECM) formation/maintenance, with no significantly down-regulated pathways. Analysis of overlapping deletions/variants demonstrated that deleterious variants in XPO4 were found in patients with laryngomalacia and sensorineural hearing loss, with the latter phenotype also being a feature of variants in the partially overlapping DFNB1 locus, yet none of these had reported corneal phenotypes. Together, these data define a novel microdeletion-associated syndromic progressive corneal opacification and suggest that a combination of genes within the microdeletion may contribute to ECM dysregulation leading to pathogenesis.
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Affiliation(s)
- Jasmine Y. Serpen
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - William Presley
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Adelyn Beil
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen T. Armenti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kayla Johnson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Shahzad I. Mian
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | - Jeffrey W. Innis
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lev Prasov
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
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2
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Huang L, Peng J, Xie Y, Zhou Y, Wang X, Wang H, Gui J, Li N. Diversity of clinical phenotypes in a cohort of Han Chinese patients with PAX6 variants. Front Genet 2023; 14:1011060. [PMID: 36816037 PMCID: PMC9934858 DOI: 10.3389/fgene.2023.1011060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
The PAX6 gene plays an important role in ocular development. Mutations of the PAX6 gene may result in a series of ocular abnormalities, including congenital aniridia, anterior segment dysgenesis (ASD), progressive corneal opacification, glaucoma, and hypoplasia of the fovea and optic nerve, leading to reduced visual acuity and even blindness. This study aimed to describe the diversity of clinical features caused by PAX6 pathogenic variants in 45 Han Chinese patients from 23 unrelated families. All patients underwent detailed clinical assessment. Genetic testing was performed to identify pathogenic variations in the PAX6 gene by next-generation sequencing, minigene splicing assay, RT-qPCR, and long-range PCR. Twenty pathogenic variations were detected in the PAX6 gene from 12 pedigrees and 11 sporadic patients, of which 12 were previously reported and 8 were novel. The clinical phenotypes obtained as a result of the PAX6 gene mutations were complicated and vary among patients, even among those who carried the same variants. Genetic testing is helpful for differential diagnosis. Our genetic findings will expand the spectrum of pathogenic variations in the PAX6 gene. PAX6 pathogenic variants not only cause defects in ocular tissues, such as the iris and retina, but also lead to maldevelopment of the whole eye, resulting in microphthalmia.
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Affiliation(s)
- Lijuan Huang
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China,Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Jiajia Peng
- Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Yan Xie
- Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Yunyu Zhou
- Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Xiaolin Wang
- Laboratory of Tumor Immunology, Beijing Children’s Hospital, National Center for Children’s Health, Beijing Pediatric Research Institute, Capital Medical University, Beijing, China
| | - Hui Wang
- Laboratory of Tumor Immunology, Beijing Children’s Hospital, National Center for Children’s Health, Beijing Pediatric Research Institute, Capital Medical University, Beijing, China
| | - Jingang Gui
- Laboratory of Tumor Immunology, Beijing Children’s Hospital, National Center for Children’s Health, Beijing Pediatric Research Institute, Capital Medical University, Beijing, China,*Correspondence: Jingang Gui, ; Ningdong Li,
| | - Ningdong Li
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China,Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Beijing, China,Department of Ophthalmology, Shanghai General Hospital, Shanghai, China,Department of Ophthalmology, Children’s Hospital, Capital Institute of Pediatrics, Beijing, China,*Correspondence: Jingang Gui, ; Ningdong Li,
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3
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Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options. Cells 2021; 10:cells10092302. [PMID: 34571952 PMCID: PMC8465583 DOI: 10.3390/cells10092302] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022] Open
Abstract
In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.
