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van Heyningen V. Stochasticity in genetics and gene regulation. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230476. [PMID: 38432316 PMCID: PMC10909507 DOI: 10.1098/rstb.2023.0476] [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: 11/09/2023] [Accepted: 12/20/2023] [Indexed: 03/05/2024] Open
Abstract
Development from fertilized egg to functioning multi-cellular organism requires precision. There is no precision, and often no survival, without plasticity. Plasticity is conferred partly by stochastic variation, present inherently in all biological systems. Gene expression levels fluctuate ubiquitously through transcription, alternative splicing, translation and turnover. Small differences in gene expression are exploited to trigger early differentiation, conferring distinct function on selected individual cells and setting in motion regulatory interactions. Non-selected cells then acquire new functions along the spatio-temporal developmental trajectory. The differentiation process has many stochastic components. Meiotic segregation, mitochondrial partitioning, X-inactivation and the dynamic DNA binding of transcription factor assemblies-all exhibit randomness. Non-random X-inactivation generally signals deleterious X-linked mutations. Correct neural wiring, such as retina to brain, arises through repeated confirmatory activity of connections made randomly. In immune system development, both B-cell antibody generation and the emergence of balanced T-cell categories begin through stochastic trial and error followed by functional selection. Aberrant selection processes lead to immune dysfunction. DNA sequence variants also arise through stochastic events: some involving environmental fluctuation (radiation or presence of pollutants), or genetic repair system malfunction. The phenotypic outcome of mutations is also fluid. Mutations may be advantageous in some circumstances, deleterious in others. This article is part of a discussion meeting issue 'Causes and consequences of stochastic processes in development and disease'.
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Affiliation(s)
- Veronica van Heyningen
- UCL Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
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2
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Jackson D, Moosajee M. The Genetic Determinants of Axial Length: From Microphthalmia to High Myopia in Childhood. Annu Rev Genomics Hum Genet 2023; 24:177-202. [PMID: 37624667 DOI: 10.1146/annurev-genom-102722-090617] [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] [Indexed: 08/27/2023]
Abstract
The axial length of the eye is critical for normal visual function by enabling light to precisely focus on the retina. The mean axial length of the adult human eye is 23.5 mm, but the molecular mechanisms regulating ocular axial length remain poorly understood. Underdevelopment can lead to microphthalmia (defined as a small eye with an axial length of less than 19 mm at 1 year of age or less than 21 mm in adulthood) within the first trimester of pregnancy. However, continued overgrowth can lead to axial high myopia (an enlarged eye with an axial length of 26.5 mm or more) at any age. Both conditions show high genetic and phenotypic heterogeneity associated with significant visual morbidity worldwide. More than 90 genes can contribute to microphthalmia, and several hundred genes are associated with myopia, yet diagnostic yields are low. Crucially, the genetic pathways underpinning the specification of eye size are only now being discovered, with evidence suggesting that shared molecular pathways regulate under- or overgrowth of the eye. Improving our mechanistic understanding of axial length determination will help better inform us of genotype-phenotype correlations in both microphthalmia and myopia, dissect gene-environment interactions in myopia, and develop postnatal therapies that may influence overall eye growth.
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Affiliation(s)
- Daniel Jackson
- Institute of Ophthalmology, University College London, London, United Kingdom;
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, United Kingdom;
- The Francis Crick Institute, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
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3
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Wang P, Wu P, Wang J, Zeng Y, Jiang Y, Wang Y, Li S, Xiao X, Zhang Q. Missense Mutations in MAB21L1: Causation of Novel Autosomal Dominant Ocular BAMD Syndrome. Invest Ophthalmol Vis Sci 2023; 64:19. [PMID: 36892533 PMCID: PMC10010443 DOI: 10.1167/iovs.64.3.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023] Open
Abstract
Purpose Biallelic MAB21L1 variants have been reported to cause autosomal recessive cerebellar, ocular, craniofacial, and genital syndrome (COFG), whereas only five heterozygous pathogenic variants have been suspected to cause autosomal dominant (AD) microphthalmia and aniridia in eight families. This study aimed to report an AD ocular syndrome (blepharophimosis plus anterior segment and macular dysgenesis [BAMD]) syndrome based on clinical and genetic findings from patients with monoallelic MAB21L1 pathogenic variants in our cohort and reported cases. Methods Potential pathogenic variants in MAB21L1 were detected from a large in-house exome sequencing dataset. Ocular phenotypes of the patients with potential pathogenic variants in MAB21L1 were summarized, and the genotype-phenotype correlation was analyzed through a comprehensive literature review. Results Three heterozygous missense variants in MAB21L1, predicted to be damaging, were detected in 5 unrelated families, including c.152G>T in 2, c.152G>A in 2, and c.155T>G in one. All were absent from gnomAD. The variants were de novo in two families, transmitted from affected parents to offspring in two families, and with an unknown origin in the other family, demonstrating strong evidence of AD inheritance. All patients revealed similar BAMD phenotypes, including blepharophimosis, anterior segment dysgenesis, and macular dysgenesis. Genotype-phenotype analysis suggested that patients with monoallelic MAB21L1 missense variants had only ocular anomalies (BAMD), whereas patients with biallelic variants presented both ocular and extraocular symptoms. Conclusions Heterozygous pathogenic variants in MAB21L1 account for a new AD BAMD syndrome, which is completely different from COFG caused by homozygous variants in MAB21L1. Nucleotide c.152 is likely a mutation hot spot, and the encoded residue of p.Arg51 might be critical for MAB21L1.
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Affiliation(s)
- Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Pengsen Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Junwen Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yiyan Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yi Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yingwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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Clinical Congenital Anophthalmos and Microphthalmos-Experiences of Patients and Their Parents after More than 10 Years of Treatment. CHILDREN (BASEL, SWITZERLAND) 2022; 10:children10010034. [PMID: 36670585 PMCID: PMC9856451 DOI: 10.3390/children10010034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/14/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022]
Abstract
Congenital clinical anophthalmos and blind microphthalmos describe the absence of an eye or the presence of a small eye in the orbit. Between 1999 and 2013, 97 children with anophthalmos or microphthalmos were treated with self-inflating, hydrophilic gel expanders at the Rostock Eye Clinic. More than a decade later, this study investigated the perspective of patients and parents regarding the treatment, the surgical outcome, and the emotional and social well-being of the patients. A total of 22 families with 16 patients sighted in the other eye and six patients blind in both eyes participated. Questionnaires were developed, including items on physical, emotional, social, and medical aspects. The patients felt emotionally stable and integrated into their social environment, with no major limitations reported by the majority. These statements were confirmed by most of the parents. Parents (67%) indicated that the success of the operation was already apparent after the first intervention and that the current situation did not play a role in the patients' social environment. The study provided new insights into the therapy results, the postoperative care, and the social and emotional stability of the prosthesis-wearing patients, indicating the chosen expander methods as promising in terms of positive postoperative care.
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Diacou R, Nandigrami P, Fiser A, Liu W, Ashery-Padan R, Cvekl A. Cell fate decisions, transcription factors and signaling during early retinal development. Prog Retin Eye Res 2022; 91:101093. [PMID: 35817658 PMCID: PMC9669153 DOI: 10.1016/j.preteyeres.2022.101093] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 12/30/2022]
Abstract
The development of the vertebrate eyes is a complex process starting from anterior-posterior and dorso-ventral patterning of the anterior neural tube, resulting in the formation of the eye field. Symmetrical separation of the eye field at the anterior neural plate is followed by two symmetrical evaginations to generate a pair of optic vesicles. Next, reciprocal invagination of the optic vesicles with surface ectoderm-derived lens placodes generates double-layered optic cups. The inner and outer layers of the optic cups develop into the neural retina and retinal pigment epithelium (RPE), respectively. In vitro produced retinal tissues, called retinal organoids, are formed from human pluripotent stem cells, mimicking major steps of retinal differentiation in vivo. This review article summarizes recent progress in our understanding of early eye development, focusing on the formation the eye field, optic vesicles, and early optic cups. Recent single-cell transcriptomic studies are integrated with classical in vivo genetic and functional studies to uncover a range of cellular mechanisms underlying early eye development. The functions of signal transduction pathways and lineage-specific DNA-binding transcription factors are dissected to explain cell-specific regulatory mechanisms underlying cell fate determination during early eye development. The functions of homeodomain (HD) transcription factors Otx2, Pax6, Lhx2, Six3 and Six6, which are required for early eye development, are discussed in detail. Comprehensive understanding of the mechanisms of early eye development provides insight into the molecular and cellular basis of developmental ocular anomalies, such as optic cup coloboma. Lastly, modeling human development and inherited retinal diseases using stem cell-derived retinal organoids generates opportunities to discover novel therapies for retinal diseases.
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Affiliation(s)
- Raven Diacou
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Prithviraj Nandigrami
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Andras Fiser
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Wei Liu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ales Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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6
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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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Chiang CJ, Cheng YC, Tsai YS, Kuo PL, Chang CH. Recurrent Fetal Anophthalmia Caused by retinoids acid gene 6 mutations: Correlation between prenatal ultrasonography, magnetic resonance imaging, and pathology. Taiwan J Obstet Gynecol 2022; 61:180-185. [PMID: 35181035 DOI: 10.1016/j.tjog.2021.11.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2021] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE Anophthalmia is an extreme form on the spectrum of anophthalmia-microphthalmia (A/M) syndrome. Most articles define fetal microphthalmia by an ocular diameter (OD) less than fifth percentile. Diagnosis of fetal microphthalmia using only orbital measurements such as interocular distance (IOD), and OD may neglect the presence or morphology of the fetal lens, hence failing to identify abnormalities of the fetal globe. CASE REPORT We hereby present a case of isolated fetal anophthalmia in two consecutive pregnancies from the same mother. Both fetuses presented as full-sized globes with absence or small size of lens under fetal ultrasound examination. Magnetic resonance imaging and pathology of the second fetus further revealed a thorough view of the underdeveloped globes. Whole exon sequencing (WES) analysis for the parents-fetus trio revealed compound heterozygous mutations of the retinoids acid gene 6 (STRA6). CONCLUSION Detailed examination for intraocular structures including fetal lens, in addition to orbital measurements by ultrasound is crucial for diagnosis of diseases in the A/M spectrum.
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Affiliation(s)
- Chia-Jung Chiang
- National Cheng Kung University Hospital, Department of Obstetrics and Gynecology, Tainan, Taiwan, ROC
| | - Yueh-Chin Cheng
- National Cheng Kung University Hospital, Department of Obstetrics and Gynecology, Tainan, Taiwan, ROC
| | - Yi-Shan Tsai
- National Cheng Kung University Hospital, Department of Radiology, Tainan, Taiwan, ROC
| | - Pao-Lin Kuo
- National Cheng Kung University Hospital, Department of Obstetrics and Gynecology, Tainan, Taiwan, ROC.
| | - Chiung-Hsin Chang
- National Cheng Kung University Hospital, Department of Obstetrics and Gynecology, Tainan, Taiwan, ROC.
