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Przyklenk M, Karmacharya S, Bonasera D, Pasanen-Zentz AL, Kmoch S, Paulsson M, Wagener R, Liccardi G, Schiavinato A. ANTXR1 deficiency promotes fibroblast senescence: implications for GAPO syndrome as a progeroid disorder. Sci Rep 2024; 14:9321. [PMID: 38653789 PMCID: PMC11039612 DOI: 10.1038/s41598-024-59901-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
ANTXR1 is one of two cell surface receptors mediating the uptake of the anthrax toxin into cells. Despite substantial research on its role in anthrax poisoning and a proposed function as a collagen receptor, ANTXR1's physiological functions remain largely undefined. Pathogenic variants in ANTXR1 lead to the rare GAPO syndrome, named for its four primary features: Growth retardation, Alopecia, Pseudoanodontia, and Optic atrophy. The disease is also associated with a complex range of other phenotypes impacting the cardiovascular, skeletal, pulmonary and nervous systems. Aberrant accumulation of extracellular matrix components and fibrosis are considered to be crucial components in the pathogenesis of GAPO syndrome, contributing to the shortened life expectancy of affected individuals. Nonetheless, the specific mechanisms connecting ANTXR1 deficiency to the clinical manifestations of GAPO syndrome are largely unexplored. In this study, we present evidence that ANTXR1 deficiency initiates a senescent phenotype in human fibroblasts, correlating with defects in nuclear architecture and actin dynamics. We provide novel insights into ANTXR1's physiological functions and propose GAPO syndrome to be reconsidered as a progeroid disorder highlighting an unexpected role for an integrin-like extracellular matrix receptor in human aging.
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Affiliation(s)
- Matthias Przyklenk
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Shreya Karmacharya
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Debora Bonasera
- Genetic Instability, Cell Death and Inflammation Laboratory, Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Arthur-Lauri Pasanen-Zentz
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Stanislav Kmoch
- Research Unit of Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Mats Paulsson
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Raimund Wagener
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Gianmaria Liccardi
- Genetic Instability, Cell Death and Inflammation Laboratory, Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany
| | - Alvise Schiavinato
- Center for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
- Department of Pediatrics and Adolescent Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
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2
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Sun Y, Guo L, Sha J, Tao H, Wang X, Liu Y, Zhai J, Wu J, Zhao Y. A fetus with Bosch-Boonstra-Schaaf optic atrophy syndrome characterized by bilateral ventricle widening: A case report and related literature review. Medicine (Baltimore) 2022; 101:e30558. [PMID: 36221391 PMCID: PMC9543064 DOI: 10.1097/md.0000000000030558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
RATIONALE Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is a rare neurodevelopmental disorder caused by loss-of-function variants in the Nuclear Receptor Subfamily 2 Group F Member 1 (NR2F1). Here, we report a case of fetal BBSOAS. The fetus is typically featured by bilateral ventricle widening in the late second trimester, meanwhile, a 7.94-Mb deletion fragment on 5q14.3q15 involving the whole NR2F1 gene was confirmed by copy number variation sequencing (CNV-Seq) combined with karyotyping analysis. Our aim is to provide comprehensive prenatal clinical management strategy for fetal BBSOAS. PATIENT CONCERNS A 29-year-old primipara and her husband were referred to our prenatal diagnosis center due to the widening of bilateral ventricles at 29 + 1 weeks of gestation age. DIAGNOSES Ultrasound revealed the fetal widening posterior horns of bilateral ventricles at the GA of 27 + 3 weeks, 11 mm on the left and 10 mm on the right. At the following 29 + 1 weeks, ultrasound showed the posterior horn of the left lateral ventricle: 12 mm while the width of the right decreased to 9 mm, and intracranial arachnoid cyst. Furthermore, MRI confirmed that intracranial cyst might originate from an enlarged cisterna venae magnae cerebri, with mild dilation of 13.5 mm on the left ventricle. The fetal karyotyping analysis and CNV-Seq detection confirmed a 7.94-Mb deleted fragment on 5q14.3q15 (89340000_97280000) through the amniocentesis at 29 + 4 weeks of GA. INTERVENTIONS The fetus was closely monitored and underwent the following assessment by the multidisciplinary team. OUTCOMES The pregnancy was terminated in the end. LESSONS It is vital to use molecular and cytogenetical detections combined with a dynamic development history to make a definite diagnosis and evaluate the genetic status for the fetuses with BBSOAS.
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Affiliation(s)
- Yu Sun
- Graduate School of Xuzhou Medical University, Jiangsu Xuzhou, China
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
- Department of obstetrics, Fengxian People’s Hospital, Xuzhou, Jiangsu, China
| | - Lili Guo
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
- Graduate School of Bengbu Medical College, Bengbu, Anhui, China
| | - Jing Sha
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Huimin Tao
- Graduate School of Xuzhou Medical University, Jiangsu Xuzhou, China
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xuezhen Wang
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
- Graduate School of Bengbu Medical College, Bengbu, Anhui, China
| | - Ying Liu
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jingfang Zhai
- Graduate School of Xuzhou Medical University, Jiangsu Xuzhou, China
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
- *Correspondence: Jingfang Zhai, Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Jiefang South Road No.199, Xuzhou, Jiangsu, 221009, China (e-mail: )
| | - Jiebin Wu
- Graduate School of Xuzhou Medical University, Jiangsu Xuzhou, China
- Department of Prenatal Diagnosis Medical Center, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yongxiu Zhao
- Department of laboratory, Taixing Maternity and Child Health Care Hospital, Taixing, Jiangsu, China
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3
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Yahalom C, Volovelsky O, Macarov M, Altalbishi A, Alsweiti Y, Schneider N, Hanany M, Khan MI, Cremers FPM, Anteby I, Banin E, Sharon D, Khateb S. SENIOR-LØKEN SYNDROME: A Case Series and Review of the Renoretinal Phenotype and Advances of Molecular Diagnosis. Retina 2021; 41:2179-2187. [PMID: 33512896 DOI: 10.1097/iae.0000000000003138] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE To report genetic and clinical findings in a case series of 10 patients from eight unrelated families diagnosed with Senior-Løken syndrome. METHODS A retrospective study of patients with Senior-Løken syndrome. Data collected included clinical findings electroretinography and ocular imaging. Genetic analysis was based on molecular inversion probes, whole-exome sequencing (WES), and Sanger sequencing. RESULTS All patients who underwent electrophysiology (8/10) had widespread photoreceptor degeneration. Genetic analysis revealed two mutations in NPHP1, two mutations in NPHP4, and two mutations in IQCB1 (NPHP5). Five of the six mutations identified in the current study were found in a single family each in our cohort. The IQCB1-p.R461* mutation has been identified in 3 families. Patients harboring mutations in IQCB1 were diagnosed with Leber congenital amaurosis, while patients with NPHP4 and NPHP1 mutations showed early and sector retinitis pigmentosa, respectively. Full-field electroretinography was extinct for 6 of 10 patients, moderately decreased for two, and unavailable for another 2 subjects. Renal involvement was evident in 7/10 patients at the time of diagnosis. Kidney function was normal (based on serum creatinine) in patients younger than 10 years. Mutations in IQCB1 were associated with high hypermetropia, whereas mutations in NPHP4 were associated with high myopia. CONCLUSION Patients presenting with infantile inherited retinal degeneration are not universally screened for renal dysfunction. Modern genetic tests can provide molecular diagnosis at an early age and therefore facilitate early diagnosis of renal disease with recommended periodic screening beyond childhood and family planning.
