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Ota J, Inooka T, Okado S, Maeda N, Koyanagi Y, Kominami T, Nishiguchi KM, Ueno S. Pathogenic variants of MFRP and PRSS56 genes are major causes of nanophthalmos in Japanese patients. Ophthalmic Genet 2023; 44:423-429. [PMID: 37501562 DOI: 10.1080/13816810.2023.2208220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/23/2023] [Accepted: 04/24/2023] [Indexed: 07/29/2023]
Abstract
BACKGROUND Nanophthalmos (NNO) is a rare condition with significantly shorter axial length than normal. Several genes are known to cause NNO, among them the MFRP and PRSS56 genes have been reported to cause majority of NNOs. The purpose of this study was to determine the genetic basis of Japanese patients with NNO. MATERIALS AND METHODS We studied seven patients with NNO. Whole exome sequencing (WES) and Sanger sequencing were performed to determine the variants causing the NNO. We also reviewed the medical charts of the patients to determine the phenotype of these seven patients. RESULTS WES revealed that four patients from three families carried homozygous frameshift variants of the PRSS56 gene (c.1066dupC). Two novel variants of the MFRP gene were detected in the other two patients: one proband had a homozygous missense variant (c.1486 G>A) and the other had a compound heterozygous variant (c.1486 G>A and c.662_663insT). The axial length of the eight eyes with the PRSS56 variant was 15.69 ± 0.48 mm (mean ± SD) and that for the 4 eyes with the MFRP variant was 15.63 ± 0.69 mm. Three of the six cases with the PRSS56 or MFRP variant had the uveal effusion syndrome. CONCLUSIONS NNOs in Japanese patients are caused by variants of the PRSS56 and MFRP genes as in other ethnic populations. In addition, two new variants of the MFRP gene were found in our cohort. The phenotypes and anomalies in Japanese patients with NNO were similar to those reported for other ethnic populations.
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Affiliation(s)
- Junya Ota
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Taiga Inooka
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Satoshi Okado
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Natsuki Maeda
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Yoshito Koyanagi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Taro Kominami
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji M Nishiguchi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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2
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Okoye O, Capasso J, Kopinsky SM, Amlie-Wolf L, Levin AV, Schneider A. SOX2 pathogenic variants with normal eyes: Expanding the phenotypic spectrum. Am J Med Genet A 2023; 191:2198-2203. [PMID: 37163579 DOI: 10.1002/ajmg.a.63239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/19/2023] [Accepted: 04/26/2023] [Indexed: 05/12/2023]
Abstract
SOX2 pathogenic variants, though rare, constitute the most commonly known genetic cause of clinical anophthalmia and microphthalmia. However, patients without major ocular malformation, but with multi-system developmental disorders, have been reported, suggesting that the range of clinical phenotypes is broader than previously appreciated. We detail two patients with bilateral structurally normal eyes along with 11 other previously published patients. Our findings suggest that there is no obvious phenotypic or genotypic pattern that may help set apart patients with normal eyes. Our patients provide further evidence for broadening the phenotypic spectrum of SOX2 mutations and re-appraising the designation of SOX2 disorder as an anophthalmia/microphthalmia syndrome. We emphasize the importance of considering SOX2 pathogenic variants in the differential diagnoses of individuals with normal eyes, who may have varying combinations of features such as developmental delay, urogenital abnormalities, gastro-intestinal anomalies, pituitary dysfunction, midline structural anomalies, and complex movement disorders, seizures or other neurological issues.
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Affiliation(s)
- Onochie Okoye
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, University of Rochester, New York, New York, USA
- Department of Ophthalmology, University of Nigeria Teaching Hospital, Enugu, Nigeria
| | - Jenina Capasso
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, University of Rochester, New York, New York, USA
- Pediatric Genetics, Golisano Children's Hospital, University of Rochester, Rochester, New York, USA
| | | | | | - Alex V Levin
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, University of Rochester, New York, New York, USA
- Pediatric Genetics, Golisano Children's Hospital, University of Rochester, Rochester, New York, USA
| | - Adele Schneider
- Department of Pediatrics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
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3
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García-Llorca A, Ólafsson KH, Sigurdsson AT, Eysteinsson T. Progressive Cone-Rod Dystrophy and RPE Dysfunction in Mitfmi/+ Mice. Genes (Basel) 2023; 14:1458. [PMID: 37510362 PMCID: PMC10379086 DOI: 10.3390/genes14071458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/11/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
Mutations in the mouse microphthalmia-associated transcription factor (Mitf) gene affect retinal pigment epithelium (RPE) differentiation and development and can lead to hypopigmentation, microphthalmia, deafness, and blindness. For instance, an association has been established between loss-of-function mutations in the mouse Mitf gene and a variety of human retinal diseases, including Waardenburg type 2 and Tietz syndromes. Although there is evidence showing that mice with the homozygous Mitfmi mutation manifest microphthalmia and osteopetrosis, there are limited or no data on the effects of the heterozygous condition in the eye. Mitf mice can therefore be regarded as an important model system for the study of human disease. Thus, we characterized Mitfmi/+ mice at 1, 3, 12, and 18 months old in comparison with age-matched wild-type mice. The light- and dark-adapted electroretinogram (ERG) recordings showed progressive cone-rod dystrophy in Mitfmi/+ mice. The RPE response was reduced in the mutant in all age groups studied. Progressive loss of pigmentation was found in Mitfmi/+ mice. Histological retinal sections revealed evidence of retinal degeneration in Mitfmi/+ mice at older ages. For the first time, we report a mouse model of progressive cone-rod dystrophy and RPE dysfunction with a mutation in the Mitf gene.
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Affiliation(s)
- Andrea García-Llorca
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
| | | | - Arnór Thorri Sigurdsson
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
| | - Thor Eysteinsson
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
- Department of Ophthalmology, Landspitali—National University Hospital, 101 Reykjavík, Iceland
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4
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Hassall MM, Javadiyan S, Klebe S, Awadalla MS, Sharma S, Qassim A, White M, Thomas PQ, Craig JE, Siggs OM. Phenotypic consequences of a nanophthalmos-associated TMEM98 variant in human and mouse. Sci Rep 2023; 13:11017. [PMID: 37419942 PMCID: PMC10328987 DOI: 10.1038/s41598-023-37855-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023] Open
Abstract
Nanophthalmos is characterised by shorter posterior and anterior segments of the eye, with a predisposition towards high hyperopia and primary angle-closure glaucoma. Variants in TMEM98 have been associated with autosomal dominant nanophthalmos in multiple kindreds, but definitive evidence for causation has been limited. Here we used CRISPR/Cas9 mutagenesis to recreate the human nanophthalmos-associated TMEM98 p.(Ala193Pro) variant in mice. The p.(Ala193Pro) variant was associated with ocular phenotypes in both mice and humans, with dominant inheritance in humans and recessive inheritance in mice. Unlike their human counterparts, p.(Ala193Pro) homozygous mutant mice had normal axial length, normal intraocular pressure, and structurally normal scleral collagen. However, in both homozygous mice and heterozygous humans, the p.(Ala193Pro) variant was associated with discrete white spots throughout the retinal fundus, with corresponding retinal folds on histology. This direct comparison of a TMEM98 variant in mouse and human suggests that certain nanophthalmos-associated phenotypes are not only a consequence of a smaller eye, but that TMEM98 may itself play a primary role in retinal and scleral structure and integrity.
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Affiliation(s)
- Mark M Hassall
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia.
| | - Shari Javadiyan
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia
| | - Sonja Klebe
- Department of Anatomical Pathology, Flinders University, Bedford Park, SA, Australia
| | - Mona S Awadalla
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia
| | - Ayub Qassim
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia
| | - Melissa White
- Department of Molecular and Cellular Biology and Robinson Research Institute, University of Adelaide, Adelaide, Australia
| | - Paul Q Thomas
- Department of Molecular and Cellular Biology and Robinson Research Institute, University of Adelaide, Adelaide, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia
| | - Owen M Siggs
- Department of Ophthalmology, Flinders University, Bedford Park, SA, Australia.
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.
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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: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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Balikov DA, Jacobson A, Prasov L. Glaucoma Syndromes: Insights into Glaucoma Genetics and Pathogenesis from Monogenic Syndromic Disorders. Genes (Basel) 2021; 12:genes12091403. [PMID: 34573386 PMCID: PMC8471311 DOI: 10.3390/genes12091403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 11/21/2022] Open
Abstract
Monogenic syndromic disorders frequently feature ocular manifestations, one of which is glaucoma. In many cases, glaucoma in children may go undetected, especially in those that have other severe systemic conditions that affect other parts of the eye and the body. Similarly, glaucoma may be the first presenting sign of a systemic syndrome. Awareness of syndromes associated with glaucoma is thus critical both for medical geneticists and ophthalmologists. In this review, we highlight six categories of disorders that feature glaucoma and other ocular or systemic manifestations: anterior segment dysgenesis syndromes, aniridia, metabolic disorders, collagen/vascular disorders, immunogenetic disorders, and nanophthalmos. The genetics, ocular and systemic features, and current and future treatment strategies are discussed. Findings from rare diseases also uncover important genes and pathways that may be involved in more common forms of glaucoma, and potential novel therapeutic strategies to target these pathways.
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Affiliation(s)
- Daniel A. Balikov
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
| | - Adam Jacobson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
| | - Lev Prasov
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; (D.A.B.); (A.J.)