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Chesneau B, Aubert-Mucca M, Fremont F, Pechmeja J, Soler V, Isidor B, Nizon M, Dollfus H, Kaplan J, Fares-Taie L, Rozet JM, Busa T, Lacombe D, Naudion S, Amiel J, Rio M, Attie-Bitach T, Lesage C, Thouvenin D, Odent S, Morel G, Vincent-Delorme C, Boute O, Vanlerberghe C, Dieux A, Boussion S, Faivre L, Pinson L, Laffargue F, Le Guyader G, Le Meur G, Prieur F, Lambert V, Laudier B, Cottereau E, Ayuso C, Corton-Pérez M, Bouneau L, Le Caignec C, Gaston V, Jeanton-Scaramouche C, Dupin-Deguine D, Calvas P, Chassaing N, Plaisancié J. First evidence of SOX2 mutations in Peters' anomaly: lessons from molecular screening of 95 patients. Clin Genet 2022; 101:494-506. [PMID: 35170016 DOI: 10.1111/cge.14123] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/10/2022] [Accepted: 02/12/2022] [Indexed: 11/30/2022]
Abstract
Peters' anomaly (PA) is a rare anterior segment dysgenesis characterized by central corneal opacity and irido-lenticulo-corneal adhesions. Several genes are involved in syndromic or isolated PA (B3GLCT, PAX6, PITX3, FOXE3, CYP1B1). Some Copy Number Variations (CNVs) have also been occasionally reported. Despite this genetic heterogeneity, most of patients remain without genetic diagnosis. We retrieved a cohort of 95 individuals with PA and performed genotyping using a combination of Comparative genomic hybridization, whole genome, exome and targeted sequencing of 119 genes associated with ocular development anomalies. Causative genetic defects involving 12 genes and CNVs were identified for 1/3 of patients. Unsurprisingly, B3GLCT and PAX6 were the most frequently implicated genes, respectively in syndromic and isolated PA. Unexpectedly, the third gene involved in our cohort was SOX2, the major gene of micro-anophthalmia. Four unrelated patients with PA (isolated or with microphthalmia) were carrying pathogenic variants in this gene that was never associated with PA before. Here we described the largest cohort of PA patients ever reported. The genetic bases of PA are still to be explored as genetic diagnosis was unavailable for 2/3 of patients. Nevertheless, we showed here for the first time the involvement of SOX2 in PA, offering new evidence for its role in corneal transparency and anterior segment development. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Bertrand Chesneau
- Génétique Médicale, Hôpital Purpan, CHU, Toulouse, France.,Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France
| | | | - Félix Fremont
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France.,Service d'ophtalmologie, Hôpital Purpan, CHU Toulouse, France
| | - Jacmine Pechmeja
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France.,Service d'ophtalmologie, Hôpital Purpan, CHU Toulouse, France
| | - Vincent Soler
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France.,Service d'ophtalmologie, Hôpital Purpan, CHU Toulouse, France
| | - Bertrand Isidor
- Génétique Médicale, Institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Mathilde Nizon
- Génétique Médicale, Institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Hélène Dollfus
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), Hôpitaux Universitaires, Strasbourg, France
| | - Josseline Kaplan
- Laboratoire de Génétique Ophtalmologique, INSERM U1163, Institut Imagine, Paris, France
| | - Lucas Fares-Taie
- Laboratoire de Génétique Ophtalmologique, INSERM U1163, Institut Imagine, Paris, France
| | - Jean-Michel Rozet
- Laboratoire de Génétique Ophtalmologique, INSERM U1163, Institut Imagine, Paris, France
| | - Tiffany Busa
- Génétique Clinique, AP- HM CHU Timone Enfants, Marseille, France
| | - Didier Lacombe
- Département de Génétique Médicale, CHU Bordeaux, Bordeaux, France
| | - Sophie Naudion
- Département de Génétique Médicale, CHU Bordeaux, Bordeaux, France
| | - Jeanne Amiel
- Service de Génétique Médicale, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Marlène Rio
- Service de Génétique Médicale, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Tania Attie-Bitach
- Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, AP-, HP, Paris, France
| | | | | | - Sylvie Odent
- Service de Génétique Clinique, Centre Labellisé pour les Anomalies du Développement Ouest, CHU Rennes; Institut de Génétique et Développement de Rennes, CNRS, UMR 6290, Université de Rennes, ERN ITHACA, France
| | - Godelieve Morel
- Service de Génétique Clinique, Centre Labellisé pour les Anomalies du Développement Ouest, CHU Rennes; Institut de Génétique et Développement de Rennes, CNRS, UMR 6290, Université de Rennes, ERN ITHACA, France
| | | | | | | | | | | | - Laurence Faivre
- Centre de Référence Anomalies du Développement et Syndromes Malformatifs, FHU TRANSLAD, CHU, Dijon, France
| | - Lucile Pinson
- Département de Génétique Médicale, Maladies Rares et Médecine Personnalisée, CHU de Montpellier, France
| | | | | | | | | | - Victor Lambert
- Service d'ophtalmologie, Hôpital Nord, Saint-Etienne, France
| | | | | | - Carmen Ayuso
- Genetics & Genomics Department, Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD-UAM). Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Marta Corton-Pérez
- Genetics & Genomics Department, Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD-UAM). Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | | | | | | | | | | | - Patrick Calvas
- Génétique Médicale, Hôpital Purpan, CHU, Toulouse, France.,Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France
| | - Nicolas Chassaing
- Génétique Médicale, Hôpital Purpan, CHU, Toulouse, France.,Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France
| | - Julie Plaisancié
- Génétique Médicale, Hôpital Purpan, CHU, Toulouse, France.,Centre de Référence pour les Affections Rares en Génétique Ophtalmologique (CARGO), CHU, Toulouse, France.,INSERM U1214, ToNIC, Université Toulouse III, France
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9
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Schittkowski MP, Martius S, Elabbasy M, Knappe S, Guthoff RF. Therapeutic Strategies in 103 Children with Congenital Microphthalmos. Klin Monbl Augenheilkd 2022; 239:64-72. [PMID: 35120379 DOI: 10.1055/a-1685-5002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Congenital microphthalmos can either occur alone (simple microphthalmos) or be associated with other ocular malformations, such as sclerocornea or cataract (complex microphthalmos). As this is a rare condition, there are no uniform recommendations for treatment. MATERIAL AND METHODS Retrospective case series of 103 patients or a total of 114 eyes with congenital microphthalmos, with reporting of age, sex, visual acuity, pupil reaction, axial length, horizontal width of the palpebral fissure, type of therapy performed and complications. RESULTS All patients would have been able to be fitted with a prosthesis primarily. The size of the palpebral fissure depended on the underlying findings: "bilateral microphthalmos" < "microphthalmos and healthy fellow eye" < "microphthalmos and fellow anophthalmos". In order to assess visual (residual) function in an infant in the first weeks or months of life, the pupillary response is of the upmost importance in deciding on therapy, especially in unilateral disease, and as assessed with the indirect light response of the healthy eye. In about half of the cases, conservative prosthetic treatment was sufficient. After the successful initial fitting of a prosthesis, the prosthesis was enlarged according to the ocularist's instructions. If the eye length difference was so large that symmetry could not be achieved even with a double-walled prosthesis, volume filling with retrobulbar implanted self-swelling pellet expanders (osmed GmbH, Ilmenau) was offered. In almost one third of the patients, no surgical therapy or prosthetic treatment was performed. The reason for this was usually the presence of minimal visual function of the microphthalmos - ranging from light perception to hand movements. CONCLUSIONS In the case of visual function of the microphthalmos, surgical measures should not be indicated or only with extreme caution, since the preservation of the existing visual acuity must be regarded as having priority over the cosmetic findings. In cases of asymmetry or underdeveloped palpebral fissure, therapy can be started early in the first year of life without fear of resulting complications.
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Affiliation(s)
- Michael P Schittkowski
- Abteilung Augenheilkunde, Bereich Strabologie, Neuroophthalmologie und okuloplastische Chirurgie, Universitätsmedizin Göttingen, Deutschland
| | - Stefanie Martius
- Klinik und Poliklinik für Augenheilkunde, Universität Rostock, Deutschland
| | - Mohamed Elabbasy
- Abteilung Augenheilkunde, Bereich Strabologie, Neuroophthalmologie und okuloplastische Chirurgie, Universitätsmedizin Göttingen, Deutschland
| | - Steffi Knappe
- Klinik und Poliklinik für Augenheilkunde, Universität Rostock, Deutschland
| | - Rudolf F Guthoff
- Klinik und Poliklinik für Augenheilkunde, Universität Rostock, Deutschland
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10
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Amlie-Wolf L, Bardakjian T, Kopinsky SM, Reis LM, Semina EV, Schneider A. Review of 37 patients with SOX2 pathogenic variants collected by the Anophthalmia/Microphthalmia Clinical Registry and DNA research study. Am J Med Genet A 2022; 188:187-198. [PMID: 34562068 PMCID: PMC9169870 DOI: 10.1002/ajmg.a.62518] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/30/2021] [Accepted: 09/05/2021] [Indexed: 01/03/2023]
Abstract
SOX2 variants and deletions are a common cause of anophthalmia and microphthalmia (A/M). This article presents data from a cohort of patients with SOX2 variants, some of whom have been followed for 20+ years. Medical records from patients enrolled in the A/M Research Registry and carrying SOX2 variants were reviewed. Thirty-seven patients were identified, ranging in age from infant to 30 years old. Eye anomalies were bilateral in 30 patients (81.1%), unilateral in 5 (13.5%), and absent in 2 (5.4%). Intellectual disability was present in all with data available and ranged from mild to profound. Seizures were noted in 18 of 27 (66.6%) patients, usually with abnormal brain MRIs (10/15, 66.7%). Growth issues were reported in 14 of 21 patients (66.7%) and 14 of 19 (73.7%) had gonadotropin deficiency. Genitourinary anomalies were seen in 15 of 19 (78.9%) male patients and 5 of 15 (33.3%) female patients. Patients with SOX2 nucleotide variants, whole gene deletions or translocations are typically affected with bilateral or unilateral microphthalmia and anophthalmia. Other associated features include intellectual disability, seizures, brain anomalies, growth hormone deficiency, gonadotropin deficiency, and genitourinary anomalies. Recommendations for newly diagnosed patients with SOX2 variants include eye exams, MRI of the brain and orbits, endocrine and neurology examinations. Since the clinical spectrum associated with SOX2 alleles has expanded beyond the originally reported phenotypes, we propose a broader term, SOX2-associated disorder, for this condition.
