1
|
Reis LM, Seese SE, Costakos D, Semina EV. Congenital anterior segment ocular disorders: Genotype-phenotype correlations and emerging novel mechanisms. Prog Retin Eye Res 2024; 102:101288. [PMID: 39097141 PMCID: PMC11392650 DOI: 10.1016/j.preteyeres.2024.101288] [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: 03/30/2023] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/05/2024]
Abstract
Development of the anterior segment of the eye requires reciprocal sequential interactions between the arising tissues, facilitated by numerous genetic factors. Disruption of any of these processes results in congenital anomalies in the affected tissue(s) leading to anterior segment disorders (ASD) including aniridia, Axenfeld-Rieger anomaly, congenital corneal opacities (Peters anomaly, cornea plana, congenital primary aphakia), and primary congenital glaucoma. Current understanding of the genetic factors involved in ASD remains incomplete, with approximately 50% overall receiving a genetic diagnosis. While some genes are strongly associated with a specific clinical diagnosis, the majority of known factors are linked with highly variable phenotypic presentations, with pathogenic variants in FOXC1, CYP1B1, and PITX2 associated with the broadest spectrum of ASD conditions. This review discusses typical clinical presentations including associated systemic features of various forms of ASD; the latest functional data and genotype-phenotype correlations related to 25 ASD factors including newly identified genes; promising novel candidates; and current and emerging treatments for these complex conditions. Recent developments of interest in the genetics of ASD include identification of phenotypic expansions for several factors, discovery of multiple modes of inheritance for some genes, and novel mechanisms including a growing number of non-coding variants and alleles affecting specific domains/residues and requiring further studies.
Collapse
Affiliation(s)
- Linda M Reis
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Sarah E Seese
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Deborah Costakos
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Elena V Semina
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA; Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| |
Collapse
|
2
|
Hung SS, Tsai PS, Po CW, Hou PS. Pax6 isoforms shape eye development: Insights from developmental stages and organoid models. Differentiation 2024; 137:100781. [PMID: 38631141 DOI: 10.1016/j.diff.2024.100781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/19/2024]
Abstract
Pax6 is a critical transcription factor involved in the development of the central nervous system. However, in humans, mutations in Pax6 predominantly result in iris deficiency rather than neurological phenotypes. This may be attributed to the distinct functions of Pax6 isoforms, Pax6a and Pax6b. In this study, we investigated the spatial and temporal expression patterns of Pax6 isoforms during different stages of mouse eye development. We observed a strong correlation between Pax6a expression and the neuroretina gene Sox2, while Pax6b showed a high correlation with iris-component genes, including the mesenchymal gene Foxc1. During early patterning from E10.5, Pax6b was expressed in the hinge of the optic cup and neighboring mesenchymal cells, whereas Pax6a was absent in these regions. At E14.5, both Pax6a and Pax6b were expressed in the future iris and ciliary body, coinciding with the integration of mesenchymal cells and Mitf-positive cells in the outer region. From E18.5, Pax6 isoforms exhibited distinct expression patterns as lineage genes became more restricted. To further validate these findings, we utilized ESC-derived eye organoids, which recapitulated the temporal and spatial expression patterns of lineage genes and Pax6 isoforms. Additionally, we found that the spatial expression patterns of Foxc1 and Mitf were impaired in Pax6b-mutant ESC-derived eye organoids. This in vitro eye organoids model suggested the involvement of Pax6b-positive local mesodermal cells in iris development. These results provide valuable insights into the regulatory roles of Pax6 isoforms during iris and neuroretina development and highlight the potential of ESC-derived eye organoids as a tool for studying normal and pathological eye development.
Collapse
Affiliation(s)
- Shih-Shun Hung
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Beitou Dist, Taipei, 11221, Taiwan.
| | - Po-Sung Tsai
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Beitou Dist, Taipei, 11221, Taiwan.
| | - Ching-Wen Po
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Beitou Dist, Taipei, 11221, Taiwan; Institute of Brain Science, School of Medicine, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan.
| | - Pei-Shan Hou
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong St., Beitou Dist, Taipei, 11221, Taiwan; Institute of Brain Science, School of Medicine, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan.
| |
Collapse
|
3
|
Cole JD, McDaniel JA, Nilak J, Ban A, Rodriguez C, Hameed Z, Grannonico M, Netland PA, Yang H, Provencio I, Liu X. Characterization of neural damage and neuroinflammation in Pax6 small-eye mice. Exp Eye Res 2024; 238:109723. [PMID: 37979905 PMCID: PMC10843716 DOI: 10.1016/j.exer.2023.109723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/17/2023] [Accepted: 11/07/2023] [Indexed: 11/20/2023]
Abstract
Aniridia is a panocular condition characterized by a partial or complete loss of the iris. It manifests various developmental deficits in both the anterior and posterior segments of the eye, leading to a progressive vision loss. The homeobox gene PAX6 plays an important role in ocular development and mutations of PAX6 have been the main causative factors for aniridia. In this study, we assessed how Pax6-haploinsufficiency affects retinal morphology and vision of Pax6Sey mice using in vivo and ex vivo metrics. We used mice of C57BL/6 and 129S1/Svlmj genetic backgrounds to examine the variable severity of symptoms as reflected in human aniridia patients. Elevated intraocular pressure (IOP) was observed in Pax6Sey mice starting from post-natal day 20 (P20). Correspondingly, visual acuity showed a steady age-dependent decline in Pax6Sey mice, though these phenotypes were less severe in the 129S1/Svlmj mice. Local retinal damage with layer disorganization was assessed at P30 and P80 in the Pax6Sey mice. Interestingly, we also observed a greater number of activated Iba1+ microglia and GFAP + astrocytes in the Pax6Sey mice than in littermate controls, suggesting a possible neuroinflammatory response to Pax6 deficiencies.
Collapse
Affiliation(s)
- James D Cole
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA; Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - John A McDaniel
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Joelle Nilak
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Ashley Ban
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Carlos Rodriguez
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Zuhaad Hameed
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Marta Grannonico
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Peter A Netland
- Department of Ophthalmology, University of Virginia, Charlottesville, VA, USA
| | - Hu Yang
- Linda and Bipin Doshi Department of Chemical and Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO, USA
| | - Ignacio Provencio
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Department of Ophthalmology, University of Virginia, Charlottesville, VA, USA; Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, USA.
| | - Xiaorong Liu
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Department of Ophthalmology, University of Virginia, Charlottesville, VA, USA; Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, USA; Department of Psychology, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
4
|
Chacon-Camacho OF, Arce-Gonzalez R, Sanchez-de la Rosa F, Urióstegui-Rojas A, Hofmann-Blancas ME, Mata-Flores F, Zenteno JC. Genetic Aspects of Glaucoma: An Updated Review. Curr Mol Med 2024; 24:1231-1249. [PMID: 37272463 DOI: 10.2174/1566524023666230602143617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 06/06/2023]
Abstract
Glaucoma is a group of diverse diseases characterized by cupping of the optic nerve head due to the loss of retinal ganglion cells. It is the most common cause of irreversible blindness throughout the world; therefore, its timely diagnosis and early detection through an ophthalmological examination are very important. We, herein, present the information on the epidemiology, pathophysiology, clinical diagnosis, and treatment of glaucoma. We also emphasize the investigations of the last decades that have allowed identifying numerous genes and susceptibility genetic factors. We have also described in detail the genes whose mutations cause or contribute to the development of the disease.