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Affiliation(s)
- Claudia Yahalom
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oded Volovelsky
- Pediatric Nephrology Unit, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michal Macarov
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alaa Altalbishi
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Israel
| | - Yahya Alsweiti
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Israel
| | - Nina Schneider
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mor Hanany
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands ; and
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands ; and
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Irene Anteby
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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4
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de Vries RJ, Jaeger B, Hellebrekers DMEI, Reneman L, Verhamme C, Smeets HJM, van Maarle MC, de Visser M, Bleeker FE. Distal muscle weakness and optic atrophy without central nervous system involvement in a patient with a homozygous missense mutation in the C19ORF12-gene. Clin Neurol Neurosurg 2021; 206:106637. [PMID: 34022688 DOI: 10.1016/j.clineuro.2021.106637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/04/2021] [Accepted: 04/07/2021] [Indexed: 11/19/2022]
Abstract
Variants of the C19ORF12-gene have been described in patients with spastic paraplegia type 43 and in patients with mitochondrial membrane protein-associated neurodegeneration (MPAN), a subtype of neurodegeneration associated with brain iron accumulation (NBIA). In both subtypes optic atrophy and neuropathy have been frequently described. This case report describes a patient with bilateral optic atrophy and severe distal muscle weakness based on motor neuropathy without involvement of the central nervous system. Exome sequencing revealed a homozygous pathogenic missense variant (c.187G>C;p.Ala63Pro) of the C19ORF12-gene while iron deposits were absent on repeat MR-imaging of the brain, thus showing that peripheral neuropathy and optic neuropathy can be the sole manifestations of the C19ORF12-related disease spectrum whereby iron accumulation in the brain may be absent.
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Affiliation(s)
- R J de Vries
- Department of Clinical Genetics, Amsterdam University Medical Center, location Academic Medical Center, Amsterdam, The Netherlands
| | - B Jaeger
- Department of Neurology, Amsterdam University Medical Center, Academic Medical Center, Amsterdam, The Netherlands
| | - D M E I Hellebrekers
- Department of Clinical Genetics, Maastricht University Medical Center (MUMC), Maastricht, The Netherlands
| | - L Reneman
- Department of Radiology, Amsterdam University Medical Center, Academic Medical Center, Amsterdam, The Netherlands
| | - C Verhamme
- Department of Neurology, Amsterdam University Medical Center, Academic Medical Center, Amsterdam, The Netherlands
| | - H J M Smeets
- Department of Clinical Genetics, Maastricht University Medical Center (MUMC), Maastricht, The Netherlands; Department of Genetics and Cell Biology, School for Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
| | - M C van Maarle
- Department of Clinical Genetics, Amsterdam University Medical Center, location Academic Medical Center, Amsterdam, The Netherlands
| | - M de Visser
- Department of Neurology, Amsterdam University Medical Center, Academic Medical Center, Amsterdam, The Netherlands.
| | - F E Bleeker
- Department of Clinical Genetics, Netherlands Cancer Institute, Amsterdam, The Netherlands
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5
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Shi H, Yang J, Guo Q, Zhang M. Clinical assessment and FGFR2 mutation analysis in a Chinese family with Crouzon syndrome: A case report. Medicine (Baltimore) 2021; 100:e24991. [PMID: 33725872 PMCID: PMC7969214 DOI: 10.1097/md.0000000000024991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 02/11/2021] [Indexed: 01/05/2023] Open
Abstract
RATIONALE Crouzon syndrome is an autosomal dominant genetic disorder caused by mutations in fibroblast growth factor receptor 2 (FGFR2) and one of the most common types of craniosynostosis. Here we report the detection of FGFR2 mutation and its related clinical findings in 2 patients with Crouzon syndrome from a Chinese family. PATIENT CONCERNS We report a case of a 28-year-old male patient presented with the chief complaint of gradually blurring of his eyes over the last 6 months before visiting our clinics. History revealed low visual acuity in his right eye since childhood. Physical examination showed that both the patient and his mother have the appearance of craniofacial dysostosis, mandibular prognathism, ocular proptosis, short superior lip, scoliosis, and thoracic deformity. DIAGNOSIS Auxiliary examinations lead to the diagnosis of Crouzon syndrome with binocular optic atrophy, myelinated retina nerve fibers, and ametropia in both eyes, and amblyopia in the right eye of the male patient. The molecular genetic analysis confirmed the diagnosis by detecting a heterozygous pathogenic mutation c.1026C > G (C342W) in exon 10 of FGFR2 in both the patient and his mother, but not in any of the unaffected family members. INTERVENTIONS AND OUTCOMES None. LESSONS Our study confirms the presence of optic nerve atrophy in patients with Crouzon syndrome carrying FGFR2 C342W mutations and indicates that MRI and funduscopy should be performed to examine the optic nerve changes for patients with Crouzon syndrome.
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6
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Gilhooley MJ, Owen N, Moosajee M, Yu Wai Man P. From Transcriptomics to Treatment in Inherited Optic Neuropathies. Genes (Basel) 2021; 12:147. [PMID: 33499292 PMCID: PMC7912133 DOI: 10.3390/genes12020147] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 02/06/2023] Open
Abstract
Inherited optic neuropathies, including Leber Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA), are monogenetic diseases with a final common pathway of mitochondrial dysfunction leading to retinal ganglion cell (RGC) death and ultimately loss of vision. They are, therefore, excellent models with which to investigate this ubiquitous disease process-implicated in both common polygenetic ocular diseases (e.g., Glaucoma) and late-onset central nervous system neurodegenerative diseases (e.g., Parkinson disease). In recent years, cellular and animal models of LHON and DOA have matured in parallel with techniques (such as RNA-seq) to determine and analyze the transcriptomes of affected cells. This confluence leaves us at a particularly exciting time with the potential for the identification of novel pathogenic players and therapeutic targets. Here, we present a discussion of the importance of inherited optic neuropathies and how transcriptomic techniques can be exploited in the development of novel mutation-independent, neuroprotective therapies.
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Affiliation(s)
- Michael James Gilhooley
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK; (N.O.); (M.M.); (P.Y.W.M.)
