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Fossataro C, Pafundi PC, Mattei R, Cima V, De Rossi F, Savino G. Infantile nystagmus syndrome: An observational, retrospective, multicenter study. Optom Vis Sci 2024; 101:211-223. [PMID: 38684064 DOI: 10.1097/opx.0000000000002131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
SIGNIFICANCE This multicenter study assessed clinical and psychological aspects of infantile nystagmus syndrome (INS) focusing on its management and nonsurgical treatment. PURPOSE This study aimed to assess clinical features, management, relationship life, and psychological impact in a group of patients with nystagmus onset in pediatric age. METHODS This observational study included patients diagnosed with INS referred to two Italian centers from January 1, 2017, to December 31, 2020. Ophthalmologic and orthoptic features and impact of visual function on quality of life, according to nystagmus-specific nystagmus quality of life questionnaire, were analyzed within the overall sample and in any of INS subgroups. RESULTS Forty-three patients were included; 65.1% of them had idiopathic INS (IINS), and 34.9% had INS associated with ocular diseases (INSOD). The median age was 15.4 years (interquartile range [IQR], 10.4 to 17.3 years), significantly different between groups (median, 15.8 years among those with IINS vs. 12.3 years among those with INSOD; p<0.001). In the INSOD subgroup, strabismus was significantly more prevalent (93.3 vs. 57.1%; p=0.017). Binocular distance best-corrected visual acuity in primary position was significantly higher in the IINS subsample (p<0.001). Such behavior was further confirmed at anomalous head position evaluation (p<0.001). At near best-corrected visual acuity assessment, differences between groups were more remarkable in primary position (p<0.001) than in anomalous head position. Contrast sensitivity showed significantly higher values in the IINS subgroup (p<0.001). The nystagmus quality of life questionnaire disclosed a significantly lower score in IINS as compared with INSOD (median total score, 90.5 [IQR, 84 to 97] vs. 94 [IQR, 83.0 to 96.5]; p<0.001). CONCLUSIONS The IINS group showed significantly better ophthalmologic and orthoptic outcomes than the INSOD group. The psychological and quality-of-life impact was instead significantly greater in the IINS group. To the best of our knowledge, this is the first multicenter study investigating the clinical features of IIN and comparing the two main subgroups, IINS and INSOD.
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Affiliation(s)
| | | | - Roberta Mattei
- Ophthalmological Oncology Unit, Department of Neuroscience, Sensory Organs and Chest, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Valentina Cima
- Ophthalmological Oncology Unit, Department of Neuroscience, Sensory Organs and Chest, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Francesca De Rossi
- National Centre of Services and Research for the Prevention of Blindness and Rehabilitation of Low Vision Patients, IAPB Italia Onlus, Rome, Italy
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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] [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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Rodwell V, Patil M, Kuht HJ, Neuhauss SCF, Norton WHJ, Thomas MG. Zebrafish Optokinetic Reflex: Minimal Reporting Guidelines and Recommendations. BIOLOGY 2023; 13:4. [PMID: 38275725 PMCID: PMC10813647 DOI: 10.3390/biology13010004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Optokinetic reflex (OKR) assays in zebrafish models are a valuable tool for studying a diverse range of ophthalmological and neurological conditions. Despite its increasing popularity in recent years, there are no clear reporting guidelines for the assay. Following reporting guidelines in research enhances reproducibility, reduces bias, and mitigates underreporting and poor methodologies in published works. To better understand optimal reporting standards for an OKR assay in zebrafish, we performed a systematic literature review exploring the animal, environmental, and technical factors that should be considered. Using search criteria from three online databases, a total of 109 research papers were selected for review. Multiple crucial factors were identified, including larval characteristics, sample size, fixing method, OKR set-up, distance of stimulus, detailed stimulus parameters, eye recording, and eye movement analysis. The outcome of the literature analysis highlighted the insufficient information provided in past research papers and the lack of a systematic way to present the parameters related to each of the experimental factors. To circumvent any future errors and champion robust transparent research, we have created the zebrafish optokinetic (ZOK) reflex minimal reporting guideline.
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Affiliation(s)
- Vanessa Rodwell
- Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Leicester LE1 7RH, UK
| | - Manjiri Patil
- Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Leicester LE1 7RH, UK
| | - Helen J. Kuht
- Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Leicester LE1 7RH, UK
| | | | - William H. J. Norton
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Mervyn G. Thomas
- Ulverscroft Eye Unit, School of Psychology and Vision Sciences, University of Leicester, Leicester LE1 7RH, UK
- Department of Ophthalmology, University Hospitals of Leicester NHS Trust, Leicester Royal Infirmary, Leicester LE1 5WW, UK
- Department of Clinical Genetics, University Hospitals of Leicester NHS Trust, Leicester Royal Infirmary, Leicester LE1 5WW, UK
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Zi F, Li Z, Cheng W, Huang X, Sheng X, Rong W. Novel mutations of the X-linked genes associated with early-onset high myopia in five Chinese families. BMC Med Genomics 2023; 16:223. [PMID: 37749571 PMCID: PMC10521526 DOI: 10.1186/s12920-023-01665-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023] Open
Abstract
PURPOSE To report novel pathogenic variants of X-linked genes in five Chinese families with early-onset high myopia (eoHM) by using whole-exome sequencing and analyzing the phenotypic features. METHODS 5 probands with X-linked recessive related eoHM were collected in Ningxia Eye Hospital from January 2021 to June 2022. The probands and their family members received comprehensive ophthalmic examinations,and DNA was abstracted from patients and family members. Whole-exome sequencing was performed on probands to screen the causative variants, and all suspected pathogenic variants were determined by Sanger sequencing and co-segregation analysis was performed on available family members. The pathogenicity of novel variants was predicted using silico analysis and evaluated according to ACMG guidelines. RT-qPCR was used to detect differences in the relative mRNAs expression of candidate gene in mRNAs available with the proband and family members in the pedigree 2. The relationship between genetic variants and clinical features was analyzed. RESULTS All probands were male, and all pedigrees conformed to an X-linked recessive inheritance pattern. They were diagnosed with high myopia at their first visits between 4 and 7 years old. Spherical equivalent ranged between - 6.00D and - 11.00D.The five novel hemizygous variants were found in the probands, containing frameshift deletion variant c.797_801del (p.Val266Alafs*75) of OPN1LW gene in the pedigree 1, nonsense variant c.513G > A (p.Trp171Ter)of RP2 gene in the pedigree 2, missense variant c.98G > T (p.Cys33Phe) of GPR143 gene in the pedigree 3, frameshift deletion variant c.1876_1877del (p.Met626Valfs*22) of FRMD7 gene in the pedigree 4 and inframe deletion variant c.670_ 675del (p.Glu192_ Glu193del) of HMGB3 gene in the pedigree 5. All variants were classified as pathogenic or likely pathogenic by the interpretation principles of HGMD sequence variants and ACMG guidelines. In family 2, RT-qPCR showed that the mRNA expression of RP2 gene was lower in the proband than in other normal family members, indicating that such variant caused an effect on gene function at the mRNA expression level. Further clinical examination showed that pedigrees 1, 2, 3, and 4 were diagnosed as X-linked recessive hereditary eye disease with early-onset high myopia, including quiescent cone dysfunction, retinitis pigmentosa, ocular albinism, and idiopathic congenital nystagmus respectively. The pedigree 5 had eoHM in the right eye and ptosis in both eyes. CONCLUSION In this paper,we are the first to report five novel hemizygous variants in OPN1LW, RP2, GPR143, FRMD7, HMGB3 genes are associated with eoHM. Our study extends the genotypic spectrums for eoHM and better assists ophthalmologists in assessing, diagnosing, and conducting genetic screening for eoHM.
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Affiliation(s)
- Feiyin Zi
- Clinical Medical College, Ningxia Medical University, Yinchuan, 750001, China
| | - Zhen Li
- Department of Ophthalmology, Ningxia Eye Hospital, People's Hospital of Ningxia Hui Autonomous Region, Third Clinical Medical College of Ningxia Medical University, 936 Huanghe East Road, Jinfeng District, Yinchuan, 750001, China
| | - Wanyu Cheng
- Clinical Medical College, Ningxia Medical University, Yinchuan, 750001, China
| | - Xiaoyu Huang
- Clinical Medical College, Ningxia Medical University, Yinchuan, 750001, China
| | - Xunlun Sheng
- Gansu Aier Ophthalmiology and Optometry Hospital, 1228 Guazhou Road, Qilihe District, Lanzhou, 730050, China.
| | - Weining Rong
- Department of Ophthalmology, Ningxia Eye Hospital, People's Hospital of Ningxia Hui Autonomous Region, Third Clinical Medical College of Ningxia Medical University, 936 Huanghe East Road, Jinfeng District, Yinchuan, 750001, China.
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Hafdaoui S, Ciaccio C, Castellotti B, Sciacca FL, Pantaleoni C, D'Arrigo S. Case report: A novel pathogenic FRMD7 variant in a Turner syndrome patient with familial idiopathic infantile nystagmus. Front Neurol 2023; 14:1199095. [PMID: 37545716 PMCID: PMC10398378 DOI: 10.3389/fneur.2023.1199095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 06/28/2023] [Indexed: 08/08/2023] Open
Abstract
Infantile idiopathic nystagmus (IIN) is an oculomotor disorder characterized by involuntary bilateral, periodic ocular oscillations, predominantly on the horizontal axis. X-linked IIN (XLIIN) is the most common form of congenital nystagmus, and the FERM domain-containing gene (FRMD7) is the most common cause of pathogenesis, followed by mutations in GPR143. To date, more than 60 pathogenic FRMD7 variants have been identified, and the physiopathological pathways leading to the disease are not yet completely understood. FRMD7-associated nystagmus usually affects male patients, while it shows incomplete penetrance in female patients, who are mostly asymptomatic but sometimes present with mild ocular oscillations or, occasionally, with clear nystagmus. Here we report the first case of a patient with Turner syndrome and INN in an XLIIN pedigree, in which we identified a novel frameshift mutation (c.1492dupT) in the FRMD7 gene: the absence of one X chromosome in the patient unmasked the presence of the familial genetic nystagmus.