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Affiliation(s)
- Louise Amlie-Wolf
- Einstein Medical Center Philadelphia, West Philadelphia, Pennsylvania, USA
- Nemours Children’s Hospital Delaware, Wilmington, DE, USA
| | - Tanya Bardakjian
- Einstein Medical Center Philadelphia, West Philadelphia, Pennsylvania, USA
- Department of Pediatrics and Children’s Research Institute, Medical College of Wisconsin, Children’s Wisconsin, Milwaukee, Wisconsin, USA
| | - Sarina M. Kopinsky
- Einstein Medical Center Philadelphia, West Philadelphia, Pennsylvania, USA
| | - Linda M. Reis
- Department of Pediatrics and Children’s Research Institute, Medical College of Wisconsin, Children’s Wisconsin, Milwaukee, Wisconsin, USA
| | - Elena V. Semina
- Einstein Medical Center Philadelphia, West Philadelphia, Pennsylvania, USA
- Department of Ophthalmology and Visual Sciences, Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Adele Schneider
- Department of Neurology, Hospital of University of Pennsylvania, 330 South Ninth Street, Philadelphia, PA, USA
- Department of Pediatric Ophthalmology and Ocular Genetics, Wills Eye Hospital, 840 Walnut Street, Philadelphia, PA, USA
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11
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Daich Varela M, Hufnagel RB, Guan B, Blain D, Sapp JC, Gropman AL, Alur R, Johnston JJ, Biesecker LG, Brooks BP. Clinical diagnosis of presumed SOX2 gonadosomatic mosaicism. Ophthalmic Genet 2021; 42:320-325. [PMID: 33719903 PMCID: PMC8154737 DOI: 10.1080/13816810.2021.1888127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Purpose: To describe a family with presumed SOX2 gonadosomatic mosaicism diagnosed upon ophthalmic examination of the proband’s mother. Methods: The family underwent comprehensive ophthalmic and physical examination. Variant detection was performed using trio exome analysis on peripheral leukocyte DNA from blood and saliva samples. Variant segregation analysis was performed using a custom panel NGS sequencing. An identified variant in the SOX2 gene was confirmed in the proband by Sanger sequencing. Results: We report an individual with bilateral microphthalmia, developmental delay, hearing loss, and dysmorphic features. Her mother was found to have asymptomatic forme fruste uveal coloboma affecting her anterior segment. Her father, aunt, and sisters were unaffected. Trio exome sequence analysis showed an apparent de novo heterozygous deletion in the proband, NM_003106.3:c.70_89del, NP_003097.1:p. (Asn24Argfs*65), classified as pathogenic. Testing of the other family members’ peripheral blood and saliva was negative for this variant. The iris transillumination abnormalities in the proband’s mother supports a gonadosomatic mosaicism scenario. Conclusions: The results from this family underscore the importance of performing detailed evaluations of the parents of apparently sporadically affected individuals with heritable ophthalmic disorders. The identification of mildly affected individuals could substantially alter recurrence risks.
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Affiliation(s)
- Malena Daich Varela
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Bin Guan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Delphine Blain
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Julie C Sapp
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, USA
| | - Andrea L Gropman
- Division of Neurogenetics and Developmental Pediatrics, Children's National Hospital, Washington, District of Columbia, USA.,Department of Neurology, George Washington University, Washington, District of Columbia, USA
| | - Ramakrishna Alur
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Jennifer J Johnston
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, USA
| | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health (NIH), Bethesda, Maryland, USA
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12
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Harding P, Toms M, Schiff E, Owen N, Bell S, Lloyd IC, Moosajee M. EPHA2 Segregates with Microphthalmia and Congenital Cataracts in Two Unrelated Families. Int J Mol Sci 2021; 22:2190. [PMID: 33671840 PMCID: PMC7926380 DOI: 10.3390/ijms22042190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/12/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023] Open
Abstract
EPHA2 is a transmembrane tyrosine kinase receptor that, when disrupted, causes congenital and age-related cataracts. Cat-Map reports 22 pathogenic EPHA2 variants associated with congenital cataracts, variable microcornea, and lenticonus, but no previous association with microphthalmia (small, underdeveloped eye, ≥2 standard deviations below normal axial length). Microphthalmia arises from ocular maldevelopment with >90 monogenic causes, and can include a complex ocular phenotype. In this paper, we report two pathogenic EPHA2 variants in unrelated families presenting with bilateral microphthalmia and congenital cataracts. Whole genome sequencing through the 100,000 Genomes Project and cataract-related targeted gene panel testing identified autosomal dominant heterozygous mutations segregating with the disease: (i) missense c.1751C>T, p.(Pro584Leu) and (ii) splice site c.2826-9G>A. To functionally validate pathogenicity, morpholino knockdown of epha2a/epha2b in zebrafish resulted in significantly reduced eye size ± cataract formation. Misexpression of N-cadherin and retained fibre cell nuclei were observed in the developing lens of the epha2b knockdown morphant fish by 3 days post-fertilisation, which indicated a putative mechanism for microphthalmia pathogenesis through disruption of cadherin-mediated adherens junctions, preventing lens maturation and the critical signals stimulating eye growth. This study demonstrates a novel association of EPHA2 with microphthalmia, suggesting further analysis of pathogenic variants in unsolved microphthalmia cohorts may increase molecular diagnostic rates.
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Affiliation(s)
- Philippa Harding
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (P.H.); (M.T.); (N.O.)
| | - Maria Toms
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (P.H.); (M.T.); (N.O.)
- The Francis Crick Institute, London NW1 1AT, UK
| | - Elena Schiff
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (E.S.); (S.B.)
| | - Nicholas Owen
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (P.H.); (M.T.); (N.O.)
| | - Suzannah Bell
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (E.S.); (S.B.)
| | - Ian Christopher Lloyd
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK;
- Manchester Academic Health Sciences Centre, University of Manchester, Manchester, M13 9PT, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (P.H.); (M.T.); (N.O.)
- The Francis Crick Institute, London NW1 1AT, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (E.S.); (S.B.)
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
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13
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Congenital Malformations in Sea Turtles: Puzzling Interplay between Genes and Environment. Animals (Basel) 2021; 11:ani11020444. [PMID: 33567785 PMCID: PMC7915190 DOI: 10.3390/ani11020444] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/28/2022] Open
Abstract
Simple Summary Congenital malformations can lead to embryonic mortality in many species, and sea turtles are no exception. Genetic and/or environmental alterations occur during early development in the embryo, and may produce aberrant phenotypes, many of which are incompatible with life. Causes of malformations are multifactorial; genetic factors may include mutations, chromosomal aberrations, and inbreeding effects, whereas non-genetic factors may include nutrition, hyperthermia, low moisture, radiation, and contamination. It is possible to monitor and control some of these factors (such as temperature and humidity) in nesting beaches, and toxic compounds in feeding areas, which can be transferred to the embryo through their lipophilic properties. In this review, we describe possible causes of different types of malformations observed in sea turtle embryos, as well as some actions that may help reduce embryonic mortality. Abstract The completion of embryonic development depends, in part, on the interplay between genetic factors and environmental conditions, and any alteration during development may affect embryonic genetic and epigenetic regulatory pathways leading to congenital malformations, which are mostly incompatible with life. Oviparous reptiles, such as sea turtles, that produce numerous eggs in a clutch that is buried on the beach provide an opportunity to study embryonic mortality associated with malformations that occur at different times during development, or that prevent the hatchling from emerging from the nest. In sea turtles, the presence of congenital malformations frequently leads to mortality. A few years ago, a detailed study was performed on external congenital malformations in three species of sea turtles from the Mexican Pacific and Caribbean coasts, the hawksbill turtle, Eretmochelys imbricata (n = 23,559 eggs), the green turtle, Chelonia mydas (n = 17,690 eggs), and the olive ridley, Lepidochelys olivacea (n = 20,257 eggs), finding 63 types of congenital malformations, of which 38 were new reports. Of the three species, the olive ridley showed a higher incidence of severe anomalies in the craniofacial region (49%), indicating alterations of early developmental pathways; however, several malformations were also observed in the body, including defects in the carapace (45%) and limbs (33%), as well as pigmentation disorders (20%), indicating that deviations occurred during the middle and later stages of development. Although intrinsic factors (i.e., genetic mutations or epigenetic modifications) are difficult to monitor in the field, some environmental factors (such as the incubation temperature, humidity, and probably the status of feeding areas) are, to some extent, less difficult to monitor and/or control. In this review, we describe the aetiology of different malformations observed in sea turtle embryos, and provide some actions that can reduce embryonic mortality.
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14
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Haug P, Koller S, Maggi J, Lang E, Feil S, Wlodarczyk A, Bähr L, Steindl K, Rohrbach M, Gerth-Kahlert C, Berger W. Whole Exome Sequencing in Coloboma/Microphthalmia: Identification of Novel and Recurrent Variants in Seven Genes. Genes (Basel) 2021; 12:65. [PMID: 33418956 PMCID: PMC7825129 DOI: 10.3390/genes12010065] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/25/2020] [Accepted: 12/31/2020] [Indexed: 12/16/2022] Open
Abstract
Coloboma and microphthalmia (C/M) are related congenital eye malformations, which can cause significant visual impairment. Molecular diagnosis is challenging as the genes associated to date with C/M account for only a small percentage of cases. Overall, the genetic cause remains unknown in up to 80% of patients. High throughput DNA sequencing technologies, including whole-exome sequencing (WES), are therefore a useful and efficient tool for genetic screening and identification of new mutations and novel genes in C/M. In this study, we analyzed the DNA of 19 patients with C/M from 15 unrelated families using singleton WES and data analysis for 307 genes of interest. We identified seven novel and one recurrent potentially disease-causing variants in CRIM1, CHD7, FAT1, PTCH1, PUF60, BRPF1, and TGFB2 in 47% of our families, three of which occurred de novo. The detection rate in patients with ocular and extraocular manifestations (67%) was higher than in patients with an isolated ocular phenotype (46%). Our study highlights the significant genetic heterogeneity in C/M cohorts and emphasizes the diagnostic power of WES for the screening of patients and families with C/M.
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Affiliation(s)
- Patricia Haug
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Elena Lang
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
- Department of Ophthalmology, University Hospital and University of Zurich, 8091 Zurich, Switzerland;
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Agnès Wlodarczyk
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Luzy Bähr
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, 8952 Schlieren, Switzerland;
| | - Marianne Rohrbach
- Division of Metabolism and Children’s Research Centre, University Children’s Hospital Zurich, 8032 Zurich, Switzerland;
| | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital and University of Zurich, 8091 Zurich, Switzerland;
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (P.H.); (S.K.); (J.M.); (E.L.); (S.F.); (A.W.); (L.B.)
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8006 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8006 Zurich, Switzerland
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15
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Harding P, Cunha DL, Moosajee M. Animal and cellular models of microphthalmia. THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:2633004021997447. [PMID: 37181112 PMCID: PMC10032472 DOI: 10.1177/2633004021997447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/02/2021] [Indexed: 05/16/2023]
Abstract
Microphthalmia is a rare developmental eye disorder affecting 1 in 7000 births. It is defined as a small (axial length ⩾2 standard deviations below the age-adjusted mean) underdeveloped eye, caused by disruption of ocular development through genetic or environmental factors in the first trimester of pregnancy. Clinical phenotypic heterogeneity exists amongst patients with varying levels of severity, and associated ocular and systemic features. Up to 11% of blind children are reported to have microphthalmia, yet currently no treatments are available. By identifying the aetiology of microphthalmia and understanding how the mechanisms of eye development are disrupted, we can gain a better understanding of the pathogenesis. Animal models, mainly mouse, zebrafish and Xenopus, have provided extensive information on the genetic regulation of oculogenesis, and how perturbation of these pathways leads to microphthalmia. However, differences exist between species, hence cellular models, such as patient-derived induced pluripotent stem cell (iPSC) optic vesicles, are now being used to provide greater insights into the human disease process. Progress in 3D cellular modelling techniques has enhanced the ability of researchers to study interactions of different cell types during eye development. Through improved molecular knowledge of microphthalmia, preventative or postnatal therapies may be developed, together with establishing genotype-phenotype correlations in order to provide patients with the appropriate prognosis, multidisciplinary care and informed genetic counselling. This review summarises some key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future. Plain language summary Animal and Cellular Models of the Eye Disorder, Microphthalmia (Small Eye) Microphthalmia, meaning a small, underdeveloped eye, is a rare disorder that children are born with. Genetic changes or variations in the environment during the first 3 months of pregnancy can disrupt early development of the eye, resulting in microphthalmia. Up to 11% of blind children have microphthalmia, yet currently no treatments are available. By understanding the genes necessary for eye development, we can determine how disruption by genetic changes or environmental factors can cause this condition. This helps us understand why microphthalmia occurs, and ensure patients are provided with the appropriate clinical care and genetic counselling advice. Additionally, by understanding the causes of microphthalmia, researchers can develop treatments to prevent or reduce the severity of this condition. Animal models, particularly mice, zebrafish and frogs, which can also develop small eyes due to the same genetic/environmental changes, have helped us understand the genes which are important for eye development and can cause birth eye defects when disrupted. Studying a patient's own cells grown in the laboratory can further help researchers understand how changes in genes affect their function. Both animal and cellular models can be used to develop and test new drugs, which could provide treatment options for patients living with microphthalmia. This review summarises the key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future.
