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Su Y, Zhang J, Gao J, Ding G, Jiang H, Liu Y, Li Y, Yang G. Truncated FRMD7 proteins in congenital Nystagmus: novel frameshift mutations and proteasomal pathway implications. BMC Med Genomics 2024; 17:36. [PMID: 38279119 PMCID: PMC10811807 DOI: 10.1186/s12920-024-01817-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/23/2024] [Indexed: 01/28/2024] Open
Abstract
Idiopathic congenital nystagmus (ICN) manifests as involuntary and periodic eye movements. To identify the genetic defect associated with X-linked ICN, Whole Exome Sequencing (WES) was conducted in two affected families. We identified two frameshift mutations in FRMD7, c.1492dupT/p.(Y498Lfs*15) and c.1616delG/p.(R539Kfs*2). Plasmids harboring the mutated genes and qPCR analysis revealed mRNA stability, evading degradation via the NMD pathway, and corroborated truncated protein production via Western-blot analysis. Notably, both truncated proteins were degraded through the proteasomal (ubiquitination) pathway, suggesting potential therapeutic avenues targeting this pathway for similar mutations. Moreover, we conducted a comprehensive analysis, summarizing 140 mutations within the FRMD7 gene. Our findings highlight the FERM and FA structural domains as mutation-prone regions. Interestingly, exons 9 and 12 are the most mutated regions, but 90% (28/31) mutations in exon 9 are missense while 84% (21/25) mutations in exon 12 are frameshift. A predominant occurrence of shift code mutations was observed in exons 11 and 12, possibly associated with the localization of premature termination codons (PTCs), leading to the generation of deleterious truncated proteins. Additionally, our conjecture suggests that the loss of FRMD7 protein function might not solely drive pathology; rather, the emergence of aberrant protein function could be pivotal in nystagmus etiology. We propose a dependence of FRMD7 protein normal function primarily on its anterior domain. Future investigations are warranted to validate this hypothesis.
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Affiliation(s)
- Yuqing Su
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China
- The First Clinical College of Wuhan University, Wuhan, China
| | - Juntao Zhang
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, China
| | - Jiahui Gao
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Guoqing Ding
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Heng Jiang
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Yang Liu
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, China
| | - Yulei Li
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, China.
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang, 441053, China.
| | - Guohua Yang
- Department of Medical Genetics, School of Basic Medical Science, Wuhan University, Wuhan, China.
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, 430071, China.
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Xu J, Zheng Y, Cheng L, Sun H, Yu X, Gu F, Song E. GPR143 mutations in an X-linked infantile nystagmus syndrome cohort in Southeast China. Mol Vis 2023; 29:234-244. [PMID: 38222445 PMCID: PMC10784212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 10/25/2023] [Indexed: 01/16/2024] Open
Abstract
Purpose Infantile nystagmus syndrome (INS), or congenital nystagmus (CN), refers to a group of ocular motor disorders characterized by rapid to-and-fro oscillations of the eyes. GPR143 is the causative gene of ocular albinism type 1 (OA1), which is a special type of INS that manifests as reduced vision, nystagmus, and iris and fundus hypopigmentation. Here, we explored the genetic spectrum of INS and the genotype-phenotype correlation. Methods A total of 98 families with INS from Southeast China were recruited for this study. A sample from each participant was subjected to PCR-based DNA direct sequencing of GPR143. Varied bioinformatics analysis was subsequently used in a mutation assessment. All participants received detailed ophthalmic examinations. Results Genetic analysis identified 11 GPR143 mutations in 11.2% (11/98) of the X-linked INS families. These included seven novel mutations (c.899 C>T, c.886-2 A>G, c.1A>G, c.633_643del CCTGTTCCAAA, c.162_198delCGCGGGCCCCGGGTCCCCCGCGACGTCCCCGCCGGCC, c.628C>A, and c.178_179insGGGTCCC) and four known mutations. Patients who carried a GPR143 mutation were found to present a typical or atypical phenotype of OA1. All patients with GPR143 mutations manifested foveal hypoplasia; thus, about 45.8% (11/24) of the families with total X-linked INS exhibited foveal hypoplasia. Conclusions We discovered seven novel mutations and four previously reported mutations of GPR143 in a cohort of families with X-linked INS and enlarged the Chinese genetic spectrum of INS. These findings offer new insights for developing genetic screening strategies and shed light on the importance of conducting genetic analysis in confirming the clinical diagnosis in unresolved patients and atypical phenotypes.
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Affiliation(s)
- Jingling Xu
- Department of Ophthalmology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
- Eye Hospital of Wenzhou Medical University Wenzhou China
| | - Yihan Zheng
- Eye Hospital of Wenzhou Medical University Wenzhou China
| | - Lulu Cheng
- Eye Department in People's Hospital of Longgang District, Shenzhen, China
| | - Huihui Sun
- Eye Department of Children Hosptial in Hebei Province, Shijiazhuang, China
| | - Xinping Yu
- Eye Hospital of Wenzhou Medical University Wenzhou China
| | - Feng Gu
- Eye Hospital of Wenzhou Medical University Wenzhou China
| | - E Song
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
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Hecht I, Weiner C, Kotlyar A, Shoshany N, Pras E. Micro chromosomal deletions at the NYS7 locus and autosomal dominant nystagmus. Exp Eye Res 2023; 230:109459. [PMID: 37001852 DOI: 10.1016/j.exer.2023.109459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/13/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023]
Abstract
Nystagmus is an ocular condition characterized by bilateral involuntary ocular oscillation which can severely affect vision. When not associated with other ocular or systemic diseases, it is referred to as idiopathic or congenital motor nystagmus (CMN). Genome-wide linkage studies have previously identified several loci associated with CMN, however the genes responsible for some of these loci have yet to be identified. We have examined a large, five-generation family with autosomal dominant CMN. Our purpose was to characterize the clinical manifestations and reveal the molecular basis of the disease in this family. In addition to full ophthalmic examination and imaging, molecular analysis included copy number variation analysis, linkage studies, and Sanger sequencing. Expression analyses of candidate genes was done by real-time PCR. Of the 68 family members, 27 subjects in five-generations had CMN, in line with an autosomal dominant inheritance pattern. Molecular analysis was performed on 27 members, 15 of them affected by CMN. Copy number variation analysis using array comparative genomic hybridization (aCGH) revealed a novel deletion located on 1q32 (NYS7) among affected individuals. Linkage analysis using polymorphic markers demonstrated full segregation with a heterozygous haplotype in all affected patients, with a LOD score of >5. Sanger sequencing of affected subjects revealed a novel deletion of 732,526 bp in the linkage interval. No protein-coding genes exist within the deleted region; however, the deletion disrupts topologically associated domains encompassing the gene NR5A2 and the non-protein coding MIR181A. Both are strongly associated with other genes expressed in the retina such as PROX1, which in turn is also associated with genes related to nystagmus such as PAX6. We therefore hypothesized that the deletion might affect NR5A2 and MIR181A expression, causing CMN. Expression analysis by real-time PCR showed significantly lower expression of NR5A2, and significantly higher expression of PROX1 among patients compared with controls. To conclude, among a large five-generation family with autosomal dominant CMN, a large deletion in the interval of NYS7 was linked with the disease. No protein-coding genes exist inside the deleted region, and so the exact mechanism in which CMN is caused is uncertain. Based on topological association and expression analyses we suggest a possible mechanism for the pathogenesis.
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Affiliation(s)
- Idan Hecht
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel.
| | - Chen Weiner
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel
| | - Alina Kotlyar
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel
| | - Nadav Shoshany
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel
| | - Eran Pras
- Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Shamir Medical Center (formerly Assaf-Harofeh), Tzrifin, Israel
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [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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Nieves-Moreno M, Noval S, Peralta J, Palomares-Bralo M, del Pozo A, Garcia-Miñaur S, Santos-Simarro F, Vallespin E. Expanding the Phenotypic Spectrum of PAX6 Mutations: From Congenital Cataracts to Nystagmus. Genes (Basel) 2021; 12:genes12050707. [PMID: 34065151 PMCID: PMC8151272 DOI: 10.3390/genes12050707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/15/2022] Open
Abstract
Background: Congenital aniridia is a complex ocular disorder, usually associated with severe visual impairment, generally caused by mutations on the PAX6 gene. The clinical phenotype of PAX6 mutations is highly variable, making the genotype–phenotype correlations difficult to establish. Methods: we describe the phenotype of eight patients from seven unrelated families with confirmed mutations in PAX6, and very different clinical manifestations. Results: Only two patients had the classical aniridia phenotype while the other two presented with aniridia-related manifestations, such as aniridia-related keratopathy or partial aniridia. Congenital cataracts were the main manifestation in three of the patients in this series. All the patients had nystagmus and low visual acuity. Conclusions: The diagnosis of mild forms of aniridia is challenging, but these patients have a potentially blinding hereditary disease that might present with a more severe phenotype in future generations. Clinicians should be aware of the mild aniridia phenotype and request genetic testing to perform an accurate diagnosis.
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Affiliation(s)
- Maria Nieves-Moreno
- Department of Ophthalmology, Hospital Universitario La Paz, 28046 Madrid, Spain; (S.N.); (J.P.)
