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Csorba A, Kormányos K, Csidey M, Náray A, Kovács K, Németh O, Knézy K, Bausz M, Szigeti A, Szabó D, Corton M, Tory K, Nagy ZZ, Langenbucher A, Maka E, Szentmáry N. Examination of Subbasal Nerve Plexus and Central Corneal Stromal Microstructure in Subjects With Congenital Aniridia, Using in Vivo Confocal Laser Scanning Microscopy. Curr Eye Res 2024; 49:582-590. [PMID: 38444179 DOI: 10.1080/02713683.2024.2320779] [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: 09/05/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
PURPOSE During life up to 70% of aniridia subjects develop aniridia-associated keratopathy (AAK). AAK is characterized by limbal stem cell insufficiency, impaired corneal epithelial cell differentiation and abnormal cell adhesion, which leads to centripetal spreading vascularization, conjunctivalization, and thickening of the cornea. Our aim was to examine the subbasal nerve plexus and central corneal stromal microstructure in subjects with congenital aniridia, using in vivo confocal laser scanning microscopy CLSM. METHODS 31 eyes of 18 patients (55.6% males, mean age: 25.22 ± 16.35 years) with congenital aniridia and 46 eyes of 29 healthy subjects (41.4% males, mean age 30 ± 14.82 years) were examined using the Rostock Cornea Module of Heidelberg Retina Tomograph-III. At the subbasal nerve plexus, corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal total branch density (CTBD), and corneal nerve fiber width (CNFW) were analyzed using ACCMetrics software. Keratocyte density in the anterior, middle and posterior stroma was assessed manually. RESULTS The CNFD (2.02 ± 4.08 vs 13.99 ± 6.34/mm2), CNFL (5.78 ± 2.68 vs 10.56 ± 2.82 mm/mm2) and CTBD (15.08 ± 15.62 vs 27.44 ± 15.05/mm2) were significantly lower in congenital aniridia subjects than in controls (p < 0.001 for all). CNFW was significantly higher in aniridia subjects than in controls (0.03 ± 0.004 vs 0.02 ± 0.003 mm/mm2) (p = 0.003). Keratocyte density was significantly lower in all stromal layers of aniridia subjects than in controls (p < 0.001 for all). Stromal alterations included confluent keratocytes, keratocytes with long extensions and hyperreflective dots between keratocytes in aniridia. CONCLUSIONS Decrease in CNFD, CNFL, and CTBD, as well as increase in CNFW well refer to the congenital aniridia-associated neuropathy. The decreased keratocyte density and the stromal alterations may be related to an increased cell death in congenital aniridia, nevertheless, stromal changes in different stages of AAK have to be further analyzed in detail.
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Affiliation(s)
- Anita Csorba
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Kitti Kormányos
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Mária Csidey
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Heim Pál National Pediatric Institute, Budapest, Hungary
| | - Annamária Náray
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Universität des Saarlandes - Campus Homburg, Homburg/Saar, Germany
| | - Klaudia Kovács
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Orsolya Németh
- Department of Ophthalmology, Markusovszky University Teaching Hospital, Szombathely, Hungary
| | - Krisztina Knézy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Mária Bausz
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Andrea Szigeti
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Dorottya Szabó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Marta Corton
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, Hungarian Academy of Sciences, Budapest, Hungary
- 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | | | - Erika Maka
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Nóra Szentmáry
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Universität des Saarlandes - Campus Homburg, Homburg/Saar, Germany
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Shaw T, Barr FG, Üren A. The PAX Genes: Roles in Development, Cancer, and Other Diseases. Cancers (Basel) 2024; 16:1022. [PMID: 38473380 PMCID: PMC10931086 DOI: 10.3390/cancers16051022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Since their 1986 discovery in Drosophila, Paired box (PAX) genes have been shown to play major roles in the early development of the eye, muscle, skeleton, kidney, and other organs. Consistent with their roles as master regulators of tissue formation, the PAX family members are evolutionarily conserved, regulate large transcriptional networks, and in turn can be regulated by a variety of mechanisms. Losses or mutations in these genes can result in developmental disorders or cancers. The precise mechanisms by which PAX genes control disease pathogenesis are well understood in some cases, but much remains to be explored. A deeper understanding of the biology of these genes, therefore, has the potential to aid in the improvement of disease diagnosis and the development of new treatments.
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Affiliation(s)
- Taryn Shaw
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20001, USA
| | - Frederic G Barr
- Laboratory of Pathology, National Cancer Institute, Bethesda, MD 20892, USA
| | - Aykut Üren
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20001, USA
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Hall HN, Parry D, Halachev M, Williamson KA, Donnelly K, Campos Parada J, Bhatia S, Joseph J, Holden S, Prescott TE, Bitoun P, Kirk EP, Newbury-Ecob R, Lachlan K, Bernar J, van Heyningen V, FitzPatrick DR, Meynert A. Short-read whole genome sequencing identifies causative variants in most individuals with previously unexplained aniridia. J Med Genet 2024; 61:250-261. [PMID: 38050128 DOI: 10.1136/jmg-2023-109181] [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: 03/12/2023] [Accepted: 09/25/2023] [Indexed: 12/06/2023]
Abstract
BACKGROUND Classic aniridia is a highly penetrant autosomal dominant disorder characterised by congenital absence of the iris, foveal hypoplasia, optic disc anomalies and progressive opacification of the cornea. >90% of cases of classic aniridia are caused by heterozygous, loss-of-function variants affecting the PAX6 locus. METHODS Short-read whole genome sequencing was performed on 51 (39 affected) individuals from 37 different families who had screened negative for mutations in the PAX6 coding region. RESULTS Likely causative mutations were identified in 22 out of 37 (59%) families. In 19 out of 22 families, the causative genomic changes have an interpretable deleterious impact on the PAX6 locus. Of these 19 families, 1 has a novel heterozygous PAX6 frameshift variant missed on previous screens, 4 have single nucleotide variants (SNVs) (one novel) affecting essential splice sites of PAX6 5' non-coding exons and 2 have deep intronic SNV (one novel) resulting in gain of a donor splice site. In 12 out of 19, the causative variants are large-scale structural variants; 5 have partial or whole gene deletions of PAX6, 3 have deletions encompassing critical PAX6 cis-regulatory elements, 2 have balanced inversions with disruptive breakpoints within the PAX6 locus and 2 have complex rearrangements disrupting PAX6. The remaining 3 of 22 families have deletions encompassing FOXC1 (a known cause of atypical aniridia). Seven of the causative variants occurred de novo and one cosegregated with familial aniridia. We were unable to establish inheritance status in the remaining probands. No plausibly causative SNVs were identified in PAX6 cis-regulatory elements. CONCLUSION Whole genome sequencing proves to be an effective diagnostic test in most individuals with previously unexplained aniridia.
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Affiliation(s)
- Hildegard Nikki Hall
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - David Parry
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
- Illumina United Kingdom, Edinburgh, UK
| | - Mihail Halachev
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Kathleen A Williamson
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Kevin Donnelly
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Jose Campos Parada
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Shipra Bhatia
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Jeffrey Joseph
- MRC Human Genetics Unit, The University of Edinburgh, Edinburgh, UK
| | - Simon Holden
- East Anglia Regional Genetics Service, Addenbrooke's Hospital, Cambridge, UK
| | - Trine E Prescott
- Department of Medical Genetics, Telemark Hospital, Skien, Norway
| | - Pierre Bitoun
- Consultations de Génétique médicale, Service de Pédiatrie, CHU Paris-Nord, Hôpital Jean Verdier, Bondy, France
| | - Edwin P Kirk
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Randwick, New South Wales, Australia
| | - Ruth Newbury-Ecob
- Department of Clinical Genetics, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Katherine Lachlan
- University Hospital Southampton, NHS Foundation Trust Wessex Clinical Genetics Service, Southampton, UK
| | - Juan Bernar
- Department of Genetics, Hospital Ruber Internacional, Madrid, Spain
| | - Veronica van Heyningen
- MRC Human Genetics Unit, The University of Edinburgh, Edinburgh, UK
- Institute of Ophthalmology, University College London, London, UK
| | - David R FitzPatrick
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
| | - Alison Meynert
- Institute of Genetics and Cancer, The University of Edinburgh MRC Human Genetics Unit, Edinburgh, UK
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Liu X, Chen M, Qu X, Liu W, Dou Y, Liu Q, Shi D, Jiang M, Li H. Cis-Regulatory Elements in Mammals. Int J Mol Sci 2023; 25:343. [PMID: 38203513 PMCID: PMC10779164 DOI: 10.3390/ijms25010343] [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: 11/29/2023] [Revised: 12/21/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
In cis-regulatory elements, enhancers and promoters with complex molecular interactions are used to coordinate gene transcription through physical proximity and chemical modifications. These processes subsequently influence the phenotypic characteristics of an organism. An in-depth exploration of enhancers and promoters can substantially enhance our understanding of gene regulatory networks, shedding new light on mammalian development, evolution and disease pathways. In this review, we provide a comprehensive overview of the intrinsic structural attributes, detection methodologies as well as the operational mechanisms of enhancers and promoters, coupled with the relevant novel and innovative investigative techniques used to explore their actions. We further elucidated the state-of-the-art research on the roles of enhancers and promoters in the realms of mammalian development, evolution and disease, and we conclude with forward-looking insights into prospective research avenues.
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Affiliation(s)
| | | | | | | | | | | | | | - Mingsheng Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
| | - Hui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning 530005, China
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Marakhonov AV, Vasilyeva TA, Minzhenkova ME, Sukhanova NV, Sparber PA, Andreeva NA, Teleshova MV, Baybagisova FKM, Shilova NV, Kutsev SI, Zinchenko RA. Complex Chromosomal Rearrangement Involving Chromosomes 10 and 11, Accompanied by Two Adjacent 11p14.1p13 and 11p13p12 Deletions, Identified in a Patient with WAGR Syndrome. Int J Mol Sci 2023; 24:16923. [PMID: 38069245 PMCID: PMC10707340 DOI: 10.3390/ijms242316923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/14/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
Three years ago, our patient, at that time a 16-month-old boy, was discovered to have bilateral kidney lesions with a giant tumor in the right kidney. Chemotherapy and bilateral nephron-sparing surgery (NSS) for Wilms tumor with nephroblastomatosis was carried out. The patient also had eye affection, including glaucoma, eye enlargement, megalocornea, severe corneal swelling and opacity, complete aniridia, and nystagmus. The diagnosis of WAGR syndrome was suspected. De novo complex chromosomal rearrangement with balanced translocation t(10,11)(p15;p13) and a pericentric inversion inv(11)(p13q12), accompanied by two adjacent 11p14.1p13 and 11p13p12 deletions, were identified. Deletions are raised through the complex molecular mechanism of two subsequent rearrangements affecting chromosomes 11 and 10. WAGR syndrome diagnosis was clinically and molecularly confirmed, highlighting the necessity of comprehensive genetic testing in patients with congenital aniridia and/or WAGR syndrome.
