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Arshad MW, Shabbir MI, Asif S, Shahzad M, Leydier L, Rai SK. FRMD7 Gene Alterations in a Pakistani Family Associated with Congenital Idiopathic Nystagmus. Genes (Basel) 2023; 14:genes14020346. [PMID: 36833273 PMCID: PMC9957179 DOI: 10.3390/genes14020346] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/27/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Congenital idiopathic nystagmus (CIN) is an oculomotor disorder characterized by repetitive and rapid involuntary movement of the eye that usually develops in the first six months after birth. Unlike other forms of nystagmus, CIN is widely associated with mutations in the FRMD7 gene. This study involves the molecular genetic analysis of a consanguineous Pakistani family with individuals suffering from CIN to undermine any potential pathogenic mutations. Blood samples were taken from affected and normal individuals of the family. Genomic DNA was extracted using an in-organic method. Whole Exome Sequencing (WES) and analysis were performed to find any mutations in the causative gene. To validate the existence and co-segregation of the FRMD7 gene variant found using WES, sanger sequencing was also carried out using primers that targeted all of the FRMD7 coding exons. Additionally, the pathogenicity of the identified variant was assessed using different bioinformatic tools. The WES results identified a novel nonsense mutation in the FRMD7 (c.443T>A; p. Leu148 *) gene in affected individuals from the Pakistani family, with CIN resulting in a premature termination codon, further resulting in the formation of a destabilized protein structure that was incomplete. Co-segregation analysis revealed that affected males are hemizygous for the mutated allele c.443T>A; p. Leu148 * and the affected mother is heterozygous. Overall, such molecular genetic studies expand our current knowledge of the mutations associated with the FRMD7 gene in Pakistani families with CIN and significantly enhance our understanding of the molecular mechanisms involved in genetic disorders.
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Affiliation(s)
- Muhammad Waqar Arshad
- Department of Psychiatry, Yale School of Medicine, VA CT Healthcare Center S116A2, West Haven, CT 06516, USA
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad 44080, Pakistan
| | - Muhammad Imran Shabbir
- Department of Biological Sciences, Faculty of Basic & Applied Sciences, International Islamic University, Sector H-10, Islamabad 44000, Pakistan
- Correspondence: (M.I.S.); (S.K.R.)
| | - Saaim Asif
- Department of Biological Sciences, Faculty of Basic & Applied Sciences, International Islamic University, Sector H-10, Islamabad 44000, Pakistan
- Department of Biosciences, COMSATS University Islamabad, Islamabad Campus, Islamabad 45550, Pakistan
| | - Mohsin Shahzad
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad 44080, Pakistan
| | - Larissa Leydier
- Department of Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis, West Indies
| | - Sunil Kumar Rai
- Department of Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis, West Indies
- Correspondence: (M.I.S.); (S.K.R.)
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Papageorgiou E, Gottlob I. The challenges faced by clinicians diagnosing and treating infantile nystagmus Part I: diagnosis. EXPERT REVIEW OF OPHTHALMOLOGY 2020. [DOI: 10.1080/17469899.2021.1860754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Eleni Papageorgiou
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
- Department of Ophthalmology, University Hospital of Larissa, Larissa, Greece
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
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3
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Li Y, Jiang L, Wang L, Wang C, Liu C, Guo A, Liu M, Zhang L, Ma C, Zhang X, Gao S, Liu JY. p.His16Arg of STXBP1 (MUNC18-1) Associated With Syntaxin 3B Causes Autosomal Dominant Congenital Nystagmus. Front Cell Dev Biol 2020; 8:591781. [PMID: 33251218 PMCID: PMC7672047 DOI: 10.3389/fcell.2020.591781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/15/2020] [Indexed: 02/04/2023] Open
Abstract
Congenital nystagmus (CN) is an ocular movement disorder manifested as involuntary conjugated binocular oscillation and usually occurs in early infancy. The pathological mechanism underlying CN is still poorly understood. We mapped a novel genetic locus 9q33.1-q34.2 in a larger Chinese family with autosomal dominant CN and identified a variant (c.47A>G/p.His16Arg) of STXBP1 by exome sequencing, which fully co-segregated with the nystagmus phenotype in this family and was absent in 571 healthy unrelated individuals. The STXBP1 encodes syntaxin binding protein 1 (also known as MUNC18-1), which plays a pivotal role in neurotransmitter release. In unc-18 (nematode homolog of MUNC18-1) null Caenorhabditis elegans, we found that the p.His16Arg exhibits a compromised ability to rescue the locomotion defect and aldicarb sensitivity, indicating a functional defect in neurotransmitter release. In addition, we also found an enhanced binding of the p.His16Arg mutant to syntaxin 3B, which is a homolog of syntaxin 1A and specifically located in retinal ribbon synapses. We hypothesize that the variant p.His16Arg of STXBP1 is likely to affect neurotransmitter release in the retina, which may be the underlying etiology of CN in this family. Our results provide a new perspective on understanding the molecular mechanism of CN.
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Affiliation(s)
- Yulei Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.,School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, China
| | - Lei Jiang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Lejin Wang
- Department of Ophthalmology, Peking University People's Hospital, Beijing, China
| | - Cheng Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Chunjie Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Anyuan Guo
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xianqin Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Yu Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
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4
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Salman A, Hutton SB, Newall T, Scott JA, Griffiths HL, Lee H, Gomez-Nicola D, Lotery AJ, Self JE. Characterization of the Frmd7 Knock-Out Mice Generated by the EUCOMM/COMP Repository as a Model for Idiopathic Infantile Nystagmus (IIN). Genes (Basel) 2020; 11:genes11101157. [PMID: 33007925 PMCID: PMC7601595 DOI: 10.3390/genes11101157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
In this study, we seek to exclude other pathophysiological mechanisms by which Frmd7 knock-down may cause Idiopathic Infantile Nystagmus (IIN) using the Frmd7.tm1a and Frmd7.tm1b murine models. We used a combination of genetic, histological and visual function techniques to characterize the role of Frmd7 gene in IIN using a novel murine model for the disease. We demonstrate that the Frmd7.tm1b allele represents a more robust model of Frmd7 knock-out at the mRNA level. The expression of Frmd7 was investigated using both antibody staining and X-gal staining confirming previous reports that Frmd7 expression in the retina is restricted to starburst amacrine cells and demonstrating that X-gal staining recapitulates the expression pattern in this model. Thus, it offers a useful tool for further expression studies. We also show that gross retinal morphology and electrophysiology are unchanged in these Frmd7 mutant models when compared with wild-type mice. High-speed eye-tracking recordings of Frmd7 mutant mice confirm a specific horizontal optokinetic reflex defect. In summary, our study confirms the likely role for Frmd7 in the optokinetic reflex in mice mediated by starburst amacrine cells. We show that the Frmd7.tm1b model provides a more robust knock-out than the Frmd7.tm1a model at the mRNA level, although the functional consequence is unchanged. Finally, we establish a robust eye-tracking technique in mice that can be used in a variety of future studies using this model and others. Although our data highlight a deficit in the optiokinetic reflex as a result of the starburst amacrine cells in the retina, this does not rule out the involvement of other cells, in the brain or the retina where Frmd7 is expressed, in the pathophysiology of IIN.