- Correspondence:
| | - Susana Noval
- Department of Ophthalmology, Hospital Universitario La Paz, 28046 Madrid, Spain; (S.N.); (J.P.)
| | - Jesus Peralta
- Department of Ophthalmology, Hospital Universitario La Paz, 28046 Madrid, Spain; (S.N.); (J.P.)
| | - María Palomares-Bralo
- Department of Molecular Developmental Disorders, Medical and Molecular Genetics Institue (INGEMM) IdiPaz, CIBERER, Hospital Universitario La Paz, 28046 Madrid, Spain;
| | - Angela del Pozo
- Department of Bioinformatics, Medical and Molecular Genetics Institue (INGEMM) IdiPaz, CIBERER, Hospital Universitario La Paz, 28046 Madrid, Spain;
| | - Sixto Garcia-Miñaur
- Department of Clinical Genetics, Medical and Molecular Genetics Institue (INGEMM) IdiPaz, CIBERER, Hospital Universitario La Paz, 28046 Madrid, Spain; (S.G.-M.); (F.S.-S.)
| | - Fernando Santos-Simarro
- Department of Clinical Genetics, Medical and Molecular Genetics Institue (INGEMM) IdiPaz, CIBERER, Hospital Universitario La Paz, 28046 Madrid, Spain; (S.G.-M.); (F.S.-S.)
| | - Elena Vallespin
- Department of Molecular Ophthalmology, Medical and Molecular Genetics Institue (INGEMM) IdiPaz, CIBERER, Hospital Universitario La Paz, 28046 Madrid, Spain;
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Volk AE, Hedergott A, Preising M, Rading S, Fricke J, Herkenrath P, Nürnberg P, Altmüller J, von Ameln S, Lorenz B, Neugebauer A, Karsak M, Kubisch C. Biallelic mutations in L-dopachrome tautomerase (DCT) cause infantile nystagmus and oculocutaneous albinism. Hum Genet 2021; 140:1157-1168. [PMID: 33959807 DOI: 10.1007/s00439-021-02285-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/19/2021] [Indexed: 11/26/2022]
Abstract
Infantile nystagmus syndrome (INS) denominates early-onset, involuntary oscillatory eye movements with different etiologies. Nystagmus is also one of the symptoms in oculocutaneus albinism (OCA), a heterogeneous disease mainly caused by defects in melanin synthesis or melanosome biogenesis. Dopachrome tautomerase (DCT, also called TYRP2) together with tyrosinase (TYR) and tyrosin-related protein 1 (TYRP1) is one of the key enzymes in melanin synthesis. Although DCT´s role in pigmentation has been proven in different species, until now only mutations in TYR and TYRP1 have been found in patients with OCA. Detailed ophthalmological and orthoptic investigations identified a consanguineous family with two individuals with isolated infantile nystagmus and one family member with subtle signs of albinism. By whole-exome sequencing and segregation analysis, we identified the missense mutation c.176G > T (p.Gly59Val) in DCT in a homozygous state in all three affected family members. We show that this mutation results in incomplete protein maturation and targeting in vitro compatible with a partial or total loss of function. Subsequent screening of a cohort of patients with OCA (n = 85) and INS (n = 25) revealed two heterozygous truncating mutations, namely c.876C > A (p.Tyr292*) and c.1407G > A (p.Trp469*), in an independent patient with OCA. Taken together, our data suggest that mutations in DCT can cause a phenotypic spectrum ranging from isolated infantile nystagmus to oculocutaneous albinism.
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Affiliation(s)
- Alexander E Volk
- Institute of Human Genetics, University Medical Center Hamburg Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany.
| | - Andrea Hedergott
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, 50931, Cologne, Germany
| | - Markus Preising
- Department of Ophthalmology, Justus-Liebig-University Giessen, 35392, Giessen, Germany
| | - Sebastian Rading
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246, Hamburg, Germany
| | - Julia Fricke
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, 50931, Cologne, Germany
| | - Peter Herkenrath
- Department of Paediatrics, University of Cologne, 50931, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, 50931, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, 50931, Cologne, Germany
| | - Simon von Ameln
- Institute of Human Genetics, University of Ulm, 89081, Ulm, Germany
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, 35392, Giessen, Germany
- Department of Ophthalmology, University Hospital of Bonn, 53127, Bonn, Germany
| | - Antje Neugebauer
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, 50931, Cologne, Germany
| | - Meliha Karsak
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246, Hamburg, Germany
| | - Christian Kubisch
- Institute of Human Genetics, University Medical Center Hamburg Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany
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Jin S, Park SE, Won D, Lee ST, Han SH, Han J. TUBB3 M323V Syndrome Presents with Infantile Nystagmus. Genes (Basel) 2021; 12:genes12040575. [PMID: 33921132 PMCID: PMC8071555 DOI: 10.3390/genes12040575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 01/28/2023] Open
Abstract
Variants in the TUBB3 gene, one of the tubulin-encoding genes, are known to cause congenital fibrosis of the extraocular muscles type 3 and/or malformations of cortical development. Herein, we report a case of a 6-month-old infant with c.967A>G:p.(M323V) variant in the TUBB3 gene, who had only infantile nystagmus without other ophthalmological abnormalities. Subsequent brain magnetic resonance imaging (MRI) revealed cortical dysplasia. Neurological examinations did not reveal gross or fine motor delay, which are inconsistent with the clinical characteristics of patients with the M323V syndrome reported so far. A protein modeling showed that the M323V mutation in the TUBB3 gene interferes with αβ heterodimer formation with the TUBA1A gene. This report emphasizes the importance of considering TUBB3 and TUBA1A tubulinopathy in infantile nystagmus. A brain MRI should also be considered for these patients, although in the absence of other neurologic signs or symptoms.
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Affiliation(s)
- Soohwa Jin
- Department of Opthalmology, Yonsei University College of Medicine, Seoul 03722, Korea;
| | - Sung-Eun Park
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (S.-E.P.); (S.-H.H.)
| | - Dongju Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.)
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.)
| | - Sueng-Han Han
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (S.-E.P.); (S.-H.H.)
| | - Jinu Han
- Department of Ophthalmology, Institute of Vision Research, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
- Correspondence: ; Tel.: +82-2-2019-3445
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Kuht HJ, Han J, Maconachie GDE, Park SE, Lee ST, McLean R, Sheth V, Hisaund M, Dawar B, Sylvius N, Mahmood U, Proudlock FA, Gottlob I, Lim HT, Thomas MG. SLC38A8 mutations result in arrested retinal development with loss of cone photoreceptor specialization. Hum Mol Genet 2020; 29:2989-3002. [PMID: 32744312 PMCID: PMC7645707 DOI: 10.1093/hmg/ddaa166] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 01/09/2023] Open
Abstract
Foveal hypoplasia, optic nerve decussation defects and anterior segment dysgenesis is an autosomal recessive disorder arising from SLC38A8 mutations. SLC38A8 is a putative glutamine transporter with strong expression within the photoreceptor layer in the retina. Previous studies have been limited due to lack of quantitative data on retinal development and nystagmus characteristics. In this multi-centre study, a custom-targeted next generation sequencing (NGS) gene panel was used to identify SLC38A8 mutations from a cohort of 511 nystagmus patients. We report 16 novel SLC38A8 mutations. The sixth transmembrane domain is most frequently disrupted by missense SLC38A8 mutations. Ninety percent of our cases were initially misdiagnosed as PAX6-related phenotype or ocular albinism prior to NGS. We characterized the retinal development in vivo in patients with SLC38A8 mutations using high-resolution optical coherence tomography. All patients had severe grades of arrested retinal development with lack of a foveal pit and no cone photoreceptor outer segment lengthening. Loss of foveal specialization features such as outer segment lengthening implies reduced foveal cone density, which contributes to reduced visual acuity. Unlike other disorders (such as albinism or PAX6 mutations) which exhibit a spectrum of foveal hypoplasia, SLC38A8 mutations have arrest of retinal development at an earlier stage resulting in a more under-developed retina and severe phenotype.
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Affiliation(s)
- Helen J Kuht
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Gail D E Maconachie
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
- Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Sheffield S10 2RX, UK
| | - Sung Eun Park
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
| | - Rebecca McLean
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Viral Sheth
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Michael Hisaund
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Basu Dawar
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Nicolas Sylvius
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Usman Mahmood
- Department of Ophthalmology, Hull and East Yorkshire Hospitals NHS Trust, Hull HU3 2JZ, UK
| | - Frank A Proudlock
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Hyun Taek Lim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Mervyn G Thomas
- The University of Leicester Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester – RKCSB, PO Box 65, Leicester LE2 7LX, UK
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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10
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Syrimis A, Nicolaou N, Alexandrou A, Papaevripidou I, Nicolaou M, Loukianou E, Sismani C, Malas S, Christophidou-Anastasiadou V, Tanteles GA. Molecular analysis of Cypriot families with aniridia reveals a novel PAX6 mutation. Mol Med Rep 2018; 18:1623-1627. [PMID: 29901133 PMCID: PMC6072148 DOI: 10.3892/mmr.2018.9126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022] Open
Abstract
The present study investigated the clinical and mutational spectrum of aniridia in a cohort of 17 affected individuals from six families from Cyprus. Each proband was initially evaluated for copy number variants at the PAX6 locus and subsequently underwent PAX6 mutation screening. Sequence analysis of FOXC1 and PITX2 was performed in patients who did not carry a PAX6 mutation. The most common clinical features in the group of aniridia patients associated with aniridia were nystagmus, cataracts and glaucoma. PAX6 pathogenic mutations were identified in five out of six families (a diagnostic yield of 84%). Previously reported pathogenic mutations in PAX6 were identified in four families, which comprise p.R203*, p.R240* and p.R317*. In addition, a novel pathogenic variant (p.E220Gfs*23) was identified in a single family. No pathogenic mutations were detected in PAX6, FOXC1 or PITX2 in the only patient with a sporadic form of aniridia‑like phenotype, confirming the genetic heterogeneity associated with this disease. To the best of our knowledge this is the first report on the mutational spectrum of PAX6 in aniridia patients of Cypriot ancestry. Mutational screening of PAX6 serves a crucial role in distinguishing isolated from syndromic forms of aniridia, and it may therefore eliminate the need for renal ultrasound scan surveillance, delineate the phenotype and improve genetic counseling.