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Affiliation(s)
- Andrey V. Marakhonov
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Tatyana A. Vasilyeva
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Marina E. Minzhenkova
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Natella V. Sukhanova
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Peter A. Sparber
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Natalya A. Andreeva
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Moscow 117997, Russia; (N.A.A.); (M.V.T.)
| | - Margarita V. Teleshova
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Moscow 117997, Russia; (N.A.A.); (M.V.T.)
| | | | - Nadezhda V. Shilova
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Sergey I. Kutsev
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
| | - Rena A. Zinchenko
- Research Centre for Medical Genetics, Moscow 115522, Russia; (T.A.V.); (M.E.M.); (N.V.S.); (P.A.S.); (N.V.S.); (S.I.K.); (R.A.Z.)
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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.
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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.
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Roshandel D, Semnani F, Rayati Damavandi A, Masoudi A, Baradaran-Rafii A, Watson SL, Morgan WH, McLenachan S. Genetic predisposition to ocular surface disorders and opportunities for gene-based therapies. Ocul Surf 2023; 29:150-165. [PMID: 37192706 DOI: 10.1016/j.jtos.2023.05.003] [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: 02/28/2023] [Revised: 04/24/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
The ocular surface, comprised of the corneal and conjunctival epithelium, innervation system, immune components, and tear-film apparatus, plays a key role in ocular integrity as well as comfort and vision. Gene defects may result in congenital ocular or systemic disorders with prominent ocular surface involvement. Examples include epithelial corneal dystrophies, aniridia, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, xeroderma pigmentosum (XP), and hereditary sensory and autonomic neuropathy. In addition, genetic factors may interact with environmental risk factors in the development of several multifactorial ocular surface disorders (OSDs) such as autoimmune disorders, allergies, neoplasms, and dry eye disease. Advanced gene-based technologies have already been introduced in disease modelling and proof-of-concept gene therapies for monogenic OSDs. For instance, patient-derived induced pluripotent stem cells have been used for modelling aniridia-associated keratopathy (AAK), XP, and EEC syndrome. Moreover, CRISPR/Cas9 genome editing has been used for disease modelling and/or gene therapy for AAK and Meesmann's epithelial corneal dystrophy. A better understanding of the role of genetic factors in OSDs may be helpful in designing personalized disease models and treatment approaches. Gene-based approaches in monogenic OSDs and genetic predisposition to multifactorial OSDs such as immune-mediated disorders and neoplasms with known or possible genetic risk factors has been seldom reviewed. In this narrative review, we discuss the role of genetic factors in monogenic and multifactorial OSDs and potential opportunities for gene therapy.
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Affiliation(s)
- Danial Roshandel
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Farbod Semnani
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Amirmasoud Rayati Damavandi
- School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran; School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Ali Masoudi
- Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Alireza Baradaran-Rafii
- Department of Ophthalmology, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Stephanie L Watson
- The University of Sydney, Save Sight Institute, Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - William H Morgan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia
| | - Samuel McLenachan
- Lions Eye Institute, Perth, WA, Australia; Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA, Australia.
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Chesneau B, Ivashchenko V, Habib C, Gaston V, Escudié F, Morel G, Capri Y, Vincent-Delorme C, Calvas P, Chassaing N, Plaisancié J. Evaluation of somatic and/or germline mosaicism in congenital malformation of the eye. Eur J Hum Genet 2023; 31:526-530. [PMID: 36404347 PMCID: PMC10172375 DOI: 10.1038/s41431-022-01234-3] [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: 08/24/2022] [Revised: 10/17/2022] [Accepted: 11/01/2022] [Indexed: 11/22/2022] Open
Abstract
Microphthalmia, Anophthalmia and Coloboma (MAC) form a spectrum of congenital eye malformations responsible for severe visual impairment. Despite the exploration of hundreds of genes by High-Throughput Sequencing (HTS), most of the patients remain without genetic diagnosis. One explanation could be the not yet demonstrated involvement of somatic mosaicism (undetected by conventional analysis pipelines) in those patients. Furthermore, the proportion of parental germline mosaicism in presumed de novo variations is still unknown in ocular malformations. Thus, using dedicated bioinformatics pipeline designed to detect mosaic variants, we reanalysed the sequencing data obtained from a 119 ocular development genes panel performed on blood samples of 78 probands with sporadic MAC without genetic diagnosis. Using the same HTS strategy, we sequenced 80 asymptomatic parents of 41 probands carrying a disease-causing variant in an ocular development gene considered de novo after Sanger sequencing of both parents. Reanalysis of the previously sequencing data did not find any mosaic variant in probands without genetic diagnosis. However, HTS of parents revealed undetected SOX2 and PAX6 mosaic variants in two parents. Finally, this work, performed on two large cohorts of patients with MAC spectrum, provides for the first time an overview of the interest of looking for mosaicism in ocular development disorders. Somatic mosaicism does not appear to be frequent in MAC spectrum and might explain only few diagnoses. Thus, other approaches such as whole genome sequencing should be considered in those patients. Parental mosaicism is however not that rare (around 5%) and challenging for genetic counselling.
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Affiliation(s)
- Bertrand Chesneau
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | | | - Christophe Habib
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
| | - Véronique Gaston
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
| | - Fréderic Escudié
- Département d'anatomopathologie, IUCT Oncopole, Toulouse, France
| | - Godelieve Morel
- Service de Génétique Médicale, CHU de Rennes, Rennes, France
| | - Yline Capri
- Service de Génétique Médicale, Hôpital Robert Debré, APHP, Paris, France
| | | | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | - Nicolas Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France
| | - Julie Plaisancié
- Service de Génétique Médicale, Hôpital Purpan, CHU de Toulouse, Toulouse, France.
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU de Toulouse, Toulouse, France.
- INSERM U1214, ToNIC, Université Toulouse III, Toulouse, France.
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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.
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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
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10
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de Souza VS, da Cunha GCR, Versiani BR, de Oliveira CP, Rosa MTAS, de Oliveira SF, Moretti PN, Mazzeu JF, Pic-Taylor A. Characterization of Associated Nonclassical Phenotypes in Patients with Deletion in the WAGR Region Identified by Chromosomal Microarray: New Insights and Literature Review. Mol Syndromol 2022; 13:290-304. [PMID: 36158055 PMCID: PMC9421677 DOI: 10.1159/000518872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/03/2021] [Indexed: 01/03/2023] Open
Abstract
WAGR syndrome (Wilms' tumor, aniridia, genitourinary changes, and intellectual disability) is a contiguous gene deletion syndrome characterized by the joint deletion of PAX6 and WT1 genes, located in the short arm of chromosome 11. However, most deletions include other genes, leading to multiple associated phenotypes. Therefore, understanding how genes deleted together can contribute to other clinical phenotypes is still considered a challenge. In order to establish genotype-phenotype correlation in patients with interstitial deletions of the short arm of chromosome 11, we selected 17 patients with deletions identified by chromosomal microarray analysis: 4 new subjects and 13 subjects previously described in the literature with detailed clinical data. Through the analysis of deleted regions and the phenotypic changes, it was possible to suggest the contribution of specific genes to several nonclassical phenotypes, contributing to the accuracy of clinical characterization of the syndrome and emphasizing the broad phenotypic spectrum found in the patients. This study reports the first patient with a PAX6 partial deletion who does not present any eye anomaly thus opening a new set of questions about the functional activity of PAX6.
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Affiliation(s)
- Vanessa Sodré de Souza
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil
| | - Gabriela Corassa Rodrigues da Cunha
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil
| | - Beatriz R. Versiani
- Hospital de Apoio de Brasília, Secretária de Estado de Saúde do Distrito Federal, Brasília, Brazil,Hospital Universitário, Universidade de Brasília, Brasília, Brazil
| | - Claudiner Pereira de Oliveira
- Hospital de Apoio de Brasília, Secretária de Estado de Saúde do Distrito Federal, Brasília, Brazil,Hospital Universitário, Universidade de Brasília, Brasília, Brazil
| | - Maria Teresa Alves Silva Rosa
- Hospital Universitário, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil
| | - Silviene F. de Oliveira
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Patricia N. Moretti
- Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil
| | - Juliana F. Mazzeu
- Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil,Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil,*Juliana F. Mazzeu,
| | - Aline Pic-Taylor
- Programa de Pós-graduação em Biologia Animal, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências da Saúde, Universidade de Brasília, Brasília, Brazil,Programa de Pós-graduação em Ciências Médicas, Universidade de Brasília, Brasília, Brazil,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil,**Aline Pic-Taylor,
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11
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Vasilyeva TA, Marakhonov AV, Kutsev SI, Zinchenko RA. Relative Frequencies of PAX6 Mutational Events in a Russian Cohort of Aniridia Patients in Comparison with the World's Population and the Human Genome. Int J Mol Sci 2022; 23:ijms23126690. [PMID: 35743132 PMCID: PMC9223373 DOI: 10.3390/ijms23126690] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/06/2022] [Accepted: 06/13/2022] [Indexed: 12/10/2022] Open
Abstract
Genome-wide sequencing metadata allows researchers to infer bias in the relative frequencies of mutational events and to predict putative mutagenic models. In addition, much less data could be useful in the evaluation of the mutational frequency spectrum and the prevalent local mutagenic process. Here we analyzed the PAX6 gene locus for mutational spectra obtained in our own and previous studies and compared them with data on other genes as well as the whole human genome. MLPA and Sanger sequencing were used for mutation searching in a cohort of 199 index patients from Russia with aniridia and aniridia-related phenotypes. The relative frequencies of different categories of PAX6 mutations were consistent with those previously reported by other researchers. The ratio between substitutions, small indels, and chromosome deletions in the 11p13 locus was within the interval previously published for 20 disease associated genomic loci, but corresponded to a higher end due to very high frequencies of small indels and chromosome deletions. The ratio between substitutions, small indels, and chromosome deletions for disease associated genes, including the PAX6 gene as well as the share of PAX6 missense mutations, differed considerably from those typical for the whole genome.