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MESH Headings
- Alleles
- Amacrine Cells/metabolism
- Animals
- Cytoskeletal Proteins/genetics
- Cytoskeletal Proteins/metabolism
- Disease Models, Animal
- Electroretinography
- Female
- Gene Expression
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/pathology
- Genetic Diseases, X-Linked/physiopathology
- Male
- Mice
- Mice, Knockout
- Mutation
- Nystagmus, Congenital/genetics
- Nystagmus, Congenital/pathology
- Nystagmus, Congenital/physiopathology
- Nystagmus, Optokinetic
- Retina/metabolism
- Retina/pathology
- Retina/physiopathology
- Tomography, Optical Coherence
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Affiliation(s)
- Ahmed Salman
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
- Correspondence:
| | - Samuel B. Hutton
- School of Psychology, University of Sussex, Brighton BN1 9QH, UK;
| | - Tutte Newall
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Jennifer A. Scott
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Helen L. Griffiths
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Helena Lee
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton SO171BJ, UK;
| | - Andrew J. Lotery
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Jay E. Self
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
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5
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Structural variations in a non-coding region at 1q32.1 are responsible for the NYS7 locus in two large families. Hum Genet 2020; 139:1057-1064. [PMID: 32248360 PMCID: PMC7406531 DOI: 10.1007/s00439-020-02156-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/24/2020] [Indexed: 01/20/2023]
Abstract
Congenital motor nystagmus (CMN) is characterized by early-onset bilateral ocular oscillations without other ocular deficits. To date, mutations in only one gene have been identified to be responsible for CMN, i.e., FRMD7 for X-linked CMN. Four loci for autosomal dominant CMN, including NYS7 (OMIM 614826), have been mapped but the causative genes have yet to be identified. NYS7 was mapped to 1q32.1 based on independent genome-wide linkage scan on two large families with CMN. In this study, mutations in all known protein-coding genes, both intronic sequence with predicted effect and coding sequence, in the linkage interval were excluded by whole-genome sequencing. Then, long-read genome sequencing based on the Nanopore platform was performed with a sample from each of the two families. Two deletions with an overlapping region of 775,699 bp, located in a region without any known protein-coding genes, were identified in the two families in the linkage region. The two deletions as well as their breakpoints were confirmed by Sanger sequencing and co-segregated with CMN in the two families. The 775,699 bp deleted region contains uncharacterized non-protein-coding expressed sequences and pseudogenes but no protein-coding genes. However, Hi-C data predicted that the deletions span two topologically associated domains and probably lead to a change in the 3D genomic architecture. These results provide novel evidence of a strong association between structural variations in non-coding genomic regions and human hereditary diseases like CMN with a potential mechanism involving changes in 3D genome architecture, which provides clues regarding the molecular pathogenicity of CMN.
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Mayer AK, Mahajnah M, Thomas MG, Cohen Y, Habib A, Schulze M, Maconachie GDE, AlMoallem B, De Baere E, Lorenz B, Traboulsi EI, Kohl S, Azem A, Bauer P, Gottlob I, Sharkia R, Wissinger B. Homozygous stop mutation in AHR causes autosomal recessive foveal hypoplasia and infantile nystagmus. Brain 2020; 142:1528-1534. [PMID: 31009037 DOI: 10.1093/brain/awz098] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 02/04/2019] [Accepted: 02/16/2019] [Indexed: 01/27/2023] Open
Abstract
Herein we present a consanguineous family with three children affected by foveal hypoplasia with infantile nystagmus, following an autosomal recessive mode of inheritance. The patients showed normal electroretinography responses, no signs of albinism, and no anterior segment or brain abnormalities. Upon whole exome sequencing, we identified a homozygous mutation (c.1861C>T;p.Q621*) in the aryl hydrocarbon receptor (AHR) gene that perfectly co-segregated with the disease in the larger family. AHR is a ligand-activated transcription factor that has been intensively studied in xenobiotic-induced toxicity. Further, it has been shown to play a physiological role under normal cellular conditions, such as in immunity, inflammatory response and neurogenesis. Notably, knockout of the Ahr gene in mouse impairs optic nerve myelin sheath formation and results in oculomotor deficits sharing many features with our patients: the eye movement disorder in Ahr-/- mice appears early in development and presents as conjugate horizontal pendular nystagmus. We therefore propose AHR to be a novel disease gene for a new, recessively inherited disorder in humans, characterized by infantile nystagmus and foveal hypoplasia.
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Affiliation(s)
- Anja K Mayer
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Muhammad Mahajnah
- Child Neurology and Development Center, Hillel-Yaffe Medical Center, Hadera, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Mervyn G Thomas
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Yuval Cohen
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Ophthalmology Department, Hillel Yaffe Medical Center, Hadera, Israel
| | - Adib Habib
- Pediatric Department, St. Vincent French Hospital, Nazareth, Israel
| | - Martin Schulze
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Gail D E Maconachie
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Basamat AlMoallem
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium.,Department of Ophthalmology, King Abdul-Aziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Birgit Lorenz
- Department of Ophthalmology, Justus Liebig University Giessen, Giessen, Germany
| | | | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Irene Gottlob
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Rajech Sharkia
- The Triangle Regional Research and Development Center, Kfar Qari', Israel.,Beit-Berl Academic College, Beit-Berl, Israel
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
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Wang Z, Wang M, Wang C, Lu B. Identification and functional characterization of a novel missense mutation in FRMD7 responsible for idiopathic congenital nystagmus. Acta Biochim Biophys Sin (Shanghai) 2019; 51:178-184. [PMID: 30576400 DOI: 10.1093/abbs/gmy161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/21/2018] [Indexed: 11/14/2022] Open
Abstract
Idiopathic congenital nystagmus (ICN) is a genetically heterogeneous eye movement disorder which seriously reduces childhood visual acuity. X-linked inheritance is the most common pattern, and mutations in FERM domain-containing protein 7 (FRMD7) are the major cause. Here, we recruited a four-generation Chinese family with X-linked ICN for the causative mutational screening of FRMD7. A novel missense variant, c.805 A > C, was identified in the proband. The mutation was confirmed in all the affected individuals but was not detected in unaffected family members or 100 unrelated Chinese male controls. The mutation causes a substitution of lysine to glutamine at position 269 (p.Lys269Gln, K269Q). The FRMD7 mutant inhibits the formation and extension of neurites. Moreover, the mutation disrupts FRMD7 interaction with calcium/calmodulin-dependent serine protein kinase and neurite formation. Together, our data expand the mutation spectrum of FRMD7 causing ICN and provide an insight into the pathogenesis of nystagmus.