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Affiliation(s)
- Andreas Syrimis
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Nayia Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Michael Nicolaou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Eleni Loukianou
- Department of Ophthalmology, Nicosia General Hospital, 2029 Nicosia, Cyprus
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Stavros Malas
- Department of Developmental and Functional Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
| | - Violetta Christophidou-Anastasiadou
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
- Department of Clinical Genetics, Archbishop Makarios III Hospital, 2012 Nicosia, Cyprus
| | - George A. Tanteles
- Department of Clinical Genetics, The Cyprus Institute of Neurology and Genetics, 2370 Nicosia, Cyprus
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Rim JH, Lee ST, Gee HY, Lee BJ, Choi JR, Park HW, Han SH, Han J. Accuracy of Next-Generation Sequencing for Molecular Diagnosis in Patients With Infantile Nystagmus Syndrome. JAMA Ophthalmol 2017; 135:1376-1385. [PMID: 29145603 PMCID: PMC6583550 DOI: 10.1001/jamaophthalmol.2017.4859] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/23/2017] [Indexed: 01/10/2023]
Abstract
Importance Infantile nystagmus syndrome (INS) is a group of disorders presenting with genetic and clinical heterogeneities that have challenged the genetic and clinical diagnoses of INS. Precise molecular diagnosis in early infancy may result in more accurate genetic counseling and improved patient management. Objective To assess the accuracy of genomic data from next-generation sequencing (NGS) and phenotypic data to enhance the definitive diagnosis of INS. Design, Setting, and Participants A single-center retrospective case series was conducted in 48 unrelated, consecutive patients with INS, with or without associated ocular or systemic conditions, who underwent genetic testing between June 1, 2015, and January 31, 2017. Next-generation sequencing analysis was performed using a target panel that included 113 genes associated with INS (n = 47) or a TruSight One sequencing panel that included 4813 genes associated with known human phenotypes (n = 1). Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Patients underwent a detailed ophthalmic examination, including electroretinography and optical coherence tomography, if feasible. Main Outcomes and Measures Diagnostic yield of targeted NGS testing. Results Among the 48 patients (21 female and 27 male; mean [SD] age at genetic testing, 9.2 [10.3] years), 8 had a family history of nystagmus and 40 were simplex. All patients were of a single ethnicity (Korean). Genetic variants that were highly likely to be causative were identified in 28 of the 48 patients, corresponding to a molecular diagnostic yield of 58.3% (95% CI, 44.4%-72.2%). FRMD7, GPR143, and PAX6 mutations appeared to be the major genetic causes of familial INS. A total of 10 patients (21%) were reclassified to a different diagnosis based on results of NGS testing, enabling accurate clinical management. Conclusions and Relevance These findings suggest that NGS is an accurate diagnostic tool to differentiate causes of INS because diagnostic tests, such as electroretinography and optical coherence tomography, are not easily applicable in young infants. Accurate application of NGS using a standardized, stepwise, team-based approach in early childhood not only facilitated early molecular diagnosis but also led to improved personalized management in patients with INS.
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Affiliation(s)
- John Hoon Rim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Heon Yung Gee
- Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea
- Department of Pharmacology, Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Byung Joo Lee
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hye Won Park
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Sueng-Han Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Jinu Han
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
- Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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12
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Zhao H, Huang XF, Zheng ZL, Deng WL, Lei XL, Xing DJ, Ye L, Xu SZ, Chen J, Zhang F, Yu XP, Jin ZB. Molecular genetic analysis of patients with sporadic and X-linked infantile nystagmus. BMJ Open 2016; 6:e010649. [PMID: 27036142 PMCID: PMC4823450 DOI: 10.1136/bmjopen-2015-010649] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Infantile nystagmus (IN) is a genetically heterogeneous condition characterised by involuntary rhythmic oscillations of the eyes accompanied by different degrees of vision impairment. Two genes have been identified as mainly causing IN: FRMD7 and GPR143. The aim of our study was to identify the genetic basis of both sporadic IN and X-linked IN. DESIGN Prospective analysis. PATIENTS Twenty Chinese patients, including 15 sporadic IN cases and 5 from X-linked IN families, were recruited and underwent molecular genetic analysis. We first performed PCR-based DNA sequencing of the entire coding region and the splice junctions of the FRMD7 and GPR143 genes in participants. Mutational analysis and co-segregation confirmation were then performed. SETTING All clinical examinations and genetic experiments were performed in the Eye Hospital of Wenzhou Medical University. RESULTS Two mutations in the FRMD7 gene, including one novel nonsense mutation (c.1090C>T, p.Q364X) and one reported missense mutation (c.781C>G, p.R261G), were identified in two of the five (40%) X-linked IN families. However, none of putative mutations were identified in FRMD7 or GPR143 in any of the sporadic cases. CONCLUSIONS The results suggest that mutations in FRMD7 appeared to be the major genetic cause of X-linked IN, but not of sporadic IN. Our findings provide further insights into FRMD7 mutations, which could be helpful for future genetic diagnosis and genetic counselling of Chinese patients with nystagmus.
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Affiliation(s)
- Hui Zhao
- Wenzhou People's Hospital, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou Medical University, Wenzhou, China
| | - Xiu-Feng Huang
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Zhi-Li Zheng
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Wen-Li Deng
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Xin-Lan Lei
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Dong-Jun Xing
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Liang Ye
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Su-Zhong Xu
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Jie Chen
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Fang Zhang
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Xin-Ping Yu
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
| | - Zi-Bing Jin
- The Eye Hospital of Wenzhou Medical University, The State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, China
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [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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14
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Wang XJ, Zhao KX. [Molecular genetics advances of congenital idiopathic nystagmus]. Zhonghua Yan Ke Za Zhi 2011; 47:1038-1042. [PMID: 22336070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Congenital idiopathic nystagmus (CIN) is genetically heterogeneous. Autosomal dominant, autosomal recessive and X-linked patterns of inheritance have described. At least three distinct loci are related to autosomal dominant and X-linked patterns. One causative gene for X-linked form has been identified (FRMD7, Xq26.2) through linkage analysis. The molecular genetics advances of the congenital idiopathic nystagmus (CIN) are reviewed.
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Affiliation(s)
- Xiao-juan Wang
- Clinical College of Ophthalmology of Tianjin Medical University, Tianjin Eye Hospital and Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin 300020, China
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Tsunemi T, Ishikawa K, Tsukui K, Sumi T, Kitamura K, Mizusawa H. The effect of 3,4-diaminopyridine on the patients with hereditary pure cerebellar ataxia. J Neurol Sci 2010; 292:81-4. [PMID: 20181362 DOI: 10.1016/j.jns.2010.01.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2009] [Revised: 01/22/2010] [Accepted: 01/26/2010] [Indexed: 11/18/2022]
Abstract
BACKGROUND Downbeat nystagmus (DBN) is often seen in patients with pure cerebellar type of spinocerebellar ataxia (SCA) like spinocerebellar ataxia type 6 (SCA6). DBN frequently presents with other cerebellar symptoms such as postural imbalance or ataxia. A potassium channel blocker 3,4-diaminopyridine (3,4-DAP) has been reported to reduce DBN by increasing the excitability of Purkinje cells. OBJECTIVE The objective of this study is to determine whether 3,4-DAP has a beneficial effect on DBN along with postural imbalance and ataxic symptoms in 10 patients with SCA6 and five patients with chromosome 16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA). RESULTS The patients took 20mg of 3,4-DAP twice a day for a week. DBN was observed in seven patients with SCA6 and two with 16q-ADCA. Although 3,4-DAP significantly reduced DBN (P<0.05), other ataxic symptoms did not improved. However, 3,4-DAP showed benefit in two patients with oscillopsia. CONCLUSION 3,4-DAP may be effective on DBN and oscillopsia, although it was not proved to be effective on other symptoms of ataxia in SCA patients.
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Affiliation(s)
- Taiji Tsunemi
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
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16
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Duncombe-Poulet C. [Albinism, frequent etiology of the congenital nystagmus]. Oftalmologia 2010; 54:21-28. [PMID: 21137186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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Abstract
BACKGROUND Pierson syndrome is typically manifested with congenital nephrotic syndrome (CNS) and peculiar ocular changes. LAMB2 was the causative gene. METHODS A 3.25-year-old girl presenting with childhood-onset heavy proteinuria, bilateral myosis and nystagmus was detected on mutations of LAMB2 gene by PCR direct sequencing. RESULTS Two novel mutations were identified, C757fsX767 and P1413fsX1451, which predicted truncated proteins and were confirmed in the paternal and maternal origins, respectively. CONCLUSIONS This is the first Chinese case of Pierson syndrome diagnosed by clinical manifestations and LAMB2 gene mutations. The phenotype may be different in different ethics.
