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Khalili MR, Owji N, Zarei E, Nazari M. Consanguinity and Increased Risk of Congenital Ptosis: A Case-Control Study from Southern Iran. J Curr Ophthalmol 2022; 34:465-468. [PMID: 37180529 PMCID: PMC10170990 DOI: 10.4103/joco.joco_136_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 11/07/2022] [Accepted: 12/01/2022] [Indexed: 05/16/2023] Open
Abstract
Purpose To assess consanguinity as a probable risk factor for congenital ptosis. Methods In this case-control study, 97 patients with congenital ptosis and 97 participants as the control group were included. The age, sex, and residence area of the control group were matched with the cases. The inbreeding coefficient (F) was calculated for each participant, and the mean of the inbreeding coefficient (α) was calculated for each group. Results The prevalence of consanguineous marriage in parents of cases with congenital ptosis and those of the control group was 54.6% and 30.9%, respectively (P < 0.002). The mean of the inbreeding coefficient (α) in patients with ptosis was 0.026, whereas it was 0.016 in the control group (T = 2.51, degree of freedom = 192, P = 0.0129). Conclusions The rate of consanguineous marriage was significantly higher among the parents of patients with congenital ptosis. It implies a probable recessive pattern in the etiology of congenital ptosis.
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Affiliation(s)
- Mohammad Reza Khalili
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Address for correspondence: Mohammad Reza Khalili, Department of Ophthalmology, Poostchi Ophthalmology Research Center, School of Medicine, Shiraz University of Medical Sciences, Zand Street, Postal Code: 7134997446, Fars, Shiraz, Iran. E-mail:
| | - Naser Owji
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Elahe Zarei
- Student of Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammadreza Nazari
- Student of Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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2
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Fox SC, Widen SA, Asai-Coakwell M, Havrylov S, Benson M, Prichard LB, Baddam P, Graf D, Lehmann OJ, Waskiewicz AJ. BMP3 is a novel locus involved in the causality of ocular coloboma. Hum Genet 2022; 141:1385-1407. [PMID: 35089417 DOI: 10.1007/s00439-022-02430-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 01/04/2022] [Indexed: 12/29/2022]
Abstract
Coloboma, a congenital disorder characterized by gaps in ocular tissues, is caused when the choroid fissure fails to close during embryonic development. Several loci have been associated with coloboma, but these represent less than 40% of those that are involved with this disease. Here, we describe a novel coloboma-causing locus, BMP3. Whole exome sequencing and Sanger sequencing of patients with coloboma identified three variants in BMP3, two of which are predicted to be disease causing. Consistent with this, bmp3 mutant zebrafish have aberrant fissure closure. bmp3 is expressed in the ventral head mesenchyme and regulates phosphorylated Smad3 in a population of cells adjacent to the choroid fissure. Furthermore, mutations in bmp3 sensitize embryos to Smad3 inhibitor treatment resulting in open choroid fissures. Micro CT scans and Alcian blue staining of zebrafish demonstrate that mutations in bmp3 cause midface hypoplasia, suggesting that bmp3 regulates cranial neural crest cells. Consistent with this, we see active Smad3 in a population of periocular neural crest cells, and bmp3 mutant zebrafish have reduced neural crest cells in the choroid fissure. Taken together, these data suggest that Bmp3 controls Smad3 phosphorylation in neural crest cells to regulate early craniofacial and ocular development.
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Affiliation(s)
- Sabrina C Fox
- Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada
| | - Sonya A Widen
- Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada.,Vienna BioCenter, Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria.,Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada
| | - Mika Asai-Coakwell
- Department of Animal and Poultry and Animal Science, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Ophthalmology, University of Alberta, Edmonton, AB, Canada
| | - Serhiy Havrylov
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.,Department of Ophthalmology, University of Alberta, Edmonton, AB, Canada
| | - Matthew Benson
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.,Department of Ophthalmology, University of Alberta, Edmonton, AB, Canada
| | - Lisa B Prichard
- Department of Biological Sciences, MacEwan University, Edmonton, AB, Canada
| | - Pranidhi Baddam
- Department of Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Daniel Graf
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.,Department of Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ordan J Lehmann
- Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.,Department of Ophthalmology, University of Alberta, Edmonton, AB, Canada
| | - Andrew J Waskiewicz
- Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada. .,Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada.