Collapse
Affiliation(s)
- Oscar Francisco Chacon-Camacho
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
- Laboratorio 5 Edificio A-4, Carrera de Médico Cirujano, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Rocio Arce-Gonzalez
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | | | - Andrés Urióstegui-Rojas
- Department of Integral Ophthalmology, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | | | - Felipe Mata-Flores
- Department of Glaucoma, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Juan Carlos Zenteno
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
- Biochemistry Department, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| |
Collapse
|
5
|
Torrefranca AB, Carmona SM, Santiago APD, Cutiongco-Dela Paz E, Lingao MD. Isolated aniridia caused by a novel PAX6 heterozygous deletion mediated by multi-exon complex rearrangement. Ophthalmic Genet 2023; 44:501-504. [PMID: 36440799 DOI: 10.1080/13816810.2022.2144904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE Mutations in PAX6 gene (chromosome 11p13) encoding a transcriptional regulator involved in oculogenesis mostly present with aniridia. Aniridia is not uncommon in the Philippines but only limited information is available as yet. The purpose of this study was to present a novel, deletion mediated by complex rearrangement in PAX6 gene causing an isolated aniridia in a Filipino girl. PATIENTS AND METHODS The patient is an 8-year-old girl who came in due to leukocoria with associated nystagmus and esotropia. She presented with subnormal vision, nystagmus, aniridia, and cataractous lenses in both eyes. The family history reveals presence of the aniridia and cataract with the mother and a sibling. The patient underwent lens extraction without intraocular lens implantation bilaterally, where patient subsequently underwent intraocular lens implantation on her left eye. Systemic workup was performed including whole abdomen, renal ultrasound, blood chemistry, and urinalysis. Targeted cataract panel with WT1 and PAX6 genes revealed a novel, heterozygous PAX6-inherited mutation from the mother. This variant is a complex rearrangement in PAX6 involving partial deletions of exons 3-5, including the initiator codon. Deletions of PAX6 are part of a contiguous gene deletion syndrome - Wilms tumor, aniridia, genitourinary anomalies, and intellectual disability syndrome - and therefore evaluation of the WT1 gene was necessary to rule out this life-threatening syndrome. CONCLUSION This rare, complex rearrangement of multiple exons and deletions in PAX6 causing an isolated aniridia phenotype is probably the first reported case. The patient was managed by a multidisciplinary team and the guardians were counseled regarding the prognosis and complications.
Collapse
Affiliation(s)
- Aramis B Torrefranca
- Department of Ophthalmology and Visual Sciences, Philippine General Hospital, University of the Philippines, Manila, Philippines
| | - Suzanne Marie Carmona
- Institute of Human Genetics, National Institute of Health, University of the Philippines Manila, Manila, Philippines
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines, Manila, Philippines
| | - Alvina Pauline D Santiago
- Department of Ophthalmology and Visual Sciences, Philippine General Hospital, University of the Philippines, Manila, Philippines
| | - Eva Cutiongco-Dela Paz
- Institute of Human Genetics, National Institute of Health, University of the Philippines Manila, Manila, Philippines
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Philippine General Hospital, University of the Philippines, Manila, Philippines
| | - Michelle D Lingao
- Department of Ophthalmology and Visual Sciences, Philippine General Hospital, University of the Philippines, Manila, Philippines
| |
Collapse
|
6
|
Li Y, Chen J, Zheng Y, Chen Z, Wang T, Sun Q, Wan X, Liu H, Sun X. A novel microdeletion of 517 kb downstream of the PAX6 gene in a Chinese family with congenital aniridia. BMC Ophthalmol 2023; 23:393. [PMID: 37752489 PMCID: PMC10523764 DOI: 10.1186/s12886-023-03147-1] [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: 10/11/2022] [Accepted: 09/19/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND To identify the disease-causing gene in a Chinese family affected with congenital aniridia. METHODS Patients underwent systematic ophthalmic examinations such as anterior segment photography, fundus photography, optical coherence tomography, and fundus fluorescein angiography. The proband was screened for pathogenic variants by whole exome sequencing (WES) and copy number variant (CNV) analysis. Real-time quantitative PCR (RT-qPCR) was applied to confirm the CNV results. Breakpoints were identified by long-range PCR followed by Sanger sequencing. RESULTS All seven members of this Chinese family, including four patients and three normal individuals, were recruited for this study. All patients showed bilateral congenital aniridia with nystagmus, except the son of the proband, who presented with bilateral partial coloboma of the iris. A novel heterozygous deletion (chr11:31,139,019-31,655,997) containing the 3' regulatory enhancers of the PAX6 gene was detected in this family. We also reviewed the reported microdeletions downstream of PAX6 in patients with aniridia. CONCLUSIONS We identified a novel microdeletion, 517 kb in size located about 133 kb downstream of the PAX6 gene, responsible for congenital aniridia in this Chinese family, which expands the spectrum of aniridia-associated mutations in PAX6.
Collapse
Affiliation(s)
- Yinwen Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jieqiong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Ying Zheng
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Zhixuan Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Tao Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Qian Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xiaoling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
| | - Haiyun Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China.
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| |
Collapse
|
7
|
Lima Cunha D, Sarkar H, Eintracht J, Harding P, Zhou JH, Moosajee M. Restoration of functional PAX6 in aniridia patient iPSC-derived ocular tissue models using repurposed nonsense suppression drugs. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 33:240-253. [PMID: 37483273 PMCID: PMC10362734 DOI: 10.1016/j.omtn.2023.06.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/22/2023] [Indexed: 07/25/2023]
Abstract
Congenital aniridia is a rare, pan-ocular disease causing severe sight loss, with only symptomatic intervention offered to patients. Approximately 40% of aniridia patients present with heterozygous nonsense variants in PAX6, resulting in haploinsufficiency. Translational readthrough-inducing drugs (TRIDs) have the ability to weaken the recognition of in-frame premature termination codons (PTCs), permitting full-length protein to be translated. We established induced pluripotent stem cell (iPSC)-derived 3D optic cups and 2D limbal epithelial stem cell (LESC) models from two aniridia patients with prevalent PAX6 nonsense mutations. Both in vitro models show reduced PAX6 protein levels, mimicking the disease. The repurposed TRIDs amlexanox and 2,6-diaminopurine (DAP) and the positive control compounds ataluren and G418 were tested for their efficiency. Amlexanox was identified as the most promising TRID, increasing full-length PAX6 levels in both models and rescuing the disease phenotype through normalization of VSX2 and cell proliferation in the optic cups and reduction of ABCG2 protein and SOX10 expression in LESCs. This study highlights the significance of patient iPSC-derived cells as a new model system for aniridia and proposes amlexanox as a new putative treatment for nonsense-mediated aniridia.
