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Kaginalkar A, Tandon R, Vanathi M, Gupta N, Gupta V, Sen S, Kashyap S, Sharma A. Clinical and diagnostic imaging profile of three anterior segment dysgenesis disorders presenting with infantile corneal opacities. Taiwan J Ophthalmol 2023; 13:505-519. [PMID: 38249508 PMCID: PMC10798392 DOI: 10.4103/tjo.tjo-d-23-00134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/09/2023] [Indexed: 01/23/2024] Open
Abstract
PURPOSE To describe three anterior segment dysgenesis disorders with infantile corneal opacities, namely, congenital hereditary endothelial dystrophy (CHED), primary congenital glaucoma (PCG), and Peters anomaly (PA) in terms of clinical characteristics, histopathology, genetic association, and diagnostic imaging profiles using imaging modalities such as ultrasound biomicroscopy (UBM) and microscope-integrated intraoperative optical coherence tomography (i-OCT). MATERIALS AND METHODS Seventy-four eyes with 22 eyes of CHED, 28 eyes of PA, and 24 eyes of PCG were clinically evaluated and underwent imaging using UBM and i-OCT. Corneal buttons of 16 operated patients underwent histopathological analysis, while genetic analysis was done in 23 patients using whole-exome sequencing. RESULTS Corneal diameters (CD) and UBM parameters like anterior chamber depth (ACD), iris thickness (IT), and ciliary body (CB) thickness revealed a statistically significant difference between the three categories. In PA, 9 eyes had a third rare phenotype with only a posterior corneal defect with no iris adhesions. Genetic mutations were seen in all tested patients with CHED, in 83.3% of patients with PCG, and in 80% of patients with the third type of PA. i-OCT helped in the characterization of corneal opacity, identification of posterior corneal defects, iridocorneal adhesions, and contour of Descemet's membrane. CONCLUSION Overlapping phenotypes of the above disorders cause a diagnostic dilemma and parameters like CDs, UBM ACD, IT, and CB thickness help differentiate between them. i-OCT can help in classifying the diseases in a high resolution, non-contact manner, and can better delineate corneal characteristics. The rare third type of PA phenotype may have a genetic association.
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Affiliation(s)
- Ananya Kaginalkar
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Radhika Tandon
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - M. Vanathi
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Noopur Gupta
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Viney Gupta
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Sen
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Kashyap
- Dr. RP Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Arundhati Sharma
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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Yousaf K, Naz S, Mushtaq A, Wohler E, Sobreira N, Ho BM, Chen LJ, Chu WK, Bashir R. Exome Sequencing Reveals SLC4A11 Variant Underlying Congenital Hereditary Endothelial Dystrophy (CHED2) Misdiagnosed as Congenital Glaucoma. Genes (Basel) 2023; 14:genes14020310. [PMID: 36833236 PMCID: PMC9956413 DOI: 10.3390/genes14020310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/02/2023] [Accepted: 01/21/2023] [Indexed: 01/27/2023] Open
Abstract
Autosomal recessive congenital hereditary endothelial dystrophy (CHED2) may be misdiagnosed as primary congenital glaucoma (PCG) due to similar clinical phenotypes during early infancy. In this study, we identified a family with CHED2, which was previously misdiagnosed as having PCG, and followed up for 9 years. Linkage analysis was first completed in eight PCG-affected families, followed by whole-exome sequencing (WES) in family PKGM3. The following in silico tools were used to predict the pathogenic effects of identified variants: I-Mutant 2.0, SIFT, Polyphen-2, PROVEAN, mutation taster and PhD-SNP. After detecting an SLC4A11 variant in one family, detailed ophthalmic examinations were performed again to confirm the diagnosis. Six out of eight families had CYP1B1 gene variants responsible for PCG. However, in family PKGM3, no variants in the known PCG genes were identified. WES identified a homozygous missense variant c.2024A>C, p.(Glu675Ala) in SLC4A11. Based on the WES findings, the affected individuals underwent detailed ophthalmic examinations and were re-diagnosed with CHED2 leading to secondary glaucoma. Our results expand the genetic spectrum of CHED2. This is the first report from Pakistan of a Glu675Ala variant with CHED2 leading to secondary glaucoma. The p.Glu675Ala variant is likely a founder mutation in the Pakistani population. Our findings suggest that genome-wide neonatal screening is worthwhile to avoid the misdiagnosis of phenotypically similar diseases such as CHED2 and PCG.