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Affiliation(s)
- Tatyana A. Vasilyeva
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
| | - Andrey V. Marakhonov
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
- Correspondence: ; Tel.: +7-499-320-60-90
| | - Sergey I. Kutsev
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
| | - Rena A. Zinchenko
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
- N.A. Semashko National Research Institute of Public Health, 105064 Moscow, Russia
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12
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van Heyningen V. A Journey Through Genetics to Biology. Annu Rev Genomics Hum Genet 2022; 23:1-27. [PMID: 35567277 DOI: 10.1146/annurev-genom-010622-095109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although my engagement with human genetics emerged gradually, and sometimes serendipitously, it has held me spellbound for decades. Without my teachers, students, postdocs, colleagues, and collaborators, I would not be writing this review of my scientific adventures. Early gene and disease mapping was a satisfying puzzle-solving exercise, but building biological insight was my main goal. The project trajectory was hugely influenced by the evolutionarily conserved nature of the implicated genes and by the pace of progress in genetic technologies. The rich detail of clinical observations, particularly in eye disease, makes humans an excellent model, especially when complemented by the use of multiple other animal species for experimental validation. The contributions of collaborators and rivals also influenced our approach. We are very fortunate to work in this era of unprecedented progress in genetics and genomics. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Veronica van Heyningen
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
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13
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Kovaleva NV, Cotter PD. Factors affecting clinical manifestation of chromosomal imbalance in carriers of segmental autosomal mosaicism: differential impact of gender. J Appl Genet 2022; 63:281-291. [PMID: 34973130 PMCID: PMC8979927 DOI: 10.1007/s13353-021-00673-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/03/2021] [Accepted: 11/25/2021] [Indexed: 11/25/2022]
Abstract
Mosaicism for unbalanced chromosomal rearrangements segmental mosaicism (SM) is rare, both in patients referred for cytogenetic testing and in prenatal diagnoses. In contrast, in preimplantation embryos SM is a frequent finding and, therefore, is even more challenging. However, there is no consistency among results of published studies on the clinical outcomes of embryos with SM, primarily due to the small number of reported cases. Moreover, there is the problem of predicting the potential for the optimal development of a mosaic embryo to a healthy individual. Therefore, we suggested comparing factors predisposing to favorable and poor prognoses, identified in postnatal and prenatal cohorts of SM carriers, with those obtained from studies on preimplantation embryos. We analyzed 580 published cases of SM including (i) postnatally diagnosed affected carriers, (ii) clinically asymptomatic carriers, (iii) prenatally diagnosed carriers, and (iv) miscarriages. We observed a concordance with preimplantation diagnoses regarding the clinical significance of the extent of mosaicism as well as a predominance of deletions over other types of rearrangements. However, there is no concordance regarding excessive involvement of chromosomes 1, 5, and 9 in unbalanced rearrangements and a preferential involvement of larger chromosomes compared to short ones. Paternal age was not found to be associated with SM in postnatally disease-defined individuals. We have identified maternal age and preferential involvement of chromosome 18 in rearrangements associated with clinical manifestations. Male predominance was found among normal pregnancy outcomes and among disease-defined carriers of rearrangements resulting in a gain of genomic material. Female predominance was found among abnormal pregnancy outcomes, among disease-defined carriers of loss and gain/loss rearrangements, and among transmitting carriers of gonadal SM, both affected and asymptomatic. According to data obtained from “post-embryo” studies, clinical manifestations of chromosomal imbalance are associated with a high proportion of abnormal cells, female gender, the type of rearrangement and involved chromosome(s), and maternal age. We believe these data are instructive in the challenging medical genetic counseling of parents faced with no option other than transfer of an embryo with segmental mosaicism.
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Affiliation(s)
- Natalia V Kovaleva
- Academy of Molecular Medicine, Mytninskaya str., 12/44, St. Petersburg, 191144, Russian Federation.
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14
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Wawrocka A, Walczak-Sztulpa J, Socha M, Kuszel L, Sowinska-Seidler A, Budny B, Bukowska-Olech E, Pilas-Pomykalska M, Jamsheer A, Krawczynski MR. Homozygous microdeletion in the 11p13 region in the patient with isolated form of aniridia: New challenges in the genetic diagnostics of aniridia. Am J Med Genet A 2021; 188:642-647. [PMID: 34773354 DOI: 10.1002/ajmg.a.62559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 10/13/2021] [Accepted: 10/22/2021] [Indexed: 11/09/2022]
Abstract
Aniridia is usually an autosomal dominant, rare disorder characterized by a variable degree of hypoplasia or the absence of iris tissue, with additional ocular abnormalities. Pathogenic variants in the PAX6 gene are associated with aniridia in most patients. However, in up to 30% of individuals, disease results from 11p13 chromosomal rearrangements. Here we present a patient with a clinical diagnosis of partial aniridia born to consanguineous Polish parents. The parents were asymptomatic and ophthalmologically normal. We performed PAX6 sequencing, array comparative genomic hybridization, quantitative real-time PCR, and whole genome sequencing. aCGH revealed a homozygous deletion of the DCDC1 gene fragment in the patient. The same, but heterozygous deletion, was detected in each of the patient's asymptomatic parents and brother. In the presented family, the signs and symptoms of aniridia are observed only in the homozygous proband. Whole genome sequencing analysis was performed to determine other possible causes of the disease and did not detect any additional or alternative potentially pathogenic variant. We report a novel homozygous deletion located in the 11p13 region, which does not include the PAX6 gene or any known PAX6 enhancers. To our best knowledge, this is the first reported case of a patient presented with isolated aniridia carrying a homozygous microdeletion downstream of the PAX6 gene.
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Affiliation(s)
- Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Magdalena Socha
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Lukasz Kuszel
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Anna Sowinska-Seidler
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Bartlomiej Budny
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | | | | | - Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
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15
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Blanco-Kelly F, Tarilonte M, Villamar M, Damián A, Tamayo A, Moreno-Pelayo MA, Ayuso C, Cortón M. Genetics and epidemiology of aniridia: Updated guidelines for genetic study. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2021; 96 Suppl 1:4-14. [PMID: 34836588 DOI: 10.1016/j.oftale.2021.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 02/13/2021] [Indexed: 12/16/2022]
Abstract
Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.
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Affiliation(s)
- F Blanco-Kelly
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - M Tarilonte
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - M Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - A Damián
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - A Tamayo
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - M A Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - C Ayuso
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain
| | - M Cortón
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, Spain.
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16
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Qian T, Chen C, Li C, Gong Q, Liu K, Wang G, Schrauwen I, Xu X. A novel 4.25 kb heterozygous deletion in PAX6 in a Chinese Han family with congenital aniridia combined with cataract and nystagmus. BMC Ophthalmol 2021; 21:353. [PMID: 34610801 PMCID: PMC8491394 DOI: 10.1186/s12886-021-02120-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to identify the genetic defect in a Chinese family with congenital aniridia combined with cataract and nystagmus. METHODS Complete ophthalmic examinations, including slit-lamp biomicroscopy, dilated indirect ophthalmoscopy, anterior segment photography, and anterior segment optical coherence tomography (OCT) were performed. Blood samples were collected from all family members and genomic DNA was extracted. Genome sequencing was performed in all family members and Sanger sequencing was used to verify variant breakpoints. RESULTS All the thirteen members in this Chinese family, including seven patients and six normal people, were recruited in this study. The ophthalmic examination of affected patients in this family was consistent with congenital aniridia combined with cataract and nystagmus. A novel heterozygous deletion (NC_000011.10:g.31802307_31806556del) containing the 5' region of PAX6 gene was detected that segregated with the disease. CONCLUSION We detected a novel deletion in PAX6 responsible for congenital aniridia in the affected individuals of this Chinese family. The novel 4.25 kb deletion in PAX6 gene of our study would further broaden the genetic defects of PAX6 associated with congenital aniridia.
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Affiliation(s)
- Tianwei Qian
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, 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.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China.,Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Chong Chen
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, 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.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Caihua Li
- Genesky Biotechnologies Inc, Shanghai, China
| | - Qiaoyun Gong
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, 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.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Kun Liu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, 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.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China
| | - Gao Wang
- Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA
| | - Isabelle Schrauwen
- Department of Neurology, Columbia University Medical Center, 630W 168th St, New York, NY, 10032, USA.
| | - Xun Xu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100 Haining Rd., Shanghai, 200080, 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. .,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Disease, Shanghai, China.
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17
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Kit V, Cunha DL, Hagag AM, Moosajee M. Longitudinal genotype-phenotype analysis in 86 patients with PAX6-related aniridia. JCI Insight 2021; 6:e148406. [PMID: 34101622 PMCID: PMC8410060 DOI: 10.1172/jci.insight.148406] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/03/2021] [Indexed: 12/30/2022] Open
Abstract
Aniridia is most commonly caused by haploinsufficiency of the PAX6 gene, characterized by variable iris and foveal hypoplasia, nystagmus, cataracts, glaucoma, and aniridia-related keratopathy (ARK). Genotype-phenotype correlations have previously been described; however, detailed longitudinal studies of aniridia are less commonly reported. We identified 86 patients from 62 unrelated families with molecularly confirmed heterozygous PAX6 variants from a UK-based single-center ocular genetics service. They were categorized into mutation groups, and a retrospective review of clinical characteristics (ocular and systemic) from baseline to most recent was recorded. One hundred and seventy-two eyes were evaluated, with a mean follow-up period of 16.3 ± 12.7 years. Nystagmus was recorded in 87.2% of the eyes, and foveal hypoplasia was found in 75%. Cataracts were diagnosed in 70.3%, glaucoma in 20.6%, and ARK in 68.6% of eyes. Prevalence, age of diagnosis and surgical intervention, and need for surgical intervention varied among mutation groups. Overall, the missense mutation subgroup had the mildest phenotype, and surgically naive eyes maintained better visual acuity. Systemic evaluation identified type 2 diabetes in 12.8% of the study group, which is twice the UK prevalence. This is the largest longitudinal study of aniridia in the UK, and as such, it can provide insights into prognostic indicators for patients and guiding clinical management of both ocular and systemic features.
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Affiliation(s)
- Vivienne Kit
- Moorfields Eye Hospital, NHS Foundation Trust, London, United Kingdom.,UCL Institute of Ophthalmology, London, United Kingdom
| | | | - Ahmed M Hagag
- Moorfields Eye Hospital, NHS Foundation Trust, London, United Kingdom.,UCL Institute of Ophthalmology, London, United Kingdom
| | - Mariya Moosajee
- Moorfields Eye Hospital, NHS Foundation Trust, London, United Kingdom.,UCL Institute of Ophthalmology, London, United Kingdom.,Great Ormond Street Hospital for Children, NHS Foundation Trust, London, United Kingdom.,The Francis Crick Institute, London, United Kingdom
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18
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Blanco-Kelly F, Tarilonte M, Villamar M, Damián A, Tamayo A, Moreno-Pelayo MA, Ayuso C, Cortón M. Genetics and epidemiology of aniridia: Updated guidelines for genetic study. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2021; 96:S0365-6691(21)00124-6. [PMID: 34243981 DOI: 10.1016/j.oftal.2021.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/09/2021] [Accepted: 02/13/2021] [Indexed: 11/24/2022]
Abstract
Aniridia is a panocular disease characterized by iris hypoplasia, accompanied by other ocular manifestations, with a high clinical variability and overlapping with different abnormalities of the anterior and posterior segment. This review focuses on the genetic features of this autosomal dominant pathology, which is caused by the haploinsufficiency of the PAX6 gene. Mutations causing premature stop codons are the most frequent among the wider mutational spectrum of PAX6, with more than 600 different mutations identified so far. Recent advances in next-generation sequencing (NGS) have increased the diagnostic yield in aniridia and contributed to elucidate new etiopathogenic mechanisms leading to PAX6 haploinsufficiency. Here, we also update good practices and recommendations to improve genetic testing and clinical management of aniridia using more cost-effective NGS analysis. Those new approaches also allow studying simultaneously both structural variants and point-mutations in PAX6 as well as other genes for differential diagnosis, simultaneously. Some patients with atypical phenotypes might present mutations in FOXC1 and PITX2, both genes causing a wide spectrum of anterior segment dysgenesis, or in ITPR1, which is responsible for a distinctive form of circumpupillary iris aplasia present in Gillespie syndrome, or other mutations in minor genes. Since aniridia can also associate extraocular anomalies, as it occurs in carriers of PAX6 and WT1 microdeletions leading to WAGR syndrome, genetic studies are crucial to assure a correct diagnosis and clinical management, besides allowing prenatal and preimplantational genetic testing in families.