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4
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Long-Term Outcomes of Allogeneic Ocular Surface Reconstruction: Keratolimbal Allograft (KLAL) Followed by Penetrating Keratoplasty (PK). J Ophthalmol 2020; 2020:5189179. [PMID: 32351724 PMCID: PMC7178497 DOI: 10.1155/2020/5189179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/20/2020] [Accepted: 03/04/2020] [Indexed: 12/15/2022] Open
Abstract
Purpose Long-term results of the patients with total LSCD, who had undergone keratolimbal allograft (KLAL) for limbal reconstruction followed by penetrating keratoplasty (PK). Methods The study analyzes surgical treatment of 43 eyes with severe ocular surface disorders. All subjects underwent KLAL to achieve suitable conditions for consecutive PK. Due to failures of primary treatment in 17 eyes (39%), the KLAL was repeated. PK was performed in all the patients at 9-12 months after KLAL. As a retrospective study we analyzed data from the medical records including the preoperative and postoperative best corrected visual acuity, corneal clarity, surgical outcomes and complications, postoperative intraocular pressure, graft rejection, and other comorbidities and complications. Results The preoperative visual acuity ranged from light perception to 0.01. The final improvement of visual acuity within a gain of one or more lines with the Snellen chart, including the results of successive surgical treatments after PK, was achieved in 23 operated eyes (53%). Early graft rejection was observed in 4 eyes (9%). In 3 eyes, it was manifested as endothelial rejection, and in 1 eye, as combined endothelial and epithelial rejection. PK failure requiring repetitive PK was present in 14 eyes (32%). Phthisis bulbi developed in 6 eyes (14%). Glaucoma or ocular hypertension was reported in 25 eyes (58%). A majority were treated with up to 3 topical agents or referred for trabeculectomy in 3 cases, transscleral cyclophotocoagulation in 2 eyes, and EX-PRESS glaucoma shunt implantation in 3 cases. Conclusions Successful KLAL carries a high risk of subsequent PK failure. Visual function remains the second aim of treatment; the primary one is to stabilize the surface.
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5
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Le-Bel G, Guérin LP, Carrier P, Mouriaux F, Germain L, Guérin SL, Bazin R. Grafting of an autologous tissue-engineered human corneal epithelium to a patient with limbal stem cell deficiency (LSCD). Am J Ophthalmol Case Rep 2019; 15:100532. [PMID: 31440691 PMCID: PMC6699139 DOI: 10.1016/j.ajoc.2019.100532] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 07/30/2019] [Accepted: 07/30/2019] [Indexed: 11/30/2022] Open
Abstract
Purpose In this study, we evaluated the feasibility of recovering the corneal surface integrity in a patient suffering from unilateral LSCD through the transplantation of cultured autologous corneal epithelial cells. Methods Human corneal epithelial cells (HCECs) were isolated from a limbal biopsy of the contralateral eye of a patient with unilateral LSCD and cultured in monolayer in the presence of an irradiated human fibroblasts feeder layer (iHFL). To produce a cultured autologous corneal epithelium (CACE), HCECs were seeded on a fibrin substrate and maintained in culture until confluence. The in vitro obtained CACE was then used to treat the affected eye of the patient. Two years later, a successful penetrating keratoplasty was performed. Results Efficient restoration of the corneal epithelium was achieved following transplantation of CACE indicating probable re-colonization of the cornea by stem cells. Corneal transparency was restored after removing the scarred stroma by performing a penetrating keratoplasty. Conclusion CACE produced in vitro was shown to restore a normal corneal surface capable of sustaining a viable and clear penetrating keratoplasty and reestablished a near normal vision in a unilateral LSCD patient.