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence:
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Herrera JL, Komatsu M. R-Ras Deficiency in Pericytes Causes Frequent Microphthalmia and Perturbs Retinal Vascular Development. J Vasc Res 2021; 58:252-266. [PMID: 33873190 PMCID: PMC8263468 DOI: 10.1159/000514555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/13/2021] [Indexed: 12/11/2022] Open
Abstract
PURPOSE The retinal vasculature is heavily invested by pericytes. Small GTPase R-Ras is highly expressed in endothelial cells and pericytes, suggesting importance of this Ras homolog for the regulation of the blood vessel wall. We investigated the specific contribution of pericyte-expressed R-Ras to the development of the retinal vasculature. METHODS The effect of R-Ras deficiency in pericytes was analyzed in pericyte-targeted conditional Rras knockout mice at birth and during the capillary plexus formation in the neonatal retina. RESULTS The offspring of these mice frequently exhibited unilateral microphthalmia. Analyses of the developing retinal vasculature in the eyes without microphthalmia revealed excessive endothelial cell proliferation, sprouting, and branching of the capillary plexus in these animals. These vessels were structurally defective with diminished pericyte coverage and basement membrane formation. Furthermore, these vessels showed reduced VE-cadherin staining and significantly elevated plasma leakage indicating the breakdown of the blood-retinal barrier. This defect was associated with considerable macrophage infiltration in the retina. CONCLUSIONS The normal retinal vascular development is dependent on R-Ras expression in pericytes, and the absence of it leads to unattenuated angiogenesis and significantly weakens the blood-retinal barrier. Our findings underscore the importance of R-Ras for pericyte function during the normal eye development.
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Affiliation(s)
- Jose Luis Herrera
- Cancer and Blood Disorders Institute, Institute for Fundamental Biomedical Research, and Department of Surgery, Johns Hopkins All Children's Hospital, and Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, St. Petersburg, Florida, USA
| | - Masanobu Komatsu
- Cancer and Blood Disorders Institute, Institute for Fundamental Biomedical Research, and Department of Surgery, Johns Hopkins All Children's Hospital, and Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, St. Petersburg, Florida, USA
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Indrieri A, Franco B. Linear Skin Defects with Multiple Congenital Anomalies (LSDMCA): An Unconventional Mitochondrial Disorder. Genes (Basel) 2021; 12:genes12020263. [PMID: 33670341 PMCID: PMC7918533 DOI: 10.3390/genes12020263] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial disorders, although heterogeneous, are traditionally described as conditions characterized by encephalomyopathy, hypotonia, and progressive postnatal organ failure. Here, we provide a systematic review of Linear Skin Defects with Multiple Congenital Anomalies (LSDMCA), a rare, unconventional mitochondrial disorder which presents as a developmental disease; its main clinical features include microphthalmia with different degrees of severity, linear skin lesions, and central nervous system malformations. The molecular basis of this disorder has been elusive for several years. Mutations were eventually identified in three X-linked genes, i.e., HCCS, COX7B, and NDUFB11, which are all endowed with defined roles in the mitochondrial respiratory chain. A peculiar feature of this condition is its inheritance pattern: X-linked dominant male-lethal. Only female or XX male individuals can be observed, implying that nullisomy for these genes is incompatible with normal embryonic development in mammals. All three genes undergo X-inactivation that, according to our hypothesis, may contribute to the extreme variable expressivity observed in this condition. We propose that mitochondrial dysfunction should be considered as an underlying cause in developmental disorders. Moreover, LSDMCA should be taken into consideration by clinicians when dealing with patients with microphthalmia with or without associated skin phenotypes.
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Affiliation(s)
- Alessia Indrieri
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078 Pozzuoli, Naples, Italy;
- Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), 20090 Milan, Italy
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078 Pozzuoli, Naples, Italy;
- Medical Genetics, Department of Translational Medical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy
- Correspondence: ; Tel.: +39-081-1923-0615
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Hamline MY, Corcoran CM, Wamstad JA, Miletich I, Feng J, Lohr JL, Hemberger M, Sharpe PT, Gearhart MD, Bardwell VJ. OFCD syndrome and extraembryonic defects are revealed by conditional mutation of the Polycomb-group repressive complex 1.1 (PRC1.1) gene BCOR. Dev Biol 2020; 468:110-132. [PMID: 32692983 PMCID: PMC9583620 DOI: 10.1016/j.ydbio.2020.06.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/16/2020] [Accepted: 06/26/2020] [Indexed: 12/15/2022]
Abstract
BCOR is a critical regulator of human development. Heterozygous mutations of BCOR in females cause the X-linked developmental disorder Oculofaciocardiodental syndrome (OFCD), and hemizygous mutations of BCOR in males cause gestational lethality. BCOR associates with Polycomb group proteins to form one subfamily of the diverse Polycomb repressive complex 1 (PRC1) complexes, designated PRC1.1. Currently there is limited understanding of differing developmental roles of the various PRC1 complexes. We therefore generated a conditional exon 9-10 knockout Bcor allele and a transgenic conditional Bcor expression allele and used these to define multiple roles of Bcor, and by implication PRC1.1, in mouse development. Females heterozygous for Bcor exhibiting mosaic expression due to the X-linkage of the gene showed reduced postnatal viability and had OFCD-like defects. By contrast, Bcor hemizygosity in the entire male embryo resulted in embryonic lethality by E9.5. We further dissected the roles of Bcor, focusing on some of the tissues affected in OFCD through use of cell type specific Cre alleles. Mutation of Bcor in neural crest cells caused cleft palate, shortening of the mandible and tympanic bone, ectopic salivary glands and abnormal tongue musculature. We found that defects in the mandibular region, rather than in the palate itself, led to palatal clefting. Mutation of Bcor in hindlimb progenitor cells of the lateral mesoderm resulted in 2/3 syndactyly. Mutation of Bcor in Isl1-expressing lineages that contribute to the heart caused defects including persistent truncus arteriosus, ventricular septal defect and fetal lethality. Mutation of Bcor in extraembryonic lineages resulted in placental defects and midgestation lethality. Ubiquitous over expression of transgenic Bcor isoform A during development resulted in embryonic defects and midgestation lethality. The defects we have found in Bcor mutants provide insights into the etiology of the OFCD syndrome and how BCOR-containing PRC1 complexes function in development.
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Affiliation(s)
- Michelle Y Hamline
- The Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota, Minneapolis, MN, 55455, USA; University of Minnesota Medical Scientist Training Program, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Connie M Corcoran
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Joseph A Wamstad
- The Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Isabelle Miletich
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Jifan Feng
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK
| | - Jamie L Lohr
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Myriam Hemberger
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Paul T Sharpe
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, SE1 9RT, UK; Medical Research Council Centre for Transplantation, King's College London, London, SE1 9RT, UK
| | - Micah D Gearhart
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA; Developmental Biology Center, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Vivian J Bardwell
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA; Developmental Biology Center, University of Minnesota, Minneapolis, MN, 55455, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA.
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10
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Williamson KA, Hall HN, Owen LJ, Livesey BJ, Hanson IM, Adams GGW, Bodek S, Calvas P, Castle B, Clarke M, Deng AT, Edery P, Fisher R, Gillessen-Kaesbach G, Heon E, Hurst J, Josifova D, Lorenz B, McKee S, Meire F, Moore AT, Parker M, Reiff CM, Self J, Tobias ES, Verheij JBGM, Willems M, Williams D, van Heyningen V, Marsh JA, FitzPatrick DR. Recurrent heterozygous PAX6 missense variants cause severe bilateral microphthalmia via predictable effects on DNA-protein interaction. Genet Med 2020; 22:598-609. [PMID: 31700164 PMCID: PMC7056646 DOI: 10.1038/s41436-019-0685-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Most classical aniridia is caused by PAX6 haploinsufficiency. PAX6 missense variants can be hypomorphic or mimic haploinsufficiency. We hypothesized that missense variants also cause previously undescribed disease by altering the affinity and/or specificity of PAX6 genomic interactions. METHODS We screened PAX6 in 372 individuals with bilateral microphthalmia, anophthalmia, or coloboma (MAC) from the Medical Research Council Human Genetics Unit eye malformation cohort (HGUeye) and reviewed data from the Deciphering Developmental Disorders study. We performed cluster analysis on PAX6-associated ocular phenotypes by variant type and molecular modeling of the structural impact of 86 different PAX6 causative missense variants. RESULTS Eight different PAX6 missense variants were identified in 17 individuals (15 families) with MAC, accounting for 4% (15/372) of our cohort. Seven altered the paired domain (p.[Arg26Gln]x1, p.[Gly36Val]x1, p.[Arg38Trp]x2, p.[Arg38Gln]x1, p.[Gly51Arg]x2, p.[Ser54Arg]x2, p.[Asn124Lys]x5) and one the homeodomain (p.[Asn260Tyr]x1). p.Ser54Arg and p.Asn124Lys were exclusively associated with severe bilateral microphthalmia. MAC-associated variants were predicted to alter but not ablate DNA interaction, consistent with the electrophoretic mobility shifts observed using mutant paired domains with well-characterized PAX6-binding sites. We found no strong evidence for novel PAX6-associated extraocular disease. CONCLUSION Altering the affinity and specificity of PAX6-binding genome-wide provides a plausible mechanism for the worse-than-null effects of MAC-associated missense variants.