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Affiliation(s)
- Zhe Wang
- Department of Ophthalmology, Central Hospital of Zibo, Zibo, China
| | - Min Wang
- Department of Pathology, Jilin Cancer Hospital, Changchun, China
| | - Chengyan Wang
- Department of Ultrasound, Jilin Cancer Hospital, Changchun, China
| | - Boyang Lu
- Department of Ophthalmology, The First Hospital of Jilin University, Changchun, China
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Xiu Y, Yao Y, Yang T, Pan M, Yang H, Fang W, Gu F, Zhao J, Zhu Y. Identification of a novel idiopathic congenital nystagmus‑causing missense mutation, p.G296C, in the FRMD7 gene. Mol Med Rep 2018; 18:2816-2822. [PMID: 30015830 PMCID: PMC6102629 DOI: 10.3892/mmr.2018.9260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 06/12/2018] [Indexed: 11/06/2022] Open
Abstract
Exploring the genetic basis for idiopathic congenital nystagmus is critical for improving our understanding of its molecular pathogenesis. In the present study, direct sequencing using gene specific primers was performed in order to identify the causative mutations in two brothers from a Chinese family who had been diagnosed with idiopathic congenital nystagmus. A comprehensive ophthalmological examination, including eye movement recordings, fundus examination, and retinal optical coherence tomography imaging was also conducted, to characterize the disease phenotype. The results revealed that the two brothers exhibited clear signs of nystagmus without any other ocular anomalies. Direct sequencing revealed a G to T transition (c.886G>T) in exon 9 of the four‑point‑one, ezrin, radixin, moesin domain‑containing 7 (FRMD7) gene, which resulted in a conservative substitution of glycine to cysteine at codon 296 (p.G296C), leading to idiopathic congenital nystagmus in the two affected brothers. c.886G>T is a novel idiopathic congenital nystagmus‑inducing mutation in the FRMD7 gene. This finding expands the spectrum of known gene mutations in idiopathic congenital nystagmus, and may be useful for faster gene diagnosis, prenatal testing, the development of potential gene therapies, and for improving the understanding of the molecular pathogenesis of idiopathic congenital nystagmus.
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Affiliation(s)
- Yanghui Xiu
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Yihua Yao
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Tanchu Yang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Meihua Pan
- Eye Institute and Xiamen Eye Center Affiliated Xiamen University, Xiamen, Fujian 361001, P.R. China
| | - Hui Yang
- Department of Ophthalmology, Xiamen Children's Hospital, Xiamen, Fujian 361000, P.R. China
| | - Weifang Fang
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, P.R. China
| | - Junzhao Zhao
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Yihua Zhu
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
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9
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Holmström G, Bondeson ML, Eriksson U, Åkerblom H, Larsson E. 'Congenital' nystagmus may hide various ophthalmic diagnoses. Acta Ophthalmol 2014; 92:412-6. [PMID: 23889849 DOI: 10.1111/aos.12250] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 06/29/2013] [Indexed: 01/23/2023]
Abstract
PURPOSE To investigate whether patients registered at a low-vision centre with 'nystagmus' had any underlying, but so far unknown, ophthalmic diagnosis. METHODS All patients registered at the low-vision centre of Uppsala county with nystagmus as their major diagnosis were identified. Their medical records were studied to exclude those with other general diagnoses that could explain the nystagmus. The remaining group of patients underwent an ophthalmic examination, refraction and optical coherence tomography (OCT). Electroretinogram and genetic analyses were performed when indicated. RESULTS Sixty-two patients with nystagmus as their main diagnosis were registered at the low-vision centre, Uppsala, and 43 of them had a major diagnosis other than nystagmus. Nystagmus was the major diagnosis in 19 patients, 15 of whom, aged 6-76 years, participated in the study. Two of the patients had foveal hypoplasia and albinism, four a seemingly isolated foveal hypoplasia, three achromatopsia, one rod-cone dystrophy, one degenerative high myopia, and two could not be evaluated. Only two patients appeared to have 'congenital' nystagmus. Eleven of the patients underwent a comprehensive genetic investigation of the PAX 6 gene. In addition, four of the patients were analysed for mutations in FOXC1 and PITX2 and one in FRMD7. No mutations were found in any of the patients analysed. CONCLUSION The study illustrates that many patients in our study group with nystagmus had underlying ophthalmic diagnoses. Early diagnosis is important to facilitate habilitation and to provide genetic counselling and, in the future, possibly also gene therapy.
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Affiliation(s)
- Gerd Holmström
- Department of Neuroscience/Ophthalmology, Uppsala University, Uppsala, Sweden
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10
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Identifcation of a novel mutation p.I240T in the FRMD7 gene in a family with congenital nystagmus. Sci Rep 2013; 3:3084. [PMID: 24169426 PMCID: PMC3812648 DOI: 10.1038/srep03084] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/14/2013] [Indexed: 11/17/2022] Open
Abstract
Congenital Nystagmus (CN) is a genetically heterogeneous ocular disease, which causes a significant proportion of childhood visual impairment. To identify the underlying genetic defect of a CN family, twenty-two members were recruited. Genotype analysis showed that affected individuals shared a common haplotype with markers flanking FRMD7 locus. Sequencing FRMD7 revealed a T > C transition in exon 8, causing a conservative substitution of Isoleucine to Tyrosine at codon 240. By protein structural modeling, we found the mutation may disrupt the hydrophobic core and destabilize the protein structure. We reviewed the literature and found that exons 2, 8, and 9 (11.4% of the sequence of FRMD7 mRNA) represent the majority (55.3%) of the reported FRMD7 mutations. In summary, we identified a novel mutation in FRMD7, showed its molecular consequence, and revealed the mutation-rich exons of the FRMD7 gene. Collectively, this provides molecular insights for future CN clinical genetic diagnosis and treatment.