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK
| | - Nicholas Owen
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK; (N.O.); (M.M.); (P.Y.W.M.)
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK; (N.O.); (M.M.); (P.Y.W.M.)
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK
- The Francis Crick Institute, 1 Midland Road, Somers Town, London NW1 1AT, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Patrick Yu Wai Man
- Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK; (N.O.); (M.M.); (P.Y.W.M.)
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK
- Department of Clinical Neurosciences, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
- MRC Mitochondrial Biology Unit, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
- Cambridge Eye Unit, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 0QQ, UK
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7
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Affiliation(s)
- Leon S Edwards
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
| | - Gabor M Halmagyi
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
| | | | | | - Matthew C Kiernan
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
- Brain Mind Centre, University of Sydney, Sydney, Australia
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8
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Abstract
The anthrax toxin receptors-capillary morphogenesis gene 2 (CMG2) and tumor endothelial marker 8 (TEM8)-were identified almost 20 years ago, although few studies have moved beyond their roles as receptors for the anthrax toxins to address their physiological functions. In the last few years, insight into their endogenous roles has come from two rare diseases: hyaline fibromatosis syndrome, caused by mutations in CMG2, and growth retardation, alopecia, pseudo-anodontia, and optic atrophy (GAPO) syndrome, caused by loss-of-function mutations in TEM8. Although CMG2 and TEM8 are highly homologous at the protein level, the difference in disease symptoms points to variations in the physiological roles of the two anthrax receptors. Here, we focus on the similarities between these receptors in their ability to regulate extracellular matrix homeostasis, angiogenesis, cell migration, and skin elasticity. In this way, we shed light on how mutations in these two related proteins cause such seemingly different diseases and we highlight the existing knowledge gaps that could form the focus of future studies.
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Affiliation(s)
- Oksana A. Sergeeva
- Global Health Institute, School of Life Sciences, EPFL, Lausanne, Switzerland
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9
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Poole OV, Everett CM, Gandhi S, Marino S, Bugiardini E, Woodward C, Lam A, Quinlivan R, Hanna MG, Pitceathly RDS. Adult-onset Leigh syndrome linked to the novel stop codon mutation m.6579G>A in MT-CO1. Mitochondrion 2019; 47:294-297. [PMID: 30743023 DOI: 10.1016/j.mito.2019.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/02/2018] [Accepted: 02/07/2019] [Indexed: 11/17/2022]
Abstract
Adult-onset Leigh syndrome is a rare but important manifestation of mitochondrial disease. We report a 17 year old female who presented with subacute encephalopathy, brainstem and extrapyramidal signs, raised CSF lactate, and symmetrical hyperintensities in the basal ganglia on T2-weighted cerebral MRI. The presence of cytochrome c oxidase deficient fibres in muscle tissue prompted sequencing of the entire mitochondrial genome which revealed the novel stop codon mutation m.6579G>A; p.Gly226X in MT-CO1. Here we present the case and review the clinicopathological and molecular spectrum of previously reported MT-CO1 truncating mutations.
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Affiliation(s)
- Olivia V Poole
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Chris M Everett
- Department of Neurology, Southend University Hospital NHS Foundation Trust, Essex, UK; Department of Neurology, The Royal London Hospital, Barts Health NHS Trust, London, UK
| | - Sonia Gandhi
- Department of Neurology, Southend University Hospital NHS Foundation Trust, Essex, UK; Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Silvia Marino
- Cellular Pathology, The Royal London Hospital, Barts Health NHS Trust, London, UK; Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Cathy Woodward
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Amanda Lam
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK; Department of Chemical Pathology, Great Ormond Street Hospital, London, UK
| | - Ros Quinlivan
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK; Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London, UK
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Robert D S Pitceathly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.
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10
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Hussain S, Akhtar N, Qamar R, Khan N, Naeem M. Molecular Study of Nephronophthisis in 7 Unrelated Pakistani Families. Iran J Kidney Dis 2018; 12:240-242. [PMID: 30087219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/22/2018] [Indexed: 06/08/2023]
Abstract
Nephronophthisis is an autosomal recessive cystic kidney disease characterized by tubular interstitial infiltration, periglomerular fibrosis, and cysts, and is the most frequent genetic cause of end-stage renal disease in children. Nephronophthisis is pleiotropic as almost all the causative genes are involved in primary cilium and centrosome function which are found in almost all human cells. Genetic heterogeneity in nephronophthisis makes the molecular and genetic diagnosis somewhat difficult. Homozygous deletions in the nephronophthisis 1 (NPHP1) gene are the major contributor of nephronophthisis cases, while other genes accounts for less than 3% each. Nephronophthisis-related ciliopathy is a term used for extrarenal symptoms in addition to nephronophthisis. Herein, we are reporting the molecular study of 7 children from independent families fulfilling the criteria of nephronophthisis. A deletion analysis of the NPHP1 gene was performed in each case, and NPHP5 mutation screening was performed in the absence of such deletion in patients with Senior Loken syndrome.
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Affiliation(s)
| | | | | | | | - Muhammad Naeem
- Medical Genetics Research Laboratory, Department of Biotechnology, Quaid-I-Azam University, Islamabad, Pakistan.
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11
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Abstract
Hereditary cystic kidney diseases are considered as "ciliopathies" caused by abnormalities of the "primary cilia" situated on the tubules. As a result of dysplasia and dysfunction of cilia, formation of cysts occurs at various stages of life. Although occurring at a low incidence, hereditary cystic kidney diseases that develop from the fetal stage to childhood are diverse and are often associated with systemic disorders. The incidence of autosomal dominant polycystic kidney disease, which is the only adult-onset hereditary cystic kidney disease, is the highest among hereditary renal disorders.