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Affiliation(s)
- Kathleen A Williamson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - H Nikki Hall
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Liusaidh J Owen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Benjamin J Livesey
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Isabel M Hanson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | | | - Simon Bodek
- Department of Clinical Genetics, St Michael's Hospital, Southwell Street, Bristol, UK
| | - Patrick Calvas
- CHU Toulouse, Service de Génétique Médicale, Hôpital Purpan, Toulouse, France
| | - Bruce Castle
- Peninsula Clinical Genetics, Royal Devon and Exeter Hospitals (Heavitree), Exeter, UK
| | - Michael Clarke
- Newcastle Eye Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Alexander T Deng
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Patrick Edery
- Hospices Civils de Lyon, Genetic Department and National HHT Reference Center, Femme-Mère-Enfants Hospital, Bron, France
| | - Richard Fisher
- Teeside Genetics Unit, The James Cook University Hospital, Middlesbrough, UK
| | | | - Elise Heon
- Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, Toronto, ON, Canada
| | - Jane Hurst
- Department of Clinical Genetics, Great Ormond Street Hospital for Children, London, UK
| | - Dragana Josifova
- Clinical Genetics, Guys and St Thomas NHS Trust, Great Maze Pond, London, UK
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Shane McKee
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, UK
| | - Francoise Meire
- Department of Ophthalmology, Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium
| | | | - Michael Parker
- Department of Clinical Genetics, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Charlotte M Reiff
- Department of Ophthalmology, University of Freiburg, Freiburg, Germany
| | - Jay Self
- University Hospital Southampton, Southampton, UK
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Edward S Tobias
- Academic Medical Genetics and Pathology, University of Glasgow, Queen Elizabeth University Hospital, Glasgow, UK
| | - Joke B G M Verheij
- Department of Genetics, University of Groningen, University Medical Center, Groningen, The Netherlands
| | | | - Denise Williams
- Clinical Genetics Unit, Birmingham Women's Hospital, Birmingham, UK
| | - Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - David R FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
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11
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Abstract
Facioscapulohumeral muscular dystrophy (FSHD) has been associated with the genetic and epigenetic molecular features of the CpG-rich D4Z4 repeat tandem array at 4q35. Reduced DNA methylation of D4Z4 repeats is considered part of the FSHD mechanism and has been proposed as a reliable marker in the FSHD diagnostic procedure. We considered the assessment of D4Z4 DNA methylation status conducted on distinct cohorts using different methodologies. On the basis of the reported results we conclude that the percentage of DNA methylation detected at D4Z4 does not correlate with the disease status. Overall, data suggest that in the case of FSHD1, D4Z4 hypomethylation is a consequence of the chromatin structure present in the contracted allele, rather than a proxy of its function. Besides, CpG methylation at D4Z4 DNA is reduced in patients presenting diseases unrelated to muscle progressive wasting, like Bosma Arhinia and Microphthalmia syndrome, a developmental disorder, as well as ICF syndrome. Consistent with these observations, the analysis of epigenetic reprogramming at the D4Z4 locus in human embryonic and induced pluripotent stem cells indicate that other mechanisms, independent from the repeat number, are involved in the control of the epigenetic structure at D4Z4.
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Affiliation(s)
- Valentina Salsi
- Department of Life Sciences, University of Modena and Reggio Emilia, 4, 41121 Modena, Italy;
| | | | - Rossella Tupler
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 4, 41121 Modena, Italy
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 4, 41121 Modena, Italy
- Department of Molecular Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01003, USA
- Li Weibo Institute for Rare Diseases Research at the University of Massachusetts Medical School, Worcester, MA 01003, USA
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12
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Wang CY, Brand H, Shaw ND, Talkowski ME, Lee JT. Role of the Chromosome Architectural Factor SMCHD1 in X-Chromosome Inactivation, Gene Regulation, and Disease in Humans. Genetics 2019; 213:685-703. [PMID: 31420322 PMCID: PMC6781896 DOI: 10.1534/genetics.119.302600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/13/2019] [Indexed: 12/11/2022] Open
Abstract
Structural maintenance of chromosomes flexible hinge domain-containing 1 (SMCHD1) is an architectural factor critical for X-chromosome inactivation (XCI) and the repression of select autosomal gene clusters. In mice, homozygous nonsense mutations in Smchd1 cause female-specific embryonic lethality due to an XCI defect. However, although human mutations in SMCHD1 are associated with congenital arhinia and facioscapulohumeral muscular dystrophy type 2 (FSHD2), the diseases do not show a sex-specific bias, despite the essential nature of XCI in humans. To investigate whether there is a dosage imbalance for the sex chromosomes, we here analyze transcriptomic data from arhinia and FSHD2 patient blood and muscle cells. We find that X-linked dosage compensation is maintained in these patients. In mice, SMCHD1 controls not only protocadherin (Pcdh) gene clusters, but also Hox genes critical for craniofacial development. Ablating Smchd1 results in aberrant expression of these genes, coinciding with altered chromatin states and three-dimensional (3D) topological organization. In a subset of FSHD2 and arhinia patients, we also found dysregulation of clustered PCDH, but not HOX genes. Overall, our study demonstrates preservation of XCI in arhinia and FSHD2, and implicates SMCHD1 in the regulation of the 3D organization of select autosomal gene clusters.
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Affiliation(s)
- Chen-Yu Wang
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
| | - Harrison Brand
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
- Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Natalie D Shaw
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Michael E Talkowski
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
- Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115
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13
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Gamm DM, Clark E, Capowski EE, Singh R. The Role of FGF9 in the Production of Neural Retina and RPE in a Pluripotent Stem Cell Model of Early Human Retinal Development. Am J Ophthalmol 2019; 206:113-131. [PMID: 31078532 DOI: 10.1016/j.ajo.2019.04.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 04/11/2019] [Accepted: 04/18/2019] [Indexed: 12/20/2022]
Abstract
PURPOSE To investigate the role of fibroblast growth factors (FGFs) in the production of neural retina (NR) and retinal pigmented epithelium (RPE) in a human pluripotent stem cell model of early retinal development. METHODS Human induced pluripotent stem cell (hiPSC) lines from an individual with microphthalmia caused by a functional null mutation (R200Q) in visual system homeobox 2 (VSX2), a transcription factor involved in early NR progenitor cell (NRPC) production, and a normal sibling were differentiated along the retinal and forebrain lineages using an established protocol. Quantitative and global gene expression analyses (microarray and RNAseq) were used to investigate endogenous FGF expression profiles in these cultures over time. Based on these results, mutant and control hiPSC cultures were treated exogenously with selected FGFs and subjected to gene and protein expression analyses to determine their effects on RPE and NR production. RESULTS We found that FGF9 and FGF19 were selectively increased in early hiPSC-derived optic vesicles (OVs) when compared to isogenic cultures of hiPSC-derived forebrain neurospheres. Furthermore, these same FGFs were downregulated over time in (R200Q)VSX2 hiPSC-OVs relative to sibling control hiPSC-OVs. Interestingly, long-term supplementation with FGF9, but not FGF19, partially rescued the mutant retinal phenotype of the (R200Q)VSX2 hiPSC-OV model. However, antagonizing FGF9 in wild-type control hiPSCs did not alter OV development. CONCLUSIONS Our results show that FGF9 acts in concert with VSX2 to promote NR differentiation in hiPSC-OVs and has potential to be used to manipulate early retinogenesis and mitigate ocular defects caused by functional loss of VSX2 activity. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.
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Affiliation(s)
- David M Gamm
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA; Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
| | - Eric Clark
- Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | | | - Ruchira Singh
- Department of Ophthalmology, University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, New York, USA
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14
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Cross SH, Mckie L, Keighren M, West K, Thaung C, Davey T, Soares DC, Sanchez-Pulido L, Jackson IJ. Missense Mutations in the Human Nanophthalmos Gene TMEM98 Cause Retinal Defects in the Mouse. Invest Ophthalmol Vis Sci 2019; 60:2875-2887. [PMID: 31266059 PMCID: PMC6986908 DOI: 10.1167/iovs.18-25954] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose We previously found a dominant mutation, Rwhs, causing white spots on the retina accompanied by retinal folds. Here we identify the mutant gene to be Tmem98. In humans, mutations in the orthologous gene cause nanophthalmos. We modeled these mutations in mice and characterized the mutant eye phenotypes of these and Rwhs. Methods The Rwhs mutation was identified to be a missense mutation in Tmem98 by genetic mapping and sequencing. The human TMEM98 nanophthalmos missense mutations were made in the mouse gene by CRISPR-Cas9. Eyes were examined by indirect ophthalmoscopy and the retinas imaged using a retinal camera. Electroretinography was used to study retinal function. Histology, immunohistochemistry, and electron microscopy techniques were used to study adult eyes. Results An I135T mutation of Tmem98 causes the dominant Rwhs phenotype and is perinatally lethal when homozygous. Two dominant missense mutations of TMEM98, A193P and H196P, are associated with human nanophthalmos. In the mouse these mutations cause recessive retinal defects similar to the Rwhs phenotype, either alone or in combination with each other, but do not cause nanophthalmos. The retinal folds did not affect retinal function as assessed by electroretinography. Within the folds there was accumulation of disorganized outer segment material as demonstrated by immunohistochemistry and electron microscopy, and macrophages had infiltrated into these regions. Conclusions Mutations in the mouse orthologue of the human nanophthalmos gene TMEM98 do not result in small eyes. Rather, there is localized disruption of the laminar structure of the photoreceptors.
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Affiliation(s)
- Sally H. Cross
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Lisa Mckie
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Margaret Keighren
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Katrine West
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Caroline Thaung
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, United Kingdom
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, United Kingdom
| | - Tracey Davey
- Electron Microscopy Research Services, Newcastle University, Newcastle NE2 4HH, United Kingdom
| | - Dinesh C. Soares
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Luis Sanchez-Pulido
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Ian J. Jackson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, United Kingdom
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15
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Abstract
Microphthalmos results from incomplete invagination of the optic vesicle or closure of the embryonic fissure. We present three patients with unilateral congenital microphthalmia with cyst. None of them had vision in the affected eye since birth. There was gradually increasing left eye orbital mass encroaching towards lower fornix and lower eyelid ectropion. On examination and investigations, patients had large orbital cyst with microphthalmia pushing the eyeball superiorly and posteriorly in affected orbit. Microphthalmic globe with cyst was surgically excised and histopathologically studied. Orbital cavity was big enough to occupy the conformer and the prosthetic eye after 6 weeks. Diagnosis was confirmed as large communicating orbital cyst with microphthalmia without systemic association in all the patients. None of the mothers of patients had regular antenatal check up. All the parents had consanguineous marriage. Antenatal check up with ultrasound at 14 to16 weeks of pregnancy is important for genetic counselling. Targeted abdominal ultrasound examination of pregnant women focused on the orbital region of foetus is recommended, in mothers who have children with congenital eye anomalies.