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Affiliation(s)
- Sara Hafdaoui
- Department of Pediatric Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Claudia Ciaccio
- Department of Pediatric Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Barbara Castellotti
- Department of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca L. Sciacca
- Laboratory of Cytogenetic, Neurological Biochemistry and Neuropharmacology Unit, Department of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chiara Pantaleoni
- Department of Pediatric Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stefano D'Arrigo
- Department of Pediatric Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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Liu F, Wang M, Liao M, Liu L, Jiang X. X-linked FRMD7 gene mutation in idiopathic congenital nystagmus and its role in eye movement: A case report and literature review. FRONTIERS IN OPHTHALMOLOGY 2023; 2:1080869. [PMID: 38983508 PMCID: PMC11182149 DOI: 10.3389/fopht.2022.1080869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/28/2022] [Indexed: 07/11/2024]
Abstract
Background Idiopathic congenital nystagmus (ICN) is an inherited disorder characterized by uncontrollable binocular conjugating oscillation. X-linked idiopathic congenital nystagmus is one of the most prevalent types of ICN. Elucidation of the genetic mechanisms involved in ICN will enhance our understanding of its molecular etiology. Case presentation We report a girl with uncontrollable binocular oscillation and anomalous head posture, then presented a novel heterozygous missense variant (c.686G>T) within the mutation-rich region of the FERM domain containing 7 (FRMD7) gene in her family member. The girl received occlusion therapy and surgical operation which balanced her binocular vision and corrected the anomalous head posture. Conclusions This is the first report on a mutation (c.686G>T) caused the substitution of Arg (R) with Leu (L) at position 229 (p.R229L) of the FRMD7 protein in a patient with ICN.
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Affiliation(s)
- Fanfei Liu
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Minjin Wang
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Meng Liao
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Longqian Liu
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Xiaoshuang Jiang
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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Salchow DJ. [Nystagmus in Children - a Survey]. Klin Monbl Augenheilkd 2023; 240:617-635. [PMID: 36827996 DOI: 10.1055/a-2022-1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Nystagmus describes an involuntary, periodic movement of one or both eyes. About 1/600 children and adolescents have nystagmus, most of them idiopathic infantile nystagmus (IIN), also called "congenital nystagmus", which can be caused by mutations in the FRMD7 gene. Other frequent forms of nystagmus are latent nystagmus, which is usually associated with infantile strabismus, and nystagmus associated with albinism. Sometimes difficult to distinguish in young infants is a sensory nystagmus, where a defect in the visual system reduces vision and causes nystagmus. Causes include retinal dystrophies, congenital stationary night blindness and structural ocular defects including optic nerve hypoplasia or dense bilateral congenital cataracts. Unilateral nystagmus can be the sign of an anterior visual pathway lesion. Seesaw nystagmus may be associated with suprasellar and mesodiencephalic lesions and - rarely - with retinal dystrophies.The ophthalmology plays a key role in identifying the form of nystagmus. Children with new onset nystagmus, with spasmus nutans, with vertical or unilateral nystagmus and those with seesaw nystagmus require neurologic evaluation including imaging of the brain.The treatment of nystagmus depends on the underlying cause. Even minor refractive errors should be corrected, contact lenses offer advantages over glasses.Gabapentin and memantine, possibly also carbonic anhydrase inhibitors, are effective in treating IIN, nystagmus in albinism and sensory nystagmus. Nevertheless, pharmacologic treatment of nystagmus is rarely used in children; the reasons are the limited effects on vision, the need for lifelong therapy, and potential side effects. Eye muscle surgery (Anderson procedure, Kestenbaum procedure) can correct a nystagmus-related anomalous head posture. The concept of "artifical divergence" of Cüppers may help to decrease nystagmus intensity in patients whose nystagmus dampens with convergence. The four-muscle-tenotomy, which involves disinsertion and reinsertion of the horizontal muscles at the original insertion of both eyes, has a proven but limited positive effect on visual acuity.
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Salchow DJ. Nystagmus bei Kindern – eine Übersicht. AUGENHEILKUNDE UP2DATE 2023. [DOI: 10.1055/a-1774-3608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
ZusammenfassungNystagmus ist definiert als unwillkürliche, periodische Bewegung, bei der eines oder beide Augen vom Fixationspunkt wegdriften (sog. Drift). Auf die Drift, die langsame Phase, folgt entweder eine schnelle, refixierende Bewegung (sog. Refixationssakkade oder schnelle Phase) oder eine langsamere Bewegung zur Wiederaufnahme der Fixation. In dieser Übersichtsarbeit sollen die wichtigsten Formen von Nystagmus bei Kindern erörtert werden, für eine Übersicht bei Erwachsenen sei auf 1 verwiesen.
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Tiriac A, Feller MB. Roles of visually evoked and spontaneous activity in the development of retinal direction selectivity maps. Trends Neurosci 2022; 45:529-538. [PMID: 35491255 DOI: 10.1016/j.tins.2022.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022]
Abstract
Detecting the direction of motion underlies many visually guided behaviors, from reflexive eye movements to identifying and catching moving objects. A subset of motion sensitive cells are direction selective - responding strongly to motion in one direction and weakly to motion in other directions. In mammals, direction-selective cells are found throughout the visual system, including the retina, superior colliculus, and primary visual cortex. Direction selectivity maps are well characterized in the mouse retina, where the preferred directions of retinal direction-selective cells follow the projections of optic flow, generated by the movements animals make as they navigate their environment. Here, we synthesize recent findings implicating activity-dependent mechanisms in the development of retinal direction selectivity maps, with primary focus on studies in mice, and discuss the implications for the development of direction-selective responses in downstream visual areas.
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Affiliation(s)
- Alexandre Tiriac
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
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Dawar B, Kuht HJ, Han J, Maconachie GDE, Thomas MG. Clinical utility gene card for FRMD7-related infantile nystagmus. Eur J Hum Genet 2021; 29:1584-1588. [PMID: 33633368 PMCID: PMC8484540 DOI: 10.1038/s41431-021-00826-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/29/2020] [Accepted: 01/24/2021] [Indexed: 02/07/2023] Open
Affiliation(s)
- Basu Dawar
- grid.9918.90000 0004 1936 8411Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX UK
| | - Helen J. Kuht
- grid.9918.90000 0004 1936 8411Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX UK
| | - Jinu Han
- grid.15444.300000 0004 0470 5454Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Gail D. E. Maconachie
- grid.9918.90000 0004 1936 8411Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX UK ,grid.11835.3e0000 0004 1936 9262Division of Ophthalmology and Orthoptics, Health Sciences School, University of Sheffield, Sheffield, UK
| | - Mervyn G. Thomas
- grid.9918.90000 0004 1936 8411Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX UK
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Huurneman B, Goossens J. Broad and Long-Lasting Vision Improvements in Youth With Infantile Nystagmus After Home Training With a Perceptual Learning App. Front Neurosci 2021; 15:651205. [PMID: 34489619 PMCID: PMC8417383 DOI: 10.3389/fnins.2021.651205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/25/2021] [Indexed: 11/16/2022] Open
Abstract
Current treatments for infantile nystagmus (IN), focused on dampening the oscillating eye movements, yield little to no improvement in visual functioning. It makes sense, however, to treat the visual impairments associated with IN with tailored sensory training. Recently, we developed such a training, targeting visual crowding as an important bottleneck in visual functioning with an eye-movement engaging letter discrimination task. This training improved visual performance of children with IN, but most children had not reached plateau performance after 10 supervised training sessions (3,500 trials). Here, we evaluate the effects of prolonged perceptual learning (14,000 trials) in 7-18-year-old children with IN and test the feasibility of tablet-based, at-home intervention. Results demonstrate that prolonged home-based perceptual training results in stable, long lasting visual acuity improvements at distance and near, with remarkably good transfer to reading and even stereopsis. Improvements on self-reported functional vision scores underline the clinical relevance of perceptual learning with e-health apps for individuals with IN.
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Affiliation(s)
- Bianca Huurneman
- Department Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands.,Royal Dutch Visio, Nijmegen, Netherlands
| | - Jeroen Goossens
- Department Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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Choi JH, Kim SJ, Thomas MG, Jung JH, Oh EH, Shin JH, Cho JW, Kim HS, Park JY, Choi SY, Choi HY, Choi KD. Diagnostic yield of targeted next-generation sequencing in infantile nystagmus syndrome. Ophthalmic Genet 2021; 42:561-569. [PMID: 34132631 DOI: 10.1080/13816810.2021.1938138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Background: Infantile nystagmus syndrome (INS) is a genetically heterogeneous disorder. Identifying genetic causes of INS would help clinicians to facilitate clinical diagnosis and provide appropriate treatment. The aim of this study was to determine the diagnostic utility of targeted next-generation sequencing (NGS) for INS.Materials and methods: We recruited 37 patients who were referred to the Neuro-ophthalmology clinics for evaluations of INS. NGS was performed using a targeted panel that included 98 candidate genes associated with INS. We identified pathogenic variants according to guidelines of the American College of Medical Genetics and Genomics. We also calculated the sensitivity and specificity of each clinical sign to assess the diagnostic yield of our gene panel.Results: After variant filtering, annotation, and interpretation, the potential pathogenic variants were detected in 13 of the 37 patients, achieving a molecular diagnostic rate of 35%. The identified genes were PAX6 (n = 4), FRMD7 (n = 4), GPR143 (n = 2), CACNA1F (n = 1), CNGA3 (n = 1) and GUCY2D (n = 1). In approximately 30% (n = 4) of the patients, the initial clinical diagnosis was revised after a molecular diagnosis was performed. The presence of a family history had the highest predictive power for a molecular diagnosis (sensitivity = 61.5%, specificity = 91.7%), and the sensitivity increased when the family history was considered together with one of two clinical signs such as pendular nystagmus waveforms or anterior segment dysgenesis.Conclusions: Our study shows that targeted NGS can be useful to determine a molecular diagnosis for patients with INS. Targeted NGS also helps to confirm a clinical diagnosis in atypical phenotypes or unresolved cases.
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Affiliation(s)
- Jae-Hwan Choi
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Su-Jin Kim
- Department of Ophthalmology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Mervyn G Thomas
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Jae-Ho Jung
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea
| | - Eun Hye Oh
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jin-Hong Shin
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jae Wook Cho
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Hyang-Sook Kim
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Ji-Yun Park
- Department of Neurology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Seo Young Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea
| | - Hee Young Choi
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea
| | - Kwang-Dong Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea
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13
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Development of the vertebrate retinal direction-selective circuit. Dev Biol 2021; 477:273-283. [PMID: 34118273 DOI: 10.1016/j.ydbio.2021.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/17/2021] [Accepted: 06/04/2021] [Indexed: 01/13/2023]
Abstract
The vertebrate retina contains an array of neural circuits that detect distinct features in visual space. Direction-selective (DS) circuits are an evolutionarily conserved retinal circuit motif - from zebrafish to rodents to primates - specialized for motion detection. During retinal development, neuronal subtypes that wire DS circuits form exquisitely precise connections with each other to shape the output of retinal ganglion cells tuned for specific speeds and directions of motion. In this review, we follow the chronology of DS circuit development in the vertebrate retina, including the cellular, molecular, and activity-dependent mechanisms that regulate the formation of DS circuits, from cell birth and migration to synapse formation and refinement. We highlight recent findings that identify genetic programs critical for specifying neuronal subtypes within DS circuits and molecular interactions essential for responses along the cardinal axes of motion. Finally, we discuss the roles of DS circuits in visual behavior and in certain human visual disease conditions. As one of the best-characterized circuits in the vertebrate retina, DS circuits represent an ideal model system for studying the development of neural connectivity at the level of individual genes, cells, and behavior.