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MESH Headings
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/pathology
- Anemia/genetics
- Anemia/pathology
- Bardet-Biedl Syndrome/genetics
- Bardet-Biedl Syndrome/pathology
- Cerebellum/abnormalities
- Cerebellum/pathology
- Ciliary Motility Disorders/genetics
- Ciliary Motility Disorders/pathology
- Ciliopathies/genetics
- Ciliopathies/pathology
- Encephalocele/genetics
- Encephalocele/pathology
- Eye Abnormalities/genetics
- Eye Abnormalities/pathology
- Humans
- Hyperuricemia/genetics
- Hyperuricemia/pathology
- Kidney Diseases, Cystic/genetics
- Kidney Diseases, Cystic/pathology
- Leber Congenital Amaurosis/genetics
- Leber Congenital Amaurosis/pathology
- Optic Atrophies, Hereditary/genetics
- Optic Atrophies, Hereditary/pathology
- Orofaciodigital Syndromes/genetics
- Orofaciodigital Syndromes/pathology
- Polycystic Kidney Diseases/genetics
- Polycystic Kidney Diseases/pathology
- Polycystic Kidney, Autosomal Dominant/genetics
- Polycystic Kidney, Autosomal Dominant/pathology
- Polycystic Kidney, Autosomal Recessive/genetics
- Polycystic Kidney, Autosomal Recessive/pathology
- Renal Insufficiency/genetics
- Renal Insufficiency/pathology
- Renin/deficiency
- Renin/genetics
- Retina/abnormalities
- Retina/pathology
- Retinitis Pigmentosa/genetics
- Retinitis Pigmentosa/pathology
- Uromodulin/deficiency
- Uromodulin/genetics
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12
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Gerards M, Sallevelt SCEH, Smeets HJM. Leigh syndrome: Resolving the clinical and genetic heterogeneity paves the way for treatment options. Mol Genet Metab 2016; 117:300-12. [PMID: 26725255 DOI: 10.1016/j.ymgme.2015.12.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 12/31/2022]
Abstract
Leigh syndrome is a progressive neurodegenerative disorder, affecting 1 in 40,000 live births. Most patients present with symptoms between the ages of three and twelve months, but adult onset Leigh syndrome has also been described. The disease course is characterized by a rapid deterioration of cognitive and motor functions, in most cases resulting in death due to respiratory failure. Despite the high genetic heterogeneity of Leigh syndrome, patients present with identical, symmetrical lesions in the basal ganglia or brainstem on MRI, while additional clinical manifestations and age of onset varies from case to case. To date, mutations in over 60 genes, both nuclear and mitochondrial DNA encoded, have been shown to cause Leigh syndrome, still explaining only half of all cases. In most patients, these mutations directly or indirectly affect the activity of the mitochondrial respiratory chain or pyruvate dehydrogenase complex. Exome sequencing has accelerated the discovery of new genes and pathways involved in Leigh syndrome, providing novel insights into the pathophysiological mechanisms. This is particularly important as no general curative treatment is available for this devastating disorder, although several recent studies imply that early treatment might be beneficial for some patients depending on the gene or process affected. Timely, gene-based personalized treatment may become an important strategy in rare, genetically heterogeneous disorders like Leigh syndrome, stressing the importance of early genetic diagnosis and identification of new genes/pathways. In this review, we provide a comprehensive overview of the most important clinical manifestations and genes/pathways involved in Leigh syndrome, and discuss the current state of therapeutic interventions in patients.
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Affiliation(s)
- Mike Gerards
- Department of Clinical Genetics, Research School GROW, Maastricht University Medical Centre, Maastricht, The Netherlands; Maastricht Center for Systems Biology (MaCSBio), Maastricht University Medical Centre, Maastricht, The Netherlands.
| | - Suzanne C E H Sallevelt
- Department of Clinical Genetics, Research School GROW, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Hubert J M Smeets
- Department of Clinical Genetics, Research School GROW, Maastricht University Medical Centre, Maastricht, The Netherlands
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13
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Ellingford JM, Sergouniotis PI, Lennon R, Bhaskar S, Williams SG, Hillman KA, O'Sullivan J, Hall G, Ramsden SC, Lloyd IC, Woolf AS, Black GCM. Pinpointing clinical diagnosis through whole exome sequencing to direct patient care: a case of Senior-Loken syndrome. Lancet 2015; 385:1916. [PMID: 25987160 PMCID: PMC7614377 DOI: 10.1016/s0140-6736(15)60496-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Jamie M Ellingford
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Panagiotis I Sergouniotis
- Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Rachel Lennon
- Department of Paediatric Nephrology, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Sanjeev Bhaskar
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Simon G Williams
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Kate A Hillman
- Department of Renal Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - James O'Sullivan
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Georgina Hall
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Simon C Ramsden
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - I Christopher Lloyd
- Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Adrian S Woolf
- Department of Paediatric Nephrology, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Graeme C M Black
- Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
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14
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Sheremet NL, Khanakova NA, Nevinitsyna TA, Tsygankova PG, Itkis IS, Krylova TD, Loginova AN, Chukhrova AL, Venkova LS, Svistunova DM, Chernoivanenko IS, Zakharova EI, Poliakov AV, Minin AA. [Modern opportunities and prospects for studying pathogenesis, diagnosing and treating hereditary optic neuropathies]. Vestn Oftalmol 2014; 130:62-70. [PMID: 25715555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To evaluate modern opportunities and prospects for studying pathogenesis and improving diagnostics and treatment of hereditary optic neuropathies (HON). MATERIAL AND METHODS The article presents summarized data on the pathogenesis, diagnostics, and treatment of HON based on modern methods of assessment. RESULTS The results of long-term worldwide studies and those performed in the Research Institute of Eye Diseases in collaboration with several other institutions are presented. Genetic testing for mitochondrial and nucleus DNA mutations that have a known association with Leber's hereditary optic neuropathy (LHON) and autosomal dominant optic neuropathy (ADON) allow verification only in half of the cases. Particular features of hereditary diseases, such as incomplete penentrance, variable expression, clinical polymorphism, difficulties in detection of hereditary sings, and genetic heterogeneity, are shown to complicate the diagnosis of HON. Spectral retinal tomography revealed characteristic morphometric changes in the macular region and peripapillary nerve fiber layer in the acute stage of LHON. Hereditary optic neuropathies result from a genetically determined decrease in mitochondrial respiratory chain complexes activity, which is associated with a decrease in ATP production. From that standpoint, studying of mitochondrial oxidative phosphorylation biochemical defects in LHON and ADON is an option for detection of mitochondrial dysfunction. Results of a newly proposed method of mitochondrial membrane potential assessment in skin fibroblasts, which can be used for differential diagnosis of mitochondrial optic nerve diseases, are presented. Possible therapeutic measures for HON are discussed. CONCLUSION In the prevailing number of cases the described clinical, molecular genetic, and cytological methods ensure proper diagnosis of hereditary optic neuropathies. Prospects of HON treatment, rather ambiguous, are associated with further studying of pathogenesis, development of drugs and gene therapy.
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15
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Oosterkamp BCM, Ockeloen CW, Carels CEL, Kuijpers-Jagtman AM. [Tooth eruption disturbances and syndromes]. Ned Tijdschr Tandheelkd 2014; 121:233-238. [PMID: 24881265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the tooth eruption mechanism, various disturbances can appear as a result of gene mutations, a consequence of which can be that tooth eruption does not occur. There are 5 syndromes which involve the complete failure of several or even all teeth to erupt, specifically: cleidocranial dysplasia, Gardner's syndrome, osteopetrosis, mucopolysaccharidosis and GAPO syndrome. Some are very rare and will seldom be encountered in a dental practice, but they show how vulnerable the tooth eruption mechanism is. Dentists are generally the ones who identify a tooth eruption problem in a patient. Since syndromes can be associated with other disorders, additional investigation by a clinical geneticist is always important when a syndrome is suspected.