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Affiliation(s)
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath
Street, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
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16
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Auer JMT, Stoddart JJ, Christodoulou I, Lima A, Skouloudaki K, Hall HN, Vukojević V, Papadopoulos DK. Of numbers and movement - understanding transcription factor pathogenesis by advanced microscopy. Dis Model Mech 2020; 13:dmm046516. [PMID: 33433399 PMCID: PMC7790199 DOI: 10.1242/dmm.046516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Transcription factors (TFs) are life-sustaining and, therefore, the subject of intensive research. By regulating gene expression, TFs control a plethora of developmental and physiological processes, and their abnormal function commonly leads to various developmental defects and diseases in humans. Normal TF function often depends on gene dosage, which can be altered by copy-number variation or loss-of-function mutations. This explains why TF haploinsufficiency (HI) can lead to disease. Since aberrant TF numbers frequently result in pathogenic abnormalities of gene expression, quantitative analyses of TFs are a priority in the field. In vitro single-molecule methodologies have significantly aided the identification of links between TF gene dosage and transcriptional outcomes. Additionally, advances in quantitative microscopy have contributed mechanistic insights into normal and aberrant TF function. However, to understand TF biology, TF-chromatin interactions must be characterised in vivo, in a tissue-specific manner and in the context of both normal and altered TF numbers. Here, we summarise the advanced microscopy methodologies most frequently used to link TF abundance to function and dissect the molecular mechanisms underlying TF HIs. Increased application of advanced single-molecule and super-resolution microscopy modalities will improve our understanding of how TF HIs drive disease.
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Affiliation(s)
- Julia M T Auer
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | - Jack J Stoddart
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | | | - Ana Lima
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | | | - Hildegard N Hall
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh EH4 1XU, UK
| | - Vladana Vukojević
- Center for Molecular Medicine (CMM), Department of Clinical Neuroscience, Karolinska Institutet, 17176 Stockholm, Sweden
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17
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Taha Najim R, Topa A, Jugård Y, Casslén B, Odersjö M, Andersson Grönlund M. Children and young adults with anophthalmia and microphthalmia: Diagnosis and Management. Acta Ophthalmol 2020; 98:848-858. [PMID: 32436650 DOI: 10.1111/aos.14427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 03/11/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE Congenital anophthalmia (A) and microphthalmia (M) are rare developmental defects, which could be isolated or syndromic. Our objective was to describe a cohort of children and young adults with A/M treated with ocular prosthesis, emphasizing clinical features, diagnosis, treatment, and follow-up. METHODS Eighteen individuals (10 female) with unilateral A (n = 3) and M (n = 15) with a mean age of 9.5 years (range 0.8-31.8) and treated with ocular prosthesis were included. Data on medical history, clinical examinations and management of ocular prosthesis were collected. Genetic screening with microarray and whole-exome sequencing targeting 121 A/M-related genes was performed. RESULTS A/M appeared isolated (seven cases) or as part of a syndromic condition (11 cases). In 4/16 patients, mutations were detected in TFAP2A, CHD7, FOXE3 and BCOR-genes. In one patient, a possibly causal microdeletion 10q11 was shown. Associated ocular anomalies such as cataract and cysts were found in 16 (89%) of the A/M eyes, and in nine (50%) ophthalmological findings were found in the fellow eyes. The median ages at which the conformer and ocular prosthesis first were initiated were 7.8 months and 1.5 years. 16/17 patients fulfilled satisfactory orbital growth and cosmetic results when treated with ocular prosthesis from an early age. CONCLUSION Based upon our findings, a multidisciplinary approach, including genetic assessment, is necessary to cover all aspects of A/M. Imaging, ultrasound and visual evoked potentials should be included. Early management is crucial for the outcome, in terms of non-ocular findings, vision in the fellow eye, and for facial cosmetic development.
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Affiliation(s)
- Rezhna Taha Najim
- Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Alexandra Topa
- Region Västra Götaland Department of Clinical Genetics and Genomics Sahlgrenska University Hospital Gothenburg Sweden
- Department of Laboratory Medicine Institute of Biomedicine Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Ylva Jugård
- Region Västra Götaland Department of Ophthalmology Hospital of Södra Älvsborg Borås Sweden
| | - Beatrice Casslén
- Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Marie Odersjö
- Region Västra Götaland Department of Otolaryngology Sahlgrenska University Hospital Gothenburg Sweden
| | - Marita Andersson Grönlund
- Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
- Region Västra Götaland Department of Ophthalmology Sahlgrenska University Hospital Mölndal Sweden
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18
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Groot AL, Kuijten MM, Remmers J, Gilani A, Mourits DL, Kraal‐Biezen E, de Graaf P, Zwijnenburg PJ, Moll AC, Tan S, Saeed P, Hartong DT. Classification for treatment urgency for the microphthalmia/anophthalmia spectrum using clinical and biometrical characteristics. Acta Ophthalmol 2020; 98:514-520. [PMID: 32100474 PMCID: PMC7497250 DOI: 10.1111/aos.14364] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 01/10/2020] [Indexed: 01/14/2023]
Abstract
PURPOSE Current clinical classifications do not distinguish between the severity of the MICrophthalmia/Anophthalmia (MICA) spectrum with regard to treatment urgency. We aim to provide parameters for distinguishing mild, moderate and severe MICA using clinical and biometrical characteristics. METHODS We performed a single-centre, cross-sectional analysis of prospective cohort of 58 MICA children from September 2013 to February 2018 seen at the Amsterdam University Medical Center, The Netherlands. All patients with a visible underdeveloped globe were included. We performed full ophthalmic evaluation including horizontal palpebral fissure length, axial length by ultrasound and/or MRI measurements, paediatric and genetic evaluation. Cases were subdivided based on clinical characteristics. Biometrical data were used to calculate the relative axial length (rAL) and the relative horizontal palpebral fissure length (rHPF) compared with the healthy contralateral eye for unilateral cases. RESULTS In previously untreated patients, a strong correlation exists between rAL and rHPF, distinguishing between severe, moderate and mild subjects using rAL of 0-45%, 45-75% and 75%-100%, respectively. Clinical subgroups were randomly dispersed throughout the scatterplot. CONCLUSION Current classifications lack clinical implications for MICA patients. We suggest measuring eyelid length and axial length to classify the severity and determine treatment strategy. The 'severe' group has obvious asymmetry and abnormal socket configuration for which therapy should quickly be initiated; the 'moderately' affected group has normal socket anatomy with a microphthalmic eye with disturbing asymmetry for which treatment should be initiated within months of development; the 'mild' group has a slightly smaller axial length or less obvious eyelid asymmetry for which reconstructive correction is possible, but expansive conformer treatment is unnecessary.
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Affiliation(s)
- Annabel L.W. Groot
- Department of OphthalmologyAmsterdam Orbital CenterAmsterdam UMCUniversity of AmsterdamAmsterdamNetherlands,Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Maayke M.P. Kuijten
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Jelmer Remmers
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Asra Gilani
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Daphne L. Mourits
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Elke Kraal‐Biezen
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Pim de Graaf
- Department of Radiology and Nuclear MedicineAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Petra J. Zwijnenburg
- Department of Clinical GeneticsAmsterdam University Medical CenterAmsterdamThe Netherlands
| | - Annette C. Moll
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Stevie Tan
- Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Peerooz Saeed
- Department of OphthalmologyAmsterdam Orbital CenterAmsterdam UMCUniversity of AmsterdamAmsterdamNetherlands,Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
| | - Dyonne T. Hartong
- Department of OphthalmologyAmsterdam Orbital CenterAmsterdam UMCUniversity of AmsterdamAmsterdamNetherlands,Department of OphthalmologyAmsterdam UMCVrije Universiteit AmsterdamAmsterdamNetherlands
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Second-tier trio exome sequencing after negative solo clinical exome sequencing: an efficient strategy to increase diagnostic yield and decipher molecular bases in undiagnosed developmental disorders. Hum Genet 2020; 139:1381-1390. [PMID: 32399599 DOI: 10.1007/s00439-020-02178-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023]
Abstract
Developmental disorders (DD), characterized by malformations/dysmorphism and/or intellectual disability, affecting around 3% of worldwide population, are mostly linked to genetic anomalies. Despite clinical exome sequencing (cES) centered on genes involved in human genetic disorders, the majority of patients affected by DD remain undiagnosed after solo-cES. Trio-based strategy is expected to facilitate variant selection thanks to rapid parental segregation. We performed a second step trio-ES (not only focusing on genes involved in human disorders) analysis in 70 patients with negative results after solo-cES. All candidate variants were shared with a MatchMaking exchange system to identify additional patients carrying variants in the same genes and with similar phenotype. In 18/70 patients (26%), we confirmed causal implication of nine OMIM-morbid genes and identified nine new strong candidate genes (eight de novo and one compound heterozygous variants). These nine new candidate genes were validated through the identification of patients with similar phenotype and genotype thanks to data sharing. Moreover, 11 genes harbored variants of unknown significance in 10/70 patients (14%). In DD, a second step trio-based ES analysis appears an efficient strategy in diagnostic and translational research to identify highly candidate genes and improve diagnostic yield.
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20
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Eintracht J, Corton M, FitzPatrick D, Moosajee M. CUGC for syndromic microphthalmia including next-generation sequencing-based approaches. Eur J Hum Genet 2020; 28:679-690. [PMID: 31896778 PMCID: PMC7171178 DOI: 10.1038/s41431-019-0565-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 01/29/2023] Open
Affiliation(s)
| | - Marta Corton
- Department of Genetics, IIS-University Hospital Fundación Jiménez Díaz-CIBERER, Madrid, Spain
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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21
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Harding P, Brooks BP, FitzPatrick D, Moosajee M. Anophthalmia including next-generation sequencing-based approaches. Eur J Hum Genet 2020; 28:388-398. [PMID: 31358957 PMCID: PMC7029013 DOI: 10.1038/s41431-019-0479-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/06/2019] [Accepted: 07/16/2019] [Indexed: 11/09/2022] Open
Abstract
Name of the disease (synonyms) See Table 1, Column 1-"Name of disease" and Column 2-"Alternative names". OMIM# of the disease See Table 1, Column 3-"OMIM# of the disease". Name of the analysed genes or DNA/chromosome segments and OMIM# of the gene(s) Core genes (irrespective of being tested by Sanger sequencing or next-generation sequencing): See Table 1, Column 4-"Cytogenetic location", Column 5-"Associated gene(s)" and Column 6-"OMIM# of associated gene(s)". Additional genes (if tested by next-generation sequencing, including Whole exome/genome sequencing and panel sequencing): See Table 2, Column 1-"Gene", Column 2-"Alternative names", Column 3-"OMIM# of gene" and Column 4-"Cytogenetic location". Review of the analytical and clinical validity as well as of the clinical utility of DNA-based testing for mutations in the gene(s) in diagnostic, predictive and prenatal settings, and for risk assessment in relatives.