Collapse
Affiliation(s)
- Dulce Lima Cunha
- UCL Institute of Ophthalmology, London, UK
- Radboud Institute of Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Hajrah Sarkar
- UCL Institute of Ophthalmology, London, UK
- The Francis Crick Institute, London, UK
| | | | | | - Jo Huiqing Zhou
- Radboud Institute of Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK
- The Francis Crick Institute, London, UK
- Moorfields Eye Hospital, London, UK
| |
Collapse
|
8
|
Wang Q, Wei WB, Shi XY, Rong WN. A novel PAX6 variant as the cause of aniridia in a Chinese patient with SRRRD. BMC Med Genomics 2023; 16:182. [PMID: 37542296 PMCID: PMC10401864 DOI: 10.1186/s12920-023-01620-w] [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: 01/27/2023] [Accepted: 07/30/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND The genotype characteristics and their associated clinical phenotypes in patients with aniridia were analyzed to explore pathogenic variants using whole-exome sequencing. METHODS One patient with aniridia was enrolled at the Beijing Tongren Hospital. Comprehensive ophthalmic and general examinations were performed on the patient. DNA was extracted from the patient, and whole-exome sequencing was performed to identify the causative variant. The pathogenicity of the variant was predicted using in silico analysis and evaluated according to American College of Medical Genetics and Genomics guidelines. Relationships between genetic variants and clinical features were analyzed. RESULTS In addition to the classical aniridia phenotype showing complete iris aplasia, foveal hypoplasia, and ectopic lentis, the patient also exhibited spontaneous reattachment rhegmatogenous retinal detachment (SRRRD). Whole-exome sequencing identified a novel heterozygous variant, exon8:c.640_646del:p.R214Pfs*28. CONCLUSIONS The present study broadens the range of genetic variants described in aniridia and presents an aniridia patient with SRRRD.
Collapse
Affiliation(s)
- Qian Wang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, China. 1 Dong Jiao Min Xiang, Dong Cheng District, Beijing, 100730, China
| | - Wen Bin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, China. 1 Dong Jiao Min Xiang, Dong Cheng District, Beijing, 100730, China
| | - Xiang Yu Shi
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, China. 1 Dong Jiao Min Xiang, Dong Cheng District, Beijing, 100730, China.
| | - Wei Ning Rong
- Ningxia Eye Hospital, People's Hospital of Ningxia Hui Autonomous Region, Third Clinical Medical College of Ningxia Medical University, Huanghe Road, Jinfeng District, the Ningxia Hui Autonomous Region, Yinchuan, 750002, China.
| |
Collapse
|
9
|
Daruich A, Duncan M, Robert MP, Lagali N, Semina EV, Aberdam D, Ferrari S, Romano V, des Roziers CB, Benkortebi R, De Vergnes N, Polak M, Chiambaretta F, Nischal KK, Behar-Cohen F, Valleix S, Bremond-Gignac D. Congenital aniridia beyond black eyes: From phenotype and novel genetic mechanisms to innovative therapeutic approaches. Prog Retin Eye Res 2023; 95:101133. [PMID: 36280537 PMCID: PMC11062406 DOI: 10.1016/j.preteyeres.2022.101133] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022]
Abstract
Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.
Collapse
Affiliation(s)
- Alejandra Daruich
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Melinda Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Matthieu P Robert
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; Borelli Centre, UMR 9010, CNRS-SSA-ENS Paris Saclay-Paris Cité University, Paris, France
| | - Neil Lagali
- Division of Ophthalmology, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, 581 83, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway
| | - Elena V Semina
- Department of Pediatrics, Children's Research Institute at the Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, 53226, USA
| | - Daniel Aberdam
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Stefano Ferrari
- Fondazione Banca degli Occhi del Veneto, Via Paccagnella 11, Venice, Italy
| | - Vito Romano
- Department of Medical and Surgical Specialties, Radiolological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Italy
| | - Cyril Burin des Roziers
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Rabia Benkortebi
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Nathalie De Vergnes
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France
| | - Michel Polak
- Pediatric Endocrinology, Gynecology and Diabetology, Hôpital Universitaire Necker Enfants Malades, AP-HP, Paris Cité University, INSERM U1016, Institut IMAGINE, France
| | | | - Ken K Nischal
- Division of Pediatric Ophthalmology, Strabismus, and Adult Motility, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Francine Behar-Cohen
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Sophie Valleix
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP. Centre Université de Paris, Fédération de Génétique et de Médecine Génomique Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris Cedex 14, France
| | - Dominique Bremond-Gignac
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France.
| |
Collapse
|
10
|
Abstract
Inherited ocular diseases comprise a heterogeneous group of rare and complex diseases, including inherited retinal diseases (IRDs) and inherited optic neuropathies. Recent success in adeno-associated virus-based gene therapy, voretigene neparvovec (Luxturna®) for RPE65-related IRDs, has heralded rapid evolution in gene therapy platform technologies and strategies, from gene augmentation to RNA editing, as well as gene agnostic approaches such as optogenetics. This review discusses the fundamentals underlying the mode of inheritance, natural history studies and clinical trial outcomes, as well as current and emerging therapies covering gene therapy strategies, cell-based therapies and bionic vision.
Collapse
Affiliation(s)
- Hwei Wuen Chan
- Department of Ophthalmology, National University Hospital, Singapore,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore,Correspondence: Dr Hwei Wuen Chan, Assistant Professor, Department of Ophthalmology (Eye), Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 7, 119228, Singapore. E-mail:
| | - Jaslyn Oh
- Department of Ophthalmology, National University Hospital, Singapore
| | - Bart Leroy
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium,Department of Head and Skin, Ghent University, Ghent, Belgium,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium,Division of Ophthalmology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| |
Collapse
|
11
|
Tamayo A, Núñez-Moreno G, Ruiz C, Plaisancie J, Damian A, Moya J, Chassaing N, Calvas P, Ayuso C, Minguez P, Corton M. Minigene Splicing Assays and Long-Read Sequencing to Unravel Pathogenic Deep-Intronic Variants in PAX6 in Congenital Aniridia. Int J Mol Sci 2023; 24:ijms24021562. [PMID: 36675087 PMCID: PMC9863980 DOI: 10.3390/ijms24021562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
PAX6 haploinsufficiency causes aniridia, a congenital eye disorder that involves the iris, and foveal hypoplasia. Comprehensive screening of the PAX6 locus, including the non-coding regions, by next-generation sequencing revealed four deep-intronic variants with potential effects on pre-RNA splicing. Nevertheless, without a functional analysis, their pathogenicity could not be established. We aimed to decipher their impact on the canonical PAX6 splicing using in vitro minigene splicing assays and nanopore-based long-read sequencing. Two multi-exonic PAX6 constructs were generated, and minigene assays were carried out. An aberrant splicing pattern was observed for two variants in intron 6, c.357+136G>A and c.357+334G>A. In both cases, several exonization events, such as pseudoexon inclusions and partial intronic retention, were observed due to the creation or activation of new/cryptic non-canonical splicing sites, including a shared intronic donor site. In contrast, two variants identified in intron 11, c.1032+170A>T and c.1033-275A>C, seemed not to affect splicing processes. We confirmed the high complexity of alternative splicing of PAX6 exon 6, which also involves unreported cryptic intronic sites. Our study highlights the importance of integrating functional studies into diagnostic algorithms to decipher the potential implication of non-coding variants, usually classified as variants of unknown significance, thus allowing variant reclassification to achieve a conclusive genetic diagnosis.