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16
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Sessa G, Hjortshøj TD, Egfjord M. [Hereditary cerebro-oculo-renal syndromes]. Ugeskr Laeger 2014; 176:V07130452. [PMID: 25350305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although many congenital diseases present disturbances of the central nervous system, eyes and renal function, only few of these have a defined genetic basis. The first clinical features of cerebro-oculo-renal diseases usually develop in early childhood and deterioration of kidney function and even end-stage kidney disease may occur in a young age. The syndromes should be considered in patients with retarded growth and development, central nervous system abnormalities, impaired vision or blindness and progressive renal failure.
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Affiliation(s)
- Galina Sessa
- Nefrologisk klinik P, Rigshospitalet, Blegdamsvej 9, 2100 København Ø.
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17
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Khanakova NA, Sheremet NL, Loginova AN, Chukhrova AL, Poliakov AV. [Hereditary optic neuropathies: clinical and molecular genetic characteristics]. Vestn Oftalmol 2013; 129:82-87. [PMID: 24624809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The article presents a review of literature on hereditary optic neuropathies: Leber mitochondrial hereditary optic neuropathy, autosomal dominant and autosomal recessive optic neuropathies, X-linked optic atrophy. Clinical and molecular genetic characteristics are covered. Isolated optic neuropathies, as well as hereditary optic disorders, being a part of a complex syndromic disease are described.
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18
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Coussa RG, Otto EA, Gee HY, Arthurs P, Ren H, Lopez I, Keser V, Fu Q, Faingold R, Khan A, Schwartzentruber J, Majewski J, Hildebrandt F, Koenekoop RK. WDR19: an ancient, retrograde, intraflagellar ciliary protein is mutated in autosomal recessive retinitis pigmentosa and in Senior-Loken syndrome. Clin Genet 2013; 84:150-9. [PMID: 23683095 PMCID: PMC3904424 DOI: 10.1111/cge.12196] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 05/15/2013] [Accepted: 05/15/2013] [Indexed: 01/30/2023]
Abstract
Autosomal recessive retinitis pigmentosa (arRP) is a clinically and genetically heterogeneous retinal disease that causes blindness. Our purpose was to identify the causal gene, describe the phenotype and delineate the mutation spectrum in a consanguineous Quebec arRP family. We performed Arrayed Primer Extension (APEX) technology to exclude ∼500 arRP mutations in ∼20 genes. Homozygosity mapping [single nucleotide polymorphism (SNP) genotyping] identified 10 novel significant homozygous regions. We performed next generation sequencing and whole exome capture. Sanger sequencing provided cosegregation. We screened another 150 retinitis pigmentosa (RP) and 200 patients with Senior-Løken Syndrome (SLS). We identified a novel missense mutation in WDR19, c.2129T>C which lead to a p.Leu710Ser. We found the same mutation in a second Quebec arRP family. Interestingly, two of seven affected members of the original family developed 'sub-clinical' renal cysts. We hypothesized that more severe WDR19 mutations may lead to severe ciliopathies and found seven WDR19 mutations in five SLS families. We identified a new gene for both arRP and SLS. WDR19 is a ciliary protein associated with the intraflagellar transport machinery. We are currently investigating the full extent of the mutation spectrum. Our findings are crucial in expanding the understanding of childhood blindness and identifying new genes.
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Affiliation(s)
- R G Coussa
- Department of Paediatric Surgery, McGill University Health Centre, Montreal, Quebec, Canada
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19
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Ronquillo CC, Bernstein PS, Baehr W. Senior-Løken syndrome: a syndromic form of retinal dystrophy associated with nephronophthisis. Vision Res 2012; 75:88-97. [PMID: 22819833 DOI: 10.1016/j.visres.2012.07.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/06/2012] [Accepted: 07/09/2012] [Indexed: 02/06/2023]
Abstract
Senior-Løken syndrome (SLS) is an autosomal recessive disease characterized by development of a retinitis pigmentosa (RP)- or Leber congenital amaurosis (LCA)-like retinal dystrophy and a medullary cystic kidney disease, nephronophthisis. Mutations in several genes (called nephrocystins) have been shown to cause SLS. The proteins encoded by these genes are localized in the connecting cilium of photoreceptor cells and in the primary cilium of kidney cells. Nephrocystins are thought to have a role in regulating transport of proteins bound to the outer segment/primary cilium; however, the precise molecular mechanisms are largely undetermined. This review will survey the biochemistry, cell biology and existing animal models for each of the nephrocystins as it relates to photoreceptor biology and pathogenesis of retinal degeneration.
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Affiliation(s)
- C C Ronquillo
- Program in Neuroscience, University of Utah Health Science Center, Salt Lake City, UT 84132, USA
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20
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Abstract
Hereditary motor sensory neuropathy type VI (HMSN VI) is hereditary neuropathy accompanied by optic neuropathy. The feasibility of Coenzyme Q10 (CoQ10) as a treatment for subacute visual impairment of HMSN VI was examined. A 37-year-old patient with HMSN VI with a novel mitofusin 2 mutation was treated with high dose of CoQ10 (200 mg/day) for eight months. Visual impairment was partially resolved after CoQ10 therapy. High dose CoQ10 therapy may improve the prognosis of subacute visual impairment in HMSN VI. To confirm the effectiveness of CoQ10 on HMSN VI, further studies are needed.
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Affiliation(s)
- Ryoichi Takahashi
- Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Japan.
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21
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Huizing M, Dorward H, Ly L, Klootwijk E, Kleta R, Skovby F, Pei W, Feldman B, Gahl WA, Anikster Y. OPA3, mutated in 3-methylglutaconic aciduria type III, encodes two transcripts targeted primarily to mitochondria. Mol Genet Metab 2010; 100:149-54. [PMID: 20350831 PMCID: PMC2872056 DOI: 10.1016/j.ymgme.2010.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 11/15/2022]
Abstract
3-Methylglutaconic aciduria type III (3-MGCA type III), caused by recessive mutations in the 2-exon gene OPA3, is characterized by early-onset bilateral optic atrophy, later-onset extrapyramidal dysfunction, and increased urinary excretion of 3-methylglutaconic acid and 3-methylglutaric acid. Here we report the identification of a novel third OPA3 coding exon, the apparent product of a segmental duplication event, resulting in two gene transcripts, OPA3A and OPA3B. OPA3A deficiency (as in optic atrophy type 3) causes up-regulation of OPA3B. OPA3 protein function remains unknown, but it contains a putative mitochondrial leader sequence, mitochondrial sorting signal and a peroxisomal sorting signal. Our green fluorescent protein tagged OPA3 expression studies found its localization to be predominantly mitochondrial. These findings thus place the cellular metabolic defect of 3-MGCA type III in the mitochondrion rather than the peroxisome and implicate loss of OPA3A rather than gain of OPA3B in disease etiology.