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Affiliation(s)
- Dan Zhao
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, PR China
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Abstract
PURPOSE To examine the pathological significance and familial occurrence of voluntary nystagmus. PATIENTS AND METHODS We examined two families orthoptically as well as with video and search-coil techniques or electronystagmography (ENG). Three members of three generations of the first family and a 9-year-old boy from a second family not related to the first were able to generate a voluntary horizontal nystagmus. RESULTS The characteristics of the nystagmus of our original patient, his daughter and 8-year-old grandson (1st family) were remarkably similar: duration of 2-5 seconds, amplitudes of 1-4 degrees and frequencies around 15 cycles/second. In the second family, our patient with a congenital esotropia and hyperopia was the only one of his family who could voluntarily produce a nystagmus of about 5 degrees and 10 cycles/second for maximum of 20 seconds. During prolonged reading, the same nystagmus with disturbing oscillopsia developed involuntarily and was not suppressible. We added +0.75 diopters to both lenses of his spectacles to account for the result of our cycloplegic refraction. This stopped the involuntary nystagmus during near fixation. DISCUSSION To avoid unintentional "bouts" of voluntary nystagmus, a reduction of the convergence impulse by plus-lenses may be effective. The parameters of voluntary nystagmus can be considered family-specific.
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Affiliation(s)
- Birte Neppert
- Department of Ophthalmology, University Hospital, Lübeck, Germany.
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Abstract
Congenital Idiopathic Nystagmus (CIN) is genetically heterogeneous. Autosomal dominant, autosomal recessive and X-linked patterns of inheritance have been reported. Linkage analysis has suggested the existence of at least three distinct loci for both autosomal dominant and x-linked forms, although as yet no disease genes have been identified. The pathophysiological mechanisms underlying nystagmus are poorly understood and it is likely that insights may arise from finding and characterizing disease genes. If linkage experiments are used to find "nystagmus genes," their power will depend heavily on accurate phenotyping to avoid misdiagnosis due to masquerading conditions and phenotypic variations within pedigrees.
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Affiliation(s)
- James Self
- University of Southampton, Southampton, UK.
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Terenziani M, Sardella M, Gamba B, Testi MA, Spreafico F, Ardissino G, Fedeli F, Fossati-Bellani F, Radice P, Perotti D. A novel WT1 mutation in a 46,XY boy with congenital bilateral cryptorchidism, nystagmus and Wilms tumor. Pediatr Nephrol 2009; 24:1413-7. [PMID: 19048299 DOI: 10.1007/s00467-008-1056-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 10/14/2008] [Accepted: 10/23/2008] [Indexed: 11/26/2022]
Abstract
The WT1 gene plays a crucial role in urogenital and gonadal development. Germline WT1 alterations have been described in a wide spectrum of pathological conditions, including kidney diseases, genital abnormalities and Wilms tumor (WT), frequently occurring in combination. We report on a novel WT1 nonsense mutation (c.1105C>T), introducing a premature stop codon in exon 8 (p.Q369X), in a young XY male patient who presented with bilateral cryptorchidism, nystagmus, mild proteinuria and WT, but no sign of severe nephropathy. Although the majority of congenital urogenital abnormalities are not due to constitutional defects of the WT1 gene, our findings provide a rational for considering WT1 mutational analysis as one of the screening options in newborns with congenital defects of the urogenital tract due to the associated high risk of WT.
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Affiliation(s)
- Monica Terenziani
- Department of Medical Oncology, Pediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy
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Li ND, Wang LM, Cui LH, Chen X, Zhu LN, Guo X, Zhao KX. [Study of gene mutation in a Chinese family with X-linked congenital nystagmus]. Zhonghua Yan Ke Za Zhi 2008; 44:138-142. [PMID: 18683699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To study the disease-causing gene for a Chinese family with X-linked congenital idiopathic nystagmus. METHODS It was a retrospective study. The phenotype of a Chinese family with congenital nystagmus was identified by investigating the history and the clinical features of each family member. The mode of inheritance in this family was ascertained by the pedigree analysis. Linkage analysis was performed to identify the possible locus harboring the disease-causing gene. Direct DNA sequence analysis was performed to find the mutation responsible for this disease. RESULTS The positive LOD score was obtained for 10 microsatellite makers on chromosome Xq25-Xq27, and the maximum LOD score with DXS1211 was 3.91. A 2-bp deletion in exon 8 of FRMD7 was detected after direct DNA sequence analysis, which was cosegregated with all patients in this family. CONCLUSION Congenital nystagmus is a clinically and genetically heterogeneous ocular movement disease. Mutation of the FRMD7 gene is the cause of congenital nystagmus in this family.
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Li ND, Cui LH, Wang LM, Ma HZ, Zhang LL, Yue YY, Zhao KX. [The G990T mutation of the FRMD7 gene in a Chinese family with congenital idiopathic nystagmus]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2008; 25:11-14. [PMID: 18247295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
OBJECTIVE To study the mutation of FRMD7 gene in a Chinese family with congenital idiopathic nystagmus. METHODS Forty-six individuals in the Chinese family with congenital idiopathic nystagmus, including 16 patients, 19 normal siblings and 11 spouses, were investigated under informed consent. Genomic DNA of all 46 members was isolated by standard protocol. The X-linked inherited pattern was ascertained by investigating the history of the family members and the clinical feature of each individual. The genome scan on X chromosome was performed after PCR amplification for microsatellite markers. LOD scores were calculated with Linkage 5.1. Direct DNA sequence analysis was carried out to find the gene mutation responsible for the disease. RESULTS A maximum LOD score of 8.55 (theta=0) was obtained with polymorphic marker DXS1047. Haplotype construction of the family defined the disease interval between DXS8059 and DXS8033. Direct DNA sequence analysis revealed a heterozygous mutation of G990T in exon 9 of the FRMD7 gene in all patients, which was not present in unaffected family members. CONCLUSION Congenital nystagmus is a clinically and genetically heterogeneous ocular movement disease. The mutation of G990T of the FRMD7 gene is the underlying molecular pathogenesis for this family with congenital nystagmus.
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Affiliation(s)
- Ning-dong Li
- Department of Ophthalmic Molecular Genetics, Tianjin Eye Hospital, Tianjin, People's Republic of China
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Shiels A, Bennett TM, Prince JB, Tychsen L. X-linked idiopathic infantile nystagmus associated with a missense mutation in FRMD7. Mol Vis 2007; 13:2233-2241. [PMID: 18087240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 11/26/2007] [Indexed: 05/25/2023] Open
Abstract
PURPOSE Infantile nystagmus is a clinically and genetically heterogeneous eye movement disorder. Here we map and identify the genetic mutation underlying X-linked idiopathic infantile nystagmus (XL-IIN) segregating in two Caucasian-American families. METHODS Eye movements were recorded using binocular infrared digital video-oculography. Genomic DNA was prepared from blood or buccal-cells, and linkage analysis was performed using short tandem repeat (STR) and single nucleotide polymorphism (SNP) markers. Pedigree and haplotype data were managed using Cyrillic, and LOD scores calculated using MLINK. Mutation profiling of PCR-amplified exons was performed by dye-terminator cycle-sequencing and analyzed by automated capillary electrophoresis. RESULTS Video-oculography of affected males recorded conjugate, horizontal, pendular nystagmus with increasing-velocity waveforms in primary gaze converting to jerk nystagmus in eccentric gaze. Linkage analysis detected significantly positive two-point LOD scores (Z) at markers DXS8078 (Z=4.82, recombination fraction [theta]=0) and DXS1047 (Z=3.87, theta=0). Haplotyping indicated that the IIN locus mapped to the physical interval DXS8057-(11.59 Mb)-rs6528335 on Xq25-q26. Sequencing of positional-candidate genes detected a c.425T>G transversion in exon-6 of the gene for FERM domain containing-7 (FRMD7) that cosegregated with affected and carrier status. In addition, the same change was found to cosegregate with IIN in a genetically unrelated family but was not detected in 192 control individuals. CONCLUSIONS The c.425T>G change is predicted to result in the missense substitution of the phylogenetically conserved leucine at codon 142 for an arginine (p.L142R), and supports a causative role for FRMD7 mutations in the pathogenesis of XL-IIN.
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Affiliation(s)
- Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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24
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Zhang B, Liu Z, Zhao G. Novel human pathological mutations. Gene symbol: FRMD7. Disease: congenital motor nystagmus. Hum Genet 2007; 122:414. [PMID: 18350647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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25
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Cha YH, Lee H, Jen JC, Kattah JC, Nelson SF, Baloh RW. Episodic vertical oscillopsia with progressive gait ataxia: clinical description of a new episodic syndrome and evidence of linkage to chromosome 13q. J Neurol Neurosurg Psychiatry 2007; 78:1273-5. [PMID: 17522101 PMCID: PMC2117610 DOI: 10.1136/jnnp.2006.111138] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We describe four families with late onset episodic vertical oscillopsia and progressive gait ataxia. Probands presented between the ages of 40 and 64 years with initial symptoms of episodic vertical oscillopsia and interictal downbeat nystagmus. A mild gait ataxia developed over several years. Triggers included physical exertion, alcohol and caffeine. Patients did not respond to acetazolamide. Genetic screening for episodic ataxia types 1 and 2, and spinocerebellar ataxias 1, 2, 3 and 6 were negative. Using ancestral identity by descent analysis and dense single nucleotide polymorphism (SNP) genotyping throughout the genome, an interval of 28.6 cM (approximately 14.2 Mb) on chromosome 13q12.11-q13.3, composed of 1259 SNPs, was shared between affected individuals in two of the four families and highlighted a region of suggestive linkage (LOD >2.7).