Collapse
Affiliation(s)
- Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871 Alcalá de Henares, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Carolina Ruiz
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Julie Plaisancie
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Alejandra Damian
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Nicolas Chassaing
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Patrick Calvas
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
| |
Collapse
|
12
|
Guo R, Zhang X, Liu A, Ji J, Liu W. Novel clinical presentation and PAX6 mutation in families with congenital aniridia. Front Med (Lausanne) 2022; 9:1042588. [PMID: 36582291 PMCID: PMC9792480 DOI: 10.3389/fmed.2022.1042588] [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: 09/12/2022] [Accepted: 11/29/2022] [Indexed: 12/14/2022] Open
Abstract
Purpose To explore the clinical phenotype and genetic defects of families with congenital aniridia. Methods Four Chinese families with aniridia were enrolled in this study. The detailed ocular presentations of the patients were recorded. Whole exome sequencing (BGI MGIEasy V4 chip) was used to detect the gene mutation. Sanger sequencing was performed to validate the potential pathogenic variants, and segregation analysis was performed on all available family members. Results By whole exome sequencing and Sanger sequencing, three recurrent mutations (c.112del, p.Arg38Glyfs*16; c.299G > A, p.Trp100* and c.718C > T, p.Arg240*) and one novel mutation (c.278_281del, p.Glu93Alafs*30) of PAX6 were identified. All the mutations were co-segregated with the phenotype in the families. We also observed spontaneous anterior lens capsule rupture in aniridia for the first time. Conclusion We report spontaneous anterior lens capsule rupture as a novel phenotype of aniridia and three recurrent mutations and one novel mutation of PAX6 in families with aniridia. Our results expanded the phenotype and genotype spectra of aniridia and can help us better understand the disease.
Collapse
Affiliation(s)
- Ruru Guo
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiaotian Zhang
- Department of Ophthalmology, Nankai University Eye Hospital, Tianjin, China,Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Aihua Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Jian Ji
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Wei Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China,*Correspondence: Wei Liu,
| |
Collapse
|
13
|
Tibrewal S, Ratna R, Gour A, Agarkar S, Dubey S, Ganesh S, Kekunnaya R, Sangwan V, Liu Y, Vanita V. Clinical and molecular aspects of congenital aniridia - A review of current concepts. Indian J Ophthalmol 2022; 70:2280-2292. [PMID: 35791108 PMCID: PMC9426064 DOI: 10.4103/ijo.ijo_2255_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Congenital aniridia is a pan ocular disorder characterized by partial or total loss of iris tissue as the defining feature. Classic aniridia, however, has a spectrum of ocular findings, including foveal hypoplasia, optic nerve hypoplasia, nystagmus, late-onset cataract, glaucoma, and keratopathy. The latter three are reasons for further visual compromise in such patients. This entity is often due to mutations in the PAX6 (Paired box protein Pax-6) gene. Recently, aniridia-like phenotypes have been reported due to non-PAX6 mutations as in PITX2, FOXC1, FOXD3, TRIM44, and CYP1B1 as well wherein there is an overlap of aniridia, such as iris defects with congenital glaucoma or anterior segment dysgenesis. In this review, we describe the various clinical features of classic aniridia, the comorbidities and their management, the mutation spectrum of the genes involved, genotype-phenotype correlation of PAX6 and non-PAX6 mutations, and the genetic testing plan. The various systemic associations and their implications in screening and genetic testing have been discussed. Finally, the future course of aniridia treatment in the form of drugs (such as ataluren) and targeted gene therapy has been discussed.
Collapse
Affiliation(s)
- Shailja Tibrewal
- Department of Ocular Genetics; Department of Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Ria Ratna
- Department of Ocular Genetics, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Abha Gour
- Department of Cornea and Anterior Segment, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Sumita Agarkar
- Department of Pediatric Ophthalmology and Strabismus, Medical Research Foundation, Sankara Netralaya, Chennai, Tamil Nadu, India
| | - Suneeta Dubey
- Department of Glaucoma, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Suma Ganesh
- Department of Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Ramesh Kekunnaya
- Child Sight Institute, Jasti V Ramanamma Children's Eye Care Centre, L V Prasad Eye Institute, KAR Campus, Hyderabad, Telangana, India
| | - Virender Sangwan
- Department of Cornea and Anterior Segment, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, USA
| | - Vanita Vanita
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, Punjab, India
| |
Collapse
|
14
|
Kaushik S, Dubey S, Choudhary S, Ratna R, Pandav SS, Khan AO. Anterior segment dysgenesis: Insights into the genetics and pathogenesis. Indian J Ophthalmol 2022; 70:2293-2303. [PMID: 35791109 PMCID: PMC9426159 DOI: 10.4103/ijo.ijo_3223_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Childhood glaucoma is a treatable cause of blindness, provided it is recognized, diagnosed, and treated in time. WHO has estimated that it is responsible for Blind Years second only to cataracts. The fundamental pathophysiology of all childhood glaucoma is impaired outflow through the trabecular meshwork. Anterior segment Dysgeneses (ASD) are a group of non-acquired ocular anomalies associated with glaucoma, characterized by developmental abnormalities of the tissues of the anterior segment. The cause is multifactorial, and many genes are involved in the development of the anterior segment. Over the last decade, molecular and developmental genetic research has transformed our understanding of the molecular basis of ASD and the developmental mechanisms underlying these conditions. Identifying the genetic changes underlying ASD has gradually led to the recognition that some of these conditions may be parts of a disease spectrum. The characterization of genes responsible for glaucoma is the critical first step toward developing diagnostic and screening tests, which could identify individuals at risk for disease before irreversible optic nerve damage occurs. It is also crucial for genetic counseling and risk stratification of later pregnancies. It also aids pre-natal testing by various methods allowing for effective genetic counseling. This review will summarize the known genetic variants associated with phenotypes of ASD and the possible significance and utility of genetic testing in the clinic.
Collapse
Affiliation(s)
- Sushmita Kaushik
- Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Suneeta Dubey
- Dr. Shroffs Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Sandeep Choudhary
- Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ria Ratna
- Dr. Shroffs Charity Eye Hospital, Daryaganj, New Delhi, India
| | - Surinder S Pandav
- Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Arif O Khan
- Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, UAE; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| |
Collapse
|
15
|
Jacobson A, Mian SI, Bohnsack BL. Clinical outcomes and visual prognostic factors in congenital aniridia. BMC Ophthalmol 2022; 22:235. [PMID: 35614435 PMCID: PMC9131660 DOI: 10.1186/s12886-022-02460-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/18/2022] [Indexed: 11/10/2022] Open
Abstract
Background Evaluate outcomes and identify prognostic factors in congenital aniridia. Methods Retrospective interventional case series of patients with congenital aniridia treated between 2012–2020. Ocular examination and surgical details were collected. Surgical failure was defined as disease progression or need for additional surgery for same/related indication. Kaplan–Meier survival curves, Wilcoxon test, and univariate and multivariate linear regression analyses were performed. Results Ninety-four patients with congenital aniridia presented at median 19.0 years. Two-thirds of patients underwent ≥ 1intraocular surgery, with average of 1.7 ± 2.3 surgeries/eye. At final follow-up (median 4.0 years), 45% of eyes had undergone lensectomy. Aphakic eyes showed worse visual acuity (VA) than phakic or pseudophakic eyes. Glaucoma affected 52% of eyes, of which half required IOP-lowering surgery. Glaucoma drainage devices showed the highest success rate (71%) at 14.2 ± 15.4 years of follow-up. Keratopathy affected 65% of eyes and one-third underwent corneal surgery. Keratoprosthesis had the longest survival rates at 10-years (64% with 95% CI [32,84]). LogMAR VA at presentation and final follow-up were not statistically different. Half of patients were legally blind at final follow-up. Final VA was associated with presenting VA, glaucoma diagnosis, and cataract or keratopathy at presentation. Penetrating keratoplasty and keratoprosthesis implantation correlated with worse BCVA. Conclusions Most aniridic patients in this large US-based cohort underwent at least 1 intraocular surgery. Cataract, glaucoma, and keratopathy were associated with worse VA and are important prognostic factors to consider when managing congenital aniridia. Supplementary Information The online version contains supplementary material available at 10.1186/s12886-022-02460-5.