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11
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Thomas S, Thomas MG, Andrews C, Chan WM, Proudlock FA, McLean RJ, Pradeep A, Engle EC, Gottlob I. Autosomal-dominant nystagmus, foveal hypoplasia and presenile cataract associated with a novel PAX6 mutation. Eur J Hum Genet 2013; 22:344-9. [PMID: 23942204 DOI: 10.1038/ejhg.2013.162] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 05/12/2013] [Accepted: 05/15/2013] [Indexed: 11/09/2022] Open
Abstract
Autosomal-dominant idiopathic infantile nystagmus has been linked to 6p12 (OMIM 164100), 7p11.2 (OMIM 608345) and 13q31-q33 (OMIM 193003). PAX6 (11p13, OMIM 607108) mutations can also cause autosomal-dominant nystagmus, typically in association with aniridia or iris hypoplasia. We studied a large multigenerational white British family with autosomal-dominant nystagmus, normal irides and presenile cataracts. An SNP-based genome-wide analysis revealed a linkage to a 13.4-MB region on chromosome 11p13 with a maximum lod score of 2.93. A mutation analysis of the entire coding region and splice junctions of the PAX6 gene revealed a novel heterozygous missense mutation (c.227C>G) that segregated with the phenotype and is predicted to result in the amino-acid substitution of proline by arginine at codon 76 p.(P76R). The amino-acid variation p.(P76R) within the paired box domain is likely to destabilise the protein due to steric hindrance as a result of the introduction of a polar and larger amino acid. Eye movement recordings showed a significant intrafamilial variability of horizontal, vertical and torsional nystagmus. High-resolution in vivo imaging of the retina using optical coherence tomography (OCT) revealed features of foveal hypoplasia, including rudimentary foveal pit, incursion of inner retinal layers, short photoreceptor outer segments and optic nerve hypoplasia. Thus, this study presents a family that segregates a PAX6 mutation with nystagmus and foveal hypoplasia in the absence of iris abnormalities. Moreover, it is the first study showing detailed characteristics using eye movement recordings of autosomal-dominant nystagmus in a multigenerational family with a novel PAX6 mutation.
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Affiliation(s)
- Shery Thomas
- 1] Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK [2] Department of Ophthalmology, Nottingham University Hospital NHS Trust, Nottingham, UK
| | - Mervyn G Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Caroline Andrews
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Wai-Man Chan
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Frank A Proudlock
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Rebecca J McLean
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Archana Pradeep
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Elizabeth C Engle
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Irene Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
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12
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Ehrt O. Infantile and acquired nystagmus in childhood. Eur J Paediatr Neurol 2012; 16:567-72. [PMID: 22459007 DOI: 10.1016/j.ejpn.2012.02.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 11/15/2022]
Abstract
Nystagmus is an involuntary, periodic eye movement caused by a slow drift of fixation which is followed by a fast refixation saccade (jerk nystagmus) or a slow movement back to fixation (pendular nystagmus). In childhood most cases are benign forms of nystagmus: idiopathic infantile, ocular or latent nystagmus. They arise at the age of 3 months, without oscillopsia and show the absence of the physiologic opto-kinetic nystagmus. A full ophthalmologic evaluation is all that is needed in most cases: albinism, macular or optic nerve hypoplasia and congenital retinal dystrophies are the most common forms of ocular nystagmus. Idiopathic infantile nystagmus can be hereditary, the most common and best analyzed form being a mutation of the FRMD7 gene on chromosome Xq26.2. The mutation shows a mild genotype-phenotype correlation. In all female carriers the opto-kinetic nystagmus is absent and half had mild nystagmus. Latent nystagmus is part of the infantile esotropia syndrome and shows the unique feature of change of direction when the fixing eye changes: it is always beating to the side of the fixing eye. There is no cure for infantile nystagmus but therapeutic options include magnifying visual aids or eye muscle surgery at the age of 6-8 y in patients with head turn. Less than 20% of childhood nystagmus are acquired and need further neurological and imaging work-up. Alarming signs and symptoms are: onset after the age of 4 months, oscillopsia, dissociated (asymmetric) nystagmus, preserved opto-kinetic nystagmus, afferent pupillary defect, papilloedema and neurological symptoms like vertigo and nausea. The most common cause is due to pathology of the anterior optic pathway (e.g. optic nerve gliomas). It shows the same clinical feature of dissociated nystagmus as spasmus nutans but has a higher frequency as in INO. Other forms of acquired nystagmus are due to brainstem, cerebellar or metabolic diseases.
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Affiliation(s)
- Oliver Ehrt
- Department of Ophthalmology, Ludwig-Maximilian University, Mathildenstr. 8, D-80336 Muenchen, Germany.
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13
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Confirmation and refinement of an autosomal dominant congenital motor nystagmus locus in chromosome 1q31.3–q32.1. J Hum Genet 2012; 57:756-9. [DOI: 10.1038/jhg.2012.103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Xiao X, Li S, Guo X, Zhang Q. A novel locus for autosomal dominant congenital motor nystagmus mapped to 1q31-q32.2 between D1S2816 and D1S2692. Hum Genet 2011; 131:697-702. [PMID: 22065086 DOI: 10.1007/s00439-011-1113-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Accepted: 10/29/2011] [Indexed: 10/15/2022]
Abstract
Congenital motor nystagmus (CMN) is characterized by bilateral involuntary ocular oscillation without any other underlying ocular or systemic diseases. An autosomal dominant CMN was identified in a large Chinese family where all patients had nystagmus since infancy. The nystagmus in the family is independent of any known ocular or systemic diseases. After exclusion of known CMN loci, a genome-wide scan was performed by genotyping microsatellite markers at about 10 cM intervals, together with two-point linkage analysis. Exome sequencing was used to screen coding exons of well-annotated genes. Sanger-dideoxy sequencing was used to verify candidate variations inside the linkage interval. Congenital motor nystagmus in this family shows linkage to markers in a 11.39 Mb (12.1 cM) region on chromosome 1q31-q32.2 between D1S2816 and D1S2692. All nine markers in the linkage interval gave positive lod scores, with D1S2655 and D1S2636 yielding lod scores of 5.16 and 5.18, respectively, at θ = 0. No causative mutation in the linkage interval was identified by exome sequencing of gDNA from four patients. A linkage study of additional families and further analysis of candidate genes may ultimately lead to identification of the gene responsible for dominantly inherited CMN.
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Affiliation(s)
- Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 510060 Guangzhou, China.