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Affiliation(s)
- Y H Cha
- Department of Neurology, University of California Los Angeles, 710 Westwood Plaza Box 951769, Los Angeles, CA 90095, USA.
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26
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Zhang B, Liu Z, Zhao G. Novel human pathological mutations. Gene symbol: FRMD7. Disease: congenital motor nystagmus. Hum Genet 2007; 122:414. [PMID: 18350648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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27
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Self JE, Shawkat F, Malpas CT, Thomas NS, Harris CM, Hodgkins PR, Chen X, Trump D, Lotery AJ. Allelic variation of the FRMD7 gene in congenital idiopathic nystagmus. ACTA ACUST UNITED AC 2007; 125:1255-63. [PMID: 17846367 DOI: 10.1001/archopht.125.9.1255] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES To perform a genotype-phenotype correlation study in an X-linked congenital idiopathic nystagmus pedigree (pedigree 1) and to assess the allelic variance of the FRMD7 gene in congenital idiopathic nystagmus. METHODS Subjects from pedigree 1 underwent detailed clinical examination including nystagmology. Screening of FRMD7 was undertaken in pedigree 1 and in 37 other congenital idiopathic nystagmus probands and controls. Direct sequencing confirmed sequence changes. X-inactivation studies were performed in pedigree 1. RESULTS The nystagmus phenotype was extremely variable in pedigree 1. We identified 2 FRMD7 mutations. However, 80% of X-linked families and 96% of simplex cases showed no mutations. X-inactivation studies demonstrated no clear causal link between skewing and variable penetrance. CONCLUSIONS We confirm profound phenotypic variation in X-linked congenital idiopathic nystagmus pedigrees. We demonstrate that other congenital nystagmus genes exist besides FRMD7. We show that the role of X inactivation in variable penetrance is unclear in congenital idiopathic nystagmus. Clinical Relevance We demonstrate that phenotypic variation of nystagmus occurs in families with FRMD7 mutations. While FRMD7 mutations may be found in some cases of X-linked congenital idiopathic nystagmus, the diagnostic yield is low. X-inactivation assays are unhelpful as a test for carrier status for this disease.
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Affiliation(s)
- James E Self
- Clinical Neurosciences Division, University of Southampton, Southampton, England
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28
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Huang XL, Isabel de Michelena M, Leon E, Maher TA, McClure R, Milunsky A. Pallister-Killian syndrome: tetrasomy of 12pter→12p11.22 in a boy with an analphoid, inverted duplicated marker chromosome. Clin Genet 2007; 72:434-40. [PMID: 17894838 DOI: 10.1111/j.1399-0004.2007.00894.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Supernumerary marker chromosomes (SMCs) without detectable alphoid DNA are predicted to have a neocentromere and have been referred to as mitotically stable neocentromere marker chromosomes (NMCs). Here we report the molecular cytogenetic characterization of a new case of Pallister-Killian syndrome (PKS) in a boy with an analphoid, inverted duplicated NMC derived from 12pter-->12p11.22 in his fibroblasts by using high-resolution comparative genetic hybridization (HR-CGH), multiplex fluorescent in situ hybridization (FISH) and bacterial artificial chromosome (BAC)-FISH mapping analyses with various alpha-satellite DNA probes, subtelomere probes and BAC-DNA probes. Precise identification of SMCs and NMCs is of essential importance in genetic counseling. HR-CGH is a more informative and often a faster way of precisely identifying the origin of SMCs. This case is the third report of PKS with an NMC containing an inverted duplication of partial 12p with available clinical data. These observations may help to determine the critical region for PKS and the mechanisms leading to the origin of the NMC derived from 12pter-->12p11.22 - a region that appears to be susceptible to the formation of neocentromeres. The use of subtelomeric probe PCP12p in buccal cells appears superior to the use of the centromere probe D12Z3 for the diagnosis of the PKS.
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Affiliation(s)
- X-L Huang
- Center for Human Genetics, Boston University School of Medicine, Boston, MA, USA
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29
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Zhang B, Liu Z, Zhao G, Xie X, Yin X, Hu Z, Xu S, Li Q, Song F, Tian J, Luo W, Ding M, Yin J, Xia K, Xia J. Novel mutations of the FRMD7 gene in X-linked congenital motor nystagmus. Mol Vis 2007; 13:1674-9. [PMID: 17893669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
PURPOSE Congenital motor nystagmus (CMN) is a relatively common oculomotor disorder characterized by bilateral uncontrollable ocular oscillations. Recently, the FRMD7 gene mutation has been identified as the genetic cause of CMN. The purpose of this study was to identify mutations of the FRMD7 gene in Chinese patients with CMN. METHODS Clinical data and genomic DNA of three Chinese CMN families were collected after informed consent. Genescan by two-point linkage analysis combined with haplotype analysis was performed and mutation screening of the FRMD7 gene was conducted by direct sequencing. RESULTS Maximum two-point LOD scores of 2.00, 1.76, and 1.16 at theta=0.00 were obtained with markers in proximity to the FRMD7 gene on chromosome Xp26 in the three CMN families. Mutation screening in the FRMD7 gene identified two novel missense mutations (c.781C>G and c.886G>C) and one reported nonsense mutation (c.1003C>T). These nucleotide alterations were not seen in unaffected members of the families or in 100 unrelated control subjects. CONCLUSIONS This study widens the mutation spectrum of the FRMD7 gene.
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Affiliation(s)
- Baorong Zhang
- Department of Neurology, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
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30
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Zhang Q, Xiao X, Li S, Guo X. FRMD7 mutations in Chinese families with X-linked congenital motor nystagmus. Mol Vis 2007; 13:1375-8. [PMID: 17768376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
PURPOSE To identify mutations causing X-linked congenital motor nystagmus (XL-CMN) in Chinese families. METHODS Genomic DNA was prepared from peripheral blood leukocytes. Cycle sequencing was used to detect the sequence variation of the FERM domain containing 7 (FRMD7) gene, where mutations have been identified recently to associate with XL-CMN. RESULTS Sequencing of the coding and the adjacent intron regions of FRMD7 identified mutations in four families with XL-CMN, c.41-43delAGA (p.Lys14del) in exon 1, c.70G>A (p.Gly24Arg) in exon 2, c.436C>T (p.Arg146Trp) in exon 6, and c.685C>T (p.Arg229Cys) in exon 8, respectively, where the last two were novel. These mutations were not detected in 196 normal controls. In the two families with X-linked recessive CMN, females carrying a heterozygous mutation in FRMD7 did not have any sign of nystagmus. CONCLUSIONS Our results provide additional evidence for mutations in FRMD7 as a common cause of XL-CMN and expand its mutation spectrum. CMN in a Chinese family with pure X-linked recessive pattern, previously mapped to Xq23-q27, is associated with the c.41-43delAGA mutation in FRMD7.
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Affiliation(s)
- Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
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31
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Schorderet DF, Tiab L, Gaillard MC, Lorenz B, Klainguti G, Kerrison JB, Traboulsi EI, Munier FL. Novel mutations in FRMD7 in X-linked congenital nystagmus. Mutation in brief #963. Online. Hum Mutat 2007; 28:525. [PMID: 17397053 DOI: 10.1002/humu.9492] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Congenital nystagmus is an eye movement disorder in which one or both eyes are in constant movement. It can be associated with a number of ocular or neurological diseases, or it can be inherited in an autosomal or X-linked fashion. The latter form is called idiopathic or motor nystagmus (CIN). Loci on the X chromosome (NYS1) and on 6p12 (NYS2), 7p11.2 (NYS3), and 13q31-q33 (NYS4) have been identified for CIN. The molecular characterization of NYS1 has recently been solved by Tarpey et al., who identified mutations in FRMD7, a gene of unclear function. We report five novel mutations in FRMD7 and confirm the role of this gene in the pathogenesis of X-linked congenital nystagmus.