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Affiliation(s)
- F Blanco-Kelly
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - M Tarilonte
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - M Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - A Damián
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - A Tamayo
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España
| | - M A Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - C Ayuso
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España
| | - M Cortón
- Departamento de Genética, Hospital Universitario Fundación Jiménez Díaz, Madrid, España; Área de Genética & Genómica, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, España; Centro de Investigación en Red de Enfermedades Raras (CIBERER), ISCIII, Madrid, España.
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19
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Filatova AY, Vasilyeva TA, Marakhonov AV, Sukhanova NV, Voskresenskaya AA, Zinchenko RA, Skoblov MY. Upstream ORF frameshift variants in the PAX6 5'UTR cause congenital aniridia. Hum Mutat 2021; 42:1053-1065. [PMID: 34174135 DOI: 10.1002/humu.24248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/24/2021] [Accepted: 06/01/2021] [Indexed: 11/12/2022]
Abstract
Congenital aniridia (AN) is a severe autosomal dominant panocular disorder associated with pathogenic variants in the PAX6 gene. Previously, we performed a molecular genetic study of a large cohort of Russian patients with AN and revealed four noncoding nucleotide variants in the PAX6 5'UTR. 14 additional PAX6-5'UTR variants were also reported in the literature, but the mechanism of their pathogenicity remained unclear. In the present study, we experimentally analyze five patient-derived PAX6 5'UTR-variants: four variants that we identified in Russian patients (c.-128-2delA, c.-125dupG, c.-122dupG, c.-118_-117del) and one previously reported (c.-52+5G>C). We show that the variants lead to a decrease in the protein translation efficiency, while mRNA expression level is not significantly reduced. Two of these variants also affect splicing. Furthermore, we predict and experimentally validate the presence of an evolutionarily conserved small uORF in the PAX6 5'UTR. All studied variants lead to the frameshift of the uORF, resulting in its extension. This extended out-of-frame uORF overlaps with the downstream CDS and thereby reduces its translation efficiency. We conclude that the uORF frameshift may be the main mechanism of pathogenicity for at least 15 out of 18 known PAX6 5'UTR variants. Moreover, we predict additional uORFs in the PAX6 5'UTR.
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Affiliation(s)
| | | | | | - Natella V Sukhanova
- Central Clinical Hospital of the Russian Academy of Sciences, Moscow, Russian Federation
| | - Anna A Voskresenskaya
- Cheboksary Branch of the S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation
| | - Rena A Zinchenko
- Research Centre for Medical Genetics, Moscow, Russian Federation.,N.A. Semashko National Research Institute of Public Health, Moscow, Russian Federation
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20
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Trajkova S, Di Gregorio E, Ferrero GB, Carli D, Pavinato L, Delplancq G, Kuentz P, Brusco A. New Insights into Potocki-Shaffer Syndrome: Report of Two Novel Cases and Literature Review. Brain Sci 2020; 10:brainsci10110788. [PMID: 33126574 PMCID: PMC7693731 DOI: 10.3390/brainsci10110788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/16/2020] [Accepted: 10/27/2020] [Indexed: 12/24/2022] Open
Abstract
Potocki-Shaffer syndrome (PSS) is a rare non-recurrent contiguous gene deletion syndrome involving chromosome 11p11.2. Current literature implies a minimal region with haploinsufficiency of three genes, ALX4 (parietal foramina), EXT2 (multiple exostoses), and PHF21A (craniofacial anomalies, and intellectual disability). The rest of the PSS phenotype is still not associated with a specific gene. We report a systematic review of the literature and included two novel cases. Because deletions are highly variable in size, we defined three groups of patients considering the PSS-genes involved. We found 23 full PSS cases (ALX4, EXT2, and PHF21A), 14 cases with EXT2-ALX4, and three with PHF21A only. Among the latter, we describe a novel male child showing developmental delay, café-au-lait spots, liner postnatal overgrowth and West-like epileptic encephalopathy. We suggest PSS cases may have epileptic spasms early in life, and PHF21A is likely to be the causative gene. Given their subtle presentation these may be overlooked and if left untreated could lead to a severe type or deterioration in the developmental plateau. If our hypothesis is correct, a timely therapy may ameliorate PSS phenotype and improve patients’ outcomes. Our analysis also shows PHF21A is a candidate for the overgrowth phenotype.
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Affiliation(s)
- Slavica Trajkova
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy; (S.T.); (L.P.)
| | - Eleonora Di Gregorio
- Medical Genetics Unit, Città della Salute e della Scienza, University Hospital, 10126 Turin, Italy; (E.D.)
| | - Giovanni Battista Ferrero
- Department of Public Health and Paediatrics, University of Torino, 10126 Turin, Italy; (G.B.F.); (D.C.)
| | - Diana Carli
- Department of Public Health and Paediatrics, University of Torino, 10126 Turin, Italy; (G.B.F.); (D.C.)
| | - Lisa Pavinato
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy; (S.T.); (L.P.)
| | - Geoffroy Delplancq
- Centre de Génétique Humaine, Université de Franche-Comté, 25000 Besançon, France; (G.D.)
- Service de Pédiatrie, CHU, 25000 Besançon, France
| | - Paul Kuentz
- Oncobiologie Génétique Bioinformatique, PCBio, Centre Hospitalier Universitaire de Besançon, 25000 Besançon, France; (P.K.)
- UMR-Inserm 1231 GAD, Génétique des Anomalies du développement, Université de Bourgogne Franche-Comté, 21000 Dijon, France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (FHU TRANSLAD), Centre Hospitalier Universitaire de Dijon et Université de Bourgogne Franche-Comté, 21000 Dijon, France
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy; (S.T.); (L.P.)
- Medical Genetics Unit, Città della Salute e della Scienza, University Hospital, 10126 Turin, Italy; (E.D.)
- Correspondence: (A.B.)
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21
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Vasilyeva TA, Marakhonov AV, Minzhenkova ME, Markova ZG, Petrova NV, Sukhanova NV, Koshkin PA, Pyankov DV, Kanivets IV, Korostelev SA, Krynskaya IA, Shilova NV, Kutsev SI, Kadyshev VV, Zinchenko RA. A sporadic case of congenital aniridia caused by pericentric inversion inv(11)(p13q14) associated with a 977 kb deletion in the 11p13 region. BMC Med Genomics 2020; 13:130. [PMID: 32948199 PMCID: PMC7499969 DOI: 10.1186/s12920-020-00790-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/02/2020] [Indexed: 11/20/2022] Open
Abstract
Background Because of the significant occurrence of “WAGR-region” deletions among de novo mutations detected in congenital aniridia, DNA diagnosis is critical for all sporadic cases of aniridia due to its help in making an early diagnosis of WAGR syndrome. Standard cytogenetic karyotype study is a necessary step of molecular diagnostics in patients with deletions and in the patients’ parents as it reveals complex chromosomal rearrangements and the risk of having another affected child, as well as to provide prenatal and/or preimplantation diagnostics. Case presentation DNA samples were obtained from the proband (a 2-year-old boy) and his two healthy parents. Molecular analysis revealed a 977.065 kb deletion that removed loci of the ELP4, PAX6, and RCN1 genes but did not affect the coding sequence of the WT1 gene. The deletion occurred de novo on the paternal allele. The patient had normal karyotype 46,XY and a de novo pericentric inversion of chromosome 11, inv(11)(p13q14). Conclusions We confirmed the diagnosis of congenital aniridia at the molecular level. For the patient, the risk of developing Wilms’ tumor is similar to that in the general population. The recurrence risk for sibs in the family is low, but considering the possibility of gonadal mosaicism, it is higher than in the general population.
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Affiliation(s)
| | | | | | - Zhanna G Markova
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Nika V Petrova
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Natella V Sukhanova
- Central Clinical Hospital of the Russian Academy of Sciences, Moscow, Russian Federation
| | | | | | | | - Sergey A Korostelev
- I.M. Sechenov First Moscow State Medical University, Moscow, Russian Federation
| | | | | | - Sergey I Kutsev
- Research Centre for Medical Genetics, Moscow, Russian Federation
| | | | - Rena A Zinchenko
- Research Centre for Medical Genetics, Moscow, Russian Federation.,N.A. Semashko National Research Institute of Public Health, Moscow, Russian Federation
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22
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Aberrant expression of PAX6 gene associated with classical aniridia: identification and functional characterization of novel noncoding mutations. J Hum Genet 2020; 66:333-338. [PMID: 32920601 DOI: 10.1038/s10038-020-00829-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/12/2020] [Accepted: 08/15/2020] [Indexed: 11/08/2022]
Abstract
The PAX6 is essential for ocular morphogenesis and is known to be highly sensitive to changes in gene expression, where neither over- nor under-expression ensures normal ocular development. Two unrelated probands with classical aniridia who were previously considered "PAX6-negative", were studied by whole-genome sequencing. Through the use of multiple in silico deep learning-based algorithms, we identified two novel putative causal mutations, c.-133_-132del in the 5' untranslated region (5'-UTR) and c.-52 + 5G>A in an intron upstream of the PAX6 gene. The luciferase activity was significantly increased and VAX2 binding was disrupted with the former 5'-UTR variant compared with wild-type sequence, which resulted in a striking overexpression of PAX6. The minigene assay showed that the c.-52 + 5G>A mutation caused defective splicing, which resulted in the formation of truncated transcripts.
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23
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Vasilyeva TA, Marakhonov AV, Sukhanova NV, Kutsev SI, Zinchenko RA. Preferentially Paternal Origin of De Novo 11p13 Chromosome Deletions Revealed in Patients with Congenital Aniridia and WAGR Syndrome. Genes (Basel) 2020; 11:genes11070812. [PMID: 32708836 PMCID: PMC7397088 DOI: 10.3390/genes11070812] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/06/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022] Open
Abstract
The frequency of pathogenic large chromosome rearrangements detected in patients with different Mendelian diseases is truly diverse and can be remarkably high. Chromosome breaks could arise through different known mechanisms. Congenital PAX6-associated aniridia is a hereditary eye disorder caused by mutations or chromosome rearrangements involving the PAX6 gene. In our recent study, we identified 11p13 chromosome deletions in 30 out of 91 probands with congenital aniridia or WAGR syndrome (characterized by Wilms’ tumor, Aniridia, and Genitourinary abnormalities as well as mental Retardation). The loss of heterozygosity analysis (LOH) was performed in 10 families with de novo chromosome deletion in proband. In 7 out of 8 informative families, the analysis revealed that deletions occurred at the paternal allele. If paternal origin is not random, chromosome breaks could arise either (i) during spermiogenesis, which is possible due to specific male chromatin epigenetic program and its vulnerability to the breakage-causing factors, or (ii) in early zygotes at a time when chromosomes transmitted from different parents still carry epigenetic marks of the origin, which is also possible due to diverse and asymmetric epigenetic reprogramming occurring in male and female pronuclei. Some new data is needed to make a well-considered conclusion on the reasons for preferential paternal origin of 11p13 deletions.