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Affiliation(s)
| | - Brian P Brooks
- Ophthalmic Genetics & Visual Function Branch, National Eye Institute, Bethesda, MD, USA
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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22
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George A, Cogliati T, Brooks BP. Genetics of syndromic ocular coloboma: CHARGE and COACH syndromes. Exp Eye Res 2020; 193:107940. [PMID: 32032630 DOI: 10.1016/j.exer.2020.107940] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 02/07/2023]
Abstract
Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed.
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Affiliation(s)
- Aman George
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Tiziana Cogliati
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA.
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23
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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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24
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Sirbu IO, Chiş AR, Moise AR. Role of carotenoids and retinoids during heart development. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158636. [PMID: 31978553 DOI: 10.1016/j.bbalip.2020.158636] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 02/08/2023]
Abstract
The nutritional requirements of the developing embryo are complex. In the case of dietary vitamin A (retinol, retinyl esters and provitamin A carotenoids), maternal derived nutrients serve as precursors to signaling molecules such as retinoic acid, which is required for embryonic patterning and organogenesis. Despite variations in the composition and levels of maternal vitamin A, embryonic tissues need to generate a precise amount of retinoic acid to avoid congenital malformations. Here, we summarize recent findings regarding the role and metabolism of vitamin A during heart development and we survey the association of genes known to affect retinoid metabolism or signaling with various inherited disorders. A better understanding of the roles of vitamin A in the heart and of the factors that affect retinoid metabolism and signaling can help design strategies to meet nutritional needs and to prevent birth defects and disorders associated with altered retinoid metabolism. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Ioan Ovidiu Sirbu
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania; Timisoara Institute of Complex Systems, V. Lucaciu 18, 300044 Timisoara, Romania.
| | - Aimée Rodica Chiş
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania
| | - Alexander Radu Moise
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada; Department of Chemistry and Biochemistry, Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON P3E 2C6, Canada.
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25
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Apam-Garduño D, Cortés-González V, Quintana-Fernández L, Martínez-Anaya D, Pérez-Vera P, Villanueva-Mendoza C. The relevance of the cytogenetic analysis in syndromic microphthalmia/anophthalmia. Ophthalmic Genet 2019; 40:584-587. [PMID: 31809626 DOI: 10.1080/13816810.2019.1698618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- David Apam-Garduño
- Genetics, Hospital "Dr. Luis Sánchez Bulnes" Asociación para Evitar la Ceguera en México, Mexico
| | - Vianney Cortés-González
- Genetics, Hospital "Dr. Luis Sánchez Bulnes" Asociación para Evitar la Ceguera en México, Mexico
| | - Luis Quintana-Fernández
- Ophthalmology, Hospital "Dr. Luis Sánchez Bulnes" Asociación para Evitar la Ceguera en México, Mexico
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26
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Kaukonen M, Woods S, Ahonen S, Lemberg S, Hellman M, Hytönen MK, Permi P, Glaser T, Lohi H. Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease. Cell Rep 2019; 23:2643-2652. [PMID: 29847795 PMCID: PMC6546432 DOI: 10.1016/j.celrep.2018.04.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/16/2018] [Accepted: 04/26/2018] [Indexed: 01/20/2023] Open
Abstract
Maternally skewed transmission of traits has been associated with genomic imprinting and oocyte-derived mRNA. We report canine congenital eye malformations, caused by an amino acid deletion (K12del) near the N terminus of retinol-binding protein (RBP4). The disease is only expressed when both dam and offspring are deletion homozygotes. RBP carries vitamin A (retinol) from hepatic stores to peripheral tissues, including the placenta and developing eye, where it is required to synthesize retinoic acid. Gestational vitamin A deficiency is a known risk factor for ocular birth defects. The K12del mutation disrupts RBP folding in vivo, decreasing its secretion from hepatocytes to serum. The maternal penetrance effect arises from an impairment in the sequential transfer of retinol across the placenta, via RBP encoded by maternal and fetal genomes. Our results demonstrate a mode of recessive maternal inheritance, with a physiological basis, and they extend previous observations on dominant-negative RBP4 alleles in humans.
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Affiliation(s)
- Maria Kaukonen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Sean Woods
- Department of Cell Biology and Human Anatomy, University of California, Davis School of Medicine, Davis, CA 95616, USA
| | - Saija Ahonen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Seppo Lemberg
- Department of Eye Diseases, Helsinki University Hospital, 00029 The Hospital District of Helsinki and Uusimaa, Finland
| | - Maarit Hellman
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Marjo K Hytönen
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland
| | - Perttu Permi
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland; Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California, Davis School of Medicine, Davis, CA 95616, USA.
| | - Hannes Lohi
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland; Research Programs Unit, Molecular Neurology, University of Helsinki, 00014 Helsinki, Finland; The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland.
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27
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Harding P, Moosajee M. The Molecular Basis of Human Anophthalmia and Microphthalmia. J Dev Biol 2019; 7:jdb7030016. [PMID: 31416264 PMCID: PMC6787759 DOI: 10.3390/jdb7030016] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 12/16/2022] Open
Abstract
Human eye development is coordinated through an extensive network of genetic signalling pathways. Disruption of key regulatory genes in the early stages of eye development can result in aborted eye formation, resulting in an absent eye (anophthalmia) or a small underdeveloped eye (microphthalmia) phenotype. Anophthalmia and microphthalmia (AM) are part of the same clinical spectrum and have high genetic heterogeneity, with >90 identified associated genes. By understanding the roles of these genes in development, including their temporal expression, the phenotypic variation associated with AM can be better understood, improving diagnosis and management. This review describes the genetic and structural basis of eye development, focusing on the function of key genes known to be associated with AM. In addition, we highlight some promising avenues of research involving multiomic approaches and disease modelling with induced pluripotent stem cell (iPSC) technology, which will aid in developing novel therapies.
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Affiliation(s)
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, 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.
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28
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Nedelec B, Rozet JM, Fares Taie L. Genetic architecture of retinoic-acid signaling-associated ocular developmental defects. Hum Genet 2019; 138:937-955. [DOI: 10.1007/s00439-019-02052-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022]
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29
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Wang S, Moise AR. Recent insights on the role and regulation of retinoic acid signaling during epicardial development. Genesis 2019; 57:e23303. [PMID: 31066193 PMCID: PMC6682438 DOI: 10.1002/dvg.23303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 12/18/2022]
Abstract
The vitamin A metabolite, retinoic acid, carries out essential and conserved roles in vertebrate heart development. Retinoic acid signals via retinoic acid receptors (RAR)/retinoid X receptors (RXRs) heterodimers to induce the expression of genes that control cell fate specification, proliferation, and differentiation. Alterations in retinoic acid levels are often associated with congenital heart defects. Therefore, embryonic levels of retinoic acid need to be carefully regulated through the activity of enzymes, binding proteins and transporters involved in vitamin A metabolism. Here, we review evidence of the complex mechanisms that control the fetal uptake and synthesis of retinoic acid from vitamin A precursors. Next, we highlight recent evidence of the role of retinoic acid in orchestrating myocardial compact zone growth and coronary vascular development.
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Affiliation(s)
- Suya Wang
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Alexander R. Moise
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada
- Departments of Chemistry and Biochemistry, and Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON, P3E 2C6 Canada
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA
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30
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Ohuchi H, Sato K, Habuta M, Fujita H, Bando T. Congenital eye anomalies: More mosaic than thought? Congenit Anom (Kyoto) 2019; 59:56-73. [PMID: 30039880 DOI: 10.1111/cga.12304] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/13/2022]
Abstract
The eye is a sensory organ that primarily captures light and provides the sense of sight, as well as delivering non-visual light information involving biological rhythms and neurophysiological activities to the brain. Since the early 1990s, rapid advances in molecular biology have enabled the identification of developmental genes, genes responsible for human congenital diseases, and relevant genes of mutant animals with various anomalies. In this review, we first look at the development of the eye, and we highlight seminal reports regarding archetypal gene defects underlying three developmental ocular disorders in humans: (1) holoprosencephaly (HPE), with cyclopia being exhibited in the most severe cases; (2) microphthalmia, anophthalmia, and coloboma (MAC) phenotypes; and (3) anterior segment dysgenesis (ASDG), known as Peters anomaly and its related disorders. The recently developed methods, such as next-generation sequencing and genome editing techniques, have aided the discovery of gene mutations in congenital eye diseases and gene functions in normal eye development. Finally, we discuss Pax6-genome edited mosaic eyes and propose that somatic mosaicism in developmental gene mutations should be considered a causal factor for variable phenotypes, sporadic cases, and de novo mutations in human developmental disorders.
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Affiliation(s)
- Hideyo Ohuchi
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keita Sato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Munenori Habuta
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hirofumi Fujita
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Tetsuya Bando
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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31
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Johnston JJ, Williamson KA, Chou CM, Sapp JC, Ansari M, Chapman HM, Cooper DN, Dabir T, Dudley JN, Holt RJ, Ragge NK, Schäffer AA, Sen SK, Slavotinek AM, FitzPatrick DR, Glaser TM, Stewart F, Black GC, Biesecker LG. NAA10 polyadenylation signal variants cause syndromic microphthalmia. J Med Genet 2019; 56:444-452. [PMID: 30842225 DOI: 10.1136/jmedgenet-2018-105836] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/21/2019] [Accepted: 01/25/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND A single variant in NAA10 (c.471+2T>A), the gene encoding N-acetyltransferase 10, has been associated with Lenz microphthalmia syndrome. In this study, we aimed to identify causative variants in families with syndromic X-linked microphthalmia. METHODS Three families, including 15 affected individuals with syndromic X-linked microphthalmia, underwent analyses including linkage analysis, exome sequencing and targeted gene sequencing. The consequences of two identified variants in NAA10 were evaluated using quantitative PCR and RNAseq. RESULTS Genetic linkage analysis in family 1 supported a candidate region on Xq27-q28, which included NAA10. Exome sequencing identified a hemizygous NAA10 polyadenylation signal (PAS) variant, chrX:153,195,397T>C, c.*43A>G, which segregated with the disease. Targeted sequencing of affected males from families 2 and 3 identified distinct NAA10 PAS variants, chrX:g.153,195,401T>C, c.*39A>G and chrX:g.153,195,400T>C, c.*40A>G. All three variants were absent from gnomAD. Quantitative PCR and RNAseq showed reduced NAA10 mRNA levels and abnormal 3' UTRs in affected individuals. Targeted sequencing of NAA10 in 376 additional affected individuals failed to identify variants in the PAS. CONCLUSION These data show that PAS variants are the most common variant type in NAA10-associated syndromic microphthalmia, suggesting reduced RNA is the molecular mechanism by which these alterations cause microphthalmia/anophthalmia. We reviewed recognised variants in PAS associated with Mendelian disorders and identified only 23 others, indicating that NAA10 harbours more than 10% of all known PAS variants. We hypothesise that PAS in other genes harbour unrecognised pathogenic variants associated with Mendelian disorders. The systematic interrogation of PAS could improve genetic testing yields.