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3
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Gayathri S, Gowda VK, Udhayabanu T, O'Callaghan B, Efthymiou S, Varalakshmi P, Benakappa N, Houlden H, Ashokkumar B. Brown-Vialetto-Van Laere and Fazio-Londe syndromes: SLC52A3 mutations with puzzling phenotypes and inheritance. Eur J Neurol 2021; 28:945-954. [PMID: 33325104 DOI: 10.1111/ene.14682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/19/2020] [Accepted: 12/10/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Brown-Vialetto-Van Laere syndrome (BVVLS) and Fazio-Londe disease (FLD) are rare neurological disorders presenting with pontobulbar palsy, muscle weakness and respiratory insufficiency. Mutations in SLC52A2 (hRFVT-2) or SLC52A3 (hRFVT-3) genes can be responsible for these disorders with an autosomal recessive pattern of inheritance. The aim of this study was to screen for mutations in SLC52A2 and SLC52A3 among Indian families diagnosed with BVVLS and FLD. METHODS SLC52A2 and SLC52A3 were screened in one FLD and three BVVLS patients by exon-specific amplification using PCR and sequencing. In silico predictions using bioinformatics tools and confocal imaging using HEK-293 cells were performed to determine the functional impact of identified mutations. RESULTS Genetic analysis of a mother and son with BVVLS was identified with a novel homozygous mutation c.710C>T (p.Ala237Val) in SLC52A3. This variant was found to have an autosomal pseudodominant pattern of inheritance, which was neither listed in the Exome Variant Server or in the 1000 Genomes Project database. In silico analysis and confocal imaging of the p.Ala237Val variant showed higher degree of disorderness in hRFVT-3 that could affect riboflavin transport. Furthermore, a common homozygous mutation c.62A>G (p.Asn21Ser) was identified in other BVVLS and FLD patients. Despite having different clinical phenotypes, both BVVLS and FLD can be attributed to this mutation. CONCLUSION A rare and peculiar pattern of autosomal pseudodominant inheritance is observed for the first time in two genetically related BVVLS cases with Indian origin and a common mutation c.62A>G (p.Asn21Ser) in SLC52A3 can be responsible for both BVVLS and FLD with variable phenotypes.
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Affiliation(s)
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | | | - Benjamin O'Callaghan
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - Stephanie Efthymiou
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | | | - Naveen Benakappa
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India
| | - Henry Houlden
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
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Tibrewal S, Subhedar K, Sen P, Mohan A, Singh S, Shah C, Nischal KK, Ganesh S. Clinical spectrum of non-syndromic microphthalmos, anophthalmos and coloboma in the paediatric population: a multicentric study from North India. Br J Ophthalmol 2020; 105:897-903. [PMID: 32829301 DOI: 10.1136/bjophthalmol-2020-316910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/10/2020] [Accepted: 06/23/2020] [Indexed: 11/04/2022]
Abstract
AIMS To describe the clinical features, visual acuity and causes of ocular morbidity in children (0-18 years) with microphthalmos, anophthalmos, and coloboma (MAC) from North India. METHODS A retrospective study conducted between October 2017 and September 2018 in three tertiary eye institutes, part of the Bodhya Eye Consortium with consensus led common pro formas. Children with complete clinical data and without syndromic/systemic involvement were included. The clinical phenotype was divided into isolated ocular coloboma (CB), coloboma with microcornea (CBMC), colobomatous microphthalmos (CBMO), non-colobomatous microphthalmos (MO) and anophthalmos (AO). RESULTS A total of 532 children with MAC were examined. Seventeen records were excluded due to incomplete data (0.2%). 515 children (845 eyes) were included: 54.4% males and 45.6% females. MAC was unilateral in 36% and bilateral in 64%. CB, CBMC, CBMO, MO and AO were seen in 26.4%, 31%, 22%, 8% and 12.5% of eyes, respectively. Nystagmus was found in 40%, strabismus in 23%, cataract in 18.7% and retinal detachment in 15%. Best-corrected visual acuity (BCVA) of <3/60 was seen in 62.4% eyes. Blindness (BCVA <3/60 in better eye) was seen in 42.8% of bilateral patients. Those with microcornea or microphthalmos with coloboma had worse BCVA (p<0.001). There were regional differences in the type of MAC phenotype presenting to the three institutes. CONCLUSION The MAC group of disorders cause significant ocular morbidity. The presence of microcornea or microphthalmos with coloboma predicts worse BCVA. The variation of the MAC phenotype with the district of origin of the patient raises questions of aetiology and is subject to further studies.