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14
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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] [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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15
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Prospective Study of the Phenotypic and Mutational Spectrum of Ocular Albinism and Oculocutaneous Albinism. Genes (Basel) 2021; 12:genes12040508. [PMID: 33808351 PMCID: PMC8065601 DOI: 10.3390/genes12040508] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/15/2021] [Accepted: 03/26/2021] [Indexed: 02/07/2023] Open
Abstract
Albinism encompasses a group of hereditary disorders characterized by reduced or absent ocular pigment and variable skin and/or hair involvement, with syndromic forms such as Hermansky-Pudlak syndrome and Chédiak-Higashi syndrome. Autosomal recessive oculocutaneous albinism (OCA) is phenotypically and genetically heterogenous (associated with seven genes). X-linked ocular albinism (OA) is associated with only one gene, GPR143. We report the clinical and genetic outcomes of 44 patients, from 40 unrelated families of diverse ethnicities, with query albinism presenting to the ocular genetics service at Moorfields Eye Hospital NHS Foundation Trust between November 2017 and October 2019. Thirty-six were children (≤ 16 years) with a median age of 31 months (range 2-186), and eight adults with a median age of 33 years (range 17-39); 52.3% (n = 23) were male. Genetic testing using whole genome sequencing (WGS, n = 9) or a targeted gene panel (n = 31) gave an overall diagnostic rate of 42.5% (44.4% (4/9) with WGS and 41.9% (13/31) with panel testing). Seventeen families had confirmed mutations in TYR (n = 9), OCA2, (n = 4), HPS1 (n = 1), HPS3 (n = 1), HPS6 (n = 1), and GPR143 (n = 1). Molecular diagnosis of albinism remains challenging due to factors such as missing heritability. Differential diagnoses must include SLC38A8-associated foveal hypoplasia and syndromic forms of albinism.
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16
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Wang XF, Chen H, Huang PJ, Feng ZK, Hua ZQ, Feng X, Han F, Xu XT, Shen RJ, Li Y, Jin ZB, Yu HY. Genotype-Phenotype Analysis and Mutation Spectrum in a Cohort of Chinese Patients With Congenital Nystagmus. Front Cell Dev Biol 2021; 9:627295. [PMID: 33732697 PMCID: PMC7958879 DOI: 10.3389/fcell.2021.627295] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/06/2021] [Indexed: 11/28/2022] Open
Abstract
Purpose: Congenital nystagmus (CN) is a genetically and clinically heterogeneous ocular disorder that manifests as involuntary, periodic oscillations of the eyes. To date, only FRMD7 and GPR143 have been reported to be responsible for causing CN. Here, we aimed to identify the disease-causing mutations and describe the clinical features in the affected members in our study. Methods: All the subjects underwent a detailed ophthalmic examination. Direct sequencing of all coding exons and splice site regions in FRMD7 and GPR143 and a mutation assessment were performed in each patient. Results: We found 14 mutations in 14/37 (37.8%) probands, including nine mutations in the FRMD7 gene and five mutations in the GPR143 gene, seven of which are novel, including c.284G>A(R95K), c.964C>T(P322S), c.284+10T>G, c.901T>C (Y301H), and c.2014_2023delTCACCCATGG(S672Pfs*12) in FRMD7, and c.250+1G>C, and c.485G>A (W162*) in GPR143. The mutation detection rate was 87.5% (7/8) of familial vs. 24.1% (7/29) of sporadic cases. Ten mutations in 24 (41.7%) non-syndromic subjects and 4 mutations in 13(30.8%) syndromic subjects were detected. A total of 77.8% (7/9) of mutations in FRMD7 were concentrated within the FERM and FA domains, while all mutations in GPR143 were located in exons 1, 2, 4 and 6. We observed that visual acuity tended to be worse in the GPR143 group than in the FRMD7 group, and no obvious difference in other clinical manifestations was found through comparisons in different groups of patients. Conclusions: This study identified 14 mutations (seven novel and seven known) in eight familial and 29 sporadic patients with congenital nystagmus, expanding the mutational spectrum and validating FRMD7 and GPR143 as mutation hotspots. These findings also revealed a significant difference in the screening rate between different groups of participants, providing new insights for the strategy of genetic screening and early clinical diagnosis of CN.
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Affiliation(s)
- Xiao-Fang Wang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Hui Chen
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Peng-Juan Huang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Zhuo-Kun Feng
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Zi-Qi Hua
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiang Feng
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Fang Han
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiao-Tao Xu
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ren-Juan Shen
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Li
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zi-Bing Jin
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Huan-Yun Yu
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, China
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17
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Ehrenberg M, Bagdonite-Bejarano L, Fulton AB, Orenstein N, Yahalom C. Genetic causes of nystagmus, foveal hypoplasia and subnormal visual acuity- other than albinism. Ophthalmic Genet 2021; 42:243-251. [PMID: 33594928 DOI: 10.1080/13816810.2021.1888128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Background: To describe genetic molecular findings in individuals with congenital nystagmus, foveal hypoplasia, and subnormal vision, with normal ocular pigmentation (absence of diffuse transillumination or transparent retinal pigment typical for albinism).Methods: This is a retrospective, multicenter study of ophthalmic, systemic, and genetic features, as collected from medical records of patients diagnosed with infantile nystagmus and foveal hypoplasia. Ophthalmic findings include best-corrected visual acuity (BCVA), biomicroscopic examination, cycloplegic refraction, retinal examination, macular optical coherence tomography, and electroretinography. Genetic information was retrieved from the participating genetic clinics and included ethnicity and molecular diagnosis.Results: Thirty-one individuals met the inclusion criteria and had a secure molecular diagnosis. Mutations in two genes predominated, constituting 77.4% of all the represented genes: SLC38A8 (45.1%) and PAX6 (32.3%). Seventy-eight percent of the subjects who had a measurable BCVA had moderate and severe visual impairment (range 20/80 to 20/270). Most patients with a mutation in SLC38A8 had mild to moderate astigmatism, while most patients with PAX6 mutation had moderate and severe myopia. Patients in the PAX6 group had variable degrees of anterior segment manifestations.Conclusion: In our cohort, the main causative genes for congenital nystagmus and foveal hypoplasia in normally pigmented eyes were SLC38A8 and PAX6. A mild phenotype in PAX6 mutations may be an under-diagnosed cause of nystagmus and foveal hypoplasia. Reaching an accurate genetic diagnosis is essential for both the patients and their family members. This enables predicting disease prognosis, tailoring correct follow-up, and providing genetic counseling and family planning to affected families.
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Affiliation(s)
- Miriam Ehrenberg
- Ophthalmology Unit, Schneider Children's Medical Center in Israel, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Anne B Fulton
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Naama Orenstein
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Genetic Department, Children's Medical Center in Israel, Petach Tikva, Israel
| | - Claudia Yahalom
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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18
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Discordant phenotypes in twins with infantile nystagmus. Sci Rep 2021; 11:2826. [PMID: 33531592 PMCID: PMC7854608 DOI: 10.1038/s41598-021-82368-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 01/18/2021] [Indexed: 11/08/2022] Open
Abstract
Infantile nystagmus (IN) may result from aetiologies including albinism and FRMD7 mutations. IN has low prevalence, and twins with IN are rare. Whilst discordant presentation has been previously reported for IN, we present for the first time the comprehensive assessment of diagnostically discordant monozygotic twins. From a cohort of over 2000 patients, we identified twins and triplets discordant for nystagmus. Using next-generation sequencing, high-resolution infra-red pupil tracking and optical coherence tomography, we characterised differences in genotype and phenotype. Monozygotic twins (n = 1), dizygotic twins (n = 3) and triplets (n = 1) were included. The monozygotic twins had concordant TYR variants. No causative variants were identified in the triplets. Dizygotic twins had discordant variants in TYR, OCA2 and FRMD7. One unaffected co-twin demonstrated sub-clinical nystagmus. Foveal hypoplasia (FH) was noted in four of five probands. Both co-twins of the monozygotic pair and triplets displayed FH. In three families, at least one parent had FH without nystagmus. FH alone may be insufficient to develop nystagmus. Whilst arrested optokinetic reflex pathway development is implicated in IN, discordant twins raise questions regarding where differences in development have arisen. In unaffected monozygotes therefore, genetic variants may predispose to oculomotor instability, with variable expressivity possibly responsible for the discordance observed.
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19
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Papageorgiou E, Gottlob I. The challenges faced by clinicians diagnosing and treating infantile nystagmus Part I: diagnosis. EXPERT REVIEW OF OPHTHALMOLOGY 2020. [DOI: 10.1080/17469899.2021.1860754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Eleni Papageorgiou
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
- Department of Ophthalmology, University Hospital of Larissa, Larissa, Greece
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, Leicester, UK
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20
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Salman A, Hutton SB, Newall T, Scott JA, Griffiths HL, Lee H, Gomez-Nicola D, Lotery AJ, Self JE. Characterization of the Frmd7 Knock-Out Mice Generated by the EUCOMM/COMP Repository as a Model for Idiopathic Infantile Nystagmus (IIN). Genes (Basel) 2020; 11:genes11101157. [PMID: 33007925 PMCID: PMC7601595 DOI: 10.3390/genes11101157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
In this study, we seek to exclude other pathophysiological mechanisms by which Frmd7 knock-down may cause Idiopathic Infantile Nystagmus (IIN) using the Frmd7.tm1a and Frmd7.tm1b murine models. We used a combination of genetic, histological and visual function techniques to characterize the role of Frmd7 gene in IIN using a novel murine model for the disease. We demonstrate that the Frmd7.tm1b allele represents a more robust model of Frmd7 knock-out at the mRNA level. The expression of Frmd7 was investigated using both antibody staining and X-gal staining confirming previous reports that Frmd7 expression in the retina is restricted to starburst amacrine cells and demonstrating that X-gal staining recapitulates the expression pattern in this model. Thus, it offers a useful tool for further expression studies. We also show that gross retinal morphology and electrophysiology are unchanged in these Frmd7 mutant models when compared with wild-type mice. High-speed eye-tracking recordings of Frmd7 mutant mice confirm a specific horizontal optokinetic reflex defect. In summary, our study confirms the likely role for Frmd7 in the optokinetic reflex in mice mediated by starburst amacrine cells. We show that the Frmd7.tm1b model provides a more robust knock-out than the Frmd7.tm1a model at the mRNA level, although the functional consequence is unchanged. Finally, we establish a robust eye-tracking technique in mice that can be used in a variety of future studies using this model and others. Although our data highlight a deficit in the optiokinetic reflex as a result of the starburst amacrine cells in the retina, this does not rule out the involvement of other cells, in the brain or the retina where Frmd7 is expressed, in the pathophysiology of IIN.