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Affiliation(s)
- Marjan Huizing
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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22
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Hanein S, Perrault I, Roche O, Gerber S, Khadom N, Rio M, Boddaert N, Jean-Pierre M, Brahimi N, Serre V, Chretien D, Delphin N, Fares-Taie L, Lachheb S, Rotig A, Meire F, Munnich A, Dufier JL, Kaplan J, Rozet JM. TMEM126A, encoding a mitochondrial protein, is mutated in autosomal-recessive nonsyndromic optic atrophy. Am J Hum Genet 2009; 84:493-8. [PMID: 19327736 DOI: 10.1016/j.ajhg.2009.03.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 11/28/2022] Open
Abstract
Nonsyndromic autosomal-recessive optic neuropathies are rare conditions of unknown genetic and molecular origin. Using an approach of whole-genome homozygosity mapping and positional cloning, we have identified the first gene, to our knowledge, responsible for this condition, TMEM126A, in a large multiplex inbred Algerian family and subsequently in three other families originating from the Maghreb. TMEM126A is conserved in higher eukaryotes and encodes a transmembrane mitochondrial protein of unknown function, supporting the view that mitochondrial dysfunction may be a hallmark of inherited optic neuropathies including isolated autosomal-recessive forms.
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Affiliation(s)
- Sylvain Hanein
- Département de Génétique, Université Paris Descartes, Unité INSERM U781, Hôpital Necker-Enfants Malades, 75015 Paris, France
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23
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Felicio AC, Godeiro-Junior C, Alberto LG, Pinto APM, Sallum JMF, Teive HG, Barsottini OGP. Familial Behr syndrome-like phenotype with autosomal dominant inheritance. Parkinsonism Relat Disord 2007; 14:370-2. [PMID: 17977780 DOI: 10.1016/j.parkreldis.2007.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 08/11/2007] [Accepted: 08/11/2007] [Indexed: 11/18/2022]
Abstract
Behr syndrome is an autosomal recessive disease characterized by early-onset ataxia, optic atrophy and other signs such as pyramidal tract dysfunction. Autosomal dominant inheritance has also been described. In this case report we present a family pedigree of patients with an inherited autosomal dominant Behr syndrome-like phenotype emphasizing their clinical and neuroimaging features.
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Affiliation(s)
- Andre C Felicio
- Department of Neurology and Neurosurgery, Federal University of São Paulo, São Paulo, Brazil.
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24
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de Brouwer APM, Williams KL, Duley JA, van Kuilenburg ABP, Nabuurs SB, Egmont-Petersen M, Lugtenberg D, Zoetekouw L, Banning MJG, Roeffen M, Hamel BCJ, Weaving L, Ouvrier RA, Donald JA, Wevers RA, Christodoulou J, van Bokhoven H. Arts syndrome is caused by loss-of-function mutations in PRPS1. Am J Hum Genet 2007; 81:507-18. [PMID: 17701896 PMCID: PMC1950830 DOI: 10.1086/520706] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 06/04/2007] [Indexed: 11/03/2022] Open
Abstract
Arts syndrome is an X-linked disorder characterized by mental retardation, early-onset hypotonia, ataxia, delayed motor development, hearing impairment, and optic atrophy. Linkage analysis in a Dutch family and an Australian family suggested that the candidate gene maps to Xq22.1-q24. Oligonucleotide microarray expression profiling of fibroblasts from two probands of the Dutch family revealed reduced expression levels of the phosphoribosyl pyrophosphate synthetase 1 gene (PRPS1). Subsequent sequencing of PRPS1 led to the identification of two different missense mutations, c.455T-->C (p.L152P) in the Dutch family and c.398A-->C (p.Q133P) in the Australian family. Both mutations result in a loss of phosphoribosyl pyrophosphate synthetase 1 activity, as was shown in silico by molecular modeling and was shown in vitro by phosphoribosyl pyrophosphate synthetase activity assays in erythrocytes and fibroblasts from patients. This is in contrast to the gain-of-function mutations in PRPS1 that were identified previously in PRPS-related gout. The loss-of-function mutations of PRPS1 likely result in impaired purine biosynthesis, which is supported by the undetectable hypoxanthine in urine and the reduced uric acid levels in serum from patients. To replenish low levels of purines, treatment with S-adenosylmethionine theoretically could have therapeutic efficacy, and a clinical trial involving the two affected Australian brothers is currently underway.
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Affiliation(s)
- Arjan P M de Brouwer
- Departments of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Wang Y, Tong Y, Hu SX, Wang JY, Shao JB, Zhang HX. [Analysis on the effect of secondary mutations on Leber's hereditary optic neuropathy]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2007; 24:397-400. [PMID: 17680528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVE To investigate the effect of secondary mutations on Leber's hereditary optic neuropathy (LHON). METHODS Three primary and 24 secondary mutations were identified in 4 Chinese families which included male offspring. RESULTS All of the four pedigrees carried classic LHON mutations at nucleotide (nt) 11778, and did not carry any point of 24 secondary mutations. Nevertheless many polymorphic points were found in the nearby fragments of these pedigrees, such as 5178, 5108, 3705, 3721, 13734, etc. CONCLUSION Male offspring sequences should be analyzed in pedigrees with LHON to avoid the influence of familial inheritance characteristic which mitochondrial DNA polymorphism carried. Existence of the "repair genes" may affect the development of LHON.
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Affiliation(s)
- Ying Wang
- Department of Ophthalmology, Eye Hospital, Academy of Chinese Medical Science, Beijing, 100040 P. R. China.
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26
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Saillour Y, Zanni G, Des Portes V, Heron D, Guibaud L, Iba-Zizen MT, Pedespan JL, Poirier K, Castelnau L, Julien C, Franconnet C, Bonthron D, Porteous ME, Chelly J, Bienvenu T. Mutations in the AP1S2 gene encoding the sigma 2 subunit of the adaptor protein 1 complex are associated with syndromic X-linked mental retardation with hydrocephalus and calcifications in basal ganglia. J Med Genet 2007; 44:739-44. [PMID: 17617514 PMCID: PMC2752185 DOI: 10.1136/jmg.2007.051334] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Fried syndrome, first described in 1972, is a rare X-linked mental retardation that has been mapped by linkage to Xp22. Clinical characteristics include mental retardation, mild facial dysmorphism, calcifications of basal ganglia and hydrocephalus. A large four-generation family in which the affected males have striking clinical features of Fried syndrome were investigated for linkage to X-chromosome markers; the results showed that the gene for this condition lies within the interval DXS7109-DXS7593 in Xp22.2. In total, 60 candidate genes located in this region, including AP1S2, which was recently shown to be involved in mental retardation, were screened for mutations. A mutation in the third intron of AP1S2 was found in all affected male subjects in this large French family. The mutation resulted in skipping of exon 3, predicting a protein with three novel amino-acids and with termination at codon 64. In addition, the first known large Scottish family affected by Fried syndrome was reinvestigated, and a new nonsense mutation, p.Gln66X, was found in exon 3. Using CT, both affected patients from the French family who were analysed had marked calcifications of the basal ganglia, as previously observed in the first Scottish family, suggesting that the presence of distinctive basal ganglia calcification is an essential parameter to recognise this syndromic disorder. It may be possible to use this feature to identify families with X-linked mental retardation that should be screened for mutations in AP1S2.