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Affiliation(s)
- Diwa Hamal
- Department of Oculoplasty, Biratnagar Eye Hospital, Biratnagar Nepal
| | | | - Priza Poudyal
- Department of Laboratory Medicine, Biratnagar Eye Hospital, Biratnagar Nepal
| | - Rohit Saiju
- Department of Oculoplasty, Tilganga Institute of Ophthalmology, Gaushala, Kathmandu, Nepal
| | - Hony Kc
- Department of Oculoplasty, Biratnagar Eye Hospital, Biratnagar Nepal
| | - Santosh Kafle
- Department of Laboratory Medicine, Biratnagar Eye Hospital, Biratnagar Nepal
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16
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Abstract
Transvaginal ultrasonography is a relatively new technique for visualizing the orbits in a fetus of 4 to 5 cm. At fifteen weeks of gestation it is possible to recognize the lenses and the hyaloid arteries in the eyes, to diagnose structural malformations such as anophthalmos, microphthalmos, buphthalmos and moderate to severe cataract. In most cases cataracts were associated with intracranial defects. We describe a case where the sonographic diagnosis of fetal cataract was confirmed by histopathological examination. A 27-year-old woman had a routine transvaginal sonography at 15 weeks’ normal gestation. Microphthalmos without a hyaloid artery and disorganization of the anterior chamber and lens consistent with cataract were demonstrated in the fetal left eye. In accordance with the parents’ decision, the pregnancy was terminated a week later. Autopsy of the fetus was done and serial sections of the left eye were studied by light microscopy. Histopathological examination verified the sonographic diagnosis of fetal cataract in a microphthalmic eye. Associated findings included malformation of the anterior segment and retinal dysplasia.
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Affiliation(s)
- M Rosner
- Eye Pathology Laboratory, Goldschleger Eye Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel-Hashomer, Israel
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17
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Shimada A, Takagi M, Nagashima Y, Miyai K, Hasegawa Y. A Novel Mutation in OTX2 Causes Combined Pituitary Hormone Deficiency, Bilateral Microphthalmia, and Agenesis of the Left Internal Carotid Artery. Horm Res Paediatr 2017; 86:62-9. [PMID: 27299576 DOI: 10.1159/000446280] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 04/15/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mutations in OTX2 cause hypopituitarism, ranging from isolated growth hormone deficiency to combined pituitary hormone deficiency (CPHD), which are commonly detected in association with severe eye abnormalities, including anophthalmia or microphthalmia. Pituitary phenotypes of OTX2 mutation carriers are highly variable; however, ACTH deficiency during the neonatal period is not common in previous reports. OBJECTIVE We report a novel missense OTX2 (R89P) mutation in a CPHD patient with severe hypoglycemia in the neonatal period due to ACTH deficiency, bilateral microphthalmia, and agenesis of the left internal carotid artery (ICA). RESULTS We identified a novel heterozygous mutation in OTX2 (c.266G>C, p.R89P). R89P OTX2 showed markedly reduced transcriptional activity of HESX1 and POU1F1 reporters compared with wild-type OTX2. A dominant negative effect was noted only in the transcription analysis with POU1F1 promoter. Electrophoretic mobility shift assay experiments showed that R89P OTX2 abrogated DNA-binding ability. CONCLUSION OTX2 mutations can cause ACTH deficiency in the neonatal period. Our study also shows that OTX2 mutations are associated with agenesis of the ICA. To the best of our knowledge, this is the first report of a transcription factor gene mutation, which was identified due to agenesis of the ICA of a patient with CPHD. This study extends our understanding of the phenotypic features, molecular mechanism, and developmental course associated with mutations in OTX2.
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18
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Lonero A, Delvecchio M, Primignani P, Caputo R, Bargiacchi S, Penco S, Mauri L, Andreucci E, Faienza MF, Cavallo L. A novel OTX2 gene frameshift mutation in a child with microphthalmia, ectopic pituitary and growth hormone deficiency. J Pediatr Endocrinol Metab 2016; 29:603-5. [PMID: 26974134 DOI: 10.1515/jpem-2015-0425] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 01/22/2016] [Indexed: 11/15/2022]
Abstract
OTX2 mutations are reported in patients with eye maldevelopment and in some cases with brain or pituitary abnormalities. We describe a child carrying a novel OTX2 heterozygous mutation. She presented microphthalmia, absence of retinal vascularization, vitreal spots and optic nerve hypoplasia in the right eye and mild macular dystrophy in the left eye. Midline brain structures and cerebral parenchyma were normal, except for the ectopic posterior pituitary gland. OTX2 sequencing showed a heterozygous c.402del mutation. Most of OTX2 mutations are nonsense or frameshift introducing a premature termination codon and resulting in a truncated protein. More rarely missense mutations occur. Our novel OTX2 mutation (c.402del) is a frameshift mutation (p.S135Lfs*43), never reported before, causing a premature codon stop 43 amino-acids downstream, which is predicted to generate a premature truncation. The mutation was associated with microphthalmia and ectopic posterior pituitary.
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19
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Gaur A, Ojha S. Oculo-facio-cardio Dental Syndrome. Indian Pediatr 2015; 52:993. [PMID: 26615357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Ajay Gaur
- Department of Pediatrics, GR Medical College, Gwalior, MP, India.
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20
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Jugård Y, Odersjö M, Topa A, Lindgren G, Andersson Grönlund M. [Anophthalmia and microphthalmia requires multidisciplinary care. Many of the children also have other medical problems]. Lakartidningen 2015; 112:DERF. [PMID: 26173131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Anophthalmia/microphthalmia (A/M) are rare congenital eye malformations. Early intervention with ocular prosthesis can stimulate orbital growth and prevent facial asymmetry. We reviewed medical records from 18 individuals with A/M (0.8-31 years) treated with ocular prosthesis at Sahlgrenska University Hospital between 2000 and 2012. A majority had other ocular findings. Seven had subnormal visual acuity in the fellow eye, one third were in contact with vision support services and half of the group wore glasses. Eleven individuals had extra-ocular findings such as cardiac defect, hearing impairment and neuropsychiatric disorders, possibly indicating syndromic conditions. We suggest that investigation of A/M children should include ultrasound of the eye, optionally visual evoked potential and magnetic resonance imaging of the CNS. The ophthalmologist should initiate treatment with prosthesis, pediatric assessment, hearing tests and genetic counseling, but should also monitor visual development of the fellow eye.
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Affiliation(s)
- Ylva Jugård
- Ögonkliniken, Södra Älvsborgs Sjukhus - Borås, Sweden - Borås, Sweden
| | - Marie Odersjö
- Titanenheten, Öron- näs- och halskliniken, Sahlgrenska Universitetssjukhuset - Göteborg, Sweden Titanenheten, Öron- näs- och halskliniken, Sahlgrenska Universitetssjukhuset - Göteborg, Sweden
| | - Alexandra Topa
- Klinisk Genetik, Sahlgrenska Universitetssjukhuset - Göteborg, Sweden Klinisk Genetik, Sahlgrenska Universitetssjukhuset - Göteborg, Sweden
| | - Gun Lindgren
- Ögonverksamheten, Sahlgrenska Universitetssjukhuset - Mölndal, Sweden Ögonverksamheten, Sahlgrenska Universitetssjukhuset - Mölndal, Sweden
| | - Marita Andersson Grönlund
- Ögonmottagningen för barn, Drottning Silvias barn- och ungdomssjukhus Sahlgrenska Universitetssjukhuset - Göteborg, Sweden Ögonmottagningen för barn, Drottning Silvias barn- och ungdomssjukhus, Sahlgrenska universitetssjukhuse - Göteborg, Sweden
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21
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Bauer BS, Sandmeyer LS, Grahn BH. Diagnostic ophthalmology. Microphthalmos and multiple ocular anomalies (MOA) OU consistent with merle ocular dysgenesis (MOD). Can Vet J 2015; 56:767-768. [PMID: 26130844 PMCID: PMC4466837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Bianca S Bauer
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
| | - Lynne S Sandmeyer
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
| | - Bruce H Grahn
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
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22
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Kluger N, Bouissou A, Tauzin L, Puechberty J, Dereure O. Congenital linear streaks on the face and neck and microphthalmia in an infant girl. Acta Derm Venereol 2014; 94:342-3. [PMID: 24096629 DOI: 10.2340/00015555-1688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Nicolas Kluger
- Department of Dermatology,, Skin and Allergy Hospital, Helsinki University Central Hospital, Meilahdentie 2, PO Box 160, FIN-00029 Helsinki, Finland
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23
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Sidoff AE, Garza L, Batlle J, Bordlee B, Palacios E, Neitzschman HR. Radiology case of the month. An infant with leukocoria: persistent fetal vasculature syndrome. Persistent fetal vasculature syndrome (PFVS) of the right eye associated with microphthalmia, bilateral optic nerve and optic chiasm hypoplasia, and absence of the neurohypophysis. J La State Med Soc 2013; 165:168-170. [PMID: 24015435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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24
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Zhang R, Huang H, Cao P, Wang Z, Chen Y, Pan Y. Sma- and Mad-related protein 7 (Smad7) is required for embryonic eye development in the mouse. J Biol Chem 2013; 288:10275-85. [PMID: 23426374 PMCID: PMC3624411 DOI: 10.1074/jbc.m112.416719] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 02/19/2013] [Indexed: 01/16/2023] Open
Abstract
Smad7 is an intracellular inhibitory protein that antagonizes the signaling of TGF-β family members. Deletion of Smad7 in the mouse leads to an abnormality in heart development. However, whether Smad7 has a functional role in the development of other organs has been elusive. Here we present evidence that Smad7 imparts a role to eye development in the mouse. Smad7 is expressed in both the lens and retina in the developing embryonic eye. Depletion of Smad7 caused various degrees of coloboma and microphthalmia with alterations in cell apoptosis and proliferation in eyes. Smad7 was implicated in lens differentiation but was not required for the induction of the lens placode. The development of the periocular mesenchyme was retarded with the down-regulation of Bmp7 and Pitx2 in mutant mice. Retinal spatial patterning was affected by Smad7 deletion and was accompanied by altered bone morphogenetic protein (BMP) signaling. At late gestation stages, TGF-β signaling was up-regulated in the differentiating retina. Smad7 mutant mice displayed an expanded optic disc with increasing of sonic hedgehog (SHH) signaling. Furthermore, loss of Smad7 led to a temporal change in retinal neurogenesis. In conclusion, our study suggests that Smad7 is essential for eye development. In addition, our data indicate that alterations in the signaling of BMP, TGF-β, and SHH likely underlie the defects in eye development caused by Smad7 deletion.