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MESH Headings
- Alleles
- Amacrine Cells/metabolism
- Animals
- Cytoskeletal Proteins/genetics
- Cytoskeletal Proteins/metabolism
- Disease Models, Animal
- Electroretinography
- Female
- Gene Expression
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/pathology
- Genetic Diseases, X-Linked/physiopathology
- Male
- Mice
- Mice, Knockout
- Mutation
- Nystagmus, Congenital/genetics
- Nystagmus, Congenital/pathology
- Nystagmus, Congenital/physiopathology
- Nystagmus, Optokinetic
- Retina/metabolism
- Retina/pathology
- Retina/physiopathology
- Tomography, Optical Coherence
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Affiliation(s)
- Ahmed Salman
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
- Correspondence:
| | - Samuel B. Hutton
- School of Psychology, University of Sussex, Brighton BN1 9QH, UK;
| | - Tutte Newall
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Jennifer A. Scott
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Helen L. Griffiths
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Helena Lee
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Diego Gomez-Nicola
- School of Biological Sciences, University of Southampton, Southampton SO171BJ, UK;
| | - Andrew J. Lotery
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
| | - Jay E. Self
- Clinical and Experimental Neurosciences, University of Southampton, Southampton SO16 6YD, UK; (T.N.); (J.A.S.); (H.L.G.); (H.L.); (A.J.L.); (J.E.S.)
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21
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Jiang L, Li Y, Yang K, Wang Y, Wang J, Cui X, Mao J, Gao Y, Yi P, Wang L, Liu JY. FRMD7 Mutations Disrupt the Interaction with GABRA2 and May Result in Infantile Nystagmus Syndrome. Invest Ophthalmol Vis Sci 2020; 61:41. [PMID: 32446246 PMCID: PMC7405782 DOI: 10.1167/iovs.61.5.41] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Purpose To identify the pathogenic gene of infantile nystagmus syndrome (INS) in three Chinese families and explore the potential pathogenic mechanism of FERM domain-containing 7 (FRMD7) mutations. Methods Genetic testing was performed via Sanger sequencing. Western blotting was used to analyze protein expression of FRMD7. Glutathione S-transferase pull-down and immunoprecipitation were conducted to investigate the proteins interacting with FRMD7. Rescue assays were performed in Caenorhabditis elegans to explore the potential role of FRMD7 in vivo. Results We recruited three Chinese families with X-linked INS and identified a duplication and two missense mutations in FRMD7: c.998dupA/p.His333Glnfs*2, c.580G>A/p.Ala194Thr, and c.973A>G/p.Arg325Gly (one in each family). Expression levels of three mutants were similar to that of wild-type FRMD7 in vitro. Interestingly, the mutant p.His333Glnfs*2 exhibited a predominantly nuclear location, whereas wild-type FRMD7 localized to the cytoplasm. In addition, we found FRMD7 to directly interact with the loop between transmembrane domains 3 and 4 of GABRA2, a type A gamma-aminobutyric acid (GABA) receptor (GABAARs) subunit critical for receptor transport and localization, whereas the mutants p.Ala194Thr and p.Arg325Gly exhibited decreased binding to GABRA2. In frm-3 (a nematode homologue of FRMD7) null C.elegans, we found that FRMD7 mutants exhibited a poor rescue effect on the defects of locomotion and fluorescence recovery after photobleaching of GABAARs. Conclusions Our findings identified three FRMD7 mutants in three Chinese families with X-linked INS and confirmed GABRA2 as a novel binding partner of FRMD7. These findings suggest that FRMD7 plays an important role by targeting GABAARs.
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22
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Hvid K, Nissen KR, Bayat A, Roos L, Grønskov K, Kessel L. Prevalence and causes of infantile nystagmus in a large population-based Danish cohort. Acta Ophthalmol 2020; 98:506-513. [PMID: 32067411 DOI: 10.1111/aos.14354] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 12/31/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE The aim of this study was to provide a population-based estimate on the prevalence of infantile nystagmus and to describe the causes in the Capital Region of Denmark. METHODS Review of medical records of children with infantile nystagmus born in the period 1 January 2010 through 31 December 2017 and living in the Capital Region of Denmark. We used birth registry data from Statistics Denmark and the National Danish Birth Registry to calculate the prevalence of nystagmus in children born at term and prematurely. RESULTS A total of 103 patients (52 males/51 females) with infantile nystagmus were included. The overall prevalence of infantile nystagmus was 6.1 per 10 000 live births. It was higher in premature children (28.4/10 000 live births) than children born at term (4.4/10 000), p < 0.0001, and highest in children born extremely preterm, (97.3/10 000). The most common cause of infantile nystagmus was ocular disease (44%) followed by idiopathic nystagmus (32%), neurological disorders and genetic syndromes (20%) and prematurity without retinopathy of prematurity as the only cause (4%). CONCLUSIONS In this study, we provide the prevalence of infantile nystagmus based on national medical records in which all residents are accounted for. Our findings show a prevalence of 6.1 per 10 000 live births but six times higher among children born preterm than born at term. Ocular disease was the leading cause of infantile nystagmus with albinism and ocular malformations as the most frequent. In 1/3 of patients, no cause could be identified.
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Affiliation(s)
- Karen Hvid
- Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Kamilla Rothe Nissen
- Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Allan Bayat
- Danish Epilepsy Centre, Dianalund, Denmark.,Department of Pediatrics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Laura Roos
- Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Karen Grønskov
- Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Line Kessel
- Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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23
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Brodsky MC. Infantile nystagmus-following the trail of evidence. J AAPOS 2020; 24:70-71. [PMID: 32151572 DOI: 10.1016/j.jaapos.2020.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Michael C Brodsky
- Departments of Ophthalmology and Neurology, Mayo Clinic, Rochester, Minnesota.
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24
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Mayer AK, Mahajnah M, Thomas MG, Cohen Y, Habib A, Schulze M, Maconachie GDE, AlMoallem B, De Baere E, Lorenz B, Traboulsi EI, Kohl S, Azem A, Bauer P, Gottlob I, Sharkia R, Wissinger B. Homozygous stop mutation in AHR causes autosomal recessive foveal hypoplasia and infantile nystagmus. Brain 2020; 142:1528-1534. [PMID: 31009037 DOI: 10.1093/brain/awz098] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 02/04/2019] [Accepted: 02/16/2019] [Indexed: 01/27/2023] Open
Abstract
Herein we present a consanguineous family with three children affected by foveal hypoplasia with infantile nystagmus, following an autosomal recessive mode of inheritance. The patients showed normal electroretinography responses, no signs of albinism, and no anterior segment or brain abnormalities. Upon whole exome sequencing, we identified a homozygous mutation (c.1861C>T;p.Q621*) in the aryl hydrocarbon receptor (AHR) gene that perfectly co-segregated with the disease in the larger family. AHR is a ligand-activated transcription factor that has been intensively studied in xenobiotic-induced toxicity. Further, it has been shown to play a physiological role under normal cellular conditions, such as in immunity, inflammatory response and neurogenesis. Notably, knockout of the Ahr gene in mouse impairs optic nerve myelin sheath formation and results in oculomotor deficits sharing many features with our patients: the eye movement disorder in Ahr-/- mice appears early in development and presents as conjugate horizontal pendular nystagmus. We therefore propose AHR to be a novel disease gene for a new, recessively inherited disorder in humans, characterized by infantile nystagmus and foveal hypoplasia.
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Affiliation(s)
- Anja K Mayer
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Muhammad Mahajnah
- Child Neurology and Development Center, Hillel-Yaffe Medical Center, Hadera, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Mervyn G Thomas
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Yuval Cohen
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.,Ophthalmology Department, Hillel Yaffe Medical Center, Hadera, Israel
| | - Adib Habib
- Pediatric Department, St. Vincent French Hospital, Nazareth, Israel
| | - Martin Schulze
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Gail D E Maconachie
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Basamat AlMoallem
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium.,Department of Ophthalmology, King Abdul-Aziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Birgit Lorenz
- Department of Ophthalmology, Justus Liebig University Giessen, Giessen, Germany
| | | | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Irene Gottlob
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Rajech Sharkia
- The Triangle Regional Research and Development Center, Kfar Qari', Israel.,Beit-Berl Academic College, Beit-Berl, Israel
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
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Fraik AK, Quackenbush C, Margres MJ, Comte S, Hamilton DG, Kozakiewicz CP, Jones M, Hamede R, Hohenlohe PA, Storfer A, Kelley JL. Transcriptomics of Tasmanian Devil ( Sarcophilus Harrisii) Ear Tissue Reveals Homogeneous Gene Expression Patterns across a Heterogeneous Landscape. Genes (Basel) 2019; 10:E801. [PMID: 31614864 PMCID: PMC6826840 DOI: 10.3390/genes10100801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023] Open
Abstract
In an era of unprecedented global change, exploring patterns of gene expression among wild populations across their geographic range is crucial for characterizing adaptive potential. RNA-sequencing studies have successfully characterized gene expression differences among populations experiencing divergent environmental conditions in a wide variety of taxa. However, few of these studies have identified transcriptomic signatures to multivariate, environmental stimuli among populations in their natural environments. Herein, we aim to identify environmental and sex-driven patterns of gene expression in the Tasmanian devil (Sarcophilus harrisii), a critically endangered species that occupies a heterogeneous environment. We performed RNA-sequencing on ear tissue biopsies from adult male and female devils from three populations at the extremes of their geographic range. There were no transcriptome-wide patterns of differential gene expression that would be suggestive of significant, environmentally-driven transcriptomic responses. The general lack of transcriptome-wide variation in gene expression levels across the devil's geographic range is consistent with previous studies that documented low levels of genetic variation in the species. However, genes previously implicated in local adaptation to abiotic environment in devils were enriched for differentially expressed genes. Additionally, three modules of co-expressed genes were significantly associated with either population of origin or sex.