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Affiliation(s)
- Gaëtan Le-Bel
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada.,Département de Chirurgie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Louis-Philippe Guérin
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Patrick Carrier
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département de Chirurgie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Frédéric Mouriaux
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada.,CNRS, UMR 6301 ISTCT, CERVOxy, GIP CYCERON, F-14074, Caen, France.,CHU de Rennes, Service d'Ophtalmologie, F-35033, Cedex 9, France
| | - Lucie Germain
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada.,Département de Chirurgie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Sylvain L Guérin
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada
| | - Richard Bazin
- CUO-Recherche, Médecine Régénératrice, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.,Centre de Recherche en Organogénèse expérimentale de l'Université Laval/LOEX, Québec, Canada.,Département d'Ophtalmologie, Faculté de médecine, Université Laval, Québec, QC, Canada
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6
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Deng SX, Borderie V, Chan CC, Dana R, Figueiredo FC, Gomes JAP, Pellegrini G, Shimmura S, Kruse FE. Global Consensus on Definition, Classification, Diagnosis, and Staging of Limbal Stem Cell Deficiency. Cornea 2019; 38:364-375. [PMID: 30614902 PMCID: PMC6363877 DOI: 10.1097/ico.0000000000001820] [Citation(s) in RCA: 183] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Despite extensive knowledge gained over the last 3 decades regarding limbal stem cell deficiency (LSCD), the disease is not clearly defined, and there is lack of agreement on the diagnostic criteria, staging, and classification system among treating physicians and research scientists working on this field. There is therefore an unmet need to obtain global consensus on the definition, classification, diagnosis, and staging of LSCD. METHODS A Limbal Stem Cell Working Group was first established by The Cornea Society in 2012. The Working Group was divided into subcommittees. Four face-to-face meetings, frequent email discussions, and teleconferences were conducted since then to obtain agreement on a strategic plan and methodology from all participants after a comprehensive literature search, and final agreement was reached on the definition, classification, diagnosis, and staging of LSCD. A writing group was formed to draft the current manuscript, which has been extensively revised to reflect the consensus of the Working Group. RESULTS A consensus was reached on the definition, classification, diagnosis, and staging of LSCD. The clinical presentation and diagnostic criteria of LSCD were clarified, and a staging system of LSCD based on clinical presentation was established. CONCLUSIONS This global consensus provides a comprehensive framework for the definition, classification, diagnosis, and staging of LSCD. The newly established criteria will aid in the correct diagnosis and formulation of an appropriate treatment for different stages of LSCD, which will facilitate a better understanding of the condition and help with clinical management, research, and clinical trials in this area.
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Affiliation(s)
- Sophie X. Deng
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles
| | - Vincent Borderie
- Quinze-Vingts National Eye Hospital, Faculté de Médecine Sorbonne Université, Paris, France
| | - Clara C. Chan
- University of Toronto Department of Ophthalmology & Vision Sciences Toronto, Ontario
| | - Reza Dana
- Massachusetts Eye and Ear Infirmary, Harvard Medical School
| | - Francisco C. Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary and Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, UK
| | - José A. P. Gomes
- Department of Ophthalmology and Visual Sciences, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), Brazil
| | - Graziella Pellegrini
- Centre for Regenerative Medicine, University of Modena and Reggio Emilia; Holostem Terapie Avanzate, Modena, Italy
| | - Shigeto Shimmura
- Department of Ophthalmology, Keio University School of Medicine, Japan
| | - Friedrich E. Kruse
- Department of Ophthalmology, University Hospital Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
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7
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Tarilonte M, Morín M, Ramos P, Galdós M, Blanco-Kelly F, Villaverde C, Rey-Zamora D, Rebolleda G, Muñoz-Negrete FJ, Tahsin-Swafiri S, Gener B, Moreno-Pelayo MA, Ayuso C, Villamar M, Corton M. Parental Mosaicism in PAX6 Causes Intra-Familial Variability: Implications for Genetic Counseling of Congenital Aniridia and Microphthalmia. Front Genet 2018; 9:479. [PMID: 30386378 PMCID: PMC6199369 DOI: 10.3389/fgene.2018.00479] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/26/2018] [Indexed: 11/17/2022] Open
Abstract
Mutations in PAX6 are involved in several developmental eye disorders. These disorders have considerable phenotypic variability, ranging from panocular forms of congenital aniridia and microphthalmia to isolated anomalies of the anterior or posterior segment. Here, we describe 3 families with variable inter-generational ocular expression of aniridia, iris coloboma, or microphthalmia, and an unusual transmission of PAX6 mutations from an unaffected or mildly affected parent; all of which raised suspicion of gonosomal mosaicism. We first identified two previously known nonsense mutations and one novel likely pathogenic missense variant in PAX6 in probands by means of targeted NGS. The subsequent segregation analysis by Sanger sequencing evidenced the presence of highly probable mosaic events in paternal blood samples. Mosaicism was further confirmed by droplet digital PCR analysis in several somatic tissues of mosaic fathers. Quantification of the mutant allele fraction in parental samples showed a marked deviation from 50%, with a range between 12 and 29% depending on cell type. Gonosomal mosaicsm was definitively confirmed in one of the families thanks to the availability of a sperm sample from the mosaic father. Thus, the recurrence risk in this family was estimated to be about one-third. This is the first report confirming parental PAX6 mosaicism as a cause of disease recurrence in aniridia and other related phenotypes. In addition, we demonstrated that post-zygotic mosaicism is a frequent and underestimated pathogenic mechanism in aniridia, explaining intra-familial phenotypic variability in many cases. Our findings may have substantial implications for genetic counseling in congenital aniridia. Thus, we also highlight the importance of comprehensive genetic screening of parents for new sporadic cases with aniridia or related developmental eye disease to more accurately assess recurrence risk. In conclusion, somatic and/or gonosomal mosaicism should be taken into consideration as a genetic factor to explain not only families with unaffected parents despite multiple affected children but also variable expressivity, apparent de novo cases, and even uncharacterized cases of aniridia and related developmental eye disorders, apparently lacking PAX6 mutations.