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Affiliation(s)
- Rui Zhang
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
| | - Heng Huang
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
| | - Peijuan Cao
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhenzhen Wang
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
| | - Yan Chen
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
| | - Yi Pan
- From the Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
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25
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Wheway G, Abdelhamed Z, Natarajan S, Toomes C, Inglehearn C, Johnson CA. Aberrant Wnt signalling and cellular over-proliferation in a novel mouse model of Meckel-Gruber syndrome. Dev Biol 2013; 377:55-66. [PMID: 23454480 DOI: 10.1016/j.ydbio.2013.02.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 02/06/2013] [Accepted: 02/13/2013] [Indexed: 11/19/2022]
Abstract
Meckel-Gruber syndrome (MKS) is an embryonic lethal ciliopathy resulting from mutations in genes encoding proteins localising to the primary cilium. Mutations in the basal body protein MKS1 account for 7% of cases of MKS. The condition affects the development of multiple organs, including brain, kidney and skeleton. Here we present a novel Mks1(tm1a(EUCOMM)Wtsi) knockout mouse which accurately recapitulates the human condition, consistently developing pre-axial polydactyly, complex posterior fossa defects (including the Dandy-Walker malformation), and renal cystic dysplasia. TOPFlash Wnt reporter assays in mouse embryonic fibroblasts (MEFs) showed general de-regulated high levels of canonical Wnt/β-catenin signalling in Mks1(-/-) cells. In addition to these signalling defects, we also observed ectopic high proliferation in the brain and kidney of mutant animals at mid- to late-gestation. The specific role of Mks1 in regulating cell proliferation was confirmed in Mks1 siRNA knockdown experiments which showed increased levels of proliferation after knockdown, an effect not seen after knockdown of other ciliopathy genes. We suggest that this is a result of the de-regulation of multiple signalling pathways (Wnt, mTOR and Hh) in the absence of functional Mks1. This novel model system offers insights into the role of MKS1 in Wnt signalling and proliferation, and the impact of deregulation of these processes on brain and kidney development in MKS, as well as expanding our understanding of the role of Mks1 in multiple signalling pathways.
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Affiliation(s)
- Gabrielle Wheway
- Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, Beckett Street, The University of Leeds, Leeds, LS9 7 TF, UK
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Xia CH, Chang B, DeRosa AM, Cheng C, White TW, Gong X. Cataracts and microphthalmia caused by a Gja8 mutation in extracellular loop 2. PLoS One 2012; 7:e52894. [PMID: 23300808 PMCID: PMC3530494 DOI: 10.1371/journal.pone.0052894] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 11/21/2012] [Indexed: 11/18/2022] Open
Abstract
The mouse semi-dominant Nm2249 mutation displays variable cataracts in heterozygous mice and smaller lenses with severe cataracts in homozygous mice. This mutation is caused by a Gja8(R205G) point mutation in the second extracellular loop of the Cx50 (or α8 connexin) protein. Immunohistological data reveal that Cx50-R205G mutant proteins and endogenous wild-type Cx46 (or α3 connexin) proteins form diffuse tiny spots rather than typical punctate signals of normal gap junctions in the lens. The level of phosphorylated Cx46 proteins is decreased in Gja8(R205G/R205G) mutant lenses. Genetic analysis reveals that the Cx50-R205G mutation needs the presence of wild-type Cx46 to disrupt lens peripheral fibers and epithelial cells. Electrophysiological data in Xenopus oocytes reveal that Cx50-R205G mutant proteins block channel function of gap junctions composed of wild-type Cx50, but only affect the gating of wild-type Cx46 channels. Both genetic and electrophysiological results suggest that Cx50-R205G mutant proteins alone are unable to form functional channels. These findings imply that the Gja8(R205G) mutation differentially impairs the functions of Cx50 and Cx46 to cause cataracts, small lenses and microphthalmia. The Gja8(R205G) mutation occurs at the same conserved residue as the human GJA8(R198W) mutation. This work provides molecular insights to understand the cataract and microphthalmia/microcornea phenotype caused by Gja8 mutations in mice and humans.
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Affiliation(s)
- Chun-hong Xia
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Adam M. DeRosa
- Physiology and Biophysics, State University of New York – Stony Brook, Stony Brook, New York, United States of America
| | - Catherine Cheng
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
| | - Thomas W. White
- Physiology and Biophysics, State University of New York – Stony Brook, Stony Brook, New York, United States of America
| | - Xiaohua Gong
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
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Indrieri A, van Rahden V, Tiranti V, Morleo M, Iaconis D, Tammaro R, D’Amato I, Conte I, Maystadt I, Demuth S, Zvulunov A, Kutsche K, Zeviani M, Franco B. Mutations in COX7B cause microphthalmia with linear skin lesions, an unconventional mitochondrial disease. Am J Hum Genet 2012; 91:942-9. [PMID: 23122588 PMCID: PMC3487127 DOI: 10.1016/j.ajhg.2012.09.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 08/31/2012] [Accepted: 09/28/2012] [Indexed: 11/16/2022] Open
Abstract
Microphthalmia with linear skin lesions (MLS) is an X-linked dominant male-lethal disorder associated with mutations in holocytochrome c-type synthase (HCCS), which encodes a crucial player of the mitochondrial respiratory chain (MRC). Unlike other mitochondrial diseases, MLS is characterized by a well-recognizable neurodevelopmental phenotype. Interestingly, not all clinically diagnosed MLS cases have mutations in HCCS, thus suggesting genetic heterogeneity for this disorder. Among the possible candidates, we analyzed the X-linked COX7B and found deleterious de novo mutations in two simplex cases and a nonsense mutation, which segregates with the disease, in a familial case. COX7B encodes a poorly characterized structural subunit of cytochrome c oxidase (COX), the MRC complex IV. We demonstrated that COX7B is indispensable for COX assembly, COX activity, and mitochondrial respiration. Downregulation of the COX7B ortholog (cox7B) in medaka (Oryzias latipes) resulted in microcephaly and microphthalmia that recapitulated the MLS phenotype and demonstrated an essential function of complex IV activity in vertebrate CNS development. Our results indicate an evolutionary conserved role of the MRC complexes III and IV for the proper development of the CNS in vertebrates and uncover a group of mitochondrial diseases hallmarked by a developmental phenotype.
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Affiliation(s)
- Alessia Indrieri
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
| | | | - Valeria Tiranti
- Unit of Molecular Neurogenetics, The Foundation “Carlo Besta” Institute of Neurology, 20126 Milan, Italy
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
| | - Daniela Iaconis
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
| | - Roberta Tammaro
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
| | - Ilaria D’Amato
- Unit of Molecular Neurogenetics, The Foundation “Carlo Besta” Institute of Neurology, 20126 Milan, Italy
| | - Ivan Conte
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
| | - Isabelle Maystadt
- Centre de Genetique Humaine, Institut de Pathologie et de Genetique, 6041 Gosselies (Charleroi), Belgium
| | | | - Alex Zvulunov
- Schneider Children’s Medical Center of Israel, Faculty of Health Sciences, Medical School for International Health, Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel
| | - Kerstin Kutsche
- Institut für Humangenetik, Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Massimo Zeviani
- Unit of Molecular Neurogenetics, The Foundation “Carlo Besta” Institute of Neurology, 20126 Milan, Italy
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine, 80131 Naples, Italy
- Medical Genetics Services, Department of Pediatrics, Federico II University, 80131 Naples, Italy
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Abstract
Ocular development is controlled by a complex network of transcription factors, cell cycle regulators, and diffusible signaling molecules. Together, these molecules regulate cell proliferation, apoptosis and specify retinal fate. In the zebrafish (Danio rerio), hmx1 is a homeobox transcription factor implicated in eye and brain development. Hmx1 transcripts were detected in the nasal retina and lens as well as otic vesicles and pharyngeal arches by 24-32 hpf. Before this stage, transcripts were more uniformly expressed in the optic vesicle. Knockdown of hmx1 led to microphthalmia. Delayed withdrawal of retinal progenitors from the cell cycle resulting in retarded retinal differentiation was observed in morphant. The retina and brain also showed an increased cell death at 24 hpf. The polarized expression of hmx1 to the nasal part in the zebrafish retina strongly suggested an involvement in the nasal-temporal patterning. However, the key patterning genes tested so far were not regulated by hmx1. Altogether, these results suggest an important role for hmx1 in retinogenesis.
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Affiliation(s)
- Gaëlle Boisset
- IRO, Institute for Research in Ophthalmology, Av Grand-Champsec 64, 1950 Sion, Switzerland
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Neroev VV, Kiseleva TN, Sudovskaia TV. [Complex ultrasound examination children with persisting hyperplastic primary vitreous]. Vestn Oftalmol 2011; 127:24-28. [PMID: 21882636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Complex ultrasound examination was performed in 108 children with unilateral congenital cataract (UCC) and persisting hyperplastic primary vitreous syndrome (PHPVS) to reveal indications and contraindications for surgery. The presence of functioning vessels with linear blood flow velocity (LBFV) measurement was performed in fibrovascular band and retrolenticular membrane (RLM) in different stages of PHPVS using color Doppler and energetic mapping. The echographic density of fibrovascular band and RLM was estimated using echodensitometry. The results of the study showed correlation of PHPVS severity and fibrovascular band diameter, LBFV in the vessels of the band and echographic density of the band, RLM and their thickness as well.