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15
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Thomas MG, Crosier M, Lindsay S, Kumar A, Thomas S, Araki M, Talbot CJ, McLean RJ, Surendran M, Taylor K, Leroy BP, Moore AT, Hunter DG, Hertle RW, Tarpey P, Langmann A, Lindner S, Brandner M, Gottlob I. The clinical and molecular genetic features of idiopathic infantile periodic alternating nystagmus. Brain 2011; 134:892-902. [PMID: 21303855 DOI: 10.1093/brain/awq373] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Periodic alternating nystagmus consists of involuntary oscillations of the eyes with cyclical changes of nystagmus direction. It can occur during infancy (e.g. idiopathic infantile periodic alternating nystagmus) or later in life. Acquired forms are often associated with cerebellar dysfunction arising due to instability of the optokinetic-vestibular systems. Idiopathic infantile periodic alternating nystagmus can be familial or occur in isolation; however, very little is known about the clinical characteristics, genetic aetiology and neural substrates involved. Five loci (NYS1-5) have been identified for idiopathic infantile nystagmus; three are autosomal (NYS2, NYS3 and NYS4) and two are X-chromosomal (NYS1 and NYS5). We previously identified the FRMD7 gene on chromosome Xq26 (NYS1 locus); mutations of FRMD7 are causative of idiopathic infantile nystagmus influencing neuronal outgrowth and development. It is unclear whether the periodic alternating nystagmus phenotype is linked to NYS1, NYS5 (Xp11.4-p11.3) or a separate locus. From a cohort of 31 X-linked families and 14 singletons (70 patients) with idiopathic infantile nystagmus we identified 10 families and one singleton (21 patients) with periodic alternating nystagmus of which we describe clinical phenotype, genetic aetiology and neural substrates involved. Periodic alternating nystagmus was not detected clinically but only on eye movement recordings. The cycle duration varied from 90 to 280 s. Optokinetic reflex was not detectable horizontally. Mutations of the FRMD7 gene were found in all 10 families and the singleton (including three novel mutations). Periodic alternating nystagmus was predominantly associated with missense mutations within the FERM domain. There was significant sibship clustering of the phenotype although in some families not all affected members had periodic alternating nystagmus. In situ hybridization studies during mid-late human embryonic stages in normal tissue showed restricted FRMD7 expression in neuronal tissue with strong hybridization signals within the afferent arms of the vestibulo-ocular reflex consisting of the otic vesicle, cranial nerve VIII and vestibular ganglia. Similarly within the afferent arm of the optokinetic reflex we showed expression in the developing neural retina and ventricular zone of the optic stalk. Strong FRMD7 expression was seen in rhombomeres 1 to 4, which give rise to the cerebellum and the common integrator site for both these reflexes (vestibular nuclei). Based on the expression and phenotypic data, we hypothesize that periodic alternating nystagmus arises from instability of the optokinetic-vestibular systems. This study shows for the first time that mutations in FRMD7 can cause idiopathic infantile periodic alternating nystagmus and may affect neuronal circuits that have been implicated in acquired forms.
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Affiliation(s)
- Mervyn G Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
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16
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Oetting WS, Armstrong CM, Holleschau AM, DeWan AT, Summers CG. Evidence for genetic heterogeneity in families with congenital motor nystagmus (CN). Ophthalmic Genet 2009. [DOI: 10.1076/1381-6810(200012)2141-hft227] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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17
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Liu JY, Ren X, Yang X, Guo T, Yao Q, Li L, Dai X, Zhang M, Wang L, Liu M, Wang QK. Identification of a novel GPR143 mutation in a large Chinese family with congenital nystagmus as the most prominent and consistent manifestation. J Hum Genet 2007; 52:565-570. [PMID: 17516023 DOI: 10.1007/s10038-007-0152-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2007] [Accepted: 04/02/2007] [Indexed: 11/24/2022]
Abstract
Congenital nystagmus is characterized by involuntary, rhythmical, repeated oscillations of one or both eyes. We studied a large Chinese family with nystagmus as a prominent and consistent manifestation phenotype in nine patients to map and identify a disease-causing gene for nystagmus. X-linked recessive inheritance was observed in the family, and foveal hypoplasia was detected in some of the nine patients. The disease gene was mapped to an approximately 10.6 Mb region flanked by DXS996 and DXS7593 on Xp22 with a significant peak multipoint LOD score. Analysis of 21 candidate genes in the region revealed a novel p.S89F mutation in the second transmembrane domain of GPR143, a G protein-coupled receptor which causes ocular albinism when mutated. All male patients in the family were hemizygous for the mutation; the female carriers were heterozygous for the mutation. The p.S89F mutation was not identified in 100 normal females or 100 normal males. Our results indicate that a mutation in the GPR143 gene can cause a variant form of ocular albinism, with congenital nystagmus as the most prominent and only consistent finding in all patients in this Chinese family. These results expand the spectrum of clinical phenotypes associated with GPR143 mutations.
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Affiliation(s)
- Jing Yu Liu
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Xiang Ren
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Xiufeng Yang
- Development of Proof-Testing, Renmin Hospital of Tanghe, Tanghe, Henan, People's Republic of China
| | - Tangying Guo
- Development of Proof-Testing, Renmin Hospital of Tanghe, Tanghe, Henan, People's Republic of China
| | - Qi Yao
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Lin Li
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic/NE40, Cleveland, OH, 44195, USA
| | - Xiaohua Dai
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Mingchang Zhang
- Department of Ophthalmology, Union Hospital, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Lejin Wang
- Eye Center, Peking University, Beijing, People's Republic of China
| | - Mugen Liu
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China.
| | - Qing K Wang
- Center for Human Genome Research and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China.
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic/NE40, Cleveland, OH, 44195, USA.
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18
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Sallmann GB, Bray PJ, Rogers S, Quince A, Cotton RGH, Carden SM. Scanning the ocular albinism 1 (OA1) gene for polymorphisms in congenital nystagmus by DHPLC. Ophthalmic Genet 2006; 27:43-9. [PMID: 16754205 DOI: 10.1080/13816810600677834] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Nystagmus is common to all types of albinism. Some subjects with nystagmus lack convincing signs of albinism, have no other visual pathway disease, and are classified as possessing congenital idiopathic nystagmus (CN). It has been postulated that CN may be a form of ocular albinism. METHODS The presence of nystagmus, iris transillumination, and visual acuity were recorded in 39 CN and albino patients and their families. Physical characteristics were also noted. DNA from buccal swabs was obtained for use in denaturing high performance liquid chromatography (DHPLC) and chemical cleavage of mismatch (CCM) to scan several hotspots for X-linked ocular albinism (OA1) mutations. RESULTS Two previously reported polymorphisms were confirmed: neither was found to be a causative mutation. CONCLUSION No correlation was identified between nystagmus and OA1.