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Affiliation(s)
- Alexandra K Fraik
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
| | - Corey Quackenbush
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
| | - Mark J Margres
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA.
| | - Sebastien Comte
- School of Natural Sciences, Hobart, TAS 7001, Australia.
- Vertebrate Pest Research Unit, NSW Department of Primary Industries, 1447 Forest Road, Orange, NSW 2800, Australia.
| | | | | | - Menna Jones
- School of Natural Sciences, Hobart, TAS 7001, Australia.
| | - Rodrigo Hamede
- School of Natural Sciences, Hobart, TAS 7001, Australia.
| | - Paul A Hohenlohe
- Department of Biological Sciences, University of Idaho, Institute for Bioinformatics and Evolutionary Studies, University of Idaho, 875 Perimeter Drive, Moscow, ID 83844, USA.
| | - Andrew Storfer
- Department of Biological Sciences, University of Idaho, Institute for Bioinformatics and Evolutionary Studies, University of Idaho, 875 Perimeter Drive, Moscow, ID 83844, USA.
| | - Joanna L Kelley
- Department of Biological Sciences, University of Idaho, Institute for Bioinformatics and Evolutionary Studies, University of Idaho, 875 Perimeter Drive, Moscow, ID 83844, USA.
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26
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Wang F, Guan H, Liu W, Zhao G, Liu S. Next-generation sequencing identifies a novel frameshift variant in FRMD7 in a Chinese family with idiopathic infantile nystagmus. J Clin Lab Anal 2019; 34:e23012. [PMID: 31495972 PMCID: PMC6977136 DOI: 10.1002/jcla.23012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 07/05/2019] [Accepted: 07/26/2019] [Indexed: 01/27/2023] Open
Abstract
Background Idiopathic infantile nystagmus (IIN) is a high genetically heterogeneous ophthalmic disease and is often associated with pathogenic mutations in FRMD7 and GPR143, respectively. Idiopathic infantile nystagmus manifests as involuntary periodic rhythmic oscillation of the eyes in the very early life, which decreases visual acuity and affects the quality of life. Objective and Methods The aim of our study was to reveal a possible pathogenic variant through the investigation of a Chinese Han family with IIN with an implementation of a next‐generation sequencing method. Isolated DNA analysis was followed by Sanger sequencing validation. We also performed the detailed ophthalmological examination of family members. Results We identified a novel frameshift variant in FRMD7 (NM_194277.2: c.1419_1422dup, p.Tyr475fs), which leads to a frameshift mutation since tyrosine (Tyr) at 475 codon of FRMD7 protein (p.Tyr475fs) and co‐segregates with IIN phenotype in this family. Conclusions We found a novel frameshift FRMD7 variant in a Chinese Han family, which may be causative variant for IIN and can further enrich the mutation spectrum and uncover the etiology of IIN.
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Affiliation(s)
- Fengqi Wang
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China.,Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hongzai Guan
- Department of Clinical Hematology, Medical College of Qingdao University, Qingdao, China
| | - Wenmiao Liu
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China.,Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Guiqiu Zhao
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shiguo Liu
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, China.,Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, China
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Michaud V, Defoort-Dhellemmes S, Drumare I, Pennamen P, Plaisant C, Lasseaux E, Arveiler B. Clinical and molecular findings of FRMD7 related congenital nystagmus as adifferential diagnosis of ocular albinism. Ophthalmic Genet 2019; 40:161-164. [PMID: 30942644 DOI: 10.1080/13816810.2019.1592201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Congenital nystagmus is one of the most common neuro-ophthalmological disorders. X chromosome-linked forms are associated with pathogenic variants of the GPR143 and FRMD7 genes. MATERIALS AND METHODS Patients' DNA was analyzed using a next-generation sequencing (NGS) panel of genes involved in albinism and related pathologies (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, C10ORF11, GPR143, SLC38A8, HPS 1 to 10, LYST, MITF, FRMD7) Results: We report a 4 generation family with 5 affected members initially referred for molecular diagnosis of ocular albinism. A missense variant of FRMD7 was found in 3 affected cases and one female carrier. We show that the disease in the affected girl is due to skewed inactivation of the X chromosome. CONCLUSIONS By compiling all the published cases we discuss the variable penetrance among females due to different types of mutation and to X-inactivation.
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Affiliation(s)
- Vincent Michaud
- a Service de Génétique Médicale , CHU de Bordeaux , Bordeaux , France
| | | | - Isabelle Drumare
- b Service d'exploration de la vision et neuro-ophtalmologie , CHRU de Lille , Lille , France
| | - Perrine Pennamen
- a Service de Génétique Médicale , CHU de Bordeaux , Bordeaux , France.,c INSERM U1211, Maladies Rares, Génétique et Métabolisme , Université de Bordeaux , Bordeaux , France
| | - Claudio Plaisant
- a Service de Génétique Médicale , CHU de Bordeaux , Bordeaux , France
| | - Eulalie Lasseaux
- a Service de Génétique Médicale , CHU de Bordeaux , Bordeaux , France
| | - Benoit Arveiler
- a Service de Génétique Médicale , CHU de Bordeaux , Bordeaux , France.,c INSERM U1211, Maladies Rares, Génétique et Métabolisme , Université de Bordeaux , Bordeaux , France
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28
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Choi JH, Jung JH, Oh EH, Shin JH, Kim HS, Seo JH, Choi SY, Kim MJ, Choi HY, Lee C, Choi KD. Genotype and Phenotype Spectrum of FRMD7-Associated Infantile Nystagmus Syndrome. Invest Ophthalmol Vis Sci 2019; 59:3181-3188. [PMID: 30025138 DOI: 10.1167/iovs.18-24207] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigate the genotype and phenotype spectrum of FRMD7-associated infantile nystagmus syndrome in Korean probands. Methods A total of 37 patients with infantile nystagmus syndrome were recruited prospectively for genetic analysis. We performed polymerase chain reaction (PCR)-based direct sequencing and haplotype analysis for FRMD7. Detailed ophthalmic examinations and eye movement recordings were compared between FRMD7 and non-FRMD7 groups. Results In 13 (35%) of 37 patients, five different mutations of FRMD7 were detected: start codon mutation c.1A>G, splice site mutation c.162+6T>C, and three missense mutations (c.575A>C, c.722A>G, and c.875T>C). The latter mutation was identified in seven unrelated patients, and always was accompanied with two single nucleotide polymorphisms of exon 12 (rs6637934, rs5977623). Compared to non-FRMD7 groups, a cup-to-disc ratio was significantly decreased in FRMD7 groups (P < 0.001), and a disc-macula distance to disc diameter ratio markedly increased in the FRMD7 group (P = 0.015). Most patients in the FRMD7 group had at least two types of the nystagmus waveforms, and the most common type was unidirectional jerk nystagmus (75%), such as pure jerk and jerk with extended foveation, followed by pendular (25%), bidirectional jerk (19%), and dual jerk (6%) nystagmus. No significant differences were observed between FRMD7 and non-FRMD7 groups in terms of the nystagmus waveform, presence of periodic alternating nystagmus, and mean foveation time. Conclusions We identified five FRMD7 mutations in 35% of our infantile nystagmus syndrome cohort, expanding its mutational spectrum. The missense mutation c.875T>C may be a common mutation arisen from the founder effect in Korea. Optic nerve dysplasia associated with FRMD7 mutations suggests that the abnormal development of afferent visual systems may affect neural circuitry within the oculomotor system.
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Affiliation(s)
- Jae-Hwan Choi
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Jae-Ho Jung
- Department of Ophthalmology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Eun Hye Oh
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Jin-Hong Shin
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Hyang-Sook Kim
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Je Hyun Seo
- Department of Ophthalmology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Seo Young Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Min-Ji Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Hee Young Choi
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Changwook Lee
- Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Sciences and Technology, Ulsan, South Korea
| | - Kwang-Dong Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
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Abstract
Eye tracking is a useful tool when studying the oscillatory eye movements associated with nystagmus. However, this oscillatory nature of nystagmus is problematic during calibration since it introduces uncertainty about where the person is actually looking. This renders comparisons between separate recordings unreliable. Still, the influence of the calibration protocol on eye movement data from people with nystagmus has not been thoroughly investigated. In this work, we propose a calibration method using Procrustes analysis in combination with an outlier correction algorithm, which is based on a model of the calibration data and on the geometry of the experimental setup. The proposed method is compared to previously used calibration polynomials in terms of accuracy, calibration plane distortion and waveform robustness. Six recordings of calibration data, validation data and optokinetic nystagmus data from people with nystagmus and seven recordings from a control group were included in the study. Fixation errors during the recording of calibration data from the healthy participants were introduced, simulating fixation errors caused by the oscillatory movements found in nystagmus data. The outlier correction algorithm improved the accuracy for all tested calibration methods. The accuracy and calibration plane distortion performance of the Procrustes analysis calibration method were similar to the top performing mapping functions for the simulated fixation errors. The performance in terms of waveform robustness was superior for the Procrustes analysis calibration compared to the other calibration methods. The overall performance of the Procrustes calibration methods was best for the datasets containing errors during the calibration.
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30
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Wang Z, Wang M, Wang C, Lu B. Identification and functional characterization of a novel missense mutation in FRMD7 responsible for idiopathic congenital nystagmus. Acta Biochim Biophys Sin (Shanghai) 2019; 51:178-184. [PMID: 30576400 DOI: 10.1093/abbs/gmy161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/21/2018] [Indexed: 11/14/2022] Open
Abstract
Idiopathic congenital nystagmus (ICN) is a genetically heterogeneous eye movement disorder which seriously reduces childhood visual acuity. X-linked inheritance is the most common pattern, and mutations in FERM domain-containing protein 7 (FRMD7) are the major cause. Here, we recruited a four-generation Chinese family with X-linked ICN for the causative mutational screening of FRMD7. A novel missense variant, c.805 A > C, was identified in the proband. The mutation was confirmed in all the affected individuals but was not detected in unaffected family members or 100 unrelated Chinese male controls. The mutation causes a substitution of lysine to glutamine at position 269 (p.Lys269Gln, K269Q). The FRMD7 mutant inhibits the formation and extension of neurites. Moreover, the mutation disrupts FRMD7 interaction with calcium/calmodulin-dependent serine protein kinase and neurite formation. Together, our data expand the mutation spectrum of FRMD7 causing ICN and provide an insight into the pathogenesis of nystagmus.