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Chao R, Nevin L, Agarwal P, Riemer J, Bai X, Delaney A, Akana M, JimenezLopez N, Bardakjian T, Schneider A, Chassaing N, Schorderet DF, FitzPatrick D, Kwok PY, Ellgaard L, Gould DB, Zhang Y, Malicki J, Baier H, Slavotinek A. A male with unilateral microphthalmia reveals a role for TMX3 in eye development. PLoS One 2010; 5:e10565. [PMID: 20485507 PMCID: PMC2868029 DOI: 10.1371/journal.pone.0010565] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 04/08/2010] [Indexed: 01/01/2023] Open
Abstract
Anophthalmia and microphthalmia are important birth defects, but their pathogenesis remains incompletely understood. We studied a patient with severe unilateral microphthalmia who had a 2.7 Mb deletion at chromosome 18q22.1 that was inherited from his mother. In-situ hybridization showed that one of the deleted genes, TMX3, was expressed in the retinal neuroepithelium and lens epithelium in the developing murine eye. We re-sequenced TMX3 in 162 patients with anophthalmia or microphthalmia, and found two missense substitutions in unrelated patients: c.116G>A, predicting p.Arg39Gln, in a male with unilateral microphthalmia and retinal coloboma, and c.322G>A, predicting p.Asp108Asn, in a female with unilateral microphthalmia and severe micrognathia. We used two antisense morpholinos targeted against the zebrafish TMX3 orthologue, zgc:110025, to examine the effects of reduced gene expression in eye development. We noted that the morphant larvae resulting from both morpholinos had significantly smaller eye sizes and reduced labeling with islet-1 antibody directed against retinal ganglion cells at 2 days post fertilization. Co-injection of human wild type TMX3 mRNA rescued the small eye phenotype obtained with both morpholinos, whereas co-injection of human TMX3(p.Arg39Gln) mutant mRNA, analogous to the mutation in the patient with microphthalmia and coloboma, did not rescue the small eye phenotype. Our results show that haploinsufficiency for TMX3 results in a small eye phenotype and represents a novel genetic cause of microphthalmia and coloboma. Future experiments to determine if other thioredoxins are important in eye morphogenesis and to clarify the mechanism of function of TMX3 in eye development are warranted.
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Affiliation(s)
- Ryan Chao
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Linda Nevin
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Pooja Agarwal
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Jan Riemer
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Xiaoyang Bai
- Departments of Ophthalmology, Anatomy and the Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Allen Delaney
- Genome Sciences Center, BC Cancer Research Center, Vancouver, British Columbia, Canada
| | - Matthew Akana
- Department of Dermatology, Cardiovascular Research Institute and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Nelson JimenezLopez
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Tanya Bardakjian
- Clinical Genetics Division, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Adele Schneider
- Clinical Genetics Division, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Nicolas Chassaing
- Service de Génétique Médicale, Université de Toulouse, Toulouse, France
| | - Daniel F. Schorderet
- Institut de Recherche en Ophtalmologie, University of Lausanne and Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - David FitzPatrick
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Pui-yan Kwok
- Department of Dermatology, Cardiovascular Research Institute and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Lars Ellgaard
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Douglas B. Gould
- Departments of Ophthalmology, Anatomy and the Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Yan Zhang
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jarema Malicki
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Herwig Baier
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Anne Slavotinek
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
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Khan A, Zafar SN. Variable retinal presentations in nanophthalmos. J PAK MED ASSOC 2009; 59:791-793. [PMID: 20361684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens/eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. We describe five cases of nanophthalmos, each of them presenting with a different fundus appearance. Our case series highlights variability of pigmentary changes from retinal flecks to bone spicules and bull's eye maculopathy, which are rare in the combinations described here.
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Affiliation(s)
- Ayesha Khan
- Al-Shifa Trust Eye Hospital, Jhelum Road, Rawalpindi, Pakistan
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Iwao K, Inatani M, Ogata-Iwao M, Yamaguchi Y, Okinami S, Tanihara H. Heparan sulfate deficiency in periocular mesenchyme causes microphthalmia and ciliary body dysgenesis. Exp Eye Res 2009; 90:81-8. [PMID: 19782070 DOI: 10.1016/j.exer.2009.09.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 08/13/2009] [Accepted: 09/17/2009] [Indexed: 11/17/2022]
Abstract
The heparan sulfate (HS) is a component of proteoglycans in the extracellular matrix and on cell surfaces, modulating developmental processes. The aim of this study is to investigate whether the defect of HS in the periocular mesenchyme impairs ocular morphogenesis. First, using Protein 0-Cre transgenic mice, we ablated Ext1, which encodes an indispensable enzyme for HS synthesis, in the developing periocular mesenchyme. The expression of Ext1 messenger RNA (mRNA) and HS were observed by RT-PCR and immunohistochemistry, respectively. The phenotypes in the mutant were evaluated by light microscopy and immunohistochemistry for cellular makers. Second, the distribution of the mutant periocular mesenchymal cells was tracked using a Rosa26 Cre-reporter gene. No mutant embryos (Protein 0-Cre;Ext1(flox/flox)) were identified after embryonic day 14.5 (E14.5). RT-PCR showed that an intense band amplified from Ext1 was observed in cDNAs from the control periocular mesenchymal cells at E13.5; however, the band for Ext1 was hardly detectable in cDNA from the mutant embryo, indicating that the mRNA was missing in the mutant periocular mesenchyme at E13.5. The HS expression was disrupted in the periocular mesenchyme of the mutant ocular tissues. The HS deficiency resulted in microphthalmia with reduced axial lengths, lens diameters, and vitreous sizes compared with the littermate eyes. The mutant embryos showed agenesis of the anterior chamber, where cells expressing Cre recombinase were distributed. Moreover, the mutants showed phenotypic alterations in the neural ectoderm including dysgenesis of the presumptive ciliary body and agenesis of the optic nerve head. These findings demonstrate that HS in the periocular mesenchyme plays a critical role in normal ocular morphogenesis, indicating reciprocal interactions between the periocular mesenchyme and the neural ectoderm.
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Affiliation(s)
- Keiichiro Iwao
- Department of Ophthalmology and Visual Science, Kumamoto University, Graduate School of Medical Sciences, 1-1-1, Honjo, 860-8556 Kumamoto City, Japan
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Abstract
Case report of a 15-year-old girl presenting with a left-sided Duane's retraction syndrome (DURS) in combination with ipsilateral retinal coloboma and contralateral microphthalmia. Abduction limitation as well as narrowing of the palpebral fissure and globe retraction during attempted adduction (type I DURS) was demonstrated in the left eye. Additionally, a retinal coloboma was observed in the nasal inferior quadrant of the left eye. No other somatic or developmental abnormalities were observed and karyotypic analysis was normal. This is the first case of non-syndromic unilateral DURS associated with a contralateral major ocular malformation. This unusual clinical combination probably arose from the embryonic action of an eye-specific disruptor.
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Affiliation(s)
- Rosa E Garnica-Hayashi
- Department of Strabismus, Instituto de Oftalmología, Fundación Conde de Valenciana, Mexico City, Mexico
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Abstract
We developed a rat line showing small eye from transgenic rats that were obtained by microinjection of a DNA segment containing the human (h)tau cDNA (GenBank: BC000558: 31-677,774-1180) expressed under control of CAG promoter, which is related to Alzheimer disease, into the pronuclei rat embryos. The rat line was established by selective brother-sister mating of rats showing small eyes. Of 11 offspring in the 11th generation, there were eight animals with microphthalmia and the transgene. The remaining three rats without transgene did not show the small eyes phenotype. The globes of affected rats were 1.2 mm in length compared with normal globes (3.5 mm), and all other ocular structures were normal. The expression of hTau protein was evident immunohistochemically in the ciliary body, extraocular muscle, lens epithelium, and pigment epithelium. Cytogenetic analysis suggested that the chromosome location of the transgene was chromosome 1 (1p12). This region may include genes related to lens development, such as Cat5.
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Affiliation(s)
- Kazuo Goto
- Central Institute for Experimental Animals, Kawasaki, Japan.
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Zapata S, Durairaj VD. Bilateral microphthalmia with orbital cysts in Wolf-Hirschhorn syndrome. ACTA ACUST UNITED AC 2008; 126:876. [PMID: 18551766 DOI: 10.1001/archopht.126.6.876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Sakazume S, Sorokina E, Iwamoto Y, Semina EV. Functional analysis of human mutations in homeodomain transcription factor PITX3. BMC Mol Biol 2007; 8:84. [PMID: 17888164 PMCID: PMC2093940 DOI: 10.1186/1471-2199-8-84] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 09/21/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The homeodomain-containing transcription factor PITX3 was shown to be essential for normal eye development in vertebrates. Human patients with point mutations in PITX3 demonstrate congenital cataracts along with anterior segment defects in some cases when one allele is affected and microphthalmia with brain malformations when both copies are mutated. The functional consequences of these human mutations remain unknown. RESULTS We studied the PITX3 mutant proteins S13N and G219fs to determine the type and severity of functional defects. Our results demonstrate alterations in DNA-binding profiles and/or transactivation activities and suggest a partial loss-of-function in both mutants with the G219fs form being more severely affected. No anomalies in cellular distribution and no dominant-negative effects were discovered for these mutants. Interestingly, the impairment of the G219fs activity varied between different ocular cell lines. CONCLUSION The G219fs mutation was found in multiple families affected with congenital cataracts along with anterior segment malformations in many members. Our data suggest that the presence/severity of anterior segment defects in families affected with G219fs may be determined by secondary factors that are expressed in the developing anterior segment structures and may modify the effect(s) of this mutation. The S13N mutant showed only minor alteration of transactivation ability and DNA binding pattern and may represent a rare polymorphism in the PITX3 gene. A possible contribution of this mutation to human disease needs to be further investigated.