Collapse
|
16
|
Aboobakar IF, Wiggs JL. The genetics of glaucoma: Disease associations, personalised risk assessment and therapeutic opportunities-A review. Clin Exp Ophthalmol 2022; 50:143-162. [PMID: 35037362 DOI: 10.1111/ceo.14035] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/23/2022]
Abstract
Glaucoma refers to a heterogenous group of disorders characterised by progressive loss of retinal ganglion cells and associated visual field loss. Both early-onset and adult-onset forms of the disease have a strong genetic component. Here, we summarise the known genetic associations for various forms of glaucoma and the possible functional roles for these genes in disease pathogenesis. We also discuss efforts to translate genetic knowledge into clinical practice, including gene-based tests for disease diagnosis and risk-stratification as well as gene-based therapies.
Collapse
Affiliation(s)
- Inas F Aboobakar
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| | - Janey L Wiggs
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
17
|
Magan T, Tanner A, Fajardo-Sanchez J, Lim KS, Goyal S, Rodrigues I, Amaya L, Trikha S, Kulkarni A, Hammond C, Lascaratos G, Yu-Wai-Man C. Long-term outcomes in Primary congenital glaucoma, aniridia and anterior segment dysgenesis. Eur J Ophthalmol 2022; 32:2920-2927. [PMID: 35001688 PMCID: PMC9373187 DOI: 10.1177/11206721211073208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Aim To determine the long-term outcomes of a cohort of complex patients with
primary congenital glaucoma, aniridia and anterior segment dysgenesis. Methods Retrospective consecutive series between 1990–2021 in two UK tertiary
centres: Guy's and St Thomas’ NHS Foundation Trust and King's College
Hospital NHS Foundation Trust. We recorded the number and types of surgical
and laser treatments along with preoperative and postoperative data,
including intraocular pressures (IOP) and anti-glaucoma medications. Results A total of 41 eyes of 21 patients were included. Primary diagnoses were
primary congenital glaucoma in 16 eyes (39.0%), aniridia in 14 eyes (34.2%),
and anterior segment dysgenesis in 8 eyes (19.5%). Sixteen eyes (39.0%) had
one or more glaucoma surgery or laser procedures for advanced glaucoma, and
the long-term follow-up was 12.8 ± 3.6 years. There was a significant
decrease in postoperative IOP (mmHg) at 3 months (16.5 ± 1.6;
p = 0.0067), 6 months (18.7 ± 2.1;
p = 0.0386), 12 months (18.6 ± 1.7;
p = 0.0229), 3 years (14.7 ± 1.2;
p = 0.0126), 5 years (15.5 ± 1.8;
p = 0.0330) and 10 years (15.4 ± 2.3;
p = 0.7780), compared to preoperatively (24.1 ± 2.6).
Surgical success (complete and qualified) was 62.5%, 50.0%, 43.8%, 46.2%,
45.5% and 28.6% at 3 months, 6 months, 12 months, 3 years, 5 years and 10
years, respectively. There was no significant change in the number of
anti-glaucoma drugs postoperatively (p > 0.05). Four
eyes (25.0%) had postoperative complications (hyphaema, hypotony) that
resolved after conservative management. Conclusions Surgical management of these complex eyes with advanced glaucoma is
challenging. Overall, the cohort had good surgical outcomes with a
significant decrease in IOP by 36.1% after long-term follow-up.
Collapse
Affiliation(s)
- Tejal Magan
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111990King's College Hospital, London, UK
| | - Alexander Tanner
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Julia Fajardo-Sanchez
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Kin Sheng Lim
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Saurabh Goyal
- Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Ian Rodrigues
- Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Luis Amaya
- Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Sameer Trikha
- Department of Ophthalmology, 111990King's College Hospital, London, UK
| | - Avinash Kulkarni
- Department of Ophthalmology, 111990King's College Hospital, London, UK
| | - Christopher Hammond
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| | - Gerassimos Lascaratos
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111990King's College Hospital, London, UK
| | - Cynthia Yu-Wai-Man
- Faculty of Life Sciences & Medicine, 111990King's College London, London, UK.,Department of Ophthalmology, 111988St Thomas' Hospital, London, UK
| |
Collapse
|
18
|
Latta L, Figueiredo FC, Ashery-Padan R, Collinson JM, Daniels J, Ferrari S, Szentmáry N, Solá S, Shalom-Feuerstein R, Lako M, Xapelli S, Aberdam D, Lagali N. Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions. Ocul Surf 2021; 22:245-266. [PMID: 34520870 DOI: 10.1016/j.jtos.2021.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/19/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022]
Abstract
Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.
Collapse
Affiliation(s)
- L Latta
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany; Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - F C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom
| | - R Ashery-Padan
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - J M Collinson
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, United Kingdom
| | - J Daniels
- Cells for Sight, UCL Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - S Ferrari
- The Veneto Eye Bank Foundation, Venice, Italy
| | - N Szentmáry
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - S Solá
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - R Shalom-Feuerstein
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - M Lako
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - S Xapelli
- Instituto Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - D Aberdam
- Centre de Recherche des Cordeliers, INSERM U1138, Team 17, France; Université de Paris, 75006, Paris, France.
| | - N Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
| |
Collapse
|
19
|
Balikov DA, Jacobson A, Prasov L. Glaucoma Syndromes: Insights into Glaucoma Genetics and Pathogenesis from Monogenic Syndromic Disorders. Genes (Basel) 2021; 12:genes12091403. [PMID: 34573386 PMCID: PMC8471311 DOI: 10.3390/genes12091403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 11/21/2022] Open
Abstract
Monogenic syndromic disorders frequently feature ocular manifestations, one of which is glaucoma. In many cases, glaucoma in children may go undetected, especially in those that have other severe systemic conditions that affect other parts of the eye and the body. Similarly, glaucoma may be the first presenting sign of a systemic syndrome. Awareness of syndromes associated with glaucoma is thus critical both for medical geneticists and ophthalmologists. In this review, we highlight six categories of disorders that feature glaucoma and other ocular or systemic manifestations: anterior segment dysgenesis syndromes, aniridia, metabolic disorders, collagen/vascular disorders, immunogenetic disorders, and nanophthalmos. The genetics, ocular and systemic features, and current and future treatment strategies are discussed. Findings from rare diseases also uncover important genes and pathways that may be involved in more common forms of glaucoma, and potential novel therapeutic strategies to target these pathways.