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Affiliation(s)
- María Tarilonte
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Matías Morín
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Patricia Ramos
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Galdós
- Department of Ophthalmology, Cruces University Hospital, Bilbao, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Dolores Rey-Zamora
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Gema Rebolleda
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Francisco J Muñoz-Negrete
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Saoud Tahsin-Swafiri
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Blanca Gener
- Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics, BioCruces Health Research Institute, Cruces University Hospital, Bilbao, Spain
| | - Miguel-Angel Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Manuela Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Corton
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
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8
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Filatova AY, Vasilyeva TA, Marakhonov AV, Voskresenskaya AA, Zinchenko RA, Skoblov MY. Functional reassessment of PAX6 single nucleotide variants by in vitro splicing assay. Eur J Hum Genet 2018; 27:488-493. [PMID: 30315214 DOI: 10.1038/s41431-018-0288-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/14/2018] [Accepted: 09/28/2018] [Indexed: 11/09/2022] Open
Abstract
Nucleotide variants that disrupt normal splicing might be the cause of a large number of diseases. Nevertheless, because of the complexity of splicing regulation, it is not always possible to accurately predict the effect of nucleotide sequence changes on splicing events and mRNA structure. Thereby, a number of newly identified nucleotide variants are falsely classified as VUS (a variant of uncertain significance). In the present study we used the minigene assay to analyze the functional consequences of six intronic (c.142-5T>G, c.142-14C>G, c.142-64A>C, c.141+4A>G, c.1032+ 6T>G, c.682+4delA), one missense (c.140A>G) and one synonymous (c.174C>T) variants in the PAX6 gene found in patients with congenital aniridia. We revealed that all except one (c.142-64A>C) variants lead to the disruption of normal splicing patterns resulting in premature termination codon formation followed by mRNA degradation through the nonsense mediated decay pathway. This produces a null allele of the PAX6 gene. That allowed us to reclassify the analyzed variants as loss-of-function and to establish their functional role.
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Affiliation(s)
| | | | - Andrey V Marakhonov
- Research Centre for Medical Genetics, Moscow, Russian Federation.,Moscow Institute of Physics and Technology (State University), Moscow, Russian Federation
| | - Anna A Voskresenskaya
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation
| | - Rena A Zinchenko
- Research Centre for Medical Genetics, Moscow, Russian Federation.,Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Mikhail Yu Skoblov
- Research Centre for Medical Genetics, Moscow, Russian Federation.,Moscow Institute of Physics and Technology (State University), Moscow, Russian Federation
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9
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Plaisancié J, Tarilonte M, Ramos P, Jeanton-Scaramouche C, Gaston V, Dollfus H, Aguilera D, Kaplan J, Fares-Taie L, Blanco-Kelly F, Villaverde C, Francannet C, Goldenberg A, Arroyo I, Rozet JM, Ayuso C, Chassaing N, Calvas P, Corton M. Implication of non-coding PAX6 mutations in aniridia. Hum Genet 2018; 137:831-846. [PMID: 30291432 DOI: 10.1007/s00439-018-1940-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/23/2018] [Indexed: 01/14/2023]
Abstract
There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.
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Affiliation(s)
- Julie Plaisancié
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France.