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Affiliation(s)
- Tatyana A. Vasilyeva
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
| | - Andrey V. Marakhonov
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
- Correspondence:
| | - Natella V. Sukhanova
- Central Clinical Hospital of the Russian Academy of Sciences, 119333 Moscow, Russia;
| | - Sergey I. Kutsev
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
| | - Rena A. Zinchenko
- Research Centre for Medical Genetics, 115522 Moscow, Russia; (T.A.V.); (S.I.K.); (R.A.Z.)
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24
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Cross E, Duncan-Flavell PJ, Howarth RJ, Crooks RO, Thomas NS, Bunyan DJ. Screening of a large PAX6 cohort identified many novel variants and emphasises the importance of the paired and homeobox domains. Eur J Med Genet 2020; 63:103940. [DOI: 10.1016/j.ejmg.2020.103940] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/20/2019] [Accepted: 04/23/2020] [Indexed: 12/21/2022]
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25
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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.
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26
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Wawrocka A, Walczak-Sztulpa J, Bukowska-Olech E, Jamsheer A, Jaworski M, Jaworski P, Krawczynski MR. Two sisters with microphthalmia and anterior segment dysgenesis secondary to a PAX6 pathogenic variant with clinically healthy parents: a case of gonadal mosaicism? Jpn J Ophthalmol 2020; 64:134-139. [DOI: 10.1007/s10384-020-00715-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/09/2019] [Indexed: 01/19/2023]
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27
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Lima Cunha D, Arno G, Corton M, Moosajee M. The Spectrum of PAX6 Mutations and Genotype-Phenotype Correlations in the Eye. Genes (Basel) 2019; 10:genes10121050. [PMID: 31861090 PMCID: PMC6947179 DOI: 10.3390/genes10121050] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022] Open
Abstract
The transcription factor PAX6 is essential in ocular development in vertebrates, being considered the master regulator of the eye. During eye development, it is essential for the correct patterning and formation of the multi-layered optic cup and it is involved in the developing lens and corneal epithelium. In adulthood, it is mostly expressed in cornea, iris, and lens. PAX6 is a dosage-sensitive gene and it is highly regulated by several elements located upstream, downstream, and within the gene. There are more than 500 different mutations described to affect PAX6 and its regulatory regions, the majority of which lead to PAX6 haploinsufficiency, causing several ocular and systemic abnormalities. Aniridia is an autosomal dominant disorder that is marked by the complete or partial absence of the iris, foveal hypoplasia, and nystagmus, and is caused by heterozygous PAX6 mutations. Other ocular abnormalities have also been associated with PAX6 changes, and genotype-phenotype correlations are emerging. This review will cover recent advancements in PAX6 regulation, particularly the role of several enhancers that are known to regulate PAX6 during eye development and disease. We will also present an updated overview of the mutation spectrum, where an increasing number of mutations in the non-coding regions have been reported. Novel genotype-phenotype correlations will also be discussed.
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Affiliation(s)
| | - Gavin Arno
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - 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
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28029 Madrid, Spain
| | - Mariya Moosajee
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Correspondence:
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28
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Xiao Y, Liu X, Yang C, Liu L, Guo X, Wang Q, Gong B. A Novel PAX6 Heterozygous Mutation Found in a Chinese Family with Congenital Aniridia. Genet Test Mol Biomarkers 2019; 23:495-500. [PMID: 31161946 DOI: 10.1089/gtmb.2018.0334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Ying Xiao
- Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Xiangqin Liu
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Chen Yang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Liping Liu
- Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Xiaoxin Guo
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Qi Wang
- Department of Ophthalmology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Bo Gong
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
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29
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Qiu JJ, Zhang Q, Geng ZX, Liu M, Zhong ZL, Chen JJ, Liu F. Identification of a novel PAX6 mutation in a Chinese family with aniridia. BMC Ophthalmol 2019; 19:10. [PMID: 30621664 PMCID: PMC6325832 DOI: 10.1186/s12886-018-1009-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/10/2018] [Indexed: 01/04/2023] Open
Abstract
Background This study aims to investigate the clinical characterization and causative genetic defect of a four-generation Chinese family with autosomal dominant aniridia. Methods The recruited family members underwent comprehensive routine and ophthalmic examinations, and Sanger sequencing was performed to screen the mutation in PAX6. Results A novel heterozygous PAX6 deletion c.435_445delTAGCGAAAAGC (p.Ser146ThrfsX9) in exon 7 was identified in all affected individuals, but this was absent in any of the unaffected family members and in the 200 unrelated controls. Conclusion A novel deletion in the PAX6 gene was identified in a Chinese family associated with aniridia, which expands the spectrum of the PAX6 mutation and its associated phenotype.
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Affiliation(s)
- Jing-Jing Qiu
- Department of Ophthalmology, the Second Affiliated Hospital of Nanchang University, No.1 Minde Road, Donghu District, Nanchang, 330006, China
| | - Qian Zhang
- Department of Ophthalmology, the Second Affiliated Hospital of Nanchang University, No.1 Minde Road, Donghu District, Nanchang, 330006, China.
| | - Zi-Xin Geng
- Department of Ophthalmology of Shanghai Tenth People's Hospital, and Tongji Eye Institute, Tongji University School of Medicine, Shanghai, 200092, China.,Department of Medical Genetics Tongji University School of Medicine, Shanghai, 200092, China
| | - Min Liu
- Department of Ophthalmology of Shanghai Tenth People's Hospital, and Tongji Eye Institute, Tongji University School of Medicine, Shanghai, 200092, China.,Department of Medical Genetics Tongji University School of Medicine, Shanghai, 200092, China
| | - Zi-Lin Zhong
- Department of Ophthalmology of Shanghai Tenth People's Hospital, and Tongji Eye Institute, Tongji University School of Medicine, Shanghai, 200092, China.,Department of Medical Genetics Tongji University School of Medicine, Shanghai, 200092, China
| | - Jian-Jun Chen
- Department of Ophthalmology of Shanghai Tenth People's Hospital, and Tongji Eye Institute, Tongji University School of Medicine, Shanghai, 200092, China.,Department of Medical Genetics Tongji University School of Medicine, Shanghai, 200092, China
| | - Fei Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Nanchang University, No.1 Minde Road, Donghu District, Nanchang, 330006, China.
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30
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Tarilonte M, Morín M, Ramos P, Galdós M, Blanco-Kelly F, Villaverde C, Rey-Zamora D, Rebolleda G, Muñoz-Negrete FJ, Tahsin-Swafiri S, Gener B, Moreno-Pelayo MA, Ayuso C, Villamar M, Corton M. Parental Mosaicism in PAX6 Causes Intra-Familial Variability: Implications for Genetic Counseling of Congenital Aniridia and Microphthalmia. Front Genet 2018; 9:479. [PMID: 30386378 PMCID: PMC6199369 DOI: 10.3389/fgene.2018.00479] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/26/2018] [Indexed: 11/17/2022] Open
Abstract
Mutations in PAX6 are involved in several developmental eye disorders. These disorders have considerable phenotypic variability, ranging from panocular forms of congenital aniridia and microphthalmia to isolated anomalies of the anterior or posterior segment. Here, we describe 3 families with variable inter-generational ocular expression of aniridia, iris coloboma, or microphthalmia, and an unusual transmission of PAX6 mutations from an unaffected or mildly affected parent; all of which raised suspicion of gonosomal mosaicism. We first identified two previously known nonsense mutations and one novel likely pathogenic missense variant in PAX6 in probands by means of targeted NGS. The subsequent segregation analysis by Sanger sequencing evidenced the presence of highly probable mosaic events in paternal blood samples. Mosaicism was further confirmed by droplet digital PCR analysis in several somatic tissues of mosaic fathers. Quantification of the mutant allele fraction in parental samples showed a marked deviation from 50%, with a range between 12 and 29% depending on cell type. Gonosomal mosaicsm was definitively confirmed in one of the families thanks to the availability of a sperm sample from the mosaic father. Thus, the recurrence risk in this family was estimated to be about one-third. This is the first report confirming parental PAX6 mosaicism as a cause of disease recurrence in aniridia and other related phenotypes. In addition, we demonstrated that post-zygotic mosaicism is a frequent and underestimated pathogenic mechanism in aniridia, explaining intra-familial phenotypic variability in many cases. Our findings may have substantial implications for genetic counseling in congenital aniridia. Thus, we also highlight the importance of comprehensive genetic screening of parents for new sporadic cases with aniridia or related developmental eye disease to more accurately assess recurrence risk. In conclusion, somatic and/or gonosomal mosaicism should be taken into consideration as a genetic factor to explain not only families with unaffected parents despite multiple affected children but also variable expressivity, apparent de novo cases, and even uncharacterized cases of aniridia and related developmental eye disorders, apparently lacking PAX6 mutations.
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Affiliation(s)
- María Tarilonte
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Matías Morín
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Patricia Ramos
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Galdós
- Department of Ophthalmology, Cruces University Hospital, Bilbao, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Dolores Rey-Zamora
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Gema Rebolleda
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Francisco J Muñoz-Negrete
- Department of Glaucoma, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Saoud Tahsin-Swafiri
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Blanca Gener
- Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics, BioCruces Health Research Institute, Cruces University Hospital, Bilbao, Spain
| | - Miguel-Angel Moreno-Pelayo
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Manuela Villamar
- Servicio de Genética, Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Corton
- Department of Genetics and Genomics, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, University Hospital - Universidad Autónoma de Madrid, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
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31
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Plaisancié J, Tarilonte M, Ramos P, Jeanton-Scaramouche C, Gaston V, Dollfus H, Aguilera D, Kaplan J, Fares-Taie L, Blanco-Kelly F, Villaverde C, Francannet C, Goldenberg A, Arroyo I, Rozet JM, Ayuso C, Chassaing N, Calvas P, Corton M. Implication of non-coding PAX6 mutations in aniridia. Hum Genet 2018; 137:831-846. [PMID: 30291432 DOI: 10.1007/s00439-018-1940-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/23/2018] [Indexed: 01/14/2023]
Abstract
There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.
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Affiliation(s)
- Julie Plaisancié
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France.