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Affiliation(s)
- Khazeema Yousaf
- Department of Biotechnology, Lahore College for Women University, Lahore 54000, Pakistan
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan
| | - Asma Mushtaq
- Department of Ophthalmology, Children’s Hospital & the Institute of Child Health, Lahore 54000, Pakistan
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong 999077, China
| | - Elizabeth Wohler
- McKusick-Nathans Department of Genetic Medicine, Baylor Hopkins Center for Mendelian Genomics, Baltimore, MD 21205, USA
| | - Nara Sobreira
- McKusick-Nathans Department of Genetic Medicine, Baylor Hopkins Center for Mendelian Genomics, Baltimore, MD 21205, USA
| | - Bo-Man Ho
- McKusick-Nathans Department of Genetic Medicine, Baylor Hopkins Center for Mendelian Genomics, Baltimore, MD 21205, USA
| | - Li-Jia Chen
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong 999077, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong 999077, China
| | - Wai-Kit Chu
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong 999077, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong 999077, China
- Correspondence: (W.-K.C.); (R.B.)
| | - Rasheeda Bashir
- Department of Biotechnology, Lahore College for Women University, Lahore 54000, Pakistan
- Correspondence: (W.-K.C.); (R.B.)
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Vanathi M, Raj N, Kusumesh R, Aron N, Gupta N, Tandon R. Update on Pediatric Corneal Diseases and Keratoplasty. Surv Ophthalmol 2022; 67:1647-1684. [PMID: 35918016 DOI: 10.1016/j.survophthal.2022.07.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 10/31/2022]
Abstract
Managing pediatric corneal disorders is challenging as the prognosis of pediatric keratoplasty depends on several factors. Advancements in the genetic basis of congenital corneal diseases and investigations in congenital corneal conditions provide a better understanding of pediatric corneal conditions. Surgeons performing keratoplasty in children now have a choice of various techniques. Evolving surgical techniques of anterior lamellar and endothelial keratoplasties has expanded the management interventions in these pediatric corneal morbidity conditions; however, considerable concerns still exist in association with corneal transplantation in infants and children. Outcomes in pediatric keratoplasty depend upon the preoperative indications, the timing of surgical intervention, intraoperative and postoperative factors including the patient/care givers' compliance. Factors such as low scleral rigidity, higher rate of graft failure, need for frequent examinations under anesthesia, and difficulty in optimal visual acuity assessment still remain a considerable challenge in pediatric scenarios. In children, deprivation amblyopia as a result of the corneal opacification can adversely affect visual development, causing dense amblyopia. Outcomes to surgical interventions for management of corneal opacification in children is further compromised by the pre-existing amblyopia apart from the concerns of refractive outcome of the graft. Graft rejection, graft infection, amblyopia, and glaucoma continue to be serious concerns. In recent years both anterior and posterior lamellar keratoplasty techniques are being increasingly performed in pediatric eyes, which offer advantages in the form of lower risk of graft rejection. The timing of surgery, careful case selection, cautious intraoperative approach, and optimal postoperative management can improve the anatomical and functional outcome in difficult cases.
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Affiliation(s)
- Murugesan Vanathi
- Cornea, Lens & Refractive Services, Dr. R P Centre for Ophthalmic Sciences - ALL INDIA INSTITUTE OF MEDICAL SCIENCES, New Delhi 110029, India.
| | - Nimmy Raj
- Cornea, Lens & Refractive Services, Dr. R P Centre for Ophthalmic Sciences - ALL INDIA INSTITUTE OF MEDICAL SCIENCES, New Delhi 110029, India
| | - Rakhi Kusumesh
- Cornea & Ocular Surface Services, Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India
| | - Neelima Aron
- Cornea, Lens & Refractive Services, Dr. R P Centre for Ophthalmic Sciences - ALL INDIA INSTITUTE OF MEDICAL SCIENCES, New Delhi 110029, India
| | - Noopur Gupta
- Cornea, Lens & Refractive Services, Dr. R P Centre for Ophthalmic Sciences - ALL INDIA INSTITUTE OF MEDICAL SCIENCES, New Delhi 110029, India
| | - Radhika Tandon
- Cornea, Lens & Refractive Services, Dr. R P Centre for Ophthalmic Sciences - ALL INDIA INSTITUTE OF MEDICAL SCIENCES, New Delhi 110029, India
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Alka K, Casey JR. Molecular phenotype of SLC4A11 missense mutants: Setting the stage for personalized medicine in corneal dystrophies. Hum Mutat 2018; 39:676-690. [PMID: 29327391 DOI: 10.1002/humu.23401] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 12/30/2022]
Abstract
SLC4A11 mutations cause cases of congenital hereditary endothelial dystrophy (CHED), Harboyan syndrome (HS), and Fuchs endothelial corneal dystrophy (FECD). Defective water reabsorption from corneal stroma by corneal endothelial cells (CECs) leads to these corneal dystrophies. SLC4A11, in the CEC basolateral membrane, facilitates transmembrane movement of H2 O, NH3 , and H+ -equivalents. Some SLC4A11 disease mutants have impaired folding, leading to a failure to move to the cell surface, which in some cases can be corrected by the drug, glafenine. To identify SLC4A11 mutants that are targets for folding-correction therapy, we examined 54 SLC4A11 missense mutants. Cell-surface trafficking was assessed on immunoblots, by the level of mature, high molecular weight, cell surface-associated form, and using a bioluminescence resonance energy transfer assay. Low level of cell surface trafficking was found in four out of 18 (20%) of FECD mutants, 19/ out of 31 (61%) of CHED mutants, and three out of five (60%) of HS mutants. Amongst ER-retained mutants, 16 showed increased plasma membrane trafficking when grown at 30°C, suggesting that their defect has potential for rescue. CHED-causing point mutations mostly resulted in folding defects, whereas the majority of FECD missense mutations did not affect trafficking, implying functional impairment. We identified mutations that make patients candidates for folding correction of their corneal dystrophy.