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Affiliation(s)
- Jennifer J Johnston
- National Institutes of Health, National Human Genome Research Institute, Bethesda, Maryland, USA
| | | | - Christopher M Chou
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Department of Emergency Medicine, The Permanente Medical Group (TPMG), Roseville/Sacramento, California, USA
| | - Julie C Sapp
- National Institutes of Health, National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Morad Ansari
- MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.,DNA Diagnostic Laboratory, South East Scotland Regional Genetics Services, Western General Hospital, Edinburgh, UK
| | - Heather M Chapman
- Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, USA
| | - David N Cooper
- Institute of Medical Genetics, Cardiff University, Cardiff, UK
| | - Tabib Dabir
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, UK
| | - Jeffrey N Dudley
- National Institutes of Health, National Human Genome Research Institute, Bethesda, Maryland, USA
| | - Richard J Holt
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK
| | - Nicola K Ragge
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.,West Midlands Regional Clinical Genetics Service and Birmingham Health Partners, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Alejandro A Schäffer
- Computational Biology Branch, National Center for Biotechnology Information, Bethesda, Maryland, USA.,Cancer Data Science Laboratory, National Cancer Institute, Bethesda, Maryland, USA
| | - Shurjo K Sen
- Leidos Biomedical Research, Inc, Basic Science Program, Cancer & Inflammation, Frederick National Laboratory for Cancer Research, Bethesda, Maryland, USA
| | - Anne M Slavotinek
- Department of Pediatrics and Institute for Human Genetics, University of California San Francisco, San Francisco, California, USA
| | | | - Thomas M Glaser
- Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, USA
| | - Fiona Stewart
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, UK
| | - Graeme Cm Black
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,St Mary's Hospital, Manchester Centre for Genomic Medicine, Manchester Academic Health Sciences Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Leslie G Biesecker
- National Institutes of Health, National Human Genome Research Institute, Bethesda, Maryland, USA
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32
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Genetics of anophthalmia and microphthalmia. Part 1: Non-syndromic anophthalmia/microphthalmia. Hum Genet 2019; 138:799-830. [PMID: 30762128 DOI: 10.1007/s00439-019-01977-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/30/2019] [Indexed: 12/22/2022]
Abstract
Eye formation is the result of coordinated induction and differentiation processes during embryogenesis. Disruption of any one of these events has the potential to cause ocular growth and structural defects, such as anophthalmia and microphthalmia (A/M). A/M can be isolated or occur with systemic anomalies, when they may form part of a recognizable syndrome. Their etiology includes genetic and environmental factors; several hundred genes involved in ocular development have been identified in humans or animal models. In humans, around 30 genes have been repeatedly implicated in A/M families, although many other genes have been described in single cases or families, and some genetic syndromes include eye anomalies occasionally as part of a wider phenotype. As a result of this broad genetic heterogeneity, with one or two notable exceptions, each gene explains only a small percentage of cases. Given the overlapping phenotypes, these genes can be most efficiently tested on panels or by whole exome/genome sequencing for the purposes of molecular diagnosis. However, despite whole exome/genome testing more than half of patients currently remain without a molecular diagnosis. The proportion of undiagnosed cases is even higher in those individuals with unilateral or milder phenotypes. Furthermore, even when a strong gene candidate is available for a patient, issues of incomplete penetrance and germinal mosaicism make diagnosis and genetic counseling challenging. In this review, we present the main genes implicated in non-syndromic human A/M phenotypes and, for practical purposes, classify them according to the most frequent or predominant phenotype each is associated with. Our intention is that this will allow clinicians to rank and prioritize their molecular analyses and interpretations according to the phenotypes of their patients.
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33
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Gergics P. Pituitary Transcription Factor Mutations Leading to Hypopituitarism. EXPERIENTIA SUPPLEMENTUM (2012) 2019; 111:263-298. [PMID: 31588536 DOI: 10.1007/978-3-030-25905-1_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Congenital pituitary hormone deficiency is a disabling condition. It is part of a spectrum of disorders including craniofacial midline developmental defects ranging from holoprosencephaly through septo-optic dysplasia to combined and isolated pituitary hormone deficiency. The first genes discovered in the human disease were based on mouse models of dwarfism due to mutations in transcription factor genes. High-throughput DNA sequencing technologies enabled clinicians and researchers to find novel genetic causes of hypopituitarism for the more than three quarters of patients without a known genetic diagnosis to date. Transcription factor (TF) genes are at the forefront of the functional analysis of novel variants of unknown significance due to the relative ease in in vitro testing in a research lab. Genetic testing in hypopituitarism is of high importance to the individual and their family to predict phenotype composition, disease progression and to avoid life-threatening complications such as secondary adrenal insufficiency.This chapter aims to highlight our current understanding about (1) the contribution of TF genes to pituitary development (2) the diversity of inheritance and phenotype features in combined and select isolated pituitary hormone deficiency and (3) provide an initial assessment on how to approach variants of unknown significance in human hypopituitarism. Our better understanding on how transcription factor gene variants lead to hypopituitarism is a meaningful step to plan advanced therapies to specific genetic changes in the future.
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Affiliation(s)
- Peter Gergics
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.
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34
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35
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Matías-Pérez D, García-Montaño LA, Cruz-Aguilar M, García-Montalvo IA, Nava-Valdéz J, Barragán-Arevalo T, Villanueva-Mendoza C, Villarroel CE, Guadarrama-Vallejo C, la Cruz RVD, Chacón-Camacho O, Zenteno JC. Identification of novel pathogenic variants and novel gene-phenotype correlations in Mexican subjects with microphthalmia and/or anophthalmia by next-generation sequencing. J Hum Genet 2018; 63:1169-1180. [PMID: 30181649 DOI: 10.1038/s10038-018-0504-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/21/2018] [Accepted: 08/03/2018] [Indexed: 01/01/2023]
Abstract
Severe congenital eye malformations, particularly microphthalmia and anophthalmia, are one of the main causes of visual handicap worldwide. They can arise from multifactorial, chromosomal, or monogenic factors and can be associated with extensive clinical variability. Genetic analysis of individuals with these defects has allowed the recognition of dozens of genes whose mutations lead to disruption of normal ocular embryonic development. Recent application of next generation sequencing (NGS) techniques for genetic screening of patients with congenital eye defects has greatly improved the recognition of monogenic cases. In this study, we applied clinical exome NGS to a group of 14 Mexican patients (including 7 familial and 7 sporadic cases) with microphthalmia and/or anophthalmia. Causal or likely causal pathogenic variants were demonstrated in ~60% (8 out of 14 patients) individuals. Seven out of 8 different identified mutations occurred in well-known microphthalmia/anophthalmia genes (OTX2, VSX2, MFRP, VSX1) or in genes associated with syndromes that include ocular defects (CHD7, COL4A1) (including two instances of CHD7 pathogenic variants). A single pathogenic variant was identified in PIEZO2, a gene that was not previously associated with isolated ocular defects. NGS efficiently identified the genetic etiology of microphthalmia/anophthalmia in ~60% of cases included in this cohort, the first from Mexican origin analyzed to date. The molecular defects identified through clinical exome sequencing in this study expands the phenotypic spectra of CHD7-associated disorders and implicate PIEZO2 as a candidate gene for major eye developmental defects.
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Affiliation(s)
| | - Leopoldo A García-Montaño
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Marisa Cruz-Aguilar
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | | | - Jessica Nava-Valdéz
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Tania Barragán-Arevalo
- Department of Human Genetics, National Institute of Pediatrics of Mexico, Mexico City, Mexico
| | - Cristina Villanueva-Mendoza
- Department of Genetics, Hospital "Dr. Luis Sanchez Bulnes", Asociación Para Evitar la Ceguera en México, Mexico City, Mexico
| | - Camilo E Villarroel
- Department of Human Genetics, National Institute of Pediatrics of Mexico, Mexico City, Mexico
| | - Clavel Guadarrama-Vallejo
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Rocío Villafuerte-de la Cruz
- Ciencias Basicas, Escuela de Medicina, Instituto Tecnológico y de Estudios Superiores de Monterrey, Monterrey, NL, Mexico
| | - Oscar Chacón-Camacho
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics-Research Unit, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico. .,Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico.
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36
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Patel N, Khan AO, Alsahli S, Abdel-Salam G, Nowilaty SR, Mansour AM, Nabil A, Al-Owain M, Sogati S, Salih MA, Kamal AM, Alsharif H, Alsaif HS, Alzahrani SS, Abdulwahab F, Ibrahim N, Hashem M, Faquih T, Shah ZA, Abouelhoda M, Monies D, Dasouki M, Shaheen R, Wakil SM, Aldahmesh MA, Alkuraya FS. Genetic investigation of 93 families with microphthalmia or posterior microphthalmos. Clin Genet 2018; 93:1210-1222. [PMID: 29450879 DOI: 10.1111/cge.13239] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 01/24/2023]
Abstract
Microphthalmia is a developmental eye defect that is highly variable in severity and in its potential for systemic association. Despite the discovery of many disease genes in microphthalmia, at least 50% of patients remain undiagnosed genetically. Here, we describe a cohort of 147 patients (93 families) from our highly consanguineous population with various forms of microphthalmia (including the distinct entity of posterior microphthalmos) that were investigated using a next-generation sequencing multi-gene panel (i-panel) as well as whole exome sequencing and molecular karyotyping. A potentially causal mutation was identified in the majority of the cohort with microphthalmia (61%) and posterior microphthalmos (82%). The identified mutations (55 point mutations, 15 of which are novel) spanned 24 known disease genes, some of which have not or only very rarely been linked to microphthalmia (PAX6, SLC18A2, DSC3 and CNKSR1). Our study has also identified interesting candidate variants in 2 genes that have not been linked to human diseases (MYO10 and ZNF219), which we present here as novel candidates for microphthalmia. In addition to revealing novel phenotypic aspects of microphthalmia, this study expands its allelic and locus heterogeneity and highlights the need for expanded testing of patients with this condition.