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Kemmanu V, Giliyar SK, Rao HL, Shetty BK, Kumaramanickavel G, McCarty CA. Consanguinity and its association with visual impairment in southern India: the Pavagada Pediatric Eye Disease Study 2. J Community Genet 2018; 10:345-350. [PMID: 30506417 DOI: 10.1007/s12687-018-0401-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022] Open
Abstract
To determine the association of consanguinity with the occurrence of genetically transmitted eye diseases in rural and urban populations in Pavagada and Madhugiri taluks, Karnataka state, south India. This study was part of a population based cross-sectional prevalence survey, "The Pavagada pediatric eye disease study 2." As a part of the demographic data, trained investigators collected information on consanguinity from the parents of children identified for the study. The children underwent visual acuity measurements and were examined by an ophthalmologist. Children with minor eye diseases were treated and those with major eye diseases were seen by a pediatric ophthalmologist. Eight thousand five hundred and fifty-three children were examined. The prevalence of ocular morbidity was 6.54% and blindness was 0.09%. The percentage of consanguineously married couples in the screened population was 34.33%. Among the blind children, 75% were blind with a disease with potential genetic etiology. Out of that, 66.67% were born out of consanguineous marriage (uncle-niece). Among children with diseases with a potential genetic etiology 54.29% of the children were born out of consanguineous union. Most of these children (71.43%) were born out of uncle-niece marriages. Further analysis showed that consanguineous parents were more likely to have children with disease with a potential genetic etiology as compared to nonconsanguineous parents (odds ratio: 2.551, p = 0.012). It is evident that consanguineous marriages, especially uncle-niece unions are common in the study area. Consanguinity is more likely to result in children with eye diseases with potential genetic etiology.
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Affiliation(s)
- Vasudha Kemmanu
- Department of Pediatric Ophthalmology and Strabismus, Narayana Nethralaya, 121/C, 1st 'R' block, Rajaji Nagar, Bangalore, Karnataka, 560010, India.
| | - Subramanya K Giliyar
- Department of Pediatric Ophthalmology and Strabismus, Narayana Nethralaya, 121/C, 1st 'R' block, Rajaji Nagar, Bangalore, Karnataka, 560010, India
| | - Harsha L Rao
- Department of Pediatric Ophthalmology and Strabismus, Narayana Nethralaya, 121/C, 1st 'R' block, Rajaji Nagar, Bangalore, Karnataka, 560010, India
| | - Bhujanga K Shetty
- Department of Pediatric Ophthalmology and Strabismus, Narayana Nethralaya, 121/C, 1st 'R' block, Rajaji Nagar, Bangalore, Karnataka, 560010, India
| | - Govindasamy Kumaramanickavel
- Department of Pediatric Ophthalmology and Strabismus, Narayana Nethralaya, 121/C, 1st 'R' block, Rajaji Nagar, Bangalore, Karnataka, 560010, India
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Mutation of IPO13 causes recessive ocular coloboma, microphthalmia, and cataract. Exp Mol Med 2018; 50:1-11. [PMID: 29700284 PMCID: PMC5938035 DOI: 10.1038/s12276-018-0079-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/22/2018] [Accepted: 02/14/2018] [Indexed: 11/12/2022] Open
Abstract
Ocular coloboma is a developmental structural defect of the eye that often occurs as complex ocular anomalies. However, its genetic etiology remains largely unexplored. Here we report the identification of mutation (c.331C>T, p.R111C) in the IPO13 gene in a consanguineous family with ocular coloboma, microphthalmia, and cataract by a combination of whole-exome sequencing and homozygosity mapping. IPO13 encodes an importin-B family protein and has been proven to be associated with the pathogenesis of coloboma and microphthalmia. We found that Ipo13 was expressed in the cornea, sclera, lens, and retina in mice. Additionally, the mRNA expression level of Ipo13 decreased significantly in the patient compared with its expression in a healthy individual. Morpholino-oligonucleotide-induced knockdown of ipo13 in zebrafish caused dose-dependent microphthalmia and coloboma, which is highly similar to the ocular phenotypes in the patient. Moreover, both visual motor response and optokinetic response were impaired severely. Notably, these ocular phenotypes in ipo13-deficient zebrafish could be rescued remarkably by full-length ipo13 mRNA, suggesting that the phenotypes observed in zebrafish were due to insufficient ipo13 function. Altogether, our findings demonstrate, for the first time, a new role of IPO13 in eye morphogenesis and that loss of function of IPO13 could lead to ocular coloboma, microphthalmia, and cataract in humans and zebrafish. In-depth genomic analysis of the family of a young man with severe visual impairment reveals a new gene involved in eye development. Ocular coloboma encompasses various hereditary disorders in which the eyes form improperly. Many of the underlying genetic factors remain unidentified. Researchers led by Zi-Bing Jin at Wenzhou Medical University in China sequenced the genes of 28-year-old man with a recessive form of ocular coloboma. By comparing these genetic data against equivalent genome sequences from his healthy parents, Jin’s team identified a gene called IPO13 as the culprit. IPO13 has not been linked to human disease before, but the researchers demonstrated that switching off IPO13 expression in zebrafish embryos gave rise to underdeveloped eyes with defects in the iris and cornea. These findings give clinicians another potential indicator for early diagnosis of ocular coloboma.