Collapse
Affiliation(s)
- Daniel A. Balikov
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
| | - Adam Jacobson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
| | - Lev Prasov
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence:
| |
Collapse
|
20
|
Nguyen HH, Pham CM, Nguyen HTT, Vu NP, Duong TT, Nguyen TD, Nguyen BD, Nguyen HV, Nong HV. Novel mutations of the PAX6, FOXC1, and PITX2 genes cause abnormal development of the iris in Vietnamese individuals. Mol Vis 2021; 27:555-563. [PMID: 34566401 PMCID: PMC8416135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/31/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Congenital iris abnormality is a feature of several genetic conditions, such as aniridia syndrome and anterior segment degeneration (ASD) disorders. Aniridia syndrome is caused by mutations in the PAX6 gene or its regulatory elements in the locus 11p13 or deletions of contiguous genes, while ASDs are the result of mutations in various genes, such as PAX6, FOXC1, PITX2, and CYP1B1. This study aims to identify pathogenic mutations in Vietnamese individuals with congenital anomalies of the iris. METHODS Genomic DNA was extracted from peripheral blood of 24 patients belonging to 15 unrelated families and their available family members. Multiplex ligation-dependent probe amplification (MLPA) was used to detect the deletions or duplications in the 11p13-14 region, including the PAX6 gene and its neighboring genes. Direct PCR sequencing was used to screen mutations in 13 exons and flanking sequences of the PAX6 gene. The patients without mutation in the PAX6 locus were further analyzed with whole exome sequencing (WES). Identified mutations were tested with segregation analysis in proband family members. RESULTS We identified a total of 8 novel and 4 recurrent mutations in 20 of 24 affected individuals from 12 families. Among these mutations, one large deletion of the whole PAX6 gene and another deletion of the PAX6 downstream region containing the DCDC1 and ELP4 genes were identified. Eight mutations were detected in PAX6, including four nonsense, three frameshift, and one splice site. In addition, two point mutations were identified in the FOXC1 and PITX2 genes in patients without mutation in PAX6. Some of the mutations segregated in an autosomal dominant pattern where family members were available. CONCLUSIONS This study provides new data on causative mutations in individuals with abnormal development of iris tissue in Vietnam. These results contribute to clinical management and genetic counseling for affected people and their families.
Collapse
Affiliation(s)
- Ha Hai Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | | | - Hoa Thi Thanh Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Nhung Phuong Vu
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Trang Thu Duong
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Ton Dang Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | | | | | - Hai Van Nong
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| |
Collapse
|
21
|
Alipanahi B, Hormozdiari F, Behsaz B, Cosentino J, McCaw ZR, Schorsch E, Sculley D, Dorfman EH, Foster PJ, Peng LH, Phene S, Hammel N, Carroll A, Khawaja AP, McLean CY. Large-scale machine-learning-based phenotyping significantly improves genomic discovery for optic nerve head morphology. Am J Hum Genet 2021; 108:1217-1230. [PMID: 34077760 PMCID: PMC8322934 DOI: 10.1016/j.ajhg.2021.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 05/10/2021] [Indexed: 02/06/2023] Open
Abstract
Genome-wide association studies (GWASs) require accurate cohort phenotyping, but expert labeling can be costly, time intensive, and variable. Here, we develop a machine learning (ML) model to predict glaucomatous optic nerve head features from color fundus photographs. We used the model to predict vertical cup-to-disc ratio (VCDR), a diagnostic parameter and cardinal endophenotype for glaucoma, in 65,680 Europeans in the UK Biobank (UKB). A GWAS of ML-based VCDR identified 299 independent genome-wide significant (GWS; p ≤ 5 × 10-8) hits in 156 loci. The ML-based GWAS replicated 62 of 65 GWS loci from a recent VCDR GWAS in the UKB for which two ophthalmologists manually labeled images for 67,040 Europeans. The ML-based GWAS also identified 93 novel loci, significantly expanding our understanding of the genetic etiologies of glaucoma and VCDR. Pathway analyses support the biological significance of the novel hits to VCDR: select loci near genes involved in neuronal and synaptic biology or harboring variants are known to cause severe Mendelian ophthalmic disease. Finally, the ML-based GWAS results significantly improve polygenic prediction of VCDR and primary open-angle glaucoma in the independent EPIC-Norfolk cohort.
Collapse
Affiliation(s)
| | | | | | | | | | | | - D Sculley
- Google Health, Cambridge, MA 02142, USA
| | | | - Paul J Foster
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | | | | | | | | | - Anthony P Khawaja
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London EC1V 9EL, UK; MRC Epidemiology Unit, University of Cambridge, Cambridge CB2 0SL, UK
| | | |
Collapse
|
22
|
Amador C, Shah R, Ghiam S, Kramerov AA, Ljubimov AV. Gene therapy in the anterior eye segment. Curr Gene Ther 2021; 22:104-131. [PMID: 33902406 DOI: 10.2174/1566523221666210423084233] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/14/2021] [Accepted: 04/04/2021] [Indexed: 11/22/2022]
Abstract
This review provides comprehensive information about the advances in gene therapy in the anterior segment of the eye including cornea, conjunctiva, lacrimal gland, and trabecular meshwork. We discuss gene delivery systems including viral and non-viral vectors as well as gene editing techniques, mainly CRISPR-Cas9, and epigenetic treatments including antisense and siRNA therapeutics. We also provide a detailed analysis of various anterior segment diseases where gene therapy has been tested with corresponding outcomes. Disease conditions include corneal and conjunctival fibrosis and scarring, corneal epithelial wound healing, corneal graft survival, corneal neovascularization, genetic corneal dystrophies, herpetic keratitis, glaucoma, dry eye disease, and other ocular surface diseases. Although most of the analyzed results on the use and validity of gene therapy at the ocular surface have been obtained in vitro or using animal models, we also discuss the available human studies. Gene therapy approaches are currently considered very promising as emerging future treatments of various diseases, and this field is rapidly expanding.
Collapse
Affiliation(s)
- Cynthia Amador
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Ruchi Shah
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Sean Ghiam
- Sackler School of Medicine, New York State/American Program of Tel Aviv University, Tel Aviv, Israel
| | - Andrei A Kramerov
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Alexander V Ljubimov
- Eye Program, Board of Governors Regenerative Medicine Institute and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| |
Collapse
|
23
|
Feng Y, Nouri K, Schimmer AD. Mitochondrial ATP-Dependent Proteases-Biological Function and Potential Anti-Cancer Targets. Cancers (Basel) 2021; 13:2020. [PMID: 33922062 PMCID: PMC8122244 DOI: 10.3390/cancers13092020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/11/2021] [Accepted: 04/18/2021] [Indexed: 12/20/2022] Open
Abstract
Cells must eliminate excess or damaged proteins to maintain protein homeostasis. To ensure protein homeostasis in the cytoplasm, cells rely on the ubiquitin-proteasome system and autophagy. In the mitochondria, protein homeostasis is regulated by mitochondria proteases, including four core ATP-dependent proteases, m-AAA, i-AAA, LonP, and ClpXP, located in the mitochondrial membrane and matrix. This review will discuss the function of mitochondrial proteases, with a focus on ClpXP as a novel therapeutic target for the treatment of malignancy. ClpXP maintains the integrity of the mitochondrial respiratory chain and regulates metabolism by degrading damaged and misfolded mitochondrial proteins. Inhibiting ClpXP genetically or chemically impairs oxidative phosphorylation and is toxic to malignant cells with high ClpXP expression. Likewise, hyperactivating the protease leads to increased degradation of ClpXP substrates and kills cancer cells. Thus, targeting ClpXP through inhibition or hyperactivation may be novel approaches for patients with malignancy.