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Affiliation(s)
- Georgina B Sallmann
- Genomic Disorders Research Centre, St. Vincent's Hospital, Victoria, Australia
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19
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Guo X, Li S, Jia X, Xiao X, Wang P, Zhang Q. Linkage analysis of two families with X-linked recessive congenital motor nystagmus. J Hum Genet 2005; 51:76-80. [PMID: 16240070 DOI: 10.1007/s10038-005-0316-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Accepted: 09/09/2005] [Indexed: 11/28/2022]
Abstract
X-linked recessive congenital motor nystagmus was identified in two Chinese families living in the Guangdong province of China. Nystagmus was noticed in early childhood. Only males in the families were affected and all obligate carriers did not have nystagmus. Linkage study was performed using microsatellite markers at about 10 cM intervals on the X chromosome. The nystagmus in these two families is linked to markers in the region of chromosome Xq23-q27, including DXS1001, DXS8009, and DXS1047. DXS1047 gave the highest lod score of 3.53 at theta = 0.
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Affiliation(s)
- Xiangming Guo
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China
| | - Shiqiang Li
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China
| | - Xiaoyun Jia
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China
| | - Xueshan Xiao
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China
| | - Panfeng Wang
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China
| | - Qingjiong Zhang
- Key Laboratory of Ophthalmology of the Ministry of Education, Sun Yat-sen University, Guangzhou, People's Republic of China.
- Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, 510060, Guangzhou, People's Republic of China.
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20
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Zhang B, Xia K, Ding M, Liang D, Liu Z, Pan Q, Hu Z, Wu LQ, Cai F, Xia J. Confirmation and refinement of a genetic locus of congenital motor nystagmus in Xq26.3-q27.1 in a Chinese family. Hum Genet 2004; 116:128-31. [PMID: 15517395 DOI: 10.1007/s00439-004-1188-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 08/26/2004] [Indexed: 10/26/2022]
Abstract
Congenital motor nystagmus (CMN), a subtype of nystagmus, may reduce vision or be associated with other, more serious, conditions that limit vision. The genetic basis for CMN is still unknown. To identify a locus for CMN, genotyping and linkage analysis were performed in 22 individuals from a Chinese family with X-linked CMN using markers from X chromosome. The maximum LOD score obtained for microsatellite maker DXS1192 linked the CMN locus in this family to Xq. By haplotype construction the locus for CMN was finally localized to an approximately 4.4-cM region at chromosome Xq26.3-q27.1. The SLC9A6 and FGF13 genes in this region, were selected and screened for mutation in this family, but no mutation was detected.
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Affiliation(s)
- Baorong Zhang
- Department of Neurology of Second Hospital, Affiliated Zhejiang University, 310009 Hangzhou, China.
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21
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Hoffmann S, Becker A, Hoerle S, Metz A, Oertel WH, Sommer N, Hemmer B. Autosomal dominant congenital nystagmus is not linked to 6p12, 7p11, and 15q11 in a German family. Am J Ophthalmol 2004; 138:439-43. [PMID: 15364228 DOI: 10.1016/j.ajo.2004.04.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2004] [Indexed: 11/26/2022]
Abstract
PURPOSE Congenital nystagmus (CN) is an eye-movement disorder that usually starts within the first months of life. Autosomal dominant, autosomal recessive, and X-chromosomal pedigree patterns are observed. Causative genes are yet unknown. Several loci were implicated to contain disease-relevant genes for autosomal dominant CN (AD CN). AD CN cosegregated with a balanced translocation of 7;15 in a family. In a large black pedigree linkage was demonstrated to 6p12. DESIGN In this study, we describe a large German family with AD congenital nystagmus. Linkage of AD in this family was tested with previously implicated loci. METHODS Affected family members and unaffected members underwent genetic analysis. Key family members underwent ophthalmologic testing and oculography. RESULTS No linkage of AD CN to the implicated loci on 6p12, and 7p11, and 15q11 was found in this study. CONCLUSION In the presented pedigree genes on 15q11, and on the assumption of full penetrance, 6p12 and 7p11 are not involved in the development of AD congenital nystagmus.
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MESH Headings
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 6/genetics
- Chromosomes, Human, Pair 7/genetics
- DNA/analysis
- Electrooculography
- Female
- Genes, Dominant
- Genetic Linkage
- Genetic Markers
- Germany/epidemiology
- Haplotypes
- Humans
- Male
- Nystagmus, Congenital/diagnosis
- Nystagmus, Congenital/epidemiology
- Nystagmus, Congenital/genetics
- Pedigree
- Polymerase Chain Reaction
- Visual Acuity
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Affiliation(s)
- Steve Hoffmann
- Department of Neurology, Philipps-University, Marburg, Germany
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22
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Abstract
Over the past decade, there has been an exponential increase in our knowledge of heritable eye conditions. Coincidentally, our ability to provide accurate genetic diagnoses has allowed appropriate counseling to patients and families. A summary of our current understanding of ocular genetics will prove useful to clinicians, researchers, and students as an introduction to the subject.
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Affiliation(s)
- Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
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23
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Hertle RW, FitzGibbon EJ, Avallone JM, Cheeseman E, Tsilou EK. Onset of oscillopsia after visual maturation in patients with congenital nystagmus. Ophthalmology 2001; 108:2301-7; discussion 2307-8. [PMID: 11733274 DOI: 10.1016/s0161-6420(01)00815-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To describe the clinical and oculographic characteristics of a cohort of five patients with congenital nystagmus (CN) and late-onset oscillopsia caused by a coincidental decline in other visual and/or ocular motor functions. DESIGN Retrospective, observational, case series. PARTICIPANTS Five visually mature patients with CN and recent-onset oscillopsia were evaluated clinically and with motility recordings. INTERVENTION Eye movement analysis was performed off-line by computer analysis of digitized data. Nystagmus was analyzed for null-zone characteristics, waveforms, frequency, amplitudes, and slow-phase drift velocity during foveation. Surgical and medical treatment of associated ocular conditions in four of five patients. MAIN OUTCOME MEASURES Presence of symptomatic oscillopsia and average time during foveation periods of slow-phase drift velocity less than 10 degrees /second. RESULTS One of the five patients had associated rod-cone dystrophy, and another had recurrence of childhood head posturing with return of an eccentric null zone. The remaining three patients had decompensated strabismus associated with their oscillopsia. All five patients complained of oscillopsia in primary position that was relieved in the four who received treatment. Treatment included prismatic correction in one patient and surgery in three. Recordings in primary position after treatment showed increased duration during foveation periods of slow-phase drift velocity less than 10 degrees /second and an overall decreased intensity (amplitude/frequency) of the nystagmus. CONCLUSIONS Symptomatic oscillopsia in patients with CN is unusual. This visually disturbing symptom can be precipitated by new or changing associated visual sensory conditions (e.g., decompensating strabismus, retinal degeneration). If the associated conditions can be treated, then accompanying oscillopsia may be relieved.