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32
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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: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [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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Dansault A, David G, Schwartz C, Jaliffa C, Vieira V, de la Houssaye G, Bigot K, Catin F, Tattu L, Chopin C, Halimi P, Roche O, Van Regemorter N, Munier F, Schorderet D, Dufier JL, Marsac C, Ricquier D, Menasche M, Penfornis A, Abitbol M. Three new PAX6 mutations including one causing an unusual ophthalmic phenotype associated with neurodevelopmental abnormalities. Mol Vis 2007; 13:511-23. [PMID: 17417613 PMCID: PMC2649307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The PAX6 gene was first described as a candidate for human aniridia. However, PAX6 expression is not restricted to the eye and it appears to be crucial for brain development. We studied PAX6 mutations in a large spectrum of patients who presented with aniridia phenotypes, Peters' anomaly, and anterior segment malformations associated or not with neurological anomalies. METHODS Patients and related families were ophthalmologically phenotyped, and in some cases neurologically and endocrinologically examined. We screened the PAX6 gene by direct sequencing in three groups of patients: those affected by aniridia; those with diverse ocular manifestations; and those with Peters' anomaly. Two mutations were investigated by generating crystallographic representations of the amino acid changes. RESULTS Three novel heterozygous mutations affecting three unrelated families were identified: the g.572T>C nucleotide change, located in exon 5, and corresponding to the Leucine 46 Proline amino-acid mutation (L46P); the g.655A>G nucleotide change, located in exon 6, and corresponding to the Serine 74 Glycine amino-acid mutation (S74G); and the nucleotide deletion 579delG del, located in exon 6, which induces a frameshift mutation leading to a stop codon (V48fsX53). The L46P mutation was identified in affected patients presenting bilateral microphthalmia, cataracts, and nystagmus. The S74G mutation was found in a large family that had congenital ocular abnormalities, diverse neurological manifestations, and variable cognitive impairments. The 579delG deletion (V48fsX53) caused in the affected members of the same family bilateral aniridia associated with congenital cataract, foveal hypolasia, and nystagmus. We also detected a novel intronic nucleotide change, IVS2+9G>A (very likely a mutation) in an apparently isolated patient affected by a complex ocular phenotype, characterized primarily by a bilateral microphthalmia. Whether this nucleotide change is indeed pathogenic remains to be demonstrated. Two previously known heterozygous mutations of the PAX6 gene sequence were also detected in patients affected by aniridia: a de novo previously known nucleotide change, g.972C>T (Q179X), in exon 8, leading to a stop codon and a heterozygous g.555C>A (C40X) recurrent nonsense mutation in exon 5. No mutations were found in patients with Peters' anomaly. CONCLUSIONS We identified three mutations associated with aniridia phenotypes (Q179X, C40X, and V48fsX53). The three other mutations reported here cause non-aniridia ocular phenotypes associated in some cases with neurological anomalies. The IVS2+9G>A nucleotide change was detected in a patient with a microphthalmia phenotype. The L46P mutation was detected in a family with microphthalmia, cataract, and nystagmus. This mutation is located in the DNA-binding paired-domain and the crystallographic representations of this mutation show that this mutation may affect the helix-turn-helix motif, and as a consequence the DNA-binding properties of the resulting mutated protein. Ser74 is located in the PAX6 PD linker region, essential for DNA recognition and DNA binding, and the side chain of the Ser74 contributes to DNA recognition by the linker domain through direct contacts. Crystallographic representations show that the S74G mutation results in no side chain and therefore perturbs the DNA-binding properties of PAX6. This study highlights the severity and diversity of the consequences of PAX6 mutations that appeared to result from the complexity of the PAX6 gene structure, and the numerous possibilities for DNA binding. This study emphasizes the fact that neurodevelopmental abnormalities may be caused by PAX6 mutations. The neuro-developmental abnormalities caused by PAX6 mutations are probably still overlooked in the current clinical examinations performed throughout the world in patients affected by PAX6 mutations.
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Affiliation(s)
- Anouk Dansault
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Gabriel David
- CNRS UPR 9078, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | | | - Carolina Jaliffa
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Véronique Vieira
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Guillaume de la Houssaye
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Karine Bigot
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Françise Catin
- Service de Neuro-Imagerie du CHU de Besançon, Doubs, France
| | - Laurent Tattu
- Service de Neurologie du CHU de Besançon, Doubs, France
| | | | - Philippe Halimi
- Service d'Imagerie de l'Hopital Européen Georges Pompidou, Paris, France
| | - Olivier Roche
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
- Service d'Ophtalmologie, Hôpital Necker-Enfants Malades, Paris, France
| | | | | | | | - Jean-Louis Dufier
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
- Service d'Ophtalmologie, Hôpital Necker-Enfants Malades, Paris, France
| | - Cécile Marsac
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Daniel Ricquier
- CNRS UPR 9078, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Maurice Menasche
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
| | - Alfred Penfornis
- Service d'Endocrinologie et Diabétologie du CHU de Besançon, Doubs, France
| | - Marc Abitbol
- EA n 2502 du Ministère de la Recherche, de l'Enseignement Supérieur et la Technologie, Center de Recherches Thérapeutiques en Ophtalmologie (CERTO), Université René Descartes-Paris V, Faculté de Médecine René Descartes-Site Necker, Paris, France
- Service d'Ophtalmologie, Hôpital Necker-Enfants Malades, Paris, France
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Self JE, Ennis S, Collins A, Shawkat F, Harris CM, Mackey DA, Hodgkins PR, Temple IK, Chen X, Lotery AJ. Fine mapping of the X-linked recessive congenital idiopathic nystagmus locus at Xq24-q26.3. Mol Vis 2006; 12:1211-6. [PMID: 17102799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
PURPOSE To refine the interval for X-linked congenital idiopathic nystagmus at Xq24-q26.3 and to evaluate a novel candidate gene (Muscleblind-like 3 gene [MBNL3]). METHODS A single pedigree with congenital idiopathic nystagmus (CIN) inherited as an X-linked recessive trait underwent detailed clinical examination including nystagmology and electrophysiological investigation in selected subjects. Following detailed phenotyping, genotyping was performed using 52 microsatellite markers spaced at an average of 5 cM along the X chromosome. Subsequent two-point and multipoint linkage analysis were performed and a candidate gene was screened for mutations by conventional sequencing. RESULTS Linkage mapping located the disease gene to a 15.5cM interval at Xq24-q26.3, between markers DXS1212 and DXS1062 with a maximum two-point LOD score of 4.24 with both markers DXS8044 and DXS994 (theta=0). Multipoint analysis indicated a LOD score of 4.54 and a critical gene interval of 8.0 cM. No mutations were found in the MBNL3 gene in this pedigree. CONCLUSIONS We describe a family with an unusual inheritance pattern most consistent with X-linked recessive inheritance with X inactivation causing manifesting females. We refine the linkage interval for X-linked recessive congenital idiopathic nystagmus and exclude MBNL3 as the causative gene in this family.
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Affiliation(s)
- James Edward Self
- Clinical Neurosciences Division, University of Southampton, Southampton, UK
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Tarpey P, Thomas S, Sarvananthan N, Mallya U, Lisgo S, Talbot CJ, Roberts EO, Awan M, Surendran M, McLean RJ, Reinecke RD, Langmann A, Lindner S, Koch M, Woodruff G, Gale R, Degg C, Droutsas K, Asproudis I, Zubcov AA, Pieh C, Veal CD, Machado RD, Backhouse OC, Baumber L, Jain S, Constantinescu CS, Brodsky MC, Hunter DG, Hertle RW, Read RJ, Edkins S, O’Meara S, Parker A, Stevens C, Teague J, Wooster R, Futreal PA, Trembath RC, Stratton MR, Raymond FL, Gottlob I. Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus. Nat Genet 2006; 38:1242-4. [PMID: 17013395 PMCID: PMC2592600 DOI: 10.1038/ng1893] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 09/01/2006] [Indexed: 11/09/2022]
Abstract
Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability.
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Affiliation(s)
- P Tarpey
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - S Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - N Sarvananthan
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - U Mallya
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
| | - S Lisgo
- Institute of Human Genetics, International Centre for Life, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - CJ Talbot
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - EO Roberts
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - M Awan
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - M Surendran
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - RJ McLean
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - RD Reinecke
- Foerderer Eye Movement Centre for Children, Wills Eye Hospital, Philadelphia, Pennsylvania, 19107 USA
| | - A Langmann
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - S Lindner
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - M Koch
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - G Woodruff
- Royal Preston Hospital, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT
| | - R Gale
- Ophthalmology, Leeds General Infirmary, Leeds, LS1 3EX, UK
| | - C Degg
- Department of Medical Physics, University Hospitals of Leicester, Leicester, LE1 5WW, UK
| | - K Droutsas
- Department of Ophthalmology, Justus-Liebig-University, 35392 Giessen, Germany
| | - I Asproudis
- Department of Ophthalmology, Medical Faculty, University Hospital of Ioannina, 45110 Ioannina, Greece
| | - AA Zubcov
- University Eye Hospital, Johann-Wolfgang-Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - C Pieh
- University Eye Hospital, Killianstr. 5, 79106 Freiburg, Germany
| | - CD Veal
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - RD Machado
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - OC Backhouse
- Ophthalmology, Leeds General Infirmary, Leeds, LS1 3EX, UK
| | - L Baumber
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - S Jain
- Royal Preston Hospital, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT
| | - CS Constantinescu
- Division of Clinical Neurology, School of Medical and Surgical Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - MC Brodsky
- Arkansas Children’s Hospital, 800 Marshall, Little Rock, Arkansas 72202, UK
| | - DG Hunter
- Department of Ophthalmology, Children’s Hospital Boston, Harvard Medical School, Boston, Mass 02115, USA
| | - RW Hertle
- University of Pittsburgh Medical Centre, Division of Paediatric Ophthalmology, Children’s Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - RJ Read
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
| | - S Edkins
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - S O’Meara
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - A Parker
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - C Stevens
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - J Teague
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - R Wooster
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - PA Futreal
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - RC Trembath
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - MR Stratton
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - FL Raymond
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
- Joint senior authors and corresponding authors and
| | - I Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
- Joint senior authors and corresponding authors and
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hope CI, Sharp DM, Hemara-Wahanui A, Sissingh JI, Lundon P, Mitchell EA, Maw MA, Clover GM. Clinical manifestations of a unique X-linked retinal disorder in a large New Zealand family with a novel mutation in CACNA1F, the gene responsible for CSNB2. Clin Exp Ophthalmol 2005; 33:129-36. [PMID: 15807819 DOI: 10.1111/j.1442-9071.2005.00987.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe the phenotype in a New Zealand family with an unusual severe X-linked retinal disorder with a novel I745T mutation in CACNA1F, the gene responsible for incomplete congenital stationary night blindness (CSNB2). METHODS Members of the family tree were invited for clinical, psychophysical and electrodiagnostic evaluation. RESULTS Male family members had severe non-progressive visual impairment, abnormal colour vision, congenital nystagmus, hyperopia and normal fundi. Some were intellectually disabled. Female family members had congenital nystagmus and decreased visual acuity frequently associated with high myopia. Electroretinograms (ERG) identified reduced rod and cone responses with negative waveform in male and female family members, with atypical features for CSNB2. CONCLUSIONS Although there were similarities to CSNB2, distinctive features in male family members included severity of phenotype, and association of intellectual disability. Moreover, all female heterozygotes had clinical and ERG abnormalities. CACNA1F encodes the Ca(v)1.4 alpha1 subunit of a voltage-gated calcium channel, which may mediate neurotransmitter release from photoreceptors. Molecular analyses, reported separately, identified a novel I745T CACNA1F mutation that was associated in vitro with major alterations in gating and kinetics of the Ca(v)1.4 channel. It is speculated that the unique phenotype described in this family may reflect similarly altered function of Ca(v)1.4 channel activity in vivo.