Collapse
Affiliation(s)
- Yue Feng
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada; (Y.F.); (K.N.)
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Kazem Nouri
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada; (Y.F.); (K.N.)
| | - Aaron D. Schimmer
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1L7, Canada; (Y.F.); (K.N.)
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
| |
Collapse
|
24
|
Shah R, Amador C, Tormanen K, Ghiam S, Saghizadeh M, Arumugaswami V, Kumar A, Kramerov AA, Ljubimov AV. Systemic diseases and the cornea. Exp Eye Res 2021; 204:108455. [PMID: 33485845 PMCID: PMC7946758 DOI: 10.1016/j.exer.2021.108455] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/08/2023]
Abstract
There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.
Collapse
Affiliation(s)
- Ruchi Shah
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
| | - Cynthia Amador
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Kati Tormanen
- Center for Neurobiology and Vaccine Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Sean Ghiam
- Sackler School of Medicine, New York State/American Program of Tel Aviv University, Tel Aviv, Israel
| | - Mehrnoosh Saghizadeh
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Vaithi Arumugaswami
- Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Ashok Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, MI, USA
| | - Andrei A Kramerov
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Alexander V Ljubimov
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
25
|
Williams AL, Bohnsack BL. The Ocular Neural Crest: Specification, Migration, and Then What? Front Cell Dev Biol 2021; 8:595896. [PMID: 33425902 PMCID: PMC7785809 DOI: 10.3389/fcell.2020.595896] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/04/2020] [Indexed: 12/11/2022] Open
Abstract
During vertebrate embryonic development, a population of dorsal neural tube-derived stem cells, termed the neural crest (NC), undergo a series of morphogenetic changes and extensive migration to become a diverse array of cell types. Around the developing eye, this multipotent ocular NC cell population, called the periocular mesenchyme (POM), comprises migratory mesenchymal cells that eventually give rise to many of the elements in the anterior of the eye, such as the cornea, sclera, trabecular meshwork, and iris. Molecular cell biology and genetic analyses of congenital eye diseases have provided important information on the regulation of NC contributions to this area of the eye. Nevertheless, a complete understanding of the NC as a contributor to ocular development remains elusive. In addition, positional information during ocular NC migration and the molecular pathways that regulate end tissue differentiation have yet to be fully elucidated. Further, the clinical challenges of ocular diseases, such as Axenfeld-Rieger syndrome (ARS), Peters anomaly (PA) and primary congenital glaucoma (PCG), strongly suggest the need for better treatments. While several aspects of NC evolution have recently been reviewed, this discussion will consolidate the most recent current knowledge on the specification, migration, and contributions of the NC to ocular development, highlighting the anterior segment and the knowledge obtained from the clinical manifestations of its associated diseases. Ultimately, this knowledge can inform translational discoveries with potential for sorely needed regenerative therapies.
Collapse
Affiliation(s)
- Antionette L Williams
- Division of Ophthalmology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States
| | - Brenda L Bohnsack
- Division of Ophthalmology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States.,Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| |
Collapse
|
26
|
Lind KT, Cost NG, Zegar K, Kuldanek SA, Enzenauer RW, Schneider KW. A rare case of an isolated PAX6 mutation, aniridia, and Wilms tumor. Ophthalmic Genet 2020; 42:216-217. [PMID: 33300417 DOI: 10.1080/13816810.2020.1852577] [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
Introduction: Wilms tumor (WT) is the most common renal malignancy of children and can be seen in WAGR syndrome (WT, aniridia, genitourinary anomalies, and intellectual disability). WAGR results from a contiguous gene deletion within the 11p13 region, encompassing the WT1 gene, often responsible for WT development, and the PAX6 gene, responsible for aniridia. Aniridia, a pan-ocular disease resulting from iris hypoplasia, is thought to increase the risk for WT development if their genetic alteration spans both the WT1 and the PAX6 genes on 11p13.Case Description: We describe a unique case of a patient with aniridia secondary to a heterozygous PAX6 nonsense mutation who developed WT despite no additional identifiable germline genetic drivers for this disease.Discussion: Isolated mutations in PAX6 previously have not been associated with increased risk of WT development case raises the question of if surveillance for WT should be continued in patients with aniridia with an isolated PAX6 mutation identified.
Collapse
Affiliation(s)
- Katherine T Lind
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Nicholas G Cost
- Department of Surgery, Division of Urology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kelsey Zegar
- Genetic Services, InformedDNA, St. Petersburg, FL, USA
| | - Susan A Kuldanek
- Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, CO, USA
| | - Robert W Enzenauer
- Department of Ophthalmology, Children's Hospital of Colorado, Aurora, CO, USA
| | - Kami W Schneider
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA.,Center for Cancer and Blood Disorders, Children's Hospital Colorado, Aurora, CO, USA
| |
Collapse
|
27
|
Morphometric analysis of the lens in human aniridia and mouse Small eye. Exp Eye Res 2020; 203:108371. [PMID: 33248069 DOI: 10.1016/j.exer.2020.108371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/17/2020] [Accepted: 11/22/2020] [Indexed: 12/16/2022]
Abstract
Congenital aniridia is caused by heterozygous mutations in the PAX6 gene. In this disease, congenital iris and foveal hypoplasia is associated with juvenile onset cataract, glaucoma, and corneal keratopathy. In rodents, Pax6 mutations result in a congenital reduction in ocular size that is not typically described in human aniridia. Here, the ocular morphometry of aniridia patients is compared with the lens phenotype of Pax6+/tm1/Pgr mice to reveal whether there are species differences in Pax6 regulation of lens development and homeostasis. Ultrasound biometry (UBM) revealed that eleven percent of aniridia patients exhibited mild microphthalmia while the anterior chamber depth of aniridic eyes was significantly reduced from 6 months of age onward. Although aniridic lens thickness was normal from birth, it was significantly decreased in aniridic lenses older than 30. Notably, 86% of aniridic lenses exhibited cataractous changes in this cohort. In addition, a significant proportion of aniridia patients develop lens subluxation as they age associated with reduced lens diameter as measured by anterior segment optical coherence tomography (AS-OCT). Analysis of young adult Pax6+/tm1/Pgr mouse lenses by micro-computed tomography (microCT), bright field and dark field imaging revealed that they are reduced in size but did not exhibit overt cataracts at this age. Overall, this study reveals that congenital microphthalmia as assessed by axial length, or microphakia, as assessed by lens thickness, are not typical in human aniridia, although these are primary manifestations of Pax6 mutations in mice, suggesting that PAX6 regulates some aspects of lens development differently between these species.