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27
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Macarez R, Amati-Bonneau P, Burelle X, Vanimschoot M, Dot C, Ocamica P, Kovalski JL, May F. [A novel mutation of the OPA1 gene responsible for isolated autosomal dominant optic atrophy in two brothers]. J Fr Ophtalmol 2007; 30:161-4. [PMID: 17318099 DOI: 10.1016/s0181-5512(07)89567-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Autosomal dominant optic atrophy, or Kjer disease, is the most frequent form of autosomal dominant optic neuropathy. We report a novel mutation of the OPA1 gene in two brothers with autosomal dominant optic atrophy and describe their clinical features. The two patients, aged 41 and 37, presented with a bilateral visual impairment that had been detected at the age of 4 in both of them. Their ophthalmoscopic examinations disclosed a bilateral optic atrophy and their Goldmann visual fields showed cecocentral scotomas. The patients thought their disease might be a Leber's hereditary optic neuropathy; however, mutations had ever been sought. When first seen by us, they wished to know whether their disorder might be transmitted to their children. They had a family history of visual impairment. We carried out mtDNA sequencing but we did not identify any primary or rare Leber's hereditary optic neuropathy mutations. On the other hand, the 30 coding exons of the OPA1 gene and the intron-exon junctions were amplified by polymerase chain reaction and sequenced. A novel mutation of the OPA1 gene was found in both brothers: a deletion of four nucleotides in intron 19, associated with anomalous splicing, demonstrating the pathogenicity of the mutation. These molecular analyses contributed to identifying a novel mutation of the OPA1 gene with a clinical phenotype of isolated optic atrophy.
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Affiliation(s)
- R Macarez
- Service d'Ophtalmologie, HIA Clermont-Tonnerre, Brest
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28
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Barbet F, Gerber S, Hakiki S, Perrault I, Hanein S, Ducroq D, Tanguy G, Dufier JL, Munnich A, Kaplan J, Rozet JM. A first locus for isolated autosomal recessive optic atrophy (ROA1) maps to chromosome 8q21-q22. Adv Exp Med Biol 2007; 572:21-7. [PMID: 17249550 DOI: 10.1007/0-387-32442-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- Fabienne Barbet
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant, Hôpital Necker-Enfants Malades, 149 rue de SRvres, 75743 Paris, France
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Abstract
INTRODUCTION Wolfram syndrome is a genetic disease with recessive autosomic transmission, associating early-onset diabetes mellitus and bilateral optical atrophy. CASE REPORT We report the case of a 47-year-old patient for whom we diagnosed a Wolfram syndrome in view of a late neurological syndrome in association with ataxia and bilateral horizontal nystagmus. The brain resonance magnetic imaging revealed a major atrophy of the brainstem and cerebellum. CONCLUSION Wolfram syndrome is a rare pathology, with fatal consequences before the age of 50. The association of diabetes mellitus and optical atrophy, especially when there are other symptoms (ataxia, deafness, diabetes insipidus, neuropsychiatric manifestations or urinary tract disorders) should lead to this diagnosis and to carry out a genetic confirmation.
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Affiliation(s)
- S Mathis
- Clinique Neurologique, CHU La Milétrie, Poitiers
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Chung KW, Kim SB, Park KD, Choi KG, Lee JH, Eun HW, Suh JS, Hwang JH, Kim WK, Seo BC, Kim SH, Son IH, Kim SM, Sunwoo IN, Choi BO. Early onset severe and late-onset mild Charcot-Marie-Tooth disease with mitofusin 2 (MFN2) mutations. Brain 2006; 129:2103-18. [PMID: 16835246 DOI: 10.1093/brain/awl174] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Mutations in the mitofusin 2 (MFN2) gene, which encodes a mitochondrial GTPase mitofusin protein, have recently been reported to cause both Charcot-Marie-Tooth 2A (CMT2A) and hereditary motor and sensory neuropathy VI (HMSN VI). It is well known that HMSN VI is an axonal CMT neuropathy with optic atrophy. However, the differences between CMT2A and HMSN VI with MFN2 mutations remained to be clarified. Therefore, we studied the phenotypic characteristics of CMT patients with MFN2 mutations. Mutations in MFN2 were screened in 62 unrelated axonal CMT neuropathy families. We calculated CMT neuropathy scores (CMTNSs) and functional disability scales (FDSs) to quantify disease severity. Twenty-one patients with the MFN2 mutations were studied by brain MRI. Ten pathogenic mutations were identified in 26 patients from 15 families (24.2%). Six of these mutations had not been reported, and de novo mutations were observed in five families (33.3%). The electrophysiological patterns of affected individuals with the MFN2 mutations were typical of axonal CMT; however, the clinical and electrophysiological characteristics were markedly different in early (<10 years) and late disease-onset (> or =10 years) groups. All patients with an early onset had severe CMTNS (> or =21) and FDS (6 or 7), whereas most patients with late onset had mild CMTNS (< or =10) and FDS (< or =3). We identified two HMSN VI families with the R364W mutation in the early onset group; however, two other families with the same mutation did not have optic atrophy. In addition, two early onset families with R94W mutations, previously reported for HMSN VI, did not have visual impairment. Interestingly, eight patients had periventricular and subcortical hyperintense lesions by brain MRI. In the late-onset group, three patients had sensorineural hearing loss and two had bilateral extensor plantar responses. We found that MFN2 mutations are the major cause of axonal CMT neuropathy, and that they are associated with variable CNS involvements. Phenotypes were significantly different in the early and late disease-onset groups. Our findings suggest that HMSN VI might be a variant of the early onset severe CMT2A phenotype.