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7
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Pillai-Kastoori L, Wen W, Morris AC. Keeping an eye on SOXC proteins. Dev Dyn 2015; 244:367-376. [PMID: 25476579 PMCID: PMC4344926 DOI: 10.1002/dvdy.24235] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/10/2014] [Accepted: 11/28/2014] [Indexed: 12/17/2022] Open
Abstract
The formation of a mature, functional eye requires a complex series of cell proliferation, migration, induction among different germinal layers, and cell differentiation. These processes are regulated by extracellular cues such as the Wnt/BMP/Hh/Fgf signaling pathways, as well as cell intrinsic transcription factors that specify cell fate. In this review article, we provide an overview of stages of embryonic eye morphogenesis, extrinsic and intrinsic factors that are required for each stage, and pediatric ocular diseases that are associated with defective eye development. In addition, we focus on recent findings about the roles of the SOXC proteins in regulating vertebrate ocular development and implicating SOXC mutations in human ocular malformations.
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Affiliation(s)
| | - Wen Wen
- Department of Biology, University of Kentucky, Lexington, Kentucky, USA
| | - Ann C. Morris
- Department of Biology, University of Kentucky, Lexington, Kentucky, USA
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9
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Kelberman D, Islam L, Lakowski J, Bacchelli C, Chanudet E, Lescai F, Patel A, Stupka E, Buck A, Wolf S, Beales PL, Jacques TS, Bitner-Glindzicz M, Liasis A, Lehmann OJ, Kohlhase J, Nischal KK, Sowden JC. Mutation of SALL2 causes recessive ocular coloboma in humans and mice. Hum Mol Genet 2014; 23:2511-26. [PMID: 24412933 PMCID: PMC3990155 DOI: 10.1093/hmg/ddt643] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Ocular coloboma is a congenital defect resulting from failure of normal closure of the optic fissure during embryonic eye development. This birth defect causes childhood blindness worldwide, yet the genetic etiology is poorly understood. Here, we identified a novel homozygous mutation in the SALL2 gene in members of a consanguineous family affected with non-syndromic ocular coloboma variably affecting the iris and retina. This mutation, c.85G>T, introduces a premature termination codon (p.Glu29*) predicted to truncate the SALL2 protein so that it lacks three clusters of zinc-finger motifs that are essential for DNA-binding activity. This discovery identifies SALL2 as the third member of the Drosophila homeotic Spalt-like family of developmental transcription factor genes implicated in human disease. SALL2 is expressed in the developing human retina at the time of, and subsequent to, optic fissure closure. Analysis of Sall2-deficient mouse embryos revealed delayed apposition of the optic fissure margins and the persistence of an anterior retinal coloboma phenotype after birth. Sall2-deficient embryos displayed correct posterior closure toward the optic nerve head, and upon contact of the fissure margins, dissolution of the basal lamina occurred and PAX2, known to be critical for this process, was expressed normally. Anterior closure was disrupted with the fissure margins failing to meet, or in some cases misaligning leading to a retinal lesion. These observations demonstrate, for the first time, a role for SALL2 in eye morphogenesis and that loss of function of the gene causes ocular coloboma in humans and mice.