Collapse
|
28
|
Cassinari K, Rovelet-Lecrux A, Tury S, Quenez O, Richard AC, Charbonnier C, Olaso R, Boland A, Deleuze JF, Besancenot JF, Delpont B, Pouliquen D, Lecoquierre F, Chambon P, Thauvin-Robinet C, Campion D, Frebourg T, Battini JL, Nicolas G. Haploinsufficiency of the Primary Familial Brain Calcification Gene SLC20A2 Mediated by Disruption of a Regulatory Element. Mov Disord 2020; 35:1336-1345. [PMID: 32506582 DOI: 10.1002/mds.28090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/17/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Primary familial brain calcification (PFBC) is a rare cerebral microvascular calcifying disorder with diverse neuropsychiatric expression. Five genes were reported as PFBC causative when carrying pathogenic variants. Haploinsufficiency of SLC20A2, which encodes an inorganic phosphate importer, is a major cause of autosomal-dominant PFBC. However, PFBC remains genetically unexplained in a proportion of patients, suggesting the existence of additional genes or cryptic mutations. We analyzed exome sequencing data of 71 unrelated, genetically unexplained PFBC patients with the aim to detect copy number variations that may disrupt the expression of core PFBC-causing genes. METHODS After the identification of a deletion upstream of SLC20A2, we assessed its consequences on gene function by reverse transcriptase droplet digital polymerase chain reaction (RT-ddPCR), an ex vivo inorganic phosphate uptake assay, and introduced the deletion of a putative SLC20A2 enhancer mapping to this region in human embryonic kidney 293 (HEK293) cells by clustered regularly interspaced short palindromic repeats (CRISPR) - CRISPR-associated protein 9 (Cas9). RESULTS The 8p11.21 deletion, segregating with PFBC in a family, mapped 35 kb upstream of SLC20A2. The deletion carriers/normal controls ratio of relative SLC20A2 mRNA levels was 60.2% (P < 0.001). This was comparable with that of patients carrying an SLC20A2 premature stop codon (63.4%; P < 0.001). The proband exhibited a 39.3% decrease of inorganic phosphate uptake in blood (P = 0.015). In HEK293 cells, we observed a 39.8% decrease in relative SLC20A2 mRNA levels after normalization on DNA copy number (P < 0.001). DISCUSSION We identified a deletion of an enhancer of SLC20A2 expression, with carriers showing haploinsufficiency in similar ranges to loss-of-function alleles, and we observed reduced mRNA levels after deleting this element in a cellular model. We propose a 3-step strategy to identify and easily assess the effect of such events. © 2020 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Kévin Cassinari
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Anne Rovelet-Lecrux
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Sandrine Tury
- Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Olivier Quenez
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Anne-Claire Richard
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Camille Charbonnier
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Robert Olaso
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Jean-François Deleuze
- Centre National de Recherche en Génomique Humaine, Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | | | - Benoit Delpont
- Department of Internal Medicine and Systemic Diseases, Dijon University Hospital, Dijon, France
| | - Dorothée Pouliquen
- Department of Neurology and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - François Lecoquierre
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Pascal Chambon
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Christel Thauvin-Robinet
- Inserm UMR 1231 GAD, Genetics of Developmental Disorders, Université de Bourgogne-Franche Comté, FHU TRANSLAD, Dijon, France
- CHU Dijon Bourgogne, Unité Fonctionnelle "Innovation diagnostique dans les maladies rares," laboratoire de génétique chromosomique et moléculaire, Plateau Technique de Biologie, Dijon, France
- Centre de Référence Maladies Rares "Déficiences Intellectuelles de causes rares," FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
| | - Dominique Campion
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
- Department of Research, Rouvray Psychiatric Hospital, Sotteville-les-Rouen, France
| | - Thierry Frebourg
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| | - Jean-Luc Battini
- Institut de Recherche en Infectiologie de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Gaël Nicolas
- Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Normandie Univ, UNIROUEN, Inserm U1245 and Rouen University Hospital, Rouen, France
| |
Collapse
|
29
|
You B, Zhang X, Xu K, Xie Y, Ye H, Li Y. Mutation spectrum of PAX6 and clinical findings in 95 Chinese patients with aniridia. Mol Vis 2020; 26:226-234. [PMID: 32214788 PMCID: PMC7093334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 03/24/2020] [Indexed: 11/03/2022] Open
Abstract
Purpose Aniridia is a rare congenital panocular disease caused by mutations in PAX6. The purposes of this study were to clarify the mutation features of PAX6 in a cohort of Chinese patients with aniridia and to describe their clinical characteristics. Methods We recruited 95 patients from 65 unrelated families clinically diagnosed with aniridia. All patients underwent ophthalmic examinations. Sanger sequencing and multiplex ligation probe amplification of PAX6 were performed to detect intragenic variants and copy number variations (CNVs). Results We identified 58 disease-causing mutations in PAX6 in 63 families; the detection rate was 96.9%. The 58 mutations included frameshift indels (27.6%), splice site changes (25.9%), nonsense mutations (20.7%), CNVs (19.0%), missense mutations (3.4%), run-on mutations (1.7%), and a synonymous mutation (1.7%). Clinical examinations revealed that 71 patients had complete or almost complete iris loss, 16 patients showed partial iris loss, and six patients had a full iris but with an abnormal structure. Conclusions The results confirmed that mutations in PAX6 are the predominant cause of aniridia, and the majority are loss-of-function mutations that usually result in classical aniridia. In contrast, missense mutations, run-on mutations, and small numbers of splicing mutations mostly lead to atypical aniridia and an intrafamilial phenotypic variability of iris hypoplasia.
Collapse
|
30
|
Abstract
Mutations in human PAX6 gene are associated with various congenital eye malformations including aniridia, foveal hypoplasia, and congenital nystagmus. These various phenotypes may depend on the mutation spectrums that can affect DNA-binding affinity, although this hypothesis is debatable. We screened PAX6 mutations in two unrelated patients with congenital nystagmus, and measured DNA-binding affinity through isothermal titration calorimetry (ITC). To elucidate phenotypic differences according to DNA-binding affinity, we also compared DNA-binding affinity among the previously reported PAX6 missense mutations within the linker region between two subdomains of the paired domain (PD). We identified two novel mutations of PAX6 gene: c.214 G > T (p.Gly72Cys) and c.249_250delinsCGC (p.Val84Alafs*8). Both were located within the linker region between the two subdomains of the PD. ITC measurement revealed that the mutation p.Val84Alafs*8 had no DNA-binding affinity, while the p.Gly72Cys mutation showed a decreased binding affinity (Kd = 0.58 μM) by approximately 1.4 times compared to the wild type-PAX6 (Kd = 0.41 μM). We also found that there was no close relationship between DNA-binding affinity and phenotypic differences. Our results suggest that the DNA-binding affinity alone might be insufficient to determine PAX6-related phenotypes, and that other modifier genes or environmental factors might affect phenotypes of the PAX6 gene.
Collapse
|
31
|
Lagali N, Wowra B, Fries FN, Latta L, Moslemani K, Utheim TP, Wylegala E, Seitz B, Käsmann-Kellner B. Early phenotypic features of aniridia-associated keratopathy and association with PAX6 coding mutations. Ocul Surf 2020; 18:130-140. [DOI: 10.1016/j.jtos.2019.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 11/06/2019] [Accepted: 11/13/2019] [Indexed: 12/23/2022]
|
32
|
Johnson AF, Nguyen HT, Veitia RA. Causes and effects of haploinsufficiency. Biol Rev Camb Philos Soc 2019; 94:1774-1785. [DOI: 10.1111/brv.12527] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Adam F. Johnson
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
| | - Ha T. Nguyen
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
| | | |
Collapse
|