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Affiliation(s)
- Satoru Sakazume
- Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Human and Molecular Genetics Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Division of Clinical Genetics, Gunma Children's Medical Center, Shibukawa, Gunma, Japan
| | - Elena Sorokina
- Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Human and Molecular Genetics Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Yoshiki Iwamoto
- Human and Molecular Genetics Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Department of Urology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Department of Surgical Research, Beckman Research Institute of the City of Hope, Duarte, CA 91010-3000, USA
| | - Elena V Semina
- Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Human and Molecular Genetics Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Li S, Goldowitz D, Swanson DJ. The requirement of pax6 for postnatal eye development: evidence from experimental mouse chimeras. Invest Ophthalmol Vis Sci 2007; 48:3292-300. [PMID: 17591901 DOI: 10.1167/iovs.06-1482] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The small eye mouse mutant (Sey) is caused by a mutation of the Pax6 gene. Previous studies, in which aggregation chimeras were used, have demonstrated that Sey/Sey cells contribute poorly to the neural retina forming small clumps of cells restricted to the inner retina at embryonic day 16.5. In addition, Sey/+ cells are absent from the lens epithelium during this embryonic period and postnatally. This study was conducted to determine the fates of these Sey/Sey and Sey/+ cells with continued development in chimeric mouse eyes. METHODS Observations were made on heterozygous and homozygous Sey cells in chimeric eyes from postnatal day (P)0 to P10. RESULTS In Sey/Sey<-->wild-type (wt) chimeras, all Sey/Sey cells originating from retinal progenitor cells died at perinatal times. The only remaining Sey/Sey cells in the neural retina were associated with blood vessels, including vascular endothelial cells, pericytes, astrocytes, and microglia, which have extraretinal origins. In contrast, Sey/+ cells formed all retinal cell classes. As previously reported, Sey/Sey cells were absent from the lens and corneal epithelium. However, in contrast to previous reports, Sey/+ cells contributed to the lens epithelium as well as corneal tissues, and Sey/Sey cells were absent from the anterior retinal pigment epithelium. CONCLUSIONS All evidence showed that, when Pax6 is absent at the initial stages of the development, Sey/Sey cells that contribute to the neural retina die, even when wild-type cells are available to provide normal environmental cues.
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Affiliation(s)
- Shengxiu Li
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Tetens J, Ganter M, Müller G, Drögemüller C. Linkage Mapping of Ovine Microphthalmia to Chromosome 23, the Sheep Orthologue of Human Chromosome 18. ACTA ACUST UNITED AC 2007; 48:3506-15. [PMID: 17652717 DOI: 10.1167/iovs.07-0041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE To characterize the phenotype and map the locus responsible for autosomal recessive inherited ovine microphthalmia (OMO) in sheep. METHODS Microphthalmia-affected lambs and their available relatives were collected in a field, and experimental matings were performed to obtain affected and normal lambs for detailed necropsy and histologic examinations. The matings resulted in 18 sheep families with 48 cases of microphthalmia. A comparative candidate gene approach was used to map the disease locus within the sheep genome. Initially, 27 loci responsible for the microphthalmia-anophthalmia phenotypes in humans or mice were selected to test for comparative linkage. Fifty flanking markers that were predicted from comparative genomic analysis to be closely linked to these genes were tested for linkage to the disease locus. After observation of statistical evidence for linkage, a confirmatory fine mapping strategy was applied by further genotyping of 43 microsatellites. RESULTS The clinical and pathologic examinations showed slightly variable expressivity of isolated bilateral microphthalmia. The anterior eye chamber was small or absent, and a white mass admixed with cystic spaces extended from the papilla to the anterior eye chamber, while no recognizable vitreous body or lens was found within the affected eyes. Significant linkage to a single candidate region was identified at sheep chromosome 23. Fine mapping and haplotype analysis assigned the candidate region to a critical interval of 12.4 cM. This ovine chromosome segment encompasses an ancestral chromosomal breakpoint corresponding to two orthologue segments of human chromosomes 18, short and long arms. For the examined animals, we excluded the complete coding region and adjacent intronic regions of ovine TGIF1 to harbor disease-causing mutations. CONCLUSIONS This is the first genetic localization for hereditary ovine isolated microphthalmia. It seems unlikely that a mutation in the TGIF1 gene is responsible for this disorder. The studied sheep represent a valuable large animal model for similar human ocular phenotypes.
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Affiliation(s)
- Jens Tetens
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Germany
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40
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Abstract
PURPOSE To evaluate the foveas of nanophthalmic patients. DESIGN Retrospective observational case series. METHODS Four nanophthalmic patients examined between April 2005 and April 2006 were included. Visual acuity (VA), refractive correction, axial length, corneal diameter, presence or lack of foveal light reflex, as well as fluorescein angiograms (FAs), and optical coherence tomography (OCT) scans of the maculae were evaluated. RESULTS None of the eight eyes had a foveal light reflex, corresponding to lack of a normal foveal pit on OCT. Fluorescein angiography showed no normal foveal avascular zones; all were either completely absent or small and rudimentary. CONCLUSIONS Nanophthalmic patients rarely have best-corrected visual acuity (BCVA) better than 20/40 at any point in their lives, even with an absence of known complications, such as uveal effusion or glaucoma. In many patients, this visual deficiency may correspond to an absent or rudimentary foveal avascular zone and lack of a normal foveal pit.
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Affiliation(s)
- Mark K Walsh
- Wilmer Ophthalmological Institute, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA
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41
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Golzio C, Martinovic-Bouriel J, Thomas S, Mougou-Zrelli S, Grattagliano-Bessieres B, Bonniere M, Delahaye S, Munnich A, Encha-Razavi F, Lyonnet S, Vekemans M, Attie-Bitach T, Etchevers HC. Matthew-Wood syndrome is caused by truncating mutations in the retinol-binding protein receptor gene STRA6. Am J Hum Genet 2007; 80:1179-87. [PMID: 17503335 PMCID: PMC1867105 DOI: 10.1086/518177] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 03/16/2007] [Indexed: 01/01/2023] Open
Abstract
Retinoic acid (RA) is a potent teratogen in all vertebrates when tight homeostatic controls on its endogenous dose, location, or timing are perturbed during early embryogenesis. STRA6 encodes an integral cell-membrane protein that favors RA uptake from soluble retinol-binding protein; its transcription is directly regulated by RA levels. Molecular analysis of STRA6 was undertaken in two human fetuses from consanguineous families we previously described with Matthew-Wood syndrome in a context of severe microphthalmia, pulmonary agenesis, bilateral diaphragmatic eventration, duodenal stenosis, pancreatic malformations, and intrauterine growth retardation. The fetuses had either a homozygous insertion/deletion in exon 2 or a homozygous insertion in exon 7 predicting a premature stop codon in STRA6 transcripts. Five other fetuses presenting at least one of the two major signs of clinical anophthalmia or pulmonary hypoplasia with at least one of the two associated signs of diaphragmatic closure defect or cardiopathy had no STRA6 mutations. These findings suggest a molecular basis for the prenatal manifestations of Matthew-Wood syndrome and suggest that phenotypic overlap with other associations may be due to genetic heterogeneity of elements common to the RA- and fibroblast growth factor-signaling cascades.
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42
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Tomohiro T, Yamane A, Asada Y. Characterization of excess hard tissue occurring in the mesio-buccal surface of the mandibular first molar in microphthalmic mouse. Arch Oral Biol 2007; 52:828-35. [PMID: 17442258 DOI: 10.1016/j.archoralbio.2007.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 02/07/2007] [Accepted: 02/28/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of the present study was to characterize the excess hard tissue on the mandible of the microphthalmic mouse having a mutation at the mitf locus. DESIGN Homozygous mutant (mi/mi) and wild-type (+/+) mice were obtained by mating a breeding pair (strain name, B6C3Fe a/a-Mitf(mi)/J). We used mi/mi and +/+ mice at ages 6, 7, 8, 9, 28, and 49 days for micro-computed tomographic and histologic analyses. RESULTS Excess hard tissue was found on the mesio-buccal surface of the mandibular first molar in all 11mi/mi mice, but none was found in the 8mi/+ or 14 +/+ mice. The excess hard tissue was located in the mental foramen connected to the mandibular canal. The mandibular canal passed near the basal part of the incisor and the root of the mandibular first molar due to aberrant development of the teeth and mandible. The excess hard tissue contained predentine immunostained for dentine sialoprotein, a marker for early stages of dentinogenesis, which was first observed at about 7 days of age. Dentine, predentine, pulp, and root-like structures were observed in the excess hard tissue, but neither enamel nor enamel organ was observed. CONCLUSION Odontogenic cells in the basal part of the incisor and/or the mandibular first molar with the ability to develop into odontoblasts and pulp cells appeared to migrate through the mandibular canal to the mental foramen, where they developed into odontoblasts and pulp-like cells, and then formed dentine and predentine-like structures.
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Affiliation(s)
- Tadafumi Tomohiro
- Department of Pediatric Dentistry, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan
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43
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Abstract
Microencephaly and microphthalmia in the embryos/fetuses from rats exposed to busulfan were histopathologically examined. Busulfan was intraperitoneally administered at 10 mg/kg on gestation days (Days) 12, 13 and 14, and then embryos/fetuses were harvested on Days 14.5, 15, 16 and 21. In the treated group on Day 21, all fetuses were small with reduced body weight, with microencephaly and microphthalmia. On Days 14.5, 15 and 16, apoptotic cells were increased in the neuroepithelium and the neural retina with a width reduction and a decrease in cell density, and the lens epithelial cells histopathologically. Mitotic inhibition was observed in the neuroepithelium, neural retina and equatorial zone of the lens. On Day 21, the cerebral cortex and the retina became markedly thinner. The lens fibers showed swollen, fragmentary and vacuolar formation in the cranial portion accompanied with small lens sizes. The anti-proliferative effects of busulfan brings about a lack of cell populations required for the normal organogenesis of the brain and eye, and leads to microencephaly and microphthalmia, featuring hypoplasia of cerebrum and hypoplasia of retina and lens with cataract, respectively.