- INSERM U1056, Université Toulouse III, Toulouse, France.
| | - M Tarilonte
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - P Ramos
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Jeanton-Scaramouche
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - V Gaston
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - H Dollfus
- Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - D Aguilera
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - J Kaplan
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - L Fares-Taie
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - F Blanco-Kelly
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Villaverde
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Francannet
- Service de Génétique Médicale, CHU Estaing, Clermont-Ferrand, France
| | - A Goldenberg
- Service de Génétique, CHU de Rouen, Centre Normand de Génomique Médicale et Médecine Personnalisée, Rouen, France
| | - I Arroyo
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetics, Hospital of Cáceres, Cáceres, Spain
| | - J M Rozet
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - C Ayuso
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - N Chassaing
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - P Calvas
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - M Corton
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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32
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The genetic architecture of aniridia and Gillespie syndrome. Hum Genet 2018; 138:881-898. [PMID: 30242502 PMCID: PMC6710220 DOI: 10.1007/s00439-018-1934-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 09/06/2018] [Indexed: 12/13/2022]
Abstract
Absence of part or all of the iris, aniridia, is a feature of several genetically distinct conditions. This review focuses on iris development and then the clinical features and molecular genetics of these iris malformations. Classical aniridia, a panocular eye malformation including foveal hypoplasia, is the archetypal phenotype associated with heterozygous PAX6 loss-of-function mutations. Since this was identified in 1991, many genetic mechanisms of PAX6 inactivation have been elucidated, the commonest alleles being intragenic mutations causing premature stop codons, followed by those causing C-terminal extensions. Rarely, aniridia cases are associated with FOXC1, PITX2 and/or their regulatory regions. Aniridia can also occur as a component of many severe global eye malformations. Gillespie syndrome—a triad of partial aniridia, non-progressive cerebellar ataxia and intellectual disability—is phenotypically and genotypically distinct from classical aniridia. The causative gene has recently been identified as ITPR1. The same characteristic Gillespie syndrome-like iris, with aplasia of the pupillary sphincter and a scalloped margin, is seen in ACTA2-related multisystemic smooth muscle dysfunction syndrome. WAGR syndrome (Wilms tumour, aniridia, genitourinary anomalies and mental retardation/intellectual disability), is caused by contiguous deletion of PAX6 and WT1 on chromosome 11p. Deletions encompassing BDNF have been causally implicated in the obesity and intellectual disability associated with the condition. Lastly, we outline a genetic investigation strategy for aniridia in light of recent developments, suggesting an approach based principally on chromosomal array and gene panel testing. This strategy aims to test all known aniridia loci—including the rarer, life-limiting causes—whilst remaining simple and practical.
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33
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Phenotype–genotype correlations and emerging pathways in ocular anterior segment dysgenesis. Hum Genet 2018; 138:899-915. [DOI: 10.1007/s00439-018-1935-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/10/2018] [Indexed: 12/11/2022]
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34
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Vasilyeva TA, Voskresenskaya AA, Pozdeyeva NA, Marakhonov AV, Zinchenko RA. PAX6 Gene Characteristic and Causative Role of PAX6 Mutations in Inherited Eye Pathologies. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418090156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Syrimis A, Nicolaou N, Alexandrou A, Papaevripidou I, Nicolaou M, Loukianou E, Sismani C, Malas S, Christophidou-Anastasiadou V, Tanteles GA. Molecular analysis of Cypriot families with aniridia reveals a novel PAX6 mutation. Mol Med Rep 2018; 18:1623-1627. [PMID: 29901133 PMCID: PMC6072148 DOI: 10.3892/mmr.2018.9126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022] Open
Abstract
The present study investigated the clinical and mutational spectrum of aniridia in a cohort of 17 affected individuals from six families from Cyprus. Each proband was initially evaluated for copy number variants at the PAX6 locus and subsequently underwent PAX6 mutation screening. Sequence analysis of FOXC1 and PITX2 was performed in patients who did not carry a PAX6 mutation. The most common clinical features in the group of aniridia patients associated with aniridia were nystagmus, cataracts and glaucoma. PAX6 pathogenic mutations were identified in five out of six families (a diagnostic yield of 84%). Previously reported pathogenic mutations in PAX6 were identified in four families, which comprise p.R203*, p.R240* and p.R317*. In addition, a novel pathogenic variant (p.E220Gfs*23) was identified in a single family. No pathogenic mutations were detected in PAX6, FOXC1 or PITX2 in the only patient with a sporadic form of aniridia‑like phenotype, confirming the genetic heterogeneity associated with this disease. To the best of our knowledge this is the first report on the mutational spectrum of PAX6 in aniridia patients of Cypriot ancestry. Mutational screening of PAX6 serves a crucial role in distinguishing isolated from syndromic forms of aniridia, and it may therefore eliminate the need for renal ultrasound scan surveillance, delineate the phenotype and improve genetic counseling.
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Affiliation(s)
- Andreas Syrimis
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Nayia Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Michael Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Eleni Loukianou
- Department of Ophthalmology, Nicosia General Hospital, 2029 Nicosia, Cyprus
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Stavros Malas
- Department of Developmental and Functional Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Violetta Christophidou-Anastasiadou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
- Department of Clinical Genetics, Archbishop Makarios III Hospital, 2012 Nicosia, Cyprus
| | - George A. Tanteles
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
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36
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Roux LN, Petit I, Domart R, Concordet JP, Qu J, Zhou H, Joliot A, Ferrigno O, Aberdam D. Modeling of Aniridia-Related Keratopathy by CRISPR/Cas9 Genome Editing of Human Limbal Epithelial Cells and Rescue by Recombinant PAX6 Protein. Stem Cells 2018; 36:1421-1429. [PMID: 29808941 DOI: 10.1002/stem.2858] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/08/2018] [Accepted: 05/14/2018] [Indexed: 12/24/2022]
Abstract
Heterozygous PAX6 gene mutations leading to haploinsufficiency are the main cause of congenital aniridia, a rare and progressive panocular disease characterized by reduced visual acuity. Up to 90% of patients suffer from aniridia-related keratopathy (ARK), caused by a combination of factors including limbal epithelial stem cell (LSC) deficiency, impaired healing response and abnormal differentiation of the corneal epithelium. It usually begins in the first decade of life, resulting in recurrent corneal erosions, sub-epithelial fibrosis, and corneal opacification. Unfortunately, there are currently no efficient treatments available for these patients and no in vitro model for this pathology. We used CRISPR/Cas9 technology to introduce into the PAX6 gene of LSCs a heterozygous nonsense mutation found in ARK patients. Nine clones carrying a p.E109X mutation on one allele were obtained with no off-target mutations. Compared with the parental LSCs, heterozygous mutant LSCs displayed reduced expression of PAX6 and marked slow-down of cell proliferation, migration and detachment. Moreover, addition to the culture medium of recombinant PAX6 protein fused to a cell penetrating peptide was able to activate the endogenous PAX6 gene and to rescue phenotypic defects of mutant LSCs, suggesting that administration of such recombinant PAX6 protein could be a promising therapeutic approach for aniridia-related keratopathy. More generally, our results demonstrate that introduction of disease mutations into LSCs by CRISPR/Cas9 genome editing allows the creation of relevant cellular models of ocular disease that should greatly facilitate screening of novel therapeutic approaches. Stem Cells 2018;36:1421-1429.
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Affiliation(s)
- Lauriane N Roux
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Isabelle Petit
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Romain Domart
- INSERM U1154, CNRS UMR 7196, Museum National d'Histoire Naturelle, Paris, France
| | - Jean-Paul Concordet
- INSERM U1154, CNRS UMR 7196, Museum National d'Histoire Naturelle, Paris, France
| | - Jieqiong Qu
- Department of Human Developmental biology, Radboud University, Nijmegen, The Netherlands.,Faculty of Sciences, Department of Human Genetics, Radboud University Nijmegen, The Netherlands
| | - Huiqing Zhou
- Department of Human Developmental biology, Radboud University, Nijmegen, The Netherlands.,Faculty of Sciences, Department of Human Genetics, Radboud University Nijmegen, The Netherlands
| | - Alain Joliot
- Collège de France CNRS/UMR 7241 - INSERM U1050, Paris, France
| | | | - Daniel Aberdam
- INSERM U976, Hôpital Saint-Louis, Paris, France.,Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
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37
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Aniridia due to a novel microdeletion affecting
$$\textit{PAX6}$$
PAX
6
regulatory enhancers: case report and review of the literature. J Genet 2018. [DOI: 10.1007/s12041-018-0925-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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38
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Phenotypic Variation in a Four-Generation Family with Aniridia Carrying a Novel PAX6 Mutation. J Ophthalmol 2018; 2018:5978293. [PMID: 29850208 PMCID: PMC5904767 DOI: 10.1155/2018/5978293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/05/2018] [Indexed: 12/14/2022] Open
Abstract
Aniridia is a congenital disease that affects almost all eye structures and is primarily caused by loss-of-function mutations in the PAX6 gene. The degree of vision loss in aniridia varies and is dependent on the extent of foveal, iris, and optic nerve hypoplasia and the presence of glaucoma, cataracts, and corneal opacification. Here, we describe a 4-generation family in which 7 individuals across 2 generations carry a novel disease-causing frameshift mutation (NM_000280.4(PAX6):c.565TC>T) in PAX6. This mutation results in an early stop codon in exon 8, which is predicted to cause nonsense-mediated decay of the truncated mRNA and a functionally null PAX6 allele. Family members with aniridia showed differences in multiple eye phenotypes including iris and optic nerve hypoplasia, congenital and acquired corneal opacification, glaucoma, and strabismus. Visual acuity ranged from 20/100 to less than 20/800. Patients who required surgical intervention for glaucoma or corneal opacification had worse visual outcomes. Our results show that family members carrying a novel PAX6 frameshift mutation have variable expressivity, leading to different ocular comorbidities and visual outcomes.
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39
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Chauhan BK, Medsinge A, Baumgartner MP, Scanga HL, Kamakari S, Gajdosova E, Camacho CJ, Nischal KK. Case series: Pyramidal cataracts, intact irides and nystagmus from three novel PAX6 mutations. Am J Ophthalmol Case Rep 2018; 10:172-179. [PMID: 29780932 PMCID: PMC5956696 DOI: 10.1016/j.ajoc.2018.02.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 02/07/2018] [Accepted: 02/26/2018] [Indexed: 11/29/2022] Open
Abstract
Purpose To investigate the association between novel PAX6 mutations to bilateral anterior pyramidal congenital cataracts (APyC), complete and intact irides, and nystagmus. Observations This is a retrospective observational case series in a multi-center setting with genetic testing. Three female patients were diagnosed with bilateral APyC, intact irides and nystagmus. Genetic testing identified the three patients had novel missense mutations in PAX6 – c.128C > T; p.Ser43Phe (S43F), c. 197T > A; p.Ile66Asn (I66N) and c.781C > G; p.Arg261Gly (R261G). Conclusions and importance This study demonstrates a novel phenotype of bilateral APyC, intact irides, and nystagmus in whom genetic testing for PAX6 identified novel missense mutations (S43F, I66N, R261G) in highly conserved DNA-binding domains. Implications of understanding why the iris is present in these cases is discussed.