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Affiliation(s)
- R W Hertle
- Laboratory of Sensorimotor Research, The National Eye Institute, The National Institutes of Health, Building 49 Room 2A50, Bethesda, MD 20892, USA
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Kerrison JB, Giorda R, Lenart TD, Drack AV, Maumenee IH. Clinical and genetic analysis of a family with X-linked congenital nystagmus (NYS1). Ophthalmic Genet 2001; 22:241-8. [PMID: 11803490 DOI: 10.1076/opge.22.4.241.2216] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To describe a family with X-linked congenital nystagmus and identify the genetic interval within which the gene is located. METHODS AND DESIGN Clinical examination with genotyping of 30 individuals from a multi-generational Caucasian family with congenital nystagmus inherited in an X-linked pattern using markers from Xq26-q27, followed by linkage analysis and sequencing of a candidate gene, solute carrier family 25, member 14 (SLC25A14), in four affected individuals from four families linked to this region. RESULTS The pattern of inheritance in the family was consistent with X-linkage with incomplete penetrance among carrier females. No affected males had affected sons. Based on the extended pedigree, the estimated penetrance among obligate female carriers (daughters of affected males) was 29% (6 of 21). Visual acuity among 15 affected individuals ranged from 20/20 to 20/70 (median 20/30). Clinical examinations, including electroretinography in two individuals, were otherwise normal except for the presence of nystagmus. Significant LOD scores (theta = 0) were found with markers DXS8057, DXS8044, DXS1047, DXS1062, DXS8072, and DXS8078, placing the gene within a approximately 5 cM interval flanked by DXS9909 and DXS1211 on the long arm of the X chromosome. Sequencing the candidate gene SLC25A14 in four affected individuals from four families linked to this region failed to reveal any mutations. CONCLUSIONS NYS1 appears to be a common gene for familial congenital idiopathic nystagmus. Linkage analysis of this family further reduces the interval in which NYS1 is located.
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Affiliation(s)
- J B Kerrison
- Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD, USA.
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25
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Rick JM, Horschke I, Neuhauss SC. Optokinetic behavior is reversed in achiasmatic mutant zebrafish larvae. Curr Biol 2000; 10:595-8. [PMID: 10837226 DOI: 10.1016/s0960-9822(00)00495-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The vertebrate optokinetic nystagmus (OKN) is a compensatory oculomotor behavior that is evoked by movement of the visual environment. It functions to stabilize visual images on the retina. The OKN can be experimentally evoked by rotating a drum fitted with stripes around the animal and has been studied extensively in many vertebrate species, including teleosts. This simple behavior has earlier been used to screen for mutations affecting visual system development in the vertebrate model organism zebrafish. In such a screen, we have found a significant number of homozygous belladonna (bel) mutant larvae to be defective in the correct execution of the OKN [1]. We now show that about 40% of homozygous bel larvae display a curious reversal of the OKN upon visual stimulation. Monocular stimulation leads to primary activation of ipsilateral eye movements in larvae that behave like the wild type. In contrast, affected larvae display contralateral activation of eye movements upon monocular stimulation. Anatomical analysis of retinal ganglion cell axon projections reveal a morphological basis for the observed behavioral defect. All animals with OKN reversal are achiasmatic. Further behavioral examination of affected larvae show that OKN-reversed animals execute this behavior in a stimulus-velocity-independent manner. Our data support a parsimonious model of optokinetic reversal by the opening of a controlling feedback loop at the level of the optic chiasm that is solely responsible for the observed behavioral abnormality in mutant belladonna larvae.
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Affiliation(s)
- J M Rick
- Department of Neuromorphology, Max-Planck-Institut für Entwicklungsbiologie, Abt. Physikalische Biologie, Brain Research Institute, University of Zürich, Zürich, Switzerland
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26
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Abstract
Nystagmus may have onset in infancy or adulthood. Infantile-onset nystagmus is commonly associated with genetic disease, and recognition of the various genetic and nongenetic diseases in which it may develop has led to the understanding that nystagmus is often a response of the oculomotor system to an early-onset, bilateral abnormality of vision. Adult-onset nystagmus most often develops as a result of nongenetic neurologic disease, and it manifests in a variety of patterns. Genetic studies have allowed further identification of the genes and genetic loci associated with nystagmus, and careful eye-movement recordings in patients with various patterns of nystagmus have further clarified the oculomotor pathophysiology.
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Affiliation(s)
- J B Kerrison
- Emory Eye Center, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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Cabot A, Rozet JM, Gerber S, Perrault I, Ducroq D, Smahi A, Souied E, Munnich A, Kaplan J. A gene for X-linked idiopathic congenital nystagmus (NYS1) maps to chromosome Xp11.4-p11.3. Am J Hum Genet 1999; 64:1141-6. [PMID: 10090899 PMCID: PMC1377838 DOI: 10.1086/302324] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Congenital nystagmus (CN) is a common oculomotor disorder (frequency of 1/1,500 live births) characterized by bilateral uncontrollable ocular oscillations, with onset typically at birth or within the first few months of life. This condition is regarded as idiopathic, after exclusion of nervous and ocular diseases. X-linked, autosomal dominant, and autosomal recessive modes of inheritance have been reported, but X-linked inheritance is probably the most common. In this article, we report the mapping of a gene for X-linked dominant CN (NYS1) to the short arm of chromosome X, by showing close linkage of NYS1 to polymorphic markers on chromosome Xp11.4-p11.3 (maximum LOD score of 3.20, over locus DXS993). Because no candidate gene, by virtue of its function, has been found in this region of chromosome Xp, further studies are required, to reduce the genetic interval encompassing the NYS1 gene. It is hoped that the complete gene characterization will address the complex pathophysiology of CN.