- INSERM U1056, Université Toulouse III, Toulouse, France.
| | - M Tarilonte
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - P Ramos
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Jeanton-Scaramouche
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - V Gaston
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - H Dollfus
- Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - D Aguilera
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - J Kaplan
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - L Fares-Taie
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - F Blanco-Kelly
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Villaverde
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Francannet
- Service de Génétique Médicale, CHU Estaing, Clermont-Ferrand, France
| | - A Goldenberg
- Service de Génétique, CHU de Rouen, Centre Normand de Génomique Médicale et Médecine Personnalisée, Rouen, France
| | - I Arroyo
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetics, Hospital of Cáceres, Cáceres, Spain
| | - J M Rozet
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - C Ayuso
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - N Chassaing
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - P Calvas
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - M Corton
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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10
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Yahalom C, Blumenfeld A, Hendler K, Wussuki-Lior O, Macarov M, Shohat M, Khateb S. Mild aniridia phenotype: an under-recognized diagnosis of a severe inherited ocular disease. Graefes Arch Clin Exp Ophthalmol 2018; 256:2157-2164. [PMID: 30167917 DOI: 10.1007/s00417-018-4119-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/13/2018] [Accepted: 08/23/2018] [Indexed: 01/30/2023] Open
Abstract
PURPOSE Aniridia is a rare panocular disorder caused by mutations in the PAX6 gene and characterized mainly by iris hypoplasia. Here, we present six families with a history of low vision/blindness with a previously undiagnosed mild aniridia phenotype with minimal iris changes. METHODS Retrospective case series of patients diagnosed with a subtle aniridia phenotype characterized by minimal iris abnormalities, foveal hypoplasia, and an identified mutation in PAX6. Data collection from patient's charts included ocular examination findings, visual acuity, refraction, and clinical pictures when available. Genetic analysis was performed by isolation of genomic DNA from peripheral blood. The main outcome was the identification of patients with mild aniridia harboring a PAX6 mutation. RESULTS In all six families, the phenotype included minimal corectopia and foveal hypoplasia; nystagmus was present in 10 out of 11 patients. A PAX6 mutation was identified in all six families; three of these mutations were identified previously, and three are novel mutations. All the mutations are located within the conventional 128-residue paired domain of PAX6. CONCLUSIONS A mild form of aniridia should be considered in the differential diagnosis of patients with low vision associated with mild iris abnormalities, nystagmus, and foveal hypoplasia. To ensure an accurate diagnosis of aniridia, minimal pupillary changes and/or incipient keratopathy should be examined. The broad phenotypic heterogeneity among aniridia leads to the fact that eye care clinicians must have a high index of suspicion for the disease when seeing undiagnosed low vision patients, because proper diagnosis can improve management as well as facilitate genetic testing and counselling.
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Affiliation(s)
- Claudia Yahalom
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel.
| | - Anat Blumenfeld
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel
| | - Karen Hendler
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel
| | - Orly Wussuki-Lior
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel
| | - Michal Macarov
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel
| | - Mordechai Shohat
- Medical Genetic Institute, Maccabi Health Services, Tel Aviv, Israel.,Bioinformatic Department, Cancer Center, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, 91120, Jerusalem, Israel
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11
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Le Q, Xu J, Deng SX. The diagnosis of limbal stem cell deficiency. Ocul Surf 2018; 16:58-69. [PMID: 29113917 PMCID: PMC5844504 DOI: 10.1016/j.jtos.2017.11.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/24/2017] [Accepted: 11/03/2017] [Indexed: 12/15/2022]
Abstract
Limbal stem cells (LSCs) maintain the normal homeostasis and wound healing of corneal epithelium. Limbal stem cell deficiency (LSCD) is a pathologic condition that results from the dysfunction and/or an insufficient quantity of LSCs. The diagnosis of LSCD has been made mainly based on medical history and clinical signs, which often are not specific to LSCD. Methods to stage the severity of LSCD have been lacking. With the application of newly developed ocular imaging modalities and molecular methods as diagnostic tools, standardized quantitative criteria for the staging of LSCD can be established. Because of these recent advancements, effective patient-specific therapy for different stages of LSCD may be feasible.
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Affiliation(s)
- Qihua Le
- Stein Eye Institute, Cornea Division, David Geffen School of Medicine, University of California, Los Angeles, USA; Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai 200031, China
| | - Jianjiang Xu
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai 200031, China
| | - Sophie X Deng
- Stein Eye Institute, Cornea Division, David Geffen School of Medicine, University of California, Los Angeles, USA.