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Affiliation(s)
- Zhe Wang
- Department of Ophthalmology, Central Hospital of Zibo, Zibo, China
| | - Min Wang
- Department of Pathology, Jilin Cancer Hospital, Changchun, China
| | - Chengyan Wang
- Department of Ultrasound, Jilin Cancer Hospital, Changchun, China
| | - Boyang Lu
- Department of Ophthalmology, The First Hospital of Jilin University, Changchun, China
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31
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Chen J, Wei Y, Tian L, Kang X. A novel frameshift mutation in FRMD7 causes X-linked infantile nystagmus in a Chinese family. BMC MEDICAL GENETICS 2019; 20:5. [PMID: 30616528 PMCID: PMC6323710 DOI: 10.1186/s12881-018-0720-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 11/14/2018] [Indexed: 12/03/2022]
Abstract
Background Infantile nystagmus (IN) is an oculomotor disorder that is characterized by conjugate involuntary, rapid and repetitive movement of the eyes. To date, the pathogenesis of IN remains unclear. Many patients show an X-linked inheritance pattern. In this study, we explored the mutation in the FERM domain-containing 7 (FRMD7) gene in a Chinese family with X-linked infantile nystagmus. Methods We conducted comprehensive ocular examinations and collected 5 ml of blood samples from members of a family with X-linked IN and 100 normal controls. Mutations in FRMD7 were identified by sequencing PCR products. Results We found a 7-bp deletion(c.823-829delACCCTAC) in the 9th exon of FRMD7 in a Chinese family with IN, which predicted a truncation of the protein. Conclusions This study reported a novel mutation of the FRMD7 gene occurred in a Chinese family with IN, thus expanding the spectrum of FRMD7 mutations causing IN, and further confirming that the mutations of FRMD7 are the underlying molecular cause of IN.
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Affiliation(s)
- Junjue Chen
- Department of Ophthalmology in XinHua hospital, Shanghai Jiao Tong University, Kongjiang road 1665, Yangpu District, Shanghai, China
| | - Yan Wei
- Department of Ophthalmology in XinHua hospital, Shanghai Jiao Tong University, Kongjiang road 1665, Yangpu District, Shanghai, China
| | - Linlu Tian
- Department of Ophthalmology in XinHua hospital, Shanghai Jiao Tong University, Kongjiang road 1665, Yangpu District, Shanghai, China
| | - Xiaoli Kang
- Department of Ophthalmology in XinHua hospital, Shanghai Jiao Tong University, Kongjiang road 1665, Yangpu District, Shanghai, China.
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32
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Xiu Y, Yao Y, Yang T, Pan M, Yang H, Fang W, Gu F, Zhao J, Zhu Y. Identification of a novel idiopathic congenital nystagmus‑causing missense mutation, p.G296C, in the FRMD7 gene. Mol Med Rep 2018; 18:2816-2822. [PMID: 30015830 PMCID: PMC6102629 DOI: 10.3892/mmr.2018.9260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 06/12/2018] [Indexed: 11/06/2022] Open
Abstract
Exploring the genetic basis for idiopathic congenital nystagmus is critical for improving our understanding of its molecular pathogenesis. In the present study, direct sequencing using gene specific primers was performed in order to identify the causative mutations in two brothers from a Chinese family who had been diagnosed with idiopathic congenital nystagmus. A comprehensive ophthalmological examination, including eye movement recordings, fundus examination, and retinal optical coherence tomography imaging was also conducted, to characterize the disease phenotype. The results revealed that the two brothers exhibited clear signs of nystagmus without any other ocular anomalies. Direct sequencing revealed a G to T transition (c.886G>T) in exon 9 of the four‑point‑one, ezrin, radixin, moesin domain‑containing 7 (FRMD7) gene, which resulted in a conservative substitution of glycine to cysteine at codon 296 (p.G296C), leading to idiopathic congenital nystagmus in the two affected brothers. c.886G>T is a novel idiopathic congenital nystagmus‑inducing mutation in the FRMD7 gene. This finding expands the spectrum of known gene mutations in idiopathic congenital nystagmus, and may be useful for faster gene diagnosis, prenatal testing, the development of potential gene therapies, and for improving the understanding of the molecular pathogenesis of idiopathic congenital nystagmus.
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Affiliation(s)
- Yanghui Xiu
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Yihua Yao
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Tanchu Yang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Meihua Pan
- Eye Institute and Xiamen Eye Center Affiliated Xiamen University, Xiamen, Fujian 361001, P.R. China
| | - Hui Yang
- Department of Ophthalmology, Xiamen Children's Hospital, Xiamen, Fujian 361000, P.R. China
| | - Weifang Fang
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, P.R. China
| | - Junzhao Zhao
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Yihua Zhu
- The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
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34
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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: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [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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35
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Bertsch M, Floyd M, Kehoe T, Pfeifer W, Drack AV. The clinical evaluation of infantile nystagmus: What to do first and why. Ophthalmic Genet 2017; 38:22-33. [PMID: 28177849 DOI: 10.1080/13816810.2016.1266667] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Infantile nystagmus has many causes, some life threatening. We determined the most common diagnoses in order to develop a testing algorithm. METHODS Retrospective chart review. Exclusion criteria were no nystagmus, acquired after 6 months, or lack of examination. DATA COLLECTED pediatric eye examination findings, ancillary testing, order of testing, referral, and final diagnoses. Final diagnosis was defined as meeting published clinical criteria and/or confirmed by diagnostic testing. Patients with a diagnosis not meeting the definition were "unknown." Patients with incomplete testing were "incomplete." Patients with multiple plausible etiologies were "multifactorial." Patients with negative complete workup were "motor." RESULTS A total of 284 charts were identified; 202 met inclusion criteria. The three most common causes were Albinism (19%), Leber Congenital Amaurosis (LCA; 14%), and Non-LCA retinal dystrophy (13%). Anatomic retinal disorders comprised 10%, motor another 10%. The most common first test was MRI (74/202) with a diagnostic yield of 16%. For 28 MRI-first patients, nystagmus alone was the indication; for 46 MRI-first patients other neurologic signs were present. 0/28 nystagmus-only patients had a diagnostic MRI while 14/46 (30%) with neurologic signs did. The yield of ERG as first test was 56%, OCT 55%, and molecular genetic testing 47%. Overall, 90% of patients had an etiology identified. CONCLUSION The most common causes of infantile nystagmus were retinal disorders (56%), however the most common first test was brain MRI. For patients without other neurologic stigmata complete pediatric eye examination, ERG, OCT, and molecular genetic testing had a higher yield than MRI scan. If MRI is not diagnostic, a complete ophthalmologic workup should be pursued.
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Affiliation(s)
- Morgan Bertsch
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
| | - Michael Floyd
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA.,b HealthPartners , Minneapolis , Minnesota , USA
| | - Taylor Kehoe
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA.,c Physician Assistant Program , University of Iowa , Iowa City , Iowa , USA
| | - Wanda Pfeifer
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
| | - Arlene V Drack
- a Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research , Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City , Iowa , USA
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Clinical feature and waveform in infantile nystagmus syndrome in children with FRMD7 gene mutations. SCIENCE CHINA-LIFE SCIENCES 2017. [PMID: 28623544 DOI: 10.1007/s11427-017-9089-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Infant nystagmus sydrome presents as involuntary eye movement disorder and can affect seriously ocular function. We performed a retrospective study of clinical data and FRMD7 genetic test results in 12 cases of infantile nystagmus syndrome to correlate waveform, stereopsis, and visual acuity. The patients (age 6.40±2.67 years) had FRMD7 mutations as follows: missense in eight cases, shear in two cases, frameshift in one case, and non-frameshift in one case. Horizontal jerk waveform was observed in six cases, versus horizontal pendulum in five cases and dual jerk in one case. The uncorrected visual acuity (24 eyes) was 0.21±0.12, compared with a corrected visual acuity (24 eyes) of 0.32±0.14. All patients had simultaneous perception, versus fusion function in 10 cases (83.33%) and stereoscopic vision in seven cases (58.33%) using the synoptophore. Eleven cases (91.67%) detected the stereo fly, compared with five cases (41.67%) for stereoscopic circles and seven cases (58.33%) for stereoscopic animals by Titmus test. Stereoscopic vision using the synoptophore did not correlate with the frequency, amplitude, or intensity of nystagmus or with corrected binocular visual acuity. The infantile nystagmus syndrome with FRMD7 mutations in our cases was caused primarily de novo and missense mutations. Visual acuity and binocular visual function were significant impaired, and the waveform was generally horizontal jerk. Also, an infrared videonystagmogram can record the frequency, amplitude, and intensity of nystagmus accurately.
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Verma R, Ramkumar HL, Zhang K, Granet DB, Hertle RW. X-Linked Idiopathic Infantile Nystagmus (XLIIN): Case Report and Review of Literature. CURRENT OPHTHALMOLOGY REPORTS 2017. [DOI: 10.1007/s40135-017-0139-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Richards MD, Wong A. Infantile nystagmus syndrome: clinical characteristics, current theories of pathogenesis, diagnosis, and management. Can J Ophthalmol 2016; 50:400-8. [PMID: 26651297 DOI: 10.1016/j.jcjo.2015.07.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/12/2015] [Accepted: 07/22/2015] [Indexed: 11/25/2022]
Abstract
Infantile nystagmus syndrome (INS) is an important clinical diagnosis because it is a common presenting sign of many ocular, neurologic, and systemic diseases. Although INS has been studied for more than a century, its diagnosis and treatment remains a challenge to clinicians because of its varied manifestations and multiple associations, and its pathogenesis continues to rouse considerable scientific debate. Fueled by these challenges, recent basic research and clinical investigations have provided new insights into INS. New genetic discoveries and technological advances in ocular imaging have refined our understanding of INS subtypes and offer new diagnostic possibilities. Unexpected surgical outcomes have led to new understanding of its pathogenesis based on novel hypothesized pathways of ocular motor control. Comparative studies on nonhuman visual systems have also informed models of the neural substrate of INS in humans. This review brings together the classic profile of this disorder with recent research to provide an update on the clinical features of INS, an overview of the current theories on how and why INS develops, and a practical approach to the diagnosis and management of INS.
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Affiliation(s)
- Michael D Richards
- Department of Ophthalmology & Vision Sciences, The Hospital for Sick Children; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ont..
| | - Agnes Wong
- Department of Ophthalmology & Vision Sciences, The Hospital for Sick Children; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ont
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Morrie RD, Feller MB. Development of synaptic connectivity in the retinal direction selective circuit. Curr Opin Neurobiol 2016; 40:45-52. [PMID: 27380013 DOI: 10.1016/j.conb.2016.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/07/2016] [Accepted: 06/21/2016] [Indexed: 12/26/2022]
Abstract
Direction selectivity is a classic neuronal computation that has been described in many different sensory systems. The circuit basis of this computation is perhaps best understood in the retina, where direction selectivity is the result of asymmetric connectivity patterns between excitatory and inhibitory circuit components. Retinal direction selective circuits emerge before eye-opening, though components of the circuit undergo refinement after vision begins. These features make the direction selective circuit a rich model in which to investigate neuronal circuit assembly. In this Opinion, we highlight recent experiments investigating the contribution of various molecular cues, as well as neuronal activity, to the development of the retinal direction selective circuit.