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Barnard S, Shneor E, Brauner J, Millodot M, Gordon-Shaag A. Bilateral chorioretinal coloboma discovered with ultra-wide field retinal imaging. JOURNAL OF OPTOMETRY 2012; 5:150-154. [PMCID: PMC3860861 DOI: 10.1016/j.optom.2012.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 06/07/2023]
Abstract
Uveal coloboma results from incomplete closure of the optic cup fissure. While conducting an evaluation of a new ultra-wide field retinal imaging camera (Optomap), which provides a view of the fundus up to 200° at one time without mydriasis, we discovered a case of bilateral chorioretinal coloboma in a 21-year-old student. The lesion was located in the midperiphery of each eye less than 2 disc diameters (DD) below the optic disc in the inferonasal quadrants. The size of the coloboma in the right eye was 1.8 DD in height and 1.3 DD in width, while the left lesion was 2.4 DD in height and 2.6 DD in width. The subject was totally asymptomatic and without any complication such as retinal detachment or choroidal neovascularization, which often accompany this type of lesion. The visual field of each eye displayed an absolute scotoma corresponding to the size and location of the coloboma. No management was necessary but the subject was advised to report for visual examination at regular intervals because complications can occur at any age.
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Affiliation(s)
- Simon Barnard
- Hadassah Academic College, Department of Optometry, Jerusalem, Israel
| | - Einat Shneor
- Hadassah Academic College, Department of Optometry, Jerusalem, Israel
| | - Joel Brauner
- Hadassah Academic College, Department of Optometry, Jerusalem, Israel
| | - Michel Millodot
- Hong Kong Polytechnic, School of Optometry, Hong Kong, China
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Nirmalan PK, Krishnaiah S, Nutheti R, Shamanna BR, Rao GN, Thomas R. Consanguinity and Eye Diseases with a Potential Genetic Etiology. Data from a Prevalence Study in Andhra Pradesh, India. Ophthalmic Epidemiol 2009; 13:7-13. [PMID: 16510341 DOI: 10.1080/09286580500473795] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To determine the prevalence of consanguinity and its potential associations with eye diseases in Andhra Pradesh state of south India. METHODS As part of a demographic interview schedule, prior to clinical examinations, trained investigators collected information regarding consanguinity of the parents from subjects randomly chosen for a population-based cross-sectional epidemiological study. Each subject underwent a detailed ocular examination including visual acuity measurements, anterior segment examinations with slit-lamp biomicroscopy, and posterior segment examinations. Adjusted odds ratios (OR), attributable risks (AR) and population attributable risks (PAR) were estimated. RESULTS We obtained details regarding consanguinity of the parents from 10,290 of the 10,293 subjects who were enumerated and examined in the study. Parental consanguinity was reported by 1822 (24.7%) rural subjects and 782 (32.9%) urban subjects. Eighty (0.008%, 95% CI: 0.006, 0.010) of the 9757 subjects had an ocular disease with a potential genetic basis. We found microcornea to be significantly associated with both an uncle-niece relationship (adjusted OR: 7.32, 95% CI: 1.73, 30.97, AR = 86.34%, PAR = 42.11%) and a first-cousin relationship between the parents (adjusted OR 4.51, 95% CI: 1.05, 19.40, AR = 77.83%, PAR = 29.02%). Retinitis pigmentosa was significantly associated with a first-cousin relationship between the parents (adjusted OR: 5.31, 95% CI: 1.00, 28.25, AR = 81.17%, PAR = 33.43%). CONCLUSIONS The high prevalence of consanguinity in this population does not appear to translate into a high prevalence of ocular malformations; however, studies with larger sample sizes are required to further explore the strength of these associations.
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Affiliation(s)
- Praveen K Nirmalan
- International Centre for Advancement of Rural Eye Care, L.V. Prasad Eye Institute, Hyderabad, Andhra Pradesh, India.
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12
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Liu C, Nathans J. An essential role for frizzled 5 in mammalian ocular development. Development 2008; 135:3567-76. [DOI: 10.1242/dev.028076] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Microphthalmia, coloboma and persistent fetal vasculature within the vitreous cavity are among the most common human congenital ocular anomalies,and each has been associated with a variety of genetic disorders. Here we show that, in the mouse, loss of frizzled 5 (Fz5) - a putative Wnt receptor expressed in the eye field, optic cup and retina - causes all of these defects with high penetrance. In the developing Fz5-/- eye, the sequence of defects, in order of appearance, is: increased cell death in the ventral retina, delayed and/or incomplete closure of the ventral fissure, an excess of mesenchymal cells in the vitreous cavity, an excess of retinal astrocyte precursors and mature astrocytes, and persistence of the hyaloid vasculature in association with a large number of pigment cells. Fz5-/- mice also exhibit a late-onset progressive retinal degeneration by ∼6 months of age, which might be related to the expression of Fz5 in Müller glia in the adult retina. These results demonstrate a central role for frizzled signaling in mammalian eye development and are likely to be relevant to the etiology of congenital human ocular anomalies.