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Affiliation(s)
- Carolyn I Hope
- Department of Ophthalmology, University of Auckland, Auckland, New Zealand.
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Vincent MC, Gallai R, Olivier D, Speeg-Schatz C, Flament J, Calvas P, Dollfus H. Variable phenotype related to a novel PAX 6 mutation (IVS4+5G>C) in a family presenting congenital nystagmus and foveal hypoplasia. Am J Ophthalmol 2004; 138:1016-21. [PMID: 15629294 DOI: 10.1016/j.ajo.2004.08.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2004] [Indexed: 11/25/2022]
Abstract
PURPOSE Several ocular defects have been identified as a consequence of the PAX6 gene mutations. With regard to the implication of this gene in unusual phenotypes, we report a family presenting with congenital nystagmus, foveal hypoplasia, and iris hypoplasia or atypical coloboma. DESIGN Observational case report. METHODS The entire transcribed region of the PAX6 gene was submitted to mutation search at the DNA and mRNA levels in five affected members of a French family in test with 82 normal subjects. RESULTS A novel heterozygous PAX6 gene splice mutation (IVS4 + 5G>C) was identified. The mutation is located in IVS4 within the consensus donor splice site. A mutant mRNA lacking exon 4 as the sole defect was evidenced. The resultant protein was predicted to contain a cryptic ATG initiation codon in exon 3 and a slightly altered paired-domain in an open reading frame extended by 13 amino acids. CONCLUSIONS The association of anterior segment anomalies and foveal hypoplasia with one of the slightest alterations of the PAX6 protein described to date confirms the association of variant phenotypes with hypomorphic alleles. Mutation screening of the PAX6 gene could be useful in elucidating the origin of complex ocular malformations.
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40
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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41
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Liu ZR, Zhang BR, Ding MP, Xia K, Hu ZM, Deng H, Xia JH. [Mapping of a pedigree with congenital nystagmus]. Yi Chuan 2004; 26:437-40. [PMID: 15640035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
To investigate the relationship between X chromosome and obligatory gene of a pedigree with congenital nystagmus,we used the following markers: DXS1214, DXS1068, DXS993, DXS8035, DXS1047, DXS8033, DXS1192 and DXS1232. Genome screening and genotyping were conducted in this pedigree of congenital nystagmus, and linkage analysis by LINKAGE package was used to determine the potential location. The linkage was not found on the Xp (All LOD score <-1) but on Xq (the maximum LOD score=2). The related gene of this pedigree was located on the long arm of X chromosome. We demonstrate that Xq26-Xq28 is a common locus for CMN. It bring us closer to the identification of a gene responsible for X-linked CMN.
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Affiliation(s)
- Zhi-Rong Liu
- Department of Neurology, the Second Affiliated Hospital of Medical School, ZheJiang University, Hangzhou 310 009, China.
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Michaelides M, Aligianis IA, Holder GE, Simunovic M, Mollon JD, Maher ER, Hunt DM, Moore AT. Cone dystrophy phenotype associated with a frameshift mutation (M280fsX291) in the alpha-subunit of cone specific transducin (GNAT2). Br J Ophthalmol 2004; 87:1317-20. [PMID: 14609822 PMCID: PMC1771876 DOI: 10.1136/bjo.87.11.1317] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To describe the phenotype of a three generation consanguineous Pakistani family containing six individuals with autosomal recessive cone dystrophy caused by mutation in GNAT2. METHODS Five of the six affected individuals underwent an ophthalmological examination, electrodiagnostic testing, fundus photography, autofluorescence imaging, and detailed psychophysical testing. RESULTS All five examined patients had a history of nystagmus from infancy, photophobia, defective colour vision, and poor visual acuity. The nystagmus in three of the individuals had lessened with time. Fundus examination revealed an abnormal foveal appearance, without frank atrophy or pigmentation. Electroretinography (ERG) revealed absent ISCEV cone flicker ERGs with some preservation of responses to short wavelength stimulation. Rod ERGs showed no definite abnormality, but maximal (mixed rod-cone) response a-wave amplitudes were mildly subnormal. Rudimentary residual colour vision was detected in three individuals. There is clinical evidence of progressive visual acuity reduction in two older individuals. CONCLUSION Mutation in the alpha-subunit of cone specific transducin (GNAT2) is characterised by an infantile onset cone dystrophy. Some affected individuals may show deterioration of visual acuity with time.
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Affiliation(s)
- M Michaelides
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EV, UK
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Dumitrescu AM, Liao XH, Best TB, Brockmann K, Refetoff S. A novel syndrome combining thyroid and neurological abnormalities is associated with mutations in a monocarboxylate transporter gene. Am J Hum Genet 2004; 74:168-75. [PMID: 14661163 PMCID: PMC1181904 DOI: 10.1086/380999] [Citation(s) in RCA: 448] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Accepted: 10/21/2003] [Indexed: 11/03/2022] Open
Abstract
Thyroid hormones are iodothyronines that control growth and development, as well as brain function and metabolism. Although thyroid hormone deficiency can be caused by defects of hormone synthesis and action, it has not been linked to a defect in cellular hormone transport. In fact, the physiological role of the several classes of membrane transporters remains unknown. We now report, for the first time, mutations in the monocarboxylate transporter 8 (MCT8) gene, located on the X chromosome, that encodes a 613-amino acid protein with 12 predicted transmembrane domains. The propositi of two unrelated families are males with abnormal relative concentrations of three circulating iodothyronines, as well as neurological abnormalities, including global developmental delay, central hypotonia, spastic quadriplegia, dystonic movements, rotary nystagmus, and impaired gaze and hearing. Heterozygous females had a milder thyroid phenotype and no neurological defects. These findings establish the physiological importance of MCT8 as a thyroid hormone transporter.
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Affiliation(s)
- Alexandra M. Dumitrescu
- Departments of Human Genetics, Medicine, and Pediatrics, and the Committee on Genetics, University of Chicago, Chicago; Saskatoon, Saskatchewan, Canada; and Department of Pediatrics and Neuropediatrics, University of Göttingen, Göttingen, Germany
| | - Xiao-Hui Liao
- Departments of Human Genetics, Medicine, and Pediatrics, and the Committee on Genetics, University of Chicago, Chicago; Saskatoon, Saskatchewan, Canada; and Department of Pediatrics and Neuropediatrics, University of Göttingen, Göttingen, Germany
| | - Thomas B. Best
- Departments of Human Genetics, Medicine, and Pediatrics, and the Committee on Genetics, University of Chicago, Chicago; Saskatoon, Saskatchewan, Canada; and Department of Pediatrics and Neuropediatrics, University of Göttingen, Göttingen, Germany
| | - Knut Brockmann
- Departments of Human Genetics, Medicine, and Pediatrics, and the Committee on Genetics, University of Chicago, Chicago; Saskatoon, Saskatchewan, Canada; and Department of Pediatrics and Neuropediatrics, University of Göttingen, Göttingen, Germany
| | - Samuel Refetoff
- Departments of Human Genetics, Medicine, and Pediatrics, and the Committee on Genetics, University of Chicago, Chicago; Saskatoon, Saskatchewan, Canada; and Department of Pediatrics and Neuropediatrics, University of Göttingen, Göttingen, Germany
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Ragge NK, Hartley C, Dearlove AM, Walker J, Russell-Eggitt I, Harris CM. Familial vestibulocerebellar disorder maps to chromosome 13q31-q33: a new nystagmus locus. J Med Genet 2003; 40:37-41. [PMID: 12525540 PMCID: PMC1735258 DOI: 10.1136/jmg.40.1.37] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To determine a gene locus for a family with a dominantly inherited vestibulocerebellar disorder characterised by early onset, but not congenital nystagmus. DESIGN Observational and experimental study. METHODS We carried out a phenotypic study of a unique four generation family with nystagmus. We performed genetic linkage studies including a genome wide search. RESULTS Affected family members developed vestibulocerebellar type nystagmus in the first two years of life. A higher incidence of strabismus was noted in affected members. Haplotype construction and analysis of recombination events linked the disorder to a locus (NYS4) on chromosome 13q31-q33 with a lod score of 6.322 at theta=0 for D13S159 and narrowed the region to a 13.8 cM region between markers D13S1300 and D13S158. CONCLUSIONS This study suggests that the early onset acquired nystagmus seen in this family is caused by a single gene defect. Identification of the gene may hold the key to understanding pathways for early eye stabilisation and strabismus.