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Affiliation(s)
- Ryan D Morrie
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, United States
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720-3200, United States.
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40
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Yonehara K, Fiscella M, Drinnenberg A, Esposti F, Trenholm S, Krol J, Franke F, Scherf BG, Kusnyerik A, Müller J, Szabo A, Jüttner J, Cordoba F, Reddy AP, Németh J, Nagy ZZ, Munier F, Hierlemann A, Roska B. Congenital Nystagmus Gene FRMD7 Is Necessary for Establishing a Neuronal Circuit Asymmetry for Direction Selectivity. Neuron 2015; 89:177-93. [PMID: 26711119 PMCID: PMC4712192 DOI: 10.1016/j.neuron.2015.11.032] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/14/2015] [Accepted: 11/18/2015] [Indexed: 12/24/2022]
Abstract
Neuronal circuit asymmetries are important components of brain circuits, but the molecular pathways leading to their establishment remain unknown. Here we found that the mutation of FRMD7, a gene that is defective in human congenital nystagmus, leads to the selective loss of the horizontal optokinetic reflex in mice, as it does in humans. This is accompanied by the selective loss of horizontal direction selectivity in retinal ganglion cells and the transition from asymmetric to symmetric inhibitory input to horizontal direction-selective ganglion cells. In wild-type retinas, we found FRMD7 specifically expressed in starburst amacrine cells, the interneuron type that provides asymmetric inhibition to direction-selective retinal ganglion cells. This work identifies FRMD7 as a key regulator in establishing a neuronal circuit asymmetry, and it suggests the involvement of a specific inhibitory neuron type in the pathophysiology of a neurological disease. Video Abstract
FRMD7 is required for the horizontal optokinetic reflex in mice as in humans Horizontal direction selectivity is lost in the retina of FRMD7 mutant mice Asymmetry of inhibitory inputs to horizontal DS cells is lost in FRMD7 mutant mice FRMD7 is expressed in ChAT-expressing cells in the retina of mice and primates
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Affiliation(s)
- Keisuke Yonehara
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Michele Fiscella
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering of ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Antonia Drinnenberg
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Federico Esposti
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Stuart Trenholm
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Jacek Krol
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Felix Franke
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering of ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Brigitte Gross Scherf
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Akos Kusnyerik
- Department of Ophthalmology, Semmelweis University, Mária u. 39, 1085 Budapest, Hungary
| | - Jan Müller
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering of ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Arnold Szabo
- Department of Human Morphology and Developmental Biology, Faculty of Medicine, Semmelweis University, Tűzoltó u. 58, 1094 Budapest, Hungary
| | - Josephine Jüttner
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Francisco Cordoba
- Laboratory and Animal Services, Novartis Institute for Biomedical Research, Fabrikstrasse 28, 4056 Basel, Switzerland
| | - Ashrithpal Police Reddy
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - János Németh
- Department of Ophthalmology, Semmelweis University, Mária u. 39, 1085 Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Mária u. 39, 1085 Budapest, Hungary
| | - Francis Munier
- Jules-Gonin Eye Hospital, Avenue de France 15, 1000 Lausanne, Switzerland
| | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering of ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Botond Roska
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Department of Ophthalmology, University of Basel, Mittlere Strasse 91, 4031 Basel, Switzerland.
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A novel mutation in FRMD7 causes X-linked idiopathic congenital nystagmus in a North Indian family. Neurosci Lett 2015; 597:170-5. [DOI: 10.1016/j.neulet.2015.04.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 11/19/2022]
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Kohmoto T, Okamoto N, Satomura S, Naruto T, Komori T, Hashimoto T, Imoto I. A FRMD7 variant in a Japanese family causes congenital nystagmus. Hum Genome Var 2015; 2:15002. [PMID: 27081518 PMCID: PMC4785577 DOI: 10.1038/hgv.2015.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/06/2014] [Accepted: 12/14/2014] [Indexed: 11/09/2022] Open
Abstract
Idiopathic congenital nystagmus (ICN) is a genetically heterogeneous eye movement disorder that causes a large proportion of childhood visual impairment. Here we describe a missense variant (p.L292P) within a mutation-rich region of FRMD7 detected in three affected male siblings in a Japanese family with X-linked ICN. Combining sequence analysis and results from structural and functional predictions, we report p.L292P as a variant potentially disrupting FRMD7 function associated with X-linked ICN.
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Affiliation(s)
- Tomohiro Kohmoto
- Department of Human Genetics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan; Student Lab, Faculty of Medicine, The University of Tokushima, Tokushima, Japan
| | - Nana Okamoto
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine , Kobe, Japan
| | - Shigeko Satomura
- Japanese Red Cross Tokushima Hinomine Rehabilitation Center for People with Disabilities , Tokushima, Japan
| | - Takuya Naruto
- Department of Stress Science, Institute of Health Biosciences, The University of Tokushima Graduate School , Tokushima, Japan
| | - Takahide Komori
- Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of Medicine , Kobe, Japan
| | - Toshiaki Hashimoto
- Japanese Red Cross Tokushima Hinomine Rehabilitation Center for People with Disabilities , Tokushima, Japan
| | - Issei Imoto
- Department of Human Genetics, Institute of Health Biosciences, The University of Tokushima Graduate School , Tokushima, Japan
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Papageorgiou E, McLean RJ, Gottlob I. Nystagmus in childhood. Pediatr Neonatol 2014; 55:341-51. [PMID: 25086850 DOI: 10.1016/j.pedneo.2014.02.007] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 02/24/2014] [Indexed: 11/15/2022] Open
Abstract
Nystagmus is an involuntary rhythmic oscillation of the eyes, which leads to reduced visual acuity due to the excessive motion of images on the retina. Nystagmus can be grouped into infantile nystagmus (IN), which usually appears in the first 3-6 months of life, and acquired nystagmus (AN), which appears later. IN can be idiopathic or associated to albinism, retinal disease, low vision, or visual deprivation in early life, for example due to congenital cataracts, optic nerve hypoplasia, and retinal dystrophies, or it can be part of neurological syndromes and neurologic diseases. It is important to differentiate between infantile and acquired nystagmus. This can be achieved by considering not only the time of onset of the nystagmus, but also the waveform characteristics of the nystagmus. Neurological disease should be suspected when the nystagmus is asymmetrical or unilateral. Electrophysiology, laboratory tests, neurological, and imaging work-up may be necessary, in order to exclude any underlying ocular or systemic pathology in a child with nystagmus. Furthermore, the recent introduction of hand-held spectral domain optical coherence tomography (HH SD-OCT) provides detailed assessment of foveal structure in several pediatric eye conditions associated with nystagmus and it can been used to determine the underlying cause of infantile nystagmus. Additionally, the development of novel methods to record eye movements can help to obtain more detailed information and assist the diagnosis. Recent advances in the field of genetics have identified the FRMD7 gene as the major cause of hereditary X-linked nystagmus, which will possibly guide research towards gene therapy in the future. Treatment options for nystagmus involve pharmacological and surgical interventions. Clinically proven pharmacological treatments for nystagmus, such as gabapentin and memantine, are now beginning to emerge. In cases of obvious head posture, eye muscle surgery can be performed to shift the null zone of the nystagmus into the primary position, and also to alleviate neck problems that can arise due to an abnormal head posture.
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Affiliation(s)
- Eleni Papageorgiou
- Ophthalmology Group, University of Leicester, Faculty of Medicine and Biological Sciences, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Rebecca J McLean
- Ophthalmology Group, University of Leicester, Faculty of Medicine and Biological Sciences, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Irene Gottlob
- Ophthalmology Group, University of Leicester, Faculty of Medicine and Biological Sciences, Leicester Royal Infirmary, Leicester, United Kingdom.
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Li Y, Pu J, Zhang B. Expression of a novel splice variant of FRMD7 in developing human fetal brains that is upregulated upon the differentiation of NT2 cells. Exp Ther Med 2014; 8:1131-1136. [PMID: 25187810 PMCID: PMC4151643 DOI: 10.3892/etm.2014.1916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 08/04/2014] [Indexed: 12/15/2022] Open
Abstract
FRMD7 mutations are associated with X-linked idiopathic congenital nystagmus (ICN); however, the underlying mechanisms whereby mutations of FRMD7 lead to ICN remain unclear. In a previous study, the first FRMD7 splice variant (FRMD7-S) was cloned and identified, and FRMD7-S was hypothesized to play a significant role in neuronal differentiation and development. The present study investigated a novel multiple exon-skipping mRNA splice variant of FRMD7, termed FRMD7_SV2, which was detected in NT2 cells using northern blotting. The mRNA expression levels of FRMD7_SV2 in the developing human fetal brain were examined using reverse transcription polymerase chain reaction (PCR), while the expression levels in NT2 cells treated with retinoid acid (RA) or bone morphogenetic protein-2 were investigated using quantitative PCR. The results revealed that the expression of FRMD7_SV2 was spatially and temporally restricted in human fetal brain development, and was upregulated upon RA-induced neuronal differentiation of the NT2 cells. These results indicated that as a novel splice variant of FRMD7, FRMD7_SV2 may play a role in neuronal development.
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Affiliation(s)
- Yingzhi Li
- Department of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Jiali Pu
- Department of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Baorong Zhang
- Department of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
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Abstract
PURPOSE OF REVIEW Mechanisms underlying infantile nystagmus are unclear. The aim of this review is to outline recent developments in understanding the aetiology of infantile nystagmus. RECENT FINDINGS There have been advances in understanding mechanisms underlying idiopathic infantile nystagmus, which has progressed through determining the role of the FRMD7 gene in controlling neurite outgrowth, and albinism, in which recent models have investigated the possibility of retinal miswiring leading to nystagmus. We also briefly review aetiology of infantile nystagmus in afferent visual deficits caused by ocular disease, and PAX6 mutations. Improved phenotypical characterization of all these infantile nystagmus subtypes has been achieved recently through high-resolution retinal imaging using optical coherence tomography. Several new hypotheses proposing common mechanisms that could underlie various infantile nystagmus subtypes are also highlighted. SUMMARY Although there is still no consensus of opinion regarding the mechanisms causing infantile nystagmus, identification of new genes and determining their cellular function, phenotypical characterization of genetic subtypes, and improvements in animal models have significantly advanced our understanding of infantile nystagmus. These recent developments pave the way to achieving a much clearer picture of infantile nystagmus aetiology in the future.