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Affiliation(s)
- Chunqiao Liu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jeremy Nathans
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine,Baltimore, MD 21205, USA
- Department of Ophthalmology, and the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine,Baltimore, MD 21205, USA
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Elcioglu NH, Akin B, Toker E, Elcioglu M, Kaya A, Tuncali T, Wollnik B, Hornby S, Akarsu NA. Colobomatous macrophthalmia with microcornea syndrome maps to the 2p23-p16 region. Am J Med Genet A 2007; 143A:1308-12. [PMID: 17506091 DOI: 10.1002/ajmg.a.31766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Colobomatous macrophthalmia with microcornea syndrome (OMIM 602499) is a rare, autosomal dominant malformation characterized by microcornea, uveal coloboma, axial enlargement of the globe, and myopia. Using what is currently the largest described pedigree and candidate localization approach, we first excluded the candidate genes PAX2, PAX3, PAX6, and PAX9. Subsequently, the chromosome 14q24 region containing the CHX10, SIX1, and SIX4 genes were also excluded. Positive LOD scores were obtained with the DNA markers selected from the 2p23-p16 region. A maximum pairwise LOD score of 3.61 (Theta = 0) was noted with the DNA marker D2S1788. Haplotype analysis positioned the locus between DNA markers D2S2263 and D2S1352 within a 22 Mb physical interval. This region contains major candidate genes, such as SIX2, SIX3, and CYP1B1; however, mutation analysis did not identify a causative mutation in these genes. Macrophthalmia, colobomatous, with microcornea (MACOM) is proposed as the gene symbol for this malformation linked to 2p23-p16.
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Affiliation(s)
- Nursel H Elcioglu
- Genetic Disorders Unit, Department of Pediatrics, Marmara University Medical Faculty, Istanbul, Turkey
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Ugurbas SH, Zilelioglu G, Günalp I, Kargi S. Microphthalmos: clinical and ultrasonographic findings. ANNALS OF OPHTHALMOLOGY (SKOKIE, ILL.) 2007; 39:112-122. [PMID: 17984499 DOI: 10.1007/s12009-007-0005-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 11/30/1999] [Accepted: 02/07/2007] [Indexed: 05/25/2023]
Abstract
We analyzed ocular and ultrasonographic findings of microphthalmos and associated ocular and systemic pathologies in 27 microphthalmic eyes. A high incidence of consanguinous marriages (26%) was present among the parents of patients. Associated systemic abnormalities were growth retardation, congenital rubella, cleft lip and palate, facial hemangioma, inguinal hernia, clinodactyly, Hurler syndrome, Goltz-Gorlin syndrome and Hallermann-Streiff syndrome. A variety of ocular/systemic abnormalities were encountered. Early ultrasonographic diagnosis and description of other ocular and systemic pathologies are essential.
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Affiliation(s)
- Suat Hayri Ugurbas
- Department of Ophthalmology, Zonguldak Karaelmas University Faculty of Medicine, Kozlu Zonguldak, 67600, Turkey.
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Abstract
PURPOSE OF REVIEW To integrate knowledge on the embryologic and molecular basis of optic fissure closure with clinical observations in patients with uveal coloboma. RECENT FINDINGS Closure of the optic fissure has been well characterized and many genetic alterations have been associated with coloboma; however, molecular mechanisms leading to coloboma remain largely unknown. In the past decade, we have gained better understanding of genes critical to eye development; however, mutations in these genes have been found in few individuals with coloboma. CHD7 mutations have been identified in patients with CHARGE syndrome (coloboma, heart defects, choanal atresia, retarded growth, genital anomalies, and ear anomalies or deafness). Animal models are bringing us closer to a molecular understanding of optic fissure closure. SUMMARY Optic fissure closure requires precise orchestration in timing and apposition of two poles of the optic cup. The relative roles of genetics and environment on this process remain elusive. While most cases of coloboma are sporadic, autosomal dominant, autosomal recessive, and X-linked inheritance patterns have been described. Genetically, colobomata demonstrate pleiotropy, heterogeneity, variable expressivity, and reduced penetrance. Coloboma is a complex disorder with a variable prognosis and requires regular examination to optimize visual acuity and to monitor for potential complications.
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Affiliation(s)
- Lan Chang
- National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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