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Affiliation(s)
- N K Ragge
- Department of Ophthalmology, St Thomas' Hospital, London and Moorfields Eye Hospital, London, UK.
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46
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Abstract
BACKGROUND/AIMS Past studies have explored some of the associations between particular motor and sensory characteristics and specific categories of non-neurological infantile nystagmus. The purpose of this case study is to extend this body of work significantly by describing the trends and associations found in a database of 224 subjects who have undergone extensive clinical and psychophysical evaluations. METHODS The records of 224 subjects with infantile nystagmus were examined, where 62% were idiopaths, 28% albinos, and 10% exhibited ocular anomalies. Recorded variables included age, mode of inheritance, birth history, nystagmus presentation, direction of the nystagmus, waveform types, spatial and temporal null zones, head postures and nodding, convergence, foveation, ocular alignment, refractive error, visual acuity, stereoacuity, and oscillopsia. RESULTS The age distribution of the 224 patients was between 1 month and 71 years, with the mean age and mode being 23 (SD 16) years and 16-20 years respectively. By far the most common pattern of inheritance was found to be autosomal dominant (n = 40), with the nystagmus being observed by the age of 6 months in 87% of the sample (n = 128). 139 (62%) of the 224 subjects were classified as idiopaths, 63 (28%) as albinos, and 22 (10%) exhibited ocular anomalies. Conjugate uniplanar horizontal oscillations were found in 174 (77.7%) of the sample. 32 (14.3%) had a torsional component to their nystagmus. 182 (81.2%) were classed as congenital nystagmus (CN), 32 (14.3%) as manifest latent nystagmus (MLN), and 10 (4.5%) as a CN/MLN hybrid. Neither CN nor MLN waveforms were related to any of the three subject groups (idiopaths, albinos, and ocular anomalies) MLN was found in idiopaths and albinos, but most frequently in the ocular anomaly group. The most common oscillation was a horizontal jerk with extended foveation (n = 49; 27%). The amplitudes and frequencies of the nystagmus ranged between 0.3-15.7 degrees and 0.5-8 Hz, respectively. Periodic alternating nystagmus is commonly found in albinos. Albino subjects did not show a statistically significantly higher nystagmus intensity when compared with the idiopaths (p>0.01). 105 of 143 subjects (73%) had spatial nulls within plus or minus 10 degrees of the primary position although 98 subjects (69%) employed a compensatory head posture. Subjects with spatial null zones at or beyond plus or minus 20 degrees always adopted constant head postures. Head nodding was found in 38 subjects (27% of the sample). Horizontal tropias were very common (133 out of 213; 62.4%) and all but one of the 32 subjects with MLN exhibited a squint. Adult visual acuity is strongly related to the duration and accuracy of the foveation period. Visual acuity and stereoacuity were significantly better (p<0.01) in the idiopaths compared to the albino and ocular anomaly groups. 66 subjects out of a sample of 168 (39%) indicated that they had experienced oscillopsia at some time. CONCLUSIONS There are strong ocular motor and sensory patterns and associations that can help define an infantile nystagmus. These include the nystagmus being bilateral, conjugate, horizontal uniplanar, and having an accelerating slow phase (that is, CN). Decelerating slow phases (that is, MLN) are frequently associated with strabismus and early form deprivation. Waveform shape (CN or MLN) is not pathognomonic of any of the three subject groups (idiopaths, albinos, or ocular anomalies). There is no one single stand alone ocular motor characteristic that can differentiate a benign form of infantile nystagmus (CN, MLN) from a neurological one. Rather, the clinician must consider a host of clinical features.
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Affiliation(s)
- R V Abadi
- Department of Optometry and Neuroscience, UMIST, PO Box 88, Manchester M60 1QD, UK.
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47
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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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48
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Abstract
AIMS To elucidate the molecular genetic defect of X linked congenital nystagmus associated with macular hypoplasia in three white males of a three generation family with clear features of ocular albinism in only one of them. METHODS A three generation family with congenital nystagmus following X linked inheritance, and associated with macular hypoplasia was clinically examined (three males and two obligate carriers). Flash VEP was performed to look for albino misrouting. DNA samples were subjected to PCR and subsequent analysis using SSCP for all exons of the OA1 gene. RT-PCR was performed on a mRNA preparation from a naevus from one patient. PCR products presenting divergent banding patterns in SSCP and from the RT-PCR were sequenced directly using cycle sequencing with fluorescent chain termination nucleotides and electrophoresis in a capillary sequencer. RESULTS The index case (patient 1, IV.1) was diagnosed with X linked OA1 at the age of 3 months because of typical clinical features: congenital nystagmus, iris translucency, macular hypoplasia, fundus hypopigmentation, normal pigmentation of skin and hair, and typical carrier signs of OA1 in his mother and maternal grandmother. Pigmentation of the iris and fundus had increased at the last examination at age 4 years. Albino misrouting was present at this age. In the maternal uncle (III.3, 51 years) who also suffered from congenital nystagmus there was clear macular hypoplasia and stromal focal hypopigmentation of the iris but no iris translucency or fundus hypopigmentation. Patient 3 (II.3, 79 years, maternal uncle of patient III.3) had congenital nystagmus and was highly myopic. The fundus appearance was typical for excessive myopia including macular changes. The iris did not show any translucency. Molecular genetic analysis revealed a novel 14 bp deletion of the OA1 gene at nt816 in exon 6. The mutation abolishes four amino acids (Leu 253-Ile-Ile-Cys) and covers the splice site. Nucleotides 814/815 are used as a new splice donor thus producing a frame shift in codon 252 and a new stop codon at codon 259. CONCLUSIONS Macular hypoplasia without clinically detectable hypopigmentation as the only sign of X linked OA1 has been reported occasionally in African-American, Japanese, and white patients. The present family shows absent hypopigmentation in two patients of a white family with a deletion in the OA1 gene. We propose a model of OA1 that allows increase of pigmentation with age. We hypothesise that macular hypoplasia in all forms of albinism depends on the extracellular DOPA level during embryogenesis, and that in OA1 postnatal normalisation of the extracellular DOPA level due to delayed distribution and membrane budding/fusion of melanosomes in melanocytes results in increasing pigmentation.
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Affiliation(s)
- M Preising
- Department of Paediatric Ophthalmology, Strabismology, and Ophthalmogenetics, University of Regensburg, 93042 Regensburg, Germany.
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49
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Abstract
AIM Analysis of the diseases underlying congenital nystagmus in a series of patients registered during 6 years as a prerequisite for adequate counselling of the families. PATIENTS AND METHODS Retrospective study of all patients that presented between 1992 and 1998 with congenital nystagmus not related to visual deprivation or acquired pathologies of the visual pathways. The patients were examined clinically and in dependence on the findings also by electrophysiological (Ganzfeld ERG and VEP, Albino-flash-VEP), psychophysical (colour vision, dark adaptation, spectral sensitivity), and molecular genetic methods. When estimated necessary, family members affected by history and unaffected family members were also examined. In cases of complex neuroophthalmological diseases a neuropaediatric examination including neuroimaging was initiated. RESULTS In total, 180 patients could be analysed. A sensory defect nystagmus (SDN) was present in 142 patients (79%). The diagnoses were as follows: albinism (any form) in 56 patients (30%), progressive photoreceptor dystrophy in 20 patients (11%), stationary cone dysfunction in 18 patients (10%), bilateral optic nerve hypoplasia in 15 patients (8%), chorioretinal or optic nerve colobomata in 10 patients (6%), aniridia and its variants in 10 patients (6%), familial isolated nystagmus in 8 patients (5%), and congenital stationary night blindness in 5 patients (3%). 38 patients (21%) could not (yet) be classified. DISCUSSION The prevalence of SDN as the manifesting symptom of a variety of well defined diseases in the present series of at least 79% is similar to that of 90% reported earlier. The precise diagnosis is a prerequisite for counselling the families as to functional prognosis and recurrence risk. Unnecessary neurological examinations including neuroimaging can be avoided.
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Affiliation(s)
- B Lorenz
- Abteilung für Kinderophthalmologie, Strabismologie und Ophthalmogenetik in der Klinik und Poliklinik für Augenheilkunde, Klinikum der Universität Regensburg, 93042 Regensburg.
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50
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Oetting WS, Armstrong CM, Holleschau AM, DeWan AT, Summers GC. Evidence for genetic heterogeneity in families with congenital motor nystagmus (CN). Ophthalmic Genet 2000; 21:227-33. [PMID: 11135493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Congenital motor nystagmus (CN) is a relatively common genetic disorder (approximately 1 in 1500) characterized by bilateral involuntary ocular oscillations, with onset occurring within the first six months of life. To date, three loci associated with CN have been mapped to chromosomes 6p12, Xp11.4-p11.3, and Xq26-q27. We analyzed five pedigrees segregating for CN. Mapping studies using markers in these three regions showed that only one pedigree exhibited suggestive linkage with a lod score of 2.08, straight theta=0.0, at chromosome Xp11. This pedigree had both affected male and female members, with two unaffected obligate female carriers. The remaining four pedigrees did not exhibit evidence of linkage for any of the three chromosome locations. Three of the pedigrees, Pedigrees 2, 4, and 5, exhibited several instances of male-to-male transmission, excluding X-linkage, and exhibited a lod score of -3.82, straight theta=0.0, for marker D6S459 located at 6p12, thus excluding the chromosome 6 locus. This provides evidence for at least a fourth locus associated with CN.
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Affiliation(s)
- W S Oetting
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, 55455, USA.
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