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Affiliation(s)
- A Cabot
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant, Institut National de la Santé et de la Recherche Médicale U393, Hôpital des Enfants Malades, Paris, France
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28
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Kerrison JB, Vagefi MR, Barmada MM, Maumenee IH. Congenital motor nystagmus linked to Xq26-q27. Am J Hum Genet 1999; 64:600-7. [PMID: 9973299 PMCID: PMC1377771 DOI: 10.1086/302244] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Congenital motor nystagmus (CMN) is a hereditary disorder characterized by bilateral ocular oscillations that begin in the first 6 mo of life. It must be distinguished from those genetic disorders-such as ocular albinism (OA), congenital stationary night blindness (CSNB), and blue-cone monochromatism (BCM)-in which nystagmus accompanies a clinically apparent defect in the visual sensory system. Although CMN is presumed to arise from a neurological abnormality of fixation, it is not known whether the molecular defect is located in the eye or in the brain. It may be inherited in an autosomal dominant, autosomal recessive, or X-linked pattern. Three families with CMN inherited in an X-linked, irregularly dominant pattern were investigated with linkage and candidate gene analysis. The penetrance among obligate female carriers was 54%. Evaluation of markers in the region of the genes for X-linked OA, CSNB, and BCM revealed no evidence of linkage, supporting the hypothesis that CMN represents a distinct entity. The gene was mapped to chromosome Xq26-q27 with the following markers: GATA172D05 (LOD score 3.164; recombination fraction [theta] = 0.156), DXS1047 (LOD score 10.296; theta = 0), DXS1192 (LOD score 8.174; theta = 0.027), DXS1232 (LOD score 6.015; theta = 0.036), DXS984 (LOD score 6.695; theta = 0), and GATA31E08 (LOD score 4.940; theta = 0.083). Assessment of haplotypes and multipoint linkage analysis, which gave a maximum LOD score of 10.790 with the 1-LOD-unit support interval spanning approximately 7 cM, place the gene in a region between GATA172D05 and DXS1192. Evaluation of candidate genes CDR1 and SOX3 did not reveal mutations in affected male subjects.
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Affiliation(s)
- J B Kerrison
- The Johns Hopkins Center for Hereditary Eye Diseases, Baltimore, MD 21287-9237, USA
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29
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Klein C, Vieregge P, Heide W, Kemper B, Hagedorn-Greiwe M, Hagenah J, Vollmer C, Breakefield XO, Kömpf D, Ozelius L. Exclusion of chromosome regions 6p12 and 15q11, but not chromosome region 7p11, in a German family with autosomal dominant congenital nystagmus. Genomics 1998; 54:176-7. [PMID: 9806847 DOI: 10.1006/geno.1998.5535] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
MESH Headings
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 6/genetics
- Chromosomes, Human, Pair 7/genetics
- Female
- Genes, Dominant/genetics
- Genetic Linkage
- Haplotypes
- Humans
- Karyotyping
- Male
- Nystagmus, Pathologic/congenital
- Nystagmus, Pathologic/genetics
- Nystagmus, Pathologic/physiopathology
- Pedigree
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Affiliation(s)
- C Klein
- Department of Neurology, Medical University of Lübeck, Lübeck, Germany
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30
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MacDonald IM, Haney PM, Musarella MA. Summary of ocular genetic disorders and inherited systemic conditions with eye findings. Ophthalmic Genet 1998; 19:1-17. [PMID: 9587925 DOI: 10.1076/opge.19.1.1.2181] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Of the close to 10,000 known inherited disorders that affect humankind, a disproportionately high number affect the eye. The total number of genes responsible for the normal structure, function, and differentiation of the eye is unknown, but the list of these genes is rapidly and constantly growing. The objective of this paper is to provide a current list of mapped and/or cloned human eye genes that are responsible for inherited diseases of the eye. The ophthalmologist should be aware of recent advances in molecular technology which have resulted in significant progress towards the identification of these genes. The implications of this new knowledge will be discussed herein.
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Affiliation(s)
- I M MacDonald
- Department of Ophthalmology, University of Alberta, Canada
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Kerrison JB, Koenekoop RK, Arnould VJ, Zee D, Maumenee IH. Clinical features of autosomal dominant congenital nystagmus linked to chromosome 6p12. Am J Ophthalmol 1998; 125:64-70. [PMID: 9437315 DOI: 10.1016/s0002-9394(99)80236-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To describe the clinical features of a large pedigree with autosomal dominant congenital nystagmus linked to chromosome 6p12. METHODS In a prospective evaluation of 54 living family members in a single pedigree, 21 persons were affected with autosomal dominant congenital nystagmus, and clinical examinations were performed on 14. Selected persons underwent further studies, including electroretinography, scanning laser ophthalmoscopy, nerve fiber layer studies, visual evoked potential studies, and eye movement recordings. RESULTS Among seven affected persons whose parents were able to report whether the nystagmus was present congenitally, onset at birth was noted in two persons and between 3 and 6 months in five persons. Best-corrected binocular Snellen visual acuity ranged from 20/30 to 20/100, with a mode of 20/50. Strabismus was present in 14 examined patients (36%). Eye movement recordings, performed on five persons, included asymmetric pendular (three), asymmetric pendular combined with dual waveform jerk (one), and unidirectional jerk nystagmus (one). CONCLUSIONS Autosomal dominant congenital nystagmus represents a disorder with variable expressivity. While onset is typically during infancy, it can be noted at birth. Intrafamilial variation in visual acuity, ocular alignment, and nystagmus waveform suggests a role for modifying influences on expression of disease.
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Affiliation(s)
- J B Kerrison
- Johns Hopkins Center for Hereditary Eye Diseases, Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD 21287-9237, USA.
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32
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Abstract
Current concepts of idiopathic infantile nystagmus are summarized, with special attention to treatment and differential diagnosis of this condition. Advantages of the Anderson procedure over the Kestenbaum procedure are suggested for head turn associated with this condition, and the need for further studies is acknowledged. The importance of the extended slow phase in understanding the waveforms of infantile nystagmus is stressed. Our studies reinforce what I believe to be the natural history of infantile nystagmus, as well as the history of periodic alternating nystagmus. The critical delineation of diagnosing periodic alternating nystagmus is emphasized with respect to the type of operation to avoid overcorrection of head turns in patients with nystagmus. Continued searches for manifest latent nystagmus are important, because that condition is currently the only truly treatable nystagmus. I thank the American Association for Pediatric Ophthalmology and Strabismus for the privilege and honor of presenting the 1997 Costenbader Lecture.
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Affiliation(s)
- R D Reinecke
- Foerderer Eye Movement Center for Children, Wills Eye Hospital, Department of Ophthalmology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, USA
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