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Affiliation(s)
- Kumari Alka
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Joseph R Casey
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
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Loganathan SK, Casey JR. Corneal dystrophy-causing SLC4A11 mutants: suitability for folding-correction therapy. Hum Mutat 2014; 35:1082-91. [PMID: 24916015 DOI: 10.1002/humu.22601] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/28/2014] [Indexed: 12/25/2022]
Abstract
SLC4A11 mutations cause some cases of the corneal endothelial dystrophies, congenital hereditary endothelial corneal dystrophy type 2 (CHED2), Harboyan syndrome (HS), and Fuchs endothelial corneal dystrophy (FECD). SLC4A11 protein was recently identified as facilitating water flux across membranes. SLC4A11 point mutations usually cause SLC4A11 misfolding and retention in the endoplasmic reticulum (ER). We set about to test the feasibility of rescuing misfolded SLC4A11 protein to the plasma membrane as a therapeutic approach. Using a transfected HEK293 cell model, we measured functional activity present in cells expressing SLC4A11 variants in combinations representing the state found in CHED2 carriers, affected CHED2, FECD individuals, and unaffected individuals. These cells manifest respectively about 60%, 5%, and 25% of the water flux activity, relative to the unaffected (WT alone). ER-retained CHED2 mutant SLC4A11 protein could be rescued to the plasma membrane, where it conferred 25%-30% of WT water flux level. Further, some ER-retained CHED2 mutants expressed at 30°C supported increased water flux compared with 37°C cultures. Caspase activation and cell vitality assays revealed that expression of SLC4A11 mutants in HEK293 cells does not induce cell death. We conclude that therapeutics able to increase cell surface localization of ER-retained SLC4A11 mutants hold promise to treat CHED2 and FECD patients.
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Affiliation(s)
- Sampath K Loganathan
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
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Han SB, Ang HP, Poh R, Chaurasia SS, Peh G, Liu J, Tan DTH, Vithana EN, Mehta JS. Mice with a targeted disruption of Slc4a11 model the progressive corneal changes of congenital hereditary endothelial dystrophy. Invest Ophthalmol Vis Sci 2013; 54:6179-89. [PMID: 23942972 DOI: 10.1167/iovs.13-12089] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To establish an animal model of congenital hereditary endothelial dystrophy (CHED) using Slc4a11 knockout (KO) mice and evaluate the abnormalities in the cornea and kidney. METHODS The Slc4a11 KO mouse model was generated by gene deletion. Corneal abnormalities were evaluated using slit-lamp photography, anterior segment optical coherence tomography (AS-OCT), immunohistochemistry, RT-PCR, corneal endothelial cell staining, and electron microscopy. The temporal corneal changes were also monitored. Histological and functional changes of the kidney were also evaluated. RESULTS Successful knockout of the Slc4a11 gene was confirmed by immunohistochemistry and RT-PCR. Slit-lamp photography and AS-OCT showed progressive corneal edema. Increased corneal endothelial cell size with decreased corneal endothelial cell density was observed with increased age. Scanning electron microscopy also revealed progressive cell swelling and distortion of the hexagonal cell morphology with time. Transmission electron microscopy showed characteristic ultrastructural findings of CHED, including endothelial vacuolization, thickening of the Descemet membrane, disorganization of collagen fibril, deposition of amorphous material, and progression of these changes with age. Decreased urine osmolarity and electrolyte concentrations suggesting abnormality in water resorption were also detected. CONCLUSIONS Our Slc4a11 KO mouse model successfully represents clinical manifestations of human CHED. We were able to show chronological corneal progression for the first time in a knockout mouse model as well as renal abnormalities.
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Abstract
Congenital hereditary endothelial dystrophy (CHED), presents in infancy or early childhood with bilateral clouding of corneas. This condition has previously been managed surgically with penetrating keratoplasty (PKP). Performing PKP in pediatric patients has its own set of difficulties. More recently, there has been growing interest in treating this condition with Descemet’s stripping automated endothelial keratoplasty (DSAEK). The purpose of this study is to report our experience of successfully performing DSAEK in a child with CHED.
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Affiliation(s)
- Hamed M Anwar
- Corneal and Refractive Surgery Unit, Magrabi Eye Hospital, Jeddah, Saudi Arabia
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