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Affiliation(s)
- S Furukawa
- Biological Research Laboratories, Nissan Chemical Industries, Ltd, Japan.
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44
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Abstract
Fetal alcohol spectrum disorder (FASD) is the combination of developmental, morphological, and neurological defects that result from exposing human embryos to ethanol (EtOH). Numerous embryonic structures are affected, leading to a complex viable phenotype affecting among others, the anterior/posterior axis, head, and eye formation. Recent studies have provided evidence suggesting that EtOH teratogenesis is mediated in part through a reduction in retinoic acid (RA) levels, targeting mainly the embryonic organizer (Spemann's organizer) and its subsequent functions. EtOH-treated Xenopus embryos were subjected to an analysis of gene expression patterns. Analysis of organizer-specific genes revealed a transient delay in the invagination of gsc- and chordin-positive cells that eventually reach their normal rostro-caudal position. Dorsal midline genes show defects along the rostro-caudal axis, lacking either their rostral (Xbra and Xnot2) or caudal (FoxA4b and Shh) expression domains. Head-specific markers like Otx2, en2, and Shh show abnormal expression patterns. Otx2 exhibits a reduction in expression levels, while en2 becomes restricted along the dorsal/ventral axis. During neurula stages, Shh becomes up-regulated in the rostral region and it is expressed in an abnormal pattern. These results and histological analysis suggest the existence of malformations in the brain region including a lack of the normal fore brain ventricle. An increase in the size of both the prechordal plate and the notochord was observed, while the spinal cord is narrower. The reduction in head and eye size was accompanied by changes in the eye markers, Pax6 and Tbx3. Our results provide evidence for the early molecular changes induced by EtOH exposure during embryogenesis, and may explain some of the structural changes that are part of the EtOH teratogenic phenotype also in FASD individuals.
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Affiliation(s)
- Ronit Yelin
- Department of Cellular Biochemistry and Human Genetics, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
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45
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Abstract
A case is reported with right-sided abnormalities involving the brain, eyelid, eye, face and chest. The features described are similar to those found in conditions including focal dermal hypoplasia, microphthalmia with linear skin defects, oculocerebrocutaneous syndrome and terminal osseous dysplasia and pigmentary defects. However, none of these conditions, fully explains the collection of abnormalities found in this patient.
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Affiliation(s)
- Richard B Fisher
- Department of Clinical Genetics, St James's University Hospital, Leeds Departments of Pediatrics Ophthalmology Neuroradiology, Hull Royal Infirmary, Hull, UK
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46
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Martínez-Garay I, Tomás M, Oltra S, Ramser J, Moltó MD, Prieto F, Meindl A, Kutsche K, Martínez F. A two base pair deletion in the PQBP1 gene is associated with microphthalmia, microcephaly, and mental retardation. Eur J Hum Genet 2006; 15:29-34. [PMID: 17033686 DOI: 10.1038/sj.ejhg.5201717] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
X-linked mental retardation has been traditionally divided into syndromic (S-XLMR) and non-syndromic forms (NS-XLMR), although the borderlines between these phenotypes begin to vanish and mutations in a single gene, for example PQBP1, can cause S-XLMR as well as NS-XLMR. Here, we report two maternal cousins with an apparently X-linked phenotype of mental retardation (MR), microphthalmia, choroid coloboma, microcephaly, renal hypoplasia, and spastic paraplegia. By multipoint linkage analysis with markers spanning the entire X-chromosome we mapped the disease locus to a 28-Mb interval between Xp11.4 and Xq12, including the BCOR gene. A missense mutation in BCOR was described in a family with Lenz microphthalmia syndrome, a phenotype showing substantial overlapping features with that described in the two cousins. However, no mutation in the BCOR gene was found in both patients. Subsequent mutation analysis of PQBP1, located within the delineated linkage interval in Xp11.23, revealed a 2-bp deletion, c.461_462delAG, that cosegregated with the disease. Notably, the same mutation is associated with the Hamel cerebropalatocardiac syndrome, another form of S-XLMR. Haplotype analysis suggests a germline mosaicism of the 2-bp deletion in the maternal grandmother of both affected individuals. In summary, our findings demonstrate for the first time that mutations in PQBP1 are associated with an S-XLMR phenotype including microphthalmia, thereby further extending the clinical spectrum of phenotypes associated with PQBP1 mutations.
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Affiliation(s)
- Isabel Martínez-Garay
- Unidad de Genética, Hospital Universitario La Fe, Departamento de Genética, Universidad de Valencia, Valencia, Spain
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47
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Abstract
PURPOSE Persistent hyperplastic primary vitreous (PHPV) is a developmental ocular malformation often associated with additional ocular abnormalities. This study involved a novel mouse model of PHPV, generated by a null mutation of the Ski proto-oncogene, that displays other anterior segment and retinal malformations often found in human cases of PHPV. METHODS Morphologic and histologic analyses of Ski-/- mice were used to document ocular abnormalities in comparison to those of normal littermates. Immunohistochemical studies were used to examine the expression of relevant markers of ocular and vascular development including Pax6, beta-III tubulin, and Flk1. RESULTS PHPV and microphthalmia were found in 100% of Ski-/- fetuses. Other abnormalities included anterior segment and lens dysgenesis, retinal folds, chorioretinal coloboma, and Peters anomaly. The severity was variable, even in a highly homogeneous genetic background. PHPV was characterized by the presence of retrolental fibrous and vascular tissue that did not express the neuronal marker beta-III tubulin, but was positive for Flk1 expression and contained no obviously pigmented cells. CONCLUSIONS The results show that normal ocular development requires the function of the Ski proto-oncogene, and mice lacking Ski have many features associated with PHPV, and some similarities with Peters anomaly in humans. Defects in Ski-/- mice closely resemble those described in animals lacking several of the retinoic acid receptor genes, or in animals exposed to excess retinoic acid during gestation. Ski has been shown to repress transcription induced by retinoic acid signaling, and may thus affect ocular development by regulating RA signaling.
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Affiliation(s)
- Peter McGannon
- Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland, OH 44195, USA
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48
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Sivak-Callcott JA, Linberg JV, Rootman J, White VA, Nestor S, Williams HJ. Infiltrating orbital astrocytic proliferation associated with congenitally malformed eyes. Ophthalmic Plast Reconstr Surg 2006; 22:227-9. [PMID: 16714942 DOI: 10.1097/01.iop.0000216786.71358.ad] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This report describes the clinical and pathologic findings in two adults with orbital infiltration by astrocytic cells associated with congenitally malformed eyes. Both cases had enlarging orbital masses and underwent complete resection. Histopathology revealed proliferation of astrocytes (fibrillary acidic protein-positive) that invaded the orbital tissues. To the best of our knowledge, there are no similar cases in the literature.
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49
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Schittkowski MP, Guthoff RF. Injectable self inflating hydrogel pellet expanders for the treatment of orbital volume deficiency in congenital microphthalmos: preliminary results with a new therapeutic approach. Br J Ophthalmol 2006; 90:1173-7. [PMID: 16707526 PMCID: PMC1857413 DOI: 10.1136/bjo.2006.092478] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM Children with congenital microphthalmos are usually able to wear an eye prosthesis but the cosmetic aspect is determined by the size of the orbital volume deficiency. Instead of using a ball shaped standard hydrogel expander or a regular orbital implant, which would necessitate enucleation of the microphthalmic eye, this study investigates the feasibility of volume augmentation with injectable pellet expanders, as formerly suggested for acquired anophthalmos in adults only. METHOD The pellet expander is made from a self inflating hydrogel that takes up water by osmosis (dry state: length 8 mm, diameter 2 mm, volume 0.025 ml; in vitro hydrated state after around 1 day: length 15 mm, diameter 4 mm, volume 0.24 ml; swelling capacity: 9.6-fold). This report concerns six patients (two girls and four boys) aged between 4 months and 42 months with unilateral microphthalmos who were treated by injection of 4-14 pellet expanders into the retrobulbar orbital tissue. Volume augmentation was 1-3.5 ml. The pellets were injected using a customised trocar and placed behind the microphthalmos directed into the intraconal space. RESULTS The increasing orbital volume was noticeable within 2 days and was confirmed by ultrasonography and magnetic resonance imaging. The final result can be anticipated by the volume augmentation effect produced by the amount of saline solution injected in the orbital apex region. All patients were fitted with an artificial eye, which was subsequently enlarged every 3-5 months. Anophthalmic enophthalmos was fully compensated with this technique. No complications have been encountered to date. CONCLUSIONS Orbital volume augmentation with injectable self inflating hydrogel expander pellets is apparently a safe, quick, and minimally invasive technique for various indications in orbital reconstructive surgery-for example, to treat an enophthalmic appearance in microphthalmos and congenital or acquired anophthalmos.
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Affiliation(s)
- M P Schittkowski
- Department of Opthalmology, University of Rostock, Doberaner Strasse 140, D-18055 Rostock, Germany.
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50
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Kanavin ØJ, Haakonsen M, Server A, Bajwa TJ, van der Knaap MS, Strømme P. Microphthalmia and brain atrophy: A novel neurodegenerative disease. Ann Neurol 2006; 59:719-23. [PMID: 16566018 DOI: 10.1002/ana.20827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To delineate the features of a novel neurodegenerative disease. METHODS We report three children of three related families with congenital microphthalmia and blindness, and progressive spasticity, microcephaly, seizures, and profound mental retardation. RESULTS A magnetic resonance imaging scan was normal at birth. However, follow-up studies showed progressive atrophy involving the cerebral white matter and cortex, cerebellum, brainstem, and corpus callosum. The white matter changes extended into the subcortical region leaving only small islands of remaining cortical tissue. Known metabolic conditions involving white matter degeneration were excluded. INTERPRETATION We propose this to be a novel autosomal recessive neurodegenerative disorder to be coined MOBA (microphthalmia brain atrophy) disease.
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Affiliation(s)
- Øivind J Kanavin
- Department of Pediatrics, Ullevål University Hospital, Oslo, Norway
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