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Affiliation(s)
- N Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - A O Khan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - S Alsahli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | | | - S R Nowilaty
- Vitreo-retinal Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - A M Mansour
- Department of Ophthalmology, American University of Beirut, Beirut, Lebanon
| | - A Nabil
- Human Genetics Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - M Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - S Sogati
- Department of Medical Genetics, King Fahad General Hospital, Jeddah, Saudi Arabia
| | - M A Salih
- Division of Pediatrics Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - A M Kamal
- Department of Ophthalmology, Cairo University, Cairo, Egypt
| | - H Alsharif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - H S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - S S Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - F Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - N Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - M Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - T Faquih
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Z A Shah
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - M Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - D Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - M Dasouki
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - R Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - S M Wakil
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - M A Aldahmesh
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - F S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.,Saudi Human Genome Project, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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37
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Vidya NG, Rajkumar S, Vasavada AR. Genetic investigation of ocular developmental genes in 52 patients with anophthalmia/microphthalmia. Ophthalmic Genet 2018; 39:344-352. [DOI: 10.1080/13816810.2018.1436184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Nair Gopinathan Vidya
- Department of Molecular Genetics & Biochemistry, Iladevi Cataract & IOL Research Centre, Ahmedabad, India
- Research scholar, Manipal University, Karnataka
| | - Sankaranarayanan Rajkumar
- Department of Molecular Genetics & Biochemistry, Iladevi Cataract & IOL Research Centre, Ahmedabad, India
| | - Abhay R. Vasavada
- Department of Cataract and Refractive Surgery, Raghudeep Eye Hospital, Ahmedabad, India
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38
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Errichiello E, Gorgone C, Giuliano L, Iadarola B, Cosentino E, Rossato M, Kurtas NE, Delledonne M, Mattina T, Zuffardi O. SOX2: Not always eye malformations. Severe genital but no major ocular anomalies in a female patient with the recurrent c.70del20 variant. Eur J Med Genet 2018; 61:335-340. [PMID: 29371155 DOI: 10.1016/j.ejmg.2018.01.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/29/2017] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
Abstract
SOX2 variants have been identified in multiple patients with severe ocular anomalies and pituitary dysfunction, in addition to various systemic features. We investigated a 26-year-old female patient suffering from spastic paraparesis, hypoplasia of corpus callosum, hypogonadotropic hypogonadism (HH) and intellectual disability, who was monitored for over 20 years, allowing a detailed genotype-phenotype correlation along time. Whole exome sequencing on the patient and her relatives identified a de novo SOX2 c.70del20 variant, which has been frequently reported in individuals with SOX2-related anophthalmia. Importantly, our patient lacked major ocular phenotype but showed vaginal agenesis, a feature never reported before. Although the involvement of male urogenital tract (cryptorchidism, hypospadias, small penis), is a well known consequence of SOX2 variants, their effect on the female genitalia has never been properly addressed, even considering the paradoxical female excess of SOX2 cases in the literature. Our findings emphasize the importance of testing for SOX2 variants in individuals with HH and genital anomalies even though anophthalmia or microphthalmia are not observed. Moreover, our case strengthens the role of SOX2 as a master regulator of female gonadal differentiation, as widely demonstrated for other SOX genes related to 46, XX sex reversal, such as SOX3 and SOX9.
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Affiliation(s)
| | - Cristina Gorgone
- Speciality School of Medical Genetics, University of Catania, Catania, Italy
| | - Loretta Giuliano
- Department of Medical and Surgical Sciences and Advanced Technologies "G.F. Ingrassia", University of Catania, Catania, Italy
| | - Barbara Iadarola
- Department of Biotechnologies, University of Verona, Verona, Italy
| | | | - Marzia Rossato
- Department of Biotechnologies, University of Verona, Verona, Italy
| | | | | | - Teresa Mattina
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Orsetta Zuffardi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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39
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BRD4 interacts with NIPBL and BRD4 is mutated in a Cornelia de Lange-like syndrome. Nat Genet 2018; 50:329-332. [PMID: 29379197 DOI: 10.1038/s41588-018-0042-y] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 12/29/2017] [Indexed: 11/08/2022]
Abstract
We found that the clinical phenotype associated with BRD4 haploinsufficiency overlapped with that of Cornelia de Lange syndrome (CdLS), which is most often caused by mutation of NIPBL. More typical CdLS was observed with a de novo BRD4 missense variant, which retained the ability to coimmunoprecipitate with NIPBL, but bound poorly to acetylated histones. BRD4 and NIPBL displayed correlated binding at super-enhancers and appeared to co-regulate developmental gene expression.
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40
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Pasutto F, Flinter F, Rauch A, Reis A. Novel STRA6 null mutations in the original family described with Matthew-Wood syndrome. Am J Med Genet A 2017; 176:134-138. [PMID: 29168296 DOI: 10.1002/ajmg.a.38529] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 10/15/2017] [Indexed: 01/31/2023]
Affiliation(s)
- Francesca Pasutto
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Frances Flinter
- Department of Clinical Genetics, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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41
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Unraveling the genetic cause of a consanguineous family with unilateral coloboma and retinoschisis: expanding the phenotypic variability of RAX mutations. Sci Rep 2017; 7:9064. [PMID: 28831107 PMCID: PMC5567291 DOI: 10.1038/s41598-017-09276-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/25/2017] [Indexed: 01/08/2023] Open
Abstract
Ocular coloboma is a common eye malformation arising from incomplete closure of the human optic fissure during development. Multiple genetic mutations contribute to the disease process, showing extensive genetic heterogeneity and complexity of coloboma spectrum diseases. In this study, we aimed to unravel the genetic cause of a consanguineous family with unilateral coloboma and retinoschisis. The subjects were recruited and underwent specialized ophthalmologic clinical examination. A combination of whole exome sequencing (WES), homozygosity mapping, and comprehensive variant analyses was performed to uncover the causative mutation. Only one homozygous mutation (c.113 T > C, p.I38T) in RAX gene survived our strict variant filtering process, consistent with an autosomal recessive inheritance pattern. This mutation segregated perfectly in the family and is located in a highly conserved functional domain. Crystal structure modeling indicated that I38T affected the protein structure. We describe a patient from a consanguineous Chinese family with unusual coloboma, proven to harbor a novel RAX mutation (c.113 T > C, p.I38T, homozygous), expanding the phenotypic variability of ocular coloboma and RAX mutations.
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42
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Riera M, Wert A, Nieto I, Pomares E. Panel-based whole exome sequencing identifies novel mutations in microphthalmia and anophthalmia patients showing complex Mendelian inheritance patterns. Mol Genet Genomic Med 2017; 5:709-719. [PMID: 29178648 PMCID: PMC5702572 DOI: 10.1002/mgg3.329] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/21/2017] [Accepted: 07/27/2017] [Indexed: 12/15/2022] Open
Abstract
Background Microphthalmia and anophthalmia (MA) are congenital eye abnormalities that show an extremely high clinical and genetic complexity. In this study, we evaluated the implementation of whole exome sequencing (WES) for the genetic analysis of MA patients. This approach was used to investigate three unrelated families in which previous single‐gene analyses failed to identify the molecular cause. Methods A total of 47 genes previously associated with nonsyndromic MA were included in our panel. WES was performed in one affected patient from each family using the AmpliSeqTM Exome technology and the Ion ProtonTM platform. Results A novel heterozygous OTX2 missense mutation was identified in a patient showing bilateral anophthalmia who inherited the variant from a parent who was a carrier, but showed no sign of the condition. We also describe a new PAX6 missense variant in an autosomal‐dominant pedigree affected by mild bilateral microphthalmia showing high intrafamiliar variability, with germline mosaicism determined to be the most plausible molecular cause of the disease. Finally, a heterozygous missense mutation in RBP4 was found to be responsible in an isolated case of bilateral complex microphthalmia. Conclusion This study highlights that panel‐based WES is a reliable and effective strategy for the genetic diagnosis of MA. Furthermore, using this technique, the mutational spectrum of these diseases was broadened, with novel variants identified in each of the OTX2,PAX6, and RBP4 genes. Moreover, we report new cases of reduced penetrance, mosaicism, and variable phenotypic expressivity associated with MA, further demonstrating the heterogeneity of such disorders.
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Affiliation(s)
- Marina Riera
- Departament de Genètica, Institut de Microcirurgia Ocular (IMO), Barcelona, Spain
| | - Ana Wert
- Departament d'Oftalmologia Pediàtrica, Estrabisme i Neuroftalmologia, Institut de Microcirurgia Ocular (IMO), Barcelona, Spain
| | - Isabel Nieto
- Departament de Còrnia, Cataracta i Cirurgia Refractiva, Institut de Microcirurgia Ocular (IMO), Barcelona, Spain
| | - Esther Pomares
- Departament de Genètica, Institut de Microcirurgia Ocular (IMO), Barcelona, Spain
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43
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Abstract
We describe bilateral true anophthalmia in a juvenile female eastern gray squirrel (Sciurus carolinensis) with histologic confirmation that orbital contents lacked ocular tissues. Additionally, the optic chiasm of the brain was absent and axon density in the optic tract adjacent to the lateral geniculate nucleus was reduced.
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44
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Chen CA, Yin J, Lewis RA, Schaaf CP. Genetic causes of optic nerve hypoplasia. J Med Genet 2017; 54:441-449. [PMID: 28501829 DOI: 10.1136/jmedgenet-2017-104626] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/05/2017] [Indexed: 01/25/2023]
Abstract
Optic nerve hypoplasia (ONH) is the most common congenital optic nerve anomaly and a leading cause of blindness in the USA. Although most cases of ONH occur as isolated cases within their respective families, the advancement in molecular diagnostic technology has made us realise that a substantial fraction of cases has identifiable genetic causes, typically de novo mutations. An increasing number of genes has been reported, mutations of which can cause ONH. Many of the genes involved serve as transcription factors, participating in an intricate multistep process critical to eye development and neurogenesis in the neural retina. This review will discuss the respective genes and mutations, human phenotypes, and animal models that have been created to gain a deeper understanding of the disorders. The identification of the underlying gene and mutation provides an important step in diagnosis, medical care and counselling for the affected individuals and their families. We envision that future research will lead to further disease gene identification, but will also teach us about gene-gene and gene-environment interactions relevant to optic nerve development. How much of the functional impairment of the various forms of ONH is a reflection of altered morphogenesis versus neuronal homeostasis will determine the prospect of therapeutic intervention, with the ultimate goal of improving the quality of life of the individuals affected with ONH.
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Affiliation(s)
- Chun-An Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Jiani Yin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Richard Alan Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Christian P Schaaf
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
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45
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Fang Q, George AS, Brinkmeier ML, Mortensen AH, Gergics P, Cheung LYM, Daly AZ, Ajmal A, Pérez Millán MI, Ozel AB, Kitzman JO, Mills RE, Li JZ, Camper SA. Genetics of Combined Pituitary Hormone Deficiency: Roadmap into the Genome Era. Endocr Rev 2016; 37:636-675. [PMID: 27828722 PMCID: PMC5155665 DOI: 10.1210/er.2016-1101] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/31/2016] [Indexed: 02/08/2023]
Abstract
The genetic basis for combined pituitary hormone deficiency (CPHD) is complex, involving 30 genes in a variety of syndromic and nonsyndromic presentations. Molecular diagnosis of this disorder is valuable for predicting disease progression, avoiding unnecessary surgery, and family planning. We expect that the application of high throughput sequencing will uncover additional contributing genes and eventually become a valuable tool for molecular diagnosis. For example, in the last 3 years, six new genes have been implicated in CPHD using whole-exome sequencing. In this review, we present a historical perspective on gene discovery for CPHD and predict approaches that may facilitate future gene identification projects conducted by clinicians and basic scientists. Guidelines for systematic reporting of genetic variants and assigning causality are emerging. We apply these guidelines retrospectively to reports of the genetic basis of CPHD and summarize modes of inheritance and penetrance for each of the known genes. In recent years, there have been great improvements in databases of genetic information for diverse populations. Some issues remain that make molecular diagnosis challenging in some cases. These include the inherent genetic complexity of this disorder, technical challenges like uneven coverage, differing results from variant calling and interpretation pipelines, the number of tolerated genetic alterations, and imperfect methods for predicting pathogenicity. We discuss approaches for future research in the genetics of CPHD.