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Affiliation(s)
- Bharesh K Chauhan
- UPMC Eye Center, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Anagha Medsinge
- UPMC Eye Center, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Matthew P Baumgartner
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Hannah L Scanga
- UPMC Eye Center, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Smaragda Kamakari
- Ophthalmic Genetics Unit, OMMA, Ophthalmological Institute of Athens, Katehaki 74, 11525, Athens, Greece
| | - Eva Gajdosova
- Great Ormond Street Hospital for Children, London, WC1N 3JH, UK
| | - Carlos J Camacho
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Ken K Nischal
- UPMC Eye Center, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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40
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Wawrocka A, Krawczynski MR. The genetics of aniridia - simple things become complicated. J Appl Genet 2018; 59:151-159. [PMID: 29460221 PMCID: PMC5895662 DOI: 10.1007/s13353-017-0426-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/21/2017] [Accepted: 12/21/2017] [Indexed: 12/26/2022]
Abstract
Aniridia is a rare, panocular disorder characterized by a variable degree of hypoplasia or the absence of iris tissue associated with additional ocular abnormalities. It is inherited in an autosomal dominant manner, with high penetrance and variable expression even within the same family. In most cases the disease is caused by haploinsufficiency truncating mutations in the PAX6 gene; however, in up to 30% of aniridia patients, disease results from chromosomal rearrangements at the 11p13 region. The aim of this review is to present the clinical and genetic aspects of the disease. Furthermore, we present a molecular diagnostic strategy in the aniridia patients. Recent improvement in the genetic diagnostic approach will precisely diagnosis aniridia patients, which is essential especially for children with aniridia in order to determine the risk of developing a Wilms tumor or neurodevelopmental disorder. Finally, based on the previous studies we describe the current knowledge and latest research findings in the topic of pathogenesis of aniridia and possible future treatment.
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Affiliation(s)
- Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Rokietnicka 8, 60-806, Poznan, Poland.
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Rokietnicka 8, 60-806, Poznan, Poland
- Centers for Medical Genetics GENESIS, Poznan, Poland
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41
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Landsend ES, Utheim ØA, Pedersen HR, Lagali N, Baraas RC, Utheim TP. The genetics of congenital aniridia—a guide for the ophthalmologist. Surv Ophthalmol 2018; 63:105-113. [DOI: 10.1016/j.survophthal.2017.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 01/10/2023]
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42
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Abstract
PURPOSE OF REVIEW Aniridia is a rare and panocular disorder affecting most of the ocular structures which may have significant impact on vision. The purpose of this review is to describe the clinical features, genetics, and therapeutic options for this disease and to provide an update of current knowledge and latest research findings. RECENT FINDINGS Aside from the ocular features, a variety of associated systemic abnormalities, including hormonal, metabolic, gastrointestinal, genitourinary, and neurologic pathologies have been reported in children with aniridia. Although mutations in PAX6 are a major cause of aniridia, genetic defects in nearby genes, such as TRIM44 or ELP4, have also been reported to cause aniridia. Recent improvement in genetic testing technique will help more rapid and precise diagnosis for aniridia. A promising therapeutic approach called nonsense suppression therapy has been introduced and successfully used in an animal model. SUMMARY Aniridia is a challenging disease. The progressive nature of this condition and its potential complications require continuous and life-long ophthalmologic care. Genetic diagnosis for aniridia is important for establishing definitive molecular characterization as well as identifying individuals at high risk for Wilms tumor. Recent advancement in understanding the genetic pathogenesis of this disease offers promise for the approaches to treatment.
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43
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Voskresenskaya A, Pozdeyeva N, Vasilyeva T, Batkov Y, Shipunov A, Gagloev B, Zinchenko R. Clinical and morphological manifestations of aniridia-associated keratopathy on anterior segment optical coherence tomography and in vivo confocal microscopy. Ocul Surf 2017; 15:759-769. [PMID: 28698011 DOI: 10.1016/j.jtos.2017.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 06/12/2017] [Accepted: 07/05/2017] [Indexed: 12/13/2022]
Abstract
PURPOSE The study aimed to evaluate clinical and morphological changes in the limbal palisades of Vogt (POV) at different stages of aniridia-associated keratopathy (AAK) and to assess possible utility of anterior segment optical coherence tomography (AS-OCT) for the visualization of limbal progenitor structures as it correlates to laser scanning confocal microscopy (LSCM) data. METHODS The study involved 32 patients (59 eyes) with congenital aniridia. AAK stage was defined based on biomicroscopy. Assessment of limbal zone and detection of POVs in identical areas was performed by LSCM (HRT3) and AS-OCT (RTVue XR Avanti) using 3D Cornea (En Face mode) and Cornea Cross Line protocols. RESULTS Intact and changed POVs were found in 8/8 stage 0 eyes, in 1/21 stage I and 2/13 stage II eyes. Spearman's correlation coefficient in assessing the consistency of the POV diagnostic results by LSCM and AS-OCT for the inferior limbus was rS = 0.85 (P < 0.05), for the superior limbus - rS = 0.53 (P < 0.05). AS-OCT was less sensitive for detection of partially present POVs in superior limbus. The negative correlation between AAK stage and POV preservation was determined (rS = -0.5, P < 0.05). There was no correlation between AAK stage and patient age (rS = 0.235, P = 0.209). Three patients with PAX6 3' deletion showed stage 0 AAK with intact or slightly disturbed POVs morphology and transparent cornea. CONCLUSION AS-OCT may be an additional diagnostic tool for POV visualization in vivo in aniridic patients. Its diagnostic accuracy is subject to selection of anatomic region, nystagmus and the degree of POV degradation.
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Affiliation(s)
- Anna Voskresenskaya
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation.
| | - Nadezhda Pozdeyeva
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation; Postgraduate Medical Institute, Cheboksary, Russian Federation
| | - Tatyana Vasilyeva
- Federal State Budgetary Institution, Research Center for Medical Genetics, Moscow, Russian Federation
| | - Yevgeniy Batkov
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation
| | - Aleksandr Shipunov
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation
| | - Boris Gagloev
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, Cheboksary, Russian Federation
| | - Rena Zinchenko
- Federal State Budgetary Institution, Research Center for Medical Genetics, Moscow, Russian Federation; Pirogov Russian National Research Medical University, Moscow, Russian Federation
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Sannan NS, Gregory-Evans CY, Lyons CJ, Lehman AM, Langlois S, Warner SJ, Zakrzewski H, Gregory-Evans K. Correlation of novel PAX6 gene abnormalities in aniridia and clinical presentation. Can J Ophthalmol 2017; 52:570-577. [PMID: 29217025 DOI: 10.1016/j.jcjo.2017.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/24/2017] [Accepted: 04/05/2017] [Indexed: 01/12/2023]
Abstract
OBJECTIVE To describe the clinical presentation and genotype of subjects with aniridia with a particular focus on foveal hypoplasia. DESIGN Prospective cohort study. PARTICIPANTS Thirty-three Canadian participants with aniridia and of various ethnic backgrounds residing in British Columbia. METHODS Full ophthalmic examinations and posterior segment spectral domain-optical coherence tomography (SD-OCT) imaging were performed. Foveal hypoplasia was graded independently by 2 staff ophthalmologists. PAX6 sequencing was performed and chromosomal 11p anomalies investigated. Candidate gene and single-nucleotide polymorphism sequencing in genes functionally related to PAX6 were also studied. RESULTS Best corrected visual acuities in the cohort ranged from 0.0 logMAR to no light perception. Total absence of iris tissue was seen in the majority (42 of 66 eyes). In those in whom SD-OCT was possible, foveal hypoplasia was seen in the majority (45 of 56 eyes, 80%). Molecular genetic defects involving PAX6 were identified in 30 participants (91%), including 4 novel PAX6 mutations (Gly18Val; Ser65ProfsX14; Met337ArgfsX18; Ser321CysfsX34) and 4 novel chromosome 11p deletions inclusive of PAX6 or a known PAX6 regulatory region. CONCLUSIONS The number of PAX6 mutations associated with aniridia continues to increase. Variable foveal architecture despite nearly identical anterior segment disease in 4 participants with an Ex9 ELP4-Ex4 DCDC1 deletion suggested that molecular cues causing variation in disease in the posterior segment differ from those at play in the anterior segment. Results in 3 patients without identifiable PAX6 mutations and a review of the literature suggest that such cases be described as phenocopies rather than actual cases of the syndrome of aniridia.
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Affiliation(s)
- Naif S Sannan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Cheryl Y Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Christopher J Lyons
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C; Department of Ophthalmology, BC Children's Hospital, Vancouver, B.C
| | - Anna M Lehman
- Department of Medical Genetics, University of British Columbia, Vancouver, B.C
| | - Sylvie Langlois
- Department of Medical Genetics, University of British Columbia, Vancouver, B.C
| | - Simon J Warner
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C
| | - Helen Zakrzewski
- Cumming School of Medicine, University of Calgary, Calgary, Alta
| | - Kevin Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, B.C.