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Thomas MG, Crosier M, Lindsay S, Kumar A, Araki M, Leroy BP, McLean RJ, Sheth V, Maconachie G, Thomas S, Moore AT, Gottlob I. Abnormal retinal development associated with FRMD7 mutations. Hum Mol Genet 2014; 23:4086-93. [PMID: 24688117 PMCID: PMC4082370 DOI: 10.1093/hmg/ddu122] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Idiopathic infantile nystagmus (IIN) is a genetically heterogeneous disorder, often associated with FRMD7 mutations. As the appearance of the retina is reported to be normal based on conventional fundus photography, IIN is postulated to arise from abnormal cortical development. To determine whether the afferent visual system is involved in FRMD7 mutations, we performed in situ hybridization studies in human embryonic and fetal stages (35 days post-ovulation to 9 weeks post-conception). We show a dynamic retinal expression pattern of FRMD7 during development. We observe expression within the outer neuroblastic layer, then in the inner neuroblastic layer and at 9 weeks post-conception a bilaminar expression pattern. Expression was also noted within the developing optic stalk and optic disk. We identified a large cohort of IIN patients (n = 100), and performed sequence analysis which revealed 45 patients with FRMD7 mutations. Patients with FRMD7 mutations underwent detailed retinal imaging studies using ultrahigh-resolution optical coherence tomography. The tomograms were compared with a control cohort (n = 60). The foveal pit was significantly shallower in FRMD7 patients (P < 0.0001). The optic nerve head morphology was abnormal with significantly decreased optic disk area, retinal nerve fiber layer thickness, cup area and cup depth in FRMD7 patients (P < 0.0001). This study shows for the first time that abnormal afferent system development is associated with FRMD7 mutations and could be an important etiological factor in the development of nystagmus.
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Affiliation(s)
- Mervyn G Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Moira Crosier
- MRC-Wellcome Trust Human Developmental Biology Resource (Newcastle), Institute of Human Genetics, Newcastle University, International Centre for Life, Newcastle upon Tyne NE1 3BZ, UK
| | - Susan Lindsay
- MRC-Wellcome Trust Human Developmental Biology Resource (Newcastle), Institute of Human Genetics, Newcastle University, International Centre for Life, Newcastle upon Tyne NE1 3BZ, UK
| | - Anil Kumar
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Masasuke Araki
- Department of Biological Sciences, Developmental Neurobiology Laboratory, Nara Women's University, Nara 630-8506, Japan
| | - Bart P Leroy
- Department of Ophthalmology and Centre for Medical Genetics, Ghent University and Ghent University Hospital, Ghent 9000, Belgium
| | - Rebecca J McLean
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Viral Sheth
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Gail Maconachie
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
| | - Shery Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK Department of Ophthalmology, Nottingham University Hospital NHS Trust, Nottingham, UK
| | | | - Irene Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester LE2 7LX, UK
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Guo Y, Song Z, Xu H, Yi J, Zheng W, Xiang H, Deng X, Lv H, Gao K, Qi Y, Deng H. Heterogeneous phenotype in a family with the FERM domain-containing 7 gene R335X mutation. Can J Ophthalmol 2014; 49:50-3. [PMID: 24513357 DOI: 10.1016/j.jcjo.2013.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 08/23/2013] [Accepted: 09/13/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Infantile nystagmus (IN) is characterized by bilateral involuntary, periodic, and predominantly ocular oscillations. In this article, we describe a mutation screen conducted on a 4-generation family in which 4 patients were affected with X-linked IN (XLIN). DESIGN Experimental study. PARTICIPANTS A 4-generation Chinese Han family including 4 symptomatic members with IN and 200 normal male controls. METHODS DNA was extracted from peripheral blood, and the FERM domain-containing 7 gene (FRMD7) was amplified on DNA samples of all the available family members. The mutation screen was conducted by performing direct DNA sequencing. RESULTS A nonsense mutation (R335X) in the FRMD7 gene was identified in 4 male patients and an asymptomatic female member. CONCLUSIONS Although the R335X mutation in the FRMD7 gene has been previously described, the clinical features, including both disease penetrance and severity, among individuals with FRMD7 mutation in our family vary greatly. One female member with the heterozygous R335X mutation had no clinical manifestation of the disease. This incomplete penetrance suggests that random X-chromosome inactivation may play a role in the pathogenesis of IN, and that loss of functional FRMD7 may account for the development of this disorder. Our findings may be helpful in the genetic counseling of patients with nystagmus.
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Affiliation(s)
- Yi Guo
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China; Department of Medical Information, Xiangya School of Medicine, Central South University, Changsha, China; Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hongbo Xu
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Junhui Yi
- Department of Ophthalmology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Wen Zheng
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hong Xiang
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hongwei Lv
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Kai Gao
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong Qi
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Deng
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, China.
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Zhang X, Ge X, Yu Y, Zhang Y, Wu Y, Luan Y, Sun J, Qu J, Jin ZB, Gu F. Identification of three novel mutations in the FRMD7 gene for X-linked idiopathic congenital nystagmus. Sci Rep 2014; 4:3745. [PMID: 24434814 PMCID: PMC3894538 DOI: 10.1038/srep03745] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/23/2013] [Indexed: 01/23/2023] Open
Abstract
Idiopathic congenital nystagmus (ICN) consists of involuntary and periodic ocular motility, often with seriously reduced visual acuity. To identify the genetic defects associated with X-linked ICN, we performed PCR-based DNA direct sequencing of two candidate genes, FRMD7 and GPR143, in four families. Mutation analysis led to identification of three novel mutations, p.S260R, p.Q487X, and p.V549Y fsX554, in FRMD7 in three of the recruited families. Results from structural modeling indicated that the p.S260R may potentially disrupt FRMD7 function through loss of a phosphorylation site and/or interference with protein-protein interactions. Both p.Q487X, and p.V549Y fsX554 mutations were predicted to generate nonfunctional truncated proteins. Using a capture next generation sequencing method, we excluded CASK as the responsible gene for the remaining family. Combining sequence analysis and structural modeling, we report three novel mutations in FRMD7 in three independent families with XLICN, and provide molecular insights for future XLICN diagnosis and treatment.
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Affiliation(s)
- Xiao Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Xianglian Ge
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Ying Yu
- The Community Health Service Center in Huayuan Road, Haidian District, Beijing 10088 China
| | - Yilan Zhang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Yaming Wu
- Department of Ophthalmology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000 China
| | - Yin Luan
- Department of Ophthalmology, the First Affiliated Hospital of Jilin University, Changchun, Jilin 130021 China
| | - Ji Sun
- Department of Pharmacology, University of Washington, Seattle, WA 98195 USA
| | - Jia Qu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Zi-Bing Jin
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027 China
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Identifcation of a novel mutation p.I240T in the FRMD7 gene in a family with congenital nystagmus. Sci Rep 2013; 3:3084. [PMID: 24169426 PMCID: PMC3812648 DOI: 10.1038/srep03084] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/14/2013] [Indexed: 11/17/2022] Open
Abstract
Congenital Nystagmus (CN) is a genetically heterogeneous ocular disease, which causes a significant proportion of childhood visual impairment. To identify the underlying genetic defect of a CN family, twenty-two members were recruited. Genotype analysis showed that affected individuals shared a common haplotype with markers flanking FRMD7 locus. Sequencing FRMD7 revealed a T > C transition in exon 8, causing a conservative substitution of Isoleucine to Tyrosine at codon 240. By protein structural modeling, we found the mutation may disrupt the hydrophobic core and destabilize the protein structure. We reviewed the literature and found that exons 2, 8, and 9 (11.4% of the sequence of FRMD7 mRNA) represent the majority (55.3%) of the reported FRMD7 mutations. In summary, we identified a novel mutation in FRMD7, showed its molecular consequence, and revealed the mutation-rich exons of the FRMD7 gene. Collectively, this provides molecular insights for future CN clinical genetic diagnosis and treatment.
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50
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Thomas S, Thomas MG, Andrews C, Chan WM, Proudlock FA, McLean RJ, Pradeep A, Engle EC, Gottlob I. Autosomal-dominant nystagmus, foveal hypoplasia and presenile cataract associated with a novel PAX6 mutation. Eur J Hum Genet 2013; 22:344-9. [PMID: 23942204 DOI: 10.1038/ejhg.2013.162] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 05/12/2013] [Accepted: 05/15/2013] [Indexed: 11/09/2022] Open
Abstract
Autosomal-dominant idiopathic infantile nystagmus has been linked to 6p12 (OMIM 164100), 7p11.2 (OMIM 608345) and 13q31-q33 (OMIM 193003). PAX6 (11p13, OMIM 607108) mutations can also cause autosomal-dominant nystagmus, typically in association with aniridia or iris hypoplasia. We studied a large multigenerational white British family with autosomal-dominant nystagmus, normal irides and presenile cataracts. An SNP-based genome-wide analysis revealed a linkage to a 13.4-MB region on chromosome 11p13 with a maximum lod score of 2.93. A mutation analysis of the entire coding region and splice junctions of the PAX6 gene revealed a novel heterozygous missense mutation (c.227C>G) that segregated with the phenotype and is predicted to result in the amino-acid substitution of proline by arginine at codon 76 p.(P76R). The amino-acid variation p.(P76R) within the paired box domain is likely to destabilise the protein due to steric hindrance as a result of the introduction of a polar and larger amino acid. Eye movement recordings showed a significant intrafamilial variability of horizontal, vertical and torsional nystagmus. High-resolution in vivo imaging of the retina using optical coherence tomography (OCT) revealed features of foveal hypoplasia, including rudimentary foveal pit, incursion of inner retinal layers, short photoreceptor outer segments and optic nerve hypoplasia. Thus, this study presents a family that segregates a PAX6 mutation with nystagmus and foveal hypoplasia in the absence of iris abnormalities. Moreover, it is the first study showing detailed characteristics using eye movement recordings of autosomal-dominant nystagmus in a multigenerational family with a novel PAX6 mutation.
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Affiliation(s)
- Shery Thomas
- 1] Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK [2] Department of Ophthalmology, Nottingham University Hospital NHS Trust, Nottingham, UK
| | - Mervyn G Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Caroline Andrews
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Wai-Man Chan
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Frank A Proudlock
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Rebecca J McLean
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Archana Pradeep
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
| | - Elizabeth C Engle
- 1] Department of Neurology, Ophthalmology, Medicine (Genetics), FM Kirby Neurobiology Center, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA [2] Department of Neurology, Harvard Medical School, Boston, MA, USA [3] Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Irene Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester, Leicester, UK
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