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Affiliation(s)
- Qing Fang
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Akima S George
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Michelle L Brinkmeier
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Amanda H Mortensen
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Peter Gergics
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Leonard Y M Cheung
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Alexandre Z Daly
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Adnan Ajmal
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - María Ines Pérez Millán
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - A Bilge Ozel
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Jacob O Kitzman
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Ryan E Mills
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Jun Z Li
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
| | - Sally A Camper
- Department of Human Genetics (Q.F., A.S.G., M.L.B., A.H.M., P.G., L.Y.M.C., A.Z.D., M.I.P.M., A.B.O., J.O.K., R.E.M., J.Z.L., S.A.C.), Graduate Program in Bioinformatics (A.S.G.), Endocrine Division, Department of Internal Medicine (A.A.), and Department of Computational Medicine and Bioinformatics (J.O.K., R.E.M., J.Z.L.), University of Michigan, Ann Arbor, Michigan 48109
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46
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Dennert N, Engels H, Cremer K, Becker J, Wohlleber E, Albrecht B, Ehret JK, Lüdecke HJ, Suri M, Carignani G, Renieri A, Kukuk GM, Wieland T, Andrieux J, Strom TM, Wieczorek D, Dieux-Coëslier A, Zink AM. De novo microdeletions and point mutations affecting SOX2 in three individuals with intellectual disability but without major eye malformations. Am J Med Genet A 2016; 173:435-443. [PMID: 27862890 DOI: 10.1002/ajmg.a.38034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 10/10/2016] [Indexed: 01/04/2023]
Abstract
Loss-of-function mutations and deletions of the SOX2 gene are known to cause uni- and bilateral anophthalmia and microphthalmia as well as related disorders such as anophthalmia-esophageal-genital syndrome. Thus, anophthalmia/microphthalmia is the primary indication for targeted, "phenotype first" analyses of SOX2. However, SOX2 mutations are also associated with a wide range of non-ocular abnormalities, such as postnatal growth retardation, structural brain anomalies, hypogenitalism, and developmental delay. The present report describes three patients without anophthalmia/microphthalmia and loss-of-function mutations or microdeletions of SOX2 who had been investigated in a "genotype first" manner due to intellectual disability/developmental delay using whole exome sequencing or chromosomal microarray analyses. This result prompted us to perform SOX2 Sanger sequencing in 192 developmental delay/intellectual disability patients without anophthalmia or microphthalmia. No additional SOX2 loss-of-function mutations were detected in this cohort, showing that SOX2 is clearly not a major cause of intellectual disability without anophthalmia/microphthalmia. In our three patients and four further, reported "genotype first" SOX2 microdeletion patients, anophthalmia/microphthalmia was present in less than half of the patients. Thus, SOX2 is another example of a gene whose clinical spectrum is broadened by the generation of "genotype first" findings using hypothesis-free, genome-wide methods. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Nicola Dennert
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Hartmut Engels
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Kirsten Cremer
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Jessica Becker
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Eva Wohlleber
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Beate Albrecht
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Julia K Ehret
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Hermann-Josef Lüdecke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany.,Institute of Human Genetics, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, United Kingdom
| | | | | | - Guido M Kukuk
- Department of Radiology, University of Bonn, Bonn, Germany
| | - Thomas Wieland
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Joris Andrieux
- Laboratory of Medical Genetics, Hôpital Jeanne de Flandre University Hospital, Lille, France
| | - Tim M Strom
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany.,Institute of Human Genetics, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Anne Dieux-Coëslier
- Clinical Genetics, Hôpital Jeanne de France University Hospital, Lille, France
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47
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Gonseth S, Roy R, Houseman EA, de Smith AJ, Zhou M, Lee ST, Nusslé S, Singer AW, Wrensch MR, Metayer C, Wiemels JL. Periconceptional folate consumption is associated with neonatal DNA methylation modifications in neural crest regulatory and cancer development genes. Epigenetics 2016; 10:1166-76. [PMID: 26646725 DOI: 10.1080/15592294.2015.1117889] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Folate deficiency during early embryonic development constitutes a risk factor for neural tube defects and potentially for childhood leukemia via unknown mechanisms. We tested whether folate consumption during the 12 months prior to conception induced DNA methylation modifications at birth in healthy neonates with a genome-wide and agnostic approach. We hypothesized that DNA methylation in genes involved in neural tube development and/or cancer susceptibility would be affected by folate exposure. We retrospectively assessed folate exposure at the time of conception by food-frequency questionnaires administered to the mothers of 343 healthy newborns. We measured genome-wide DNA methylation from neonatal blood spots. We implemented a method based on bootstrap resampling to decrease false-positive findings. Folate was inversely associated with DNA methylation throughout the genome. Among the top folate-associated genes that were replicated in an independent Gambian study were TFAP2A, a gene critical for neural crest development, STX11, a gene implicated in acute myeloid leukemia, and CYS1, a candidate gene for cystic kidney disease. Reduced periconceptional folate intake was associated with increased methylation and, in turn, decreased gene expression at these 3 loci. The top folate-sensitive genes defined by their associated CpG sites were enriched for numerous transcription factors by Gene Set Enrichment Analysis, including those implicated in cancer development (e.g., MYC-associated zinc finger protein). The influence of estimated periconceptional folate intake on neonatal DNA methylation levels provides potential mechanistic insights into the role of this vitamin in the development of neural tube defects and childhood cancers.
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Affiliation(s)
- Semira Gonseth
- a Department of Epidemiology and Biostatistics ; Laboratory for Molecular Epidemiology; University of California ; San Francisco , CA , USA
| | - Ritu Roy
- b Computational Biology Core; HDF Comprehensive Cancer Center; University of California ; San Francisco , CA , USA
| | - E Andres Houseman
- c College of Public Health and Human Sciences; Oregon State University ; Corvallis , OR , USA
| | - Adam J de Smith
- a Department of Epidemiology and Biostatistics ; Laboratory for Molecular Epidemiology; University of California ; San Francisco , CA , USA
| | - Mi Zhou
- a Department of Epidemiology and Biostatistics ; Laboratory for Molecular Epidemiology; University of California ; San Francisco , CA , USA
| | - Seung-Tae Lee
- d Department of Laboratory Medicine ; Yonsei University College of Medicine ; Seoul , Republic of Korea
| | - Sébastien Nusslé
- e Department of Environmental Science ; Policy & Management; University of California ; Berkeley , CA , USA
| | - Amanda W Singer
- f School of Public Health; University of California ; Berkeley , CA , USA
| | - Margaret R Wrensch
- g Department of Neurological Surgery ; University of California ; San Francisco , CA , USA
| | - Catherine Metayer
- f School of Public Health; University of California ; Berkeley , CA , USA
| | - Joseph L Wiemels
- a Department of Epidemiology and Biostatistics ; Laboratory for Molecular Epidemiology; University of California ; San Francisco , CA , USA
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48
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Ramirez-Botero AF, Pachajoa H. Syndromic microphthalmia-3 caused by a mutation on gene SOX2 in a Colombian male patient. Congenit Anom (Kyoto) 2016; 56:250-252. [PMID: 27206652 DOI: 10.1111/cga.12170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 04/14/2016] [Accepted: 05/17/2016] [Indexed: 01/18/2023]
Abstract
Syndromic microphthalmia-3 is a rare congenital syndrome associated with brain anomalies, esophageal atresia and genital anomalies. This is the case of a 4-year-old male with bilateral microphthalmia, short stature, neurodevelopmental delay, genital anomalies, and maternal exposition to glyphosate during pregnancy. Genetic testing detected a previously reported pathogenic heterozygous mutation in the SOX2 gene, confirming a diagnosis of syndromic microphthalmia-3. Whenever a patient presents bilateral microphthalmia, it is necessary to determine whether it is isolated or syndromic; afterwards, genetic testing should be performed in order to offer an effective genetic counseling.
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Affiliation(s)
- Andrés Felipe Ramirez-Botero
- Universidad Icesi, Health Science Faculty Congenital Abnormalities and Rare Diseases Research Center, Cali, Colombia
| | - Harry Pachajoa
- Universidad Icesi, Health Science Faculty Congenital Abnormalities and Rare Diseases Research Center, Cali, Colombia.,Clinical Foundation Valle del Lili, Cali, Colombia
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49
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Plaisancie J, Calvas P, Chassaing N. Genetic Advances in Microphthalmia. J Pediatr Genet 2016; 5:184-188. [PMID: 27895970 DOI: 10.1055/s-0036-1592350] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/07/2015] [Indexed: 12/18/2022]
Abstract
Congenital ocular anomalies such as anophthalmia and microphthalmia (AM) are severe craniofacial malformations in human. The etiologies of these ocular globe anomalies are diverse but the genetic origin appears to be a predominant cause. Until recently, genetic diagnosis capability was rather limited in AM patients and only a few genes were available for routine genetic testing. While some issues remain poorly understood, knowledge regarding the molecular basis of AM dramatically improved over the last years with the development of new molecular screening technologies. Thus, the genetic cause is now identifiable in more than 50% of patients with a severe bilateral eye phenotype and in around 30% of all AM patients taken together. Such advances in the knowledge of these genetic bases are important as they improve the quality of care, in terms of diagnosis, prognosis, and genetic counseling delivered to the patients and their families.
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Affiliation(s)
- Julie Plaisancie
- Department of Medical Genetics, Purpan University Hospital, Toulouse, France
| | - Patrick Calvas
- Department of Medical Genetics, Purpan University Hospital, Toulouse, France; U1056 INSERM-FRE 3742 CNRS-Université Toulouse III, Toulouse, France
| | - Nicolas Chassaing
- Department of Medical Genetics, Purpan University Hospital, Toulouse, France; U1056 INSERM-FRE 3742 CNRS-Université Toulouse III, Toulouse, France
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50
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Richardson R, Tracey-White D, Webster A, Moosajee M. The zebrafish eye-a paradigm for investigating human ocular genetics. Eye (Lond) 2016; 31:68-86. [PMID: 27612182 DOI: 10.1038/eye.2016.198] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/17/2016] [Indexed: 01/13/2023] Open
Abstract
Although human epidemiological and genetic studies are essential to elucidate the aetiology of normal and aberrant ocular development, animal models have provided us with an understanding of the pathogenesis of multiple developmental ocular malformations. Zebrafish eye development displays in depth molecular complexity and stringent spatiotemporal regulation that incorporates developmental contributions of the surface ectoderm, neuroectoderm and head mesenchyme, similar to that seen in humans. For this reason, and due to its genetic tractability, external fertilisation, and early optical clarity, the zebrafish has become an invaluable vertebrate system to investigate human ocular development and disease. Recently, zebrafish have been at the leading edge of preclinical therapy development, with their amenability to genetic manipulation facilitating the generation of robust ocular disease models required for large-scale genetic and drug screening programmes. This review presents an overview of human and zebrafish ocular development, genetic methodologies employed for zebrafish mutagenesis, relevant models of ocular disease, and finally therapeutic approaches, which may have translational leads in the future.
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Affiliation(s)
- R Richardson
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - D Tracey-White
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - A Webster
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - M Moosajee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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