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Kovaleva NV, Cotter PD. Mosaicism for structural non-centromeric autosomal rearrangements in disease-defined carriers: sex differences in the rearrangements profile and maternal age distributions. Mol Cytogenet 2017; 10:18. [PMID: 28533817 PMCID: PMC5438540 DOI: 10.1186/s13039-017-0321-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/13/2017] [Indexed: 02/08/2023] Open
Abstract
Background Mosaicism for an autosomal structural rearrangement (Rea) associated with clinical manifestation of chromosomal imbalance is rare. Consequently, there is a lack of basic epidemiological characterization of this kind of mosaicism, such as population rate, cytogenetic profile of Reas involved, maternal age distribution, and sex (male to female) ratio among Rea carriers. The objectives of the present study were: (i) determination of the Rea profile in clinically affected individuals, (ii) comparative analysis of the cytogenetic profile and involvement of single chromosomes to rearrangements in affected and previously reported asymptomatic carriers, (iii) analysis of the male/female ratio in carriers of various types of Rea, and, (iv) examination of parental ages distributions according to carriers’ sex. Results Two hundred and forty six disease-defined cases of mosaicism for autosomal non-centromeric Rea with a normal cell line of known sex were identified from the literature. There was a significant difference in single chromosome involvements compared to structural rearrangements between affected and asymptomatic carriers of unbalanced Rea, p =0.0030. In affected carriers, chromosome 18 was most frequently involved in structural rearrangements (12.6% of 246 instances). The least frequently rearranged were chromosomes 16 and 21 (0.8% and 1.2%, respectively). In asymptomatic carriers, the most frequently rearranged were chromosomes 5 and 21 (13% of 51 instances each). Among carriers of “loss” or “gain/loss” of genomic material, a female predominance was observed (50 M/89 F, different from population ratio of 1.06 at p = 0.0002). Carriers of either “gain” or balanced Rea demonstrated typical male predominance (41 M/30 F and 18 M/16 F), not different from 1.06. Maternal and paternal ages were reported in 129 and in 109 cases, respectively. There was a significant difference in maternal age distribution between male and female carriers, with mean maternal age of 25.2 years vs 28.3 years (p = 0.032). However, there was no difference in paternal age, with mean paternal age of 29.4 in both groups. Conclusion The data suggested that structural rearrangements of certain chromosomes involved in mosaicism may not be tolerated by the embryo, while others have higher survival prospects. Maternal age appears to be a risk factor for somatic mosaicism of structural Rea in female offspring or might cause an adverse effect on male embryo viability. Electronic supplementary material The online version of this article (doi:10.1186/s13039-017-0321-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Natalia V Kovaleva
- Academy of Molecular Medicine, Mytniskaya str. 12/44, St. Petersburg, 191144 Russian Federation
| | - Philip D Cotter
- Department of Pediatrics, University of California San Francisco, San Francisco, CA USA.,ResearchDx Inc., Irvine, CA USA
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Yasue A, Kono H, Habuta M, Bando T, Sato K, Inoue J, Oyadomari S, Noji S, Tanaka E, Ohuchi H. Relationship between somatic mosaicism of Pax6 mutation and variable developmental eye abnormalities-an analysis of CRISPR genome-edited mouse embryos. Sci Rep 2017; 7:53. [PMID: 28246397 PMCID: PMC5428340 DOI: 10.1038/s41598-017-00088-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 01/31/2017] [Indexed: 12/25/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system is a rapid gene-targeting technology that does not require embryonic stem cells. To demonstrate dosage effects of the Pax6 gene on eye formation, we generated Pax6-deficient mice with the CRISPR/Cas system. Eyes of founder embryos at embryonic day (E) 16.5 were examined and categorized according to macroscopic phenotype as class 1 (small eye with distinct pigmentation), class 2 (pigmentation without eye globes), or class 3 (no pigmentation and no eyes). Histologically, class 1 eyes were abnormally small in size with lens still attached to the cornea at E16.5. Class 2 eyes had no lens and distorted convoluted retinas. Class 3 eyes had only rudimentary optic vesicle-like tissues or histological anophthalmia. Genotyping of neck tissue cells from the founder embryos revealed somatic mosaicism and allelic complexity for Pax6. Relationships between eye phenotype and genotype were developed. The present results demonstrated that development of the lens from the surface ectoderm requires a higher gene dose of Pax6 than development of the retina from the optic vesicle. We further anticipate that mice with somatic mosaicism in a targeted gene generated by CRISPR/Cas-mediated genome editing will give some insights for understanding the complexity in human congenital diseases that occur in mosaic form.
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Affiliation(s)
- Akihiro Yasue
- Department of Orthodontics Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8504, Japan.
| | - Hitomi Kono
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Munenori Habuta
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Tetsuya Bando
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Keita Sato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Junji Inoue
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Seiichi Oyadomari
- Division of Molecular Biology, Institute for Advanced Enzyme Research, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Sumihare Noji
- Tokushima University, 2-24 Shinkura-cho, Tokushima, 770-8501, Japan
| | - Eiji Tanaka
- Department of Orthodontics Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8504, Japan
| | - Hideyo Ohuchi
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
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Blanco-Kelly F, Palomares M, Vallespín E, Villaverde C, Martín-Arenas R, Vélez-Monsalve C, Lorda-Sánchez I, Nevado J, Trujillo-Tiebas MJ, Lapunzina P, Ayuso C, Corton M. Improving molecular diagnosis of aniridia and WAGR syndrome using customized targeted array-based CGH. PLoS One 2017; 12:e0172363. [PMID: 28231309 PMCID: PMC5322952 DOI: 10.1371/journal.pone.0172363] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/04/2017] [Indexed: 11/18/2022] Open
Abstract
Chromosomal deletions at 11p13 are a frequent cause of congenital Aniridia, a rare pan-ocular genetic disease, and of WAGR syndrome, accounting up to 30% of cases. First-tier genetic testing for newborn with aniridia, to detect 11p13 rearrangements, includes Multiplex Ligation-dependent Probe Amplification (MLPA) and karyotyping. However, neither of these approaches allow obtaining a complete picture of the high complexity of chromosomal deletions and breakpoints in aniridia. Here, we report the development and validation of a customized targeted array-based comparative genomic hybridization, so called WAGR-array, for comprehensive high-resolution analysis of CNV in the WAGR locus. Our approach increased the detection rate in a Spanish cohort of 38 patients with aniridia, WAGR syndrome and other related ocular malformations, allowing to characterize four undiagnosed aniridia cases, and to confirm MLPA findings in four additional patients. For all patients, breakpoints were accurately established and a contiguous deletion syndrome, involving a large number of genes, was identified in three patients. Moreover, we identified novel microdeletions affecting 3' PAX6 regulatory regions in three families with isolated aniridia. This tool represents a good strategy for the genetic diagnosis of aniridia and associated syndromes, allowing for a more accurate CNVs detection, as well as a better delineation of breakpoints. Our results underline the clinical importance of performing exhaustive and accurate analysis of chromosomal rearrangements for patients with aniridia, especially newborns and those without defects in PAX6 after diagnostic screening.
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Affiliation(s)
- Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - María Palomares
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Elena Vallespín
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Cristina Villaverde
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Rubén Martín-Arenas
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Camilo Vélez-Monsalve
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Isabel Lorda-Sánchez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Julián Nevado
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - María José Trujillo-Tiebas
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Pablo Lapunzina
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Institute of Medical & Molecular Genetics (INGEMM), Hospital Universitario La Paz, Universidad Autónoma de Madrid, IdiPAZ, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- * E-mail: (CA); (MC)
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- * E-mail: (CA); (MC)
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Wang X, Shan X, Gregory-Evans CY. A mouse model of aniridia reveals the in vivo downstream targets of Pax6 driving iris and ciliary body development in the eye. Biochim Biophys Acta Mol Basis Dis 2017; 1863:60-67. [DOI: 10.1016/j.bbadis.2016.10.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 11/28/2022]
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Voskresenskaya AA, Pozdeeva NA, Vasil'eva TA, Gagloev BV, Shipunov AA, Zinchenko RA. [Diagnostic capabilities of optical coherence tomography and confocal laser scanning microscopy in studying manifestations of aniridia-associated keratopathy]. Vestn Oftalmol 2017; 133:30-44. [PMID: 29319667 DOI: 10.17116/oftalma2017133630-44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
AIM to investigate the possible use of anterior segment optical coherence tomography (AS-OCT) and laser scanning confocal microscopy (LSCM) for visualization of limbal progenitor structures and epithelial changes at different stages of aniridia-associated keratopathy (AAK) and to analyze genotype-phenotype correlations of corneal damage. MATERIAL AND METHODS Thirty-four patients (63 eyes) with congenital aniridia (CA) were subjected to epithelial cell density measurement in the central cornea as well as epithelial surface assessment with limbal palisades of Vogt (POV) detection in the corresponding sites of the two corneas. For that, LSCM (HRT3) and AS-OCT (RTVue XR Avanti) were performed. Central corneal and epithelial thicknesses were measured using the Pachymetry protocol. RESULTS There has been found an increase in the central corneal thickness (CCT) of CA patients, which correlated with the stage of AAK, and a decrease in the central epithelial thickness as compared with healthy subjects (p<0.05). The difference between the basal and wing epithelial cells density in eyes with stages I and II AAK and normal cells density at stage 0 AAK was statistically significant (p<0.05). Intact or disturbed POV were detected in all patients with PAX6 3' deletion. At that, AS-OCT findings highly agreed with LSCM images for both the inferii (rS=0.85, p<0.05) and superior limbi (rS=0.53, p<0.05). A negative correlation was established between the stage of AAK and in vivo morphology of POV (rS=-0.5, p<0.05). However, no correlation was found between the stage of AAK and patient's age (rS=0.169, p=0.174). CONCLUSION AS-OCT and LSCM are both important diagnostic tools for corneal surface monitoring in patients with limbal stem cells deficiency.
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Affiliation(s)
- A A Voskresenskaya
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Tractorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - N A Pozdeeva
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Tractorostroiteley prospekt, Cheboksary, Russian Federation, 428028; Postgraduate Doctors' Training Institute, Ministry of Healthcare and Social Development of the Chuvash Republic, 3 Krasnaya Sq., Cheboksary, Chuvash Republic, Russian Federation, 428003
| | - T A Vasil'eva
- Research Center for Medical Genetics, 1 Moskvorech'e St., Moscow, Russian Federation, 115478
| | - B V Gagloev
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Tractorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - A A Shipunov
- Cheboksary branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Tractorostroiteley prospekt, Cheboksary, Russian Federation, 428028
| | - R A Zinchenko
- Research Center for Medical Genetics, 1 Moskvorech'e St., Moscow, Russian Federation, 115478; Pirogov Russian National Research Medical University, 1 Ostrovityanova St., Moscow, Russian Federation, 117997
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50
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Franzoni A, Russo PD, Baldan F, D'Elia AV, Puppin C, Penco S, Damante G. A CGH array procedure to detect PAX6 gene structural defects. Mol Cell Probes 2016; 32:65-68. [PMID: 27919838 DOI: 10.1016/j.mcp.2016.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/01/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
Abstract
Aniridia is a rare congenital disease characterized by eye development defects, in which the more evident clinical manifestation is iris absence or malformation. In most of the patients, aniridia is associated to PAX6 gene point mutations or deletions. When these deletions are large and involve other genes, a more complex disease, named WAGR syndrome, arises. In order to develop a new tool to analyze aniridia and WAGR subjects, a CGH array (CGHa) of the PAX6 genomic region was set up. We generated a custom microarray kit using an oligonucleotide-based platform that allows high resolution molecular profiling of genomic aberrations in 20 Mb of the 11p13 chromosomal region, centered on the PAX6 gene. The average probe spacing was 100 bp. Thirty-five subjects have been analyzed. The major advantage of CGHa compared to MLPA was the knowledge of the deletions borders. Our approach identifies patients harboring deletions including the WT1 gene and, therefore, at risk for kidney tumors. The CGHa assay confirmed that several aniridia patients show a deletion at the level of ELP4 gene, without involvement of the PAX6 exonic regions. In all these patients, deletions include the PAX6 transcriptional enhancer SIMO. This finding further highlights the role of mutation/deletion of long-range enhancers in monogenic human pathology.
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Affiliation(s)
- Alessandra Franzoni
- Istituto di Genetica Medica, Azienda Ospedaliero-Universitaria di Udine, Italy
| | | | - Federica Baldan
- Dipartimento di Scienze Mediche e Biologiche, Università di Udine, Italy
| | | | - Cinzia Puppin
- Dipartimento di Scienze Mediche e Biologiche, Università di Udine, Italy
| | - Silvana Penco
- Genetica Medica, Dipartimento di Medicina di Laboratorio, Ospedale Niguarda Ca' Granda, Milano, Italy
| | - Giuseppe Damante
- Istituto di Genetica Medica, Azienda Ospedaliero-Universitaria di Udine, Italy; Dipartimento di Scienze Mediche e Biologiche, Università di Udine, Italy.
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