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12
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Familial Limbal Stem Cell Deficiency: Clinical, Cytological and Genetic Characterization. Stem Cell Rev Rep 2017; 14:148-151. [PMID: 29134474 DOI: 10.1007/s12015-017-9780-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Samant M, Chauhan BK, Lathrop KL, Nischal KK. Congenital aniridia: etiology, manifestations and management. EXPERT REVIEW OF OPHTHALMOLOGY 2016; 11:135-144. [PMID: 30100922 DOI: 10.1586/17469899.2016.1152182] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Congenital aniridia manifests as total or partial absence of the iris caused most commonly by mutations in PAX6, FOXC1, PITX2, and CYP1B1. Recently two new genes, FOXD3 and TRIM44, have also been implicated in isolated studies. We discuss the genotype-phenotype correlations for the main implicated genes. Classic aniridia is a panocular condition, which includes aniridia, cataract, corneal pannus, foveal, and optic nerve hypoplasia associated with mutations in the PAX6 gene. Classical aniridia is due to PAX6 mutations, while other genes contribute to aniridia-like phenotypes. We review the challenges involved in the management of aniridia, and discuss various surgical interventions. The clinical importance of defining the genotype in cases of congenital aniridia has become acutely apparent with the advent of possible therapies for classical aniridia, which are discussed.
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Affiliation(s)
- Monica Samant
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Bharesh K Chauhan
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | - Kira L Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.,Department of Engineering. University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15213, USA
| | - Ken K Nischal
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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14
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Sejpal K, Bakhtiari P, Deng SX. Presentation, diagnosis and management of limbal stem cell deficiency. Middle East Afr J Ophthalmol 2014; 20:5-10. [PMID: 23580847 PMCID: PMC3617528 DOI: 10.4103/0974-9233.106381] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The human corneal surface epithelium is continuously repopulated by the limbal stem cells (LSCs). Limbal Stem Cell Deficiency (LSCD) can lead to corneal opacity and vascularization, with consequent visual impairment or blindness. Many acquired and congenital diseases can lead to LCSD by direct injury to the LSCs, destruction of LSC niche, or both. Based on the severity of the disease, LSCD can present with various symptoms and signs. Although LSCD can be detected clinically, laboratory tests are necessary to confirm the diagnosis and monitor the disease progression. This article concisely reviews the clinical presentation, techniques for diagnosis and management of LSCD.
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15
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Sbordone S, Romano V, Savastano A, Piccirillo V, Savastano MC, Bifani M. Aniridia associated with lens coloboma and secondary glaucoma treated with transcorneal argon laser ciliary body photocoagulation: a case report. Case Rep Ophthalmol 2013; 4:44-7. [PMID: 23898292 PMCID: PMC3724133 DOI: 10.1159/000353356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Purpose The aim of this study is to describe the management of cataract and refractory glaucoma in a case of congenital aniridia (AN)-1. Methods In an 18-year-old female patient affected by congenital AN, bilateral coloboma of the zonula and lens, cataract and glaucoma, pars plana vitrectomy, cataract extraction and subsequent transcorneal ciliary body argon laser photocoagulation were performed. Results Five years after laser treatment, the best-corrected visual acuity was 20/50 and the intraocular pressure was stable at 18 mm Hg with topical pharmacological management consisting of timolol 0.5% and latanoprost 0.005%. Conclusions From our experience, transcorneal ciliary body photocoagulation after cataract extraction and vitrectomy could be a useful technique to manage high ocular pressure in eyes affected by congenital AN.
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Affiliation(s)
- Sandro Sbordone
- Eye Department at Second University of Naples, Naples, Italy
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16
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In vivo confocal microscopy of congenital aniridia-associated keratopathy. Eye (Lond) 2013; 27:763-6. [PMID: 23579408 DOI: 10.1038/eye.2013.50] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To explore the in vivo morphological changes of cornea and limbus in aniridia-associated keratopathy (AAK). METHODS Three cases of AAK were examined with the application of in vivo confocal microscopy (IVCM). RESULTS Abnormal structure of wing and basal layer of epithelium, the loss of subbasal nerves, and the presence of goblet cells at central cornea could be identified in the most severe case, along with the absence of Vogt palisades. The less extent of abnormalities in corneal epithelial cells, subbasal nerve, and Vogt palisades were visible in the moderate or mild cases. CONCLUSIONS The morphological changes of cornea and limbus vary in AAK, and IVCM is a promising tool to determine the degree of limbal stem cell deficiency in patients with AAK.
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