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Affiliation(s)
- K W Chung
- Department of Neurology and Ewha Medical Research Center, Ewha Woman's University, College of Medicine, Dongdaemun Hospital, 70 Jongno 6-ga, Jongno-gu, 110-783, Seoul, Korea E-mail:
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Qin M, Kondo H, Uno H, Fujiwara E, Uchio E, Tahira T, Hayashi K. Novel OPA1 mutations identified in Japanese pedigrees with optic atrophy. Mol Vis 2006; 12:485-91. [PMID: 16735988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023] Open
Abstract
PURPOSE To determine whether mutations in the OPA1 gene were present in two Japanese families with optic atrophy. METHODS Thirty exons and their boundaries of the OPA1 gene were amplified by PCR with genomic DNA as templates and directly sequenced. The detected sequence changes were confirmed to be mutations by examining whether they were present in normal control individuals. A splicing mutation was characterized by RT-PCR of total RNA of leukocytes obtained from patients and one normal individual. The mutant transcripts resulting from the splicing mutation were further confirmed and quantified by sequencing and identifying the denatured RT-PCR products by polyacrylamide electrophoresis. RESULTS One novel splicing mutation of c.871-1G>T and one novel insertion mutation of c.579_580insTT (p.R194fsX228) were identified from two familial cases, respectively. Both mutations segregated within the family heterozygously and were not found in the 189 control individuals examined. Two mutant transcripts resulted from the splicing mutation were identified through amplified OPA1 cDNA prepared from the RNA of leukocytes of the patients. One had a 21 bp deletion at the beginning of the exon 9 leading to a 7 amino acid in-frame deletion of the protein. The expression level of this mutant transcript was similar to the transcript from the wild type allele of the patient. The other mutation was a 114 bp deletion, leading to a 38 amino acid in-frame deletion that skipped all of exon 9, and the expression of this mutant transcript was much lower than the 21 bp deletion. CONCLUSIONS The predicted consequence of both mutations is the loss of GTPase activity. Our findings further establish the involvement of OPA1 mutation in Japanese patients with optic atrophy and serve as supportive evidence that haploinsufficiency of the OPA1 gene is the cause of the optic atrophy.
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Affiliation(s)
- Minghui Qin
- Division of Genome Analysis, Research Center for Genetic Information, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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Phasukkijwatana N, Chuenkongkaew WL, Suphavilai R, Suktitipat B, Pingsuthiwong S, Ruangvaravate N, Atchaneeyasakul LO, Warrasak S, Poonyathalang A, Sura T, Lertrit P. The unique characteristics of Thai Leber hereditary optic neuropathy: analysis of 30 G11778A pedigrees. J Hum Genet 2006; 51:298-304. [PMID: 16477364 DOI: 10.1007/s10038-006-0361-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Accepted: 12/13/2005] [Indexed: 01/30/2023]
Abstract
Leber hereditary optic neuropathy (LHON) is characterized by acute or subacute bilateral visual loss, and affects mostly young males. The most common mitochondrial DNA mutation responsible for LHON worldwide is G11778A. Despite different genetic backgrounds, which are believed to influence the disease expression, most features of LHON are quite common in different populations. However, there seem to be a few ethnic-specific differences. Analyses of our 30 G11778A LHON pedigrees in Thailand showed some characteristics different from those of Caucasians and Japanese. In particular, our pedigrees showed a lower male to female ratio of affected persons (2.6:1) and much higher prevalence of G11778A blood heteroplasmy (37% of the pedigrees contained at least one heteroplasmic G11778A individual). Heteroplasmicity seemed to influence disease manifestation in our patients but did not appear to alter the onset of the disease. The estimated overall penetrance of our G11778A LHON population was 37% for males and 13% for females. When each of our large pedigrees were considered separately, disease penetration varied from 9 to 45% between the pedigrees, and also varied between different branches of the same large pedigree. Survival analysis showed that the secondary LHON mutations G3316A and C3497T had a synergistic deleterious effect with the G11778A mutation, accelerating the onset of the disease in our patients.
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Affiliation(s)
- Nopasak Phasukkijwatana
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Wanicha L Chuenkongkaew
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Neurogenetics Network, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Rungnapa Suphavilai
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Bhoom Suktitipat
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Sarinee Pingsuthiwong
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Ngamkae Ruangvaravate
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - La-Ongsri Atchaneeyasakul
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Sukhuma Warrasak
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Anuchit Poonyathalang
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Thanyachai Sura
- Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
| | - Patcharee Lertrit
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
- Siriraj Neurogenetics Network, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
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Lubińiski W, Palacz O, Karczewicz D. [Electrophysiological tests in early and differential diagnosis of some hereditary retinal and optic nerve diseases]. Klin Oczna 2006; 108:93-8. [PMID: 16883951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
PURPOSE The goal of our study was to determine the value of electrophysiological tests in early and differential diagnosis of some hereditary retinal and optic nerve diseases. MATERIAL AND METHODS Review article on the basis of own experiences and results of another authors concerning to EOG, ERG, PERG, MfERG and VEP tests in evaluation of hereditary, stationary and progressive retinal diseases, as well as optic nerve diseases. RESULTS Electrophysiological tests can be abnormal even in patients without fundus changes seen in routine ophthalmological examination. CONCLUSIONS Electrophysiological tests are useful in early and differential diagnosis of some hereditary retinal and optic nerve diseases. General ophthalmologists should remember about its application, especially in difficult diagnostic cases.
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34
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Verny C, Amati-Bonneau P, Dubas F, Malthiéry Y, Reynier P, Bonneau D. [An OPA3 gene mutation is responsible for the disease associating optic atrophy and cataract with extrapyramidal signs]. Rev Neurol (Paris) 2005; 161:451-4. [PMID: 15924081 DOI: 10.1016/s0035-3787(05)85075-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION In 1961, Garcin et al. described a family with several members affected with optic atrophy associated with cataract, and neurological symptoms. The authors believed this condition to be distinct from other diseases known at that time, e.g. the Behr syndrome, Marinesco-Sjogren syndrome and Friedreich's ataxia. METHOD This family was followed over a period of 40 years and genes known to be responsible for optic atrophy were sequenced. RESULTS The G277A mutation of OPA3 gene was responsible for this familial disease. DISCUSSION A new clinical entity is identified: autosomal dominant optic atrophy and cataract, due to a heterozygous mutation of the OPA3 gene, a nuclear gene encoding a mitochondrial protein.
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Affiliation(s)
- C Verny
- Département de Neurologie, Centre Hospitalier Universitaire, Paris.
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35
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Macedo-Souza LI, Kok F, Santos S, Amorim SC, Starling A, Nishimura A, Lezirovitz K, Lino AMM, Zatz M. Spastic paraplegia, optic atrophy, and neuropathy is linked to chromosome 11q13. Ann Neurol 2005; 57:730-7. [PMID: 15852396 DOI: 10.1002/ana.20478] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report an autosomal recessive neurodegenerative disorder in 25 white members from a large inbred Brazilian family, 22 of whom were evaluated clinically. This condition is characterized by (1) subnormal vision secondary to apparently nonprogressive congenital optic atrophy; (2) onset of progressive spastic paraplegia in infancy; (3) onset of progressive motor and sensory axonal neuropathy in late childhood/early adolescence; (4) dysarthria starting in the third decade of life; (5) exacerbated acoustic startle response; and (6) progressive joint contractures and spine deformities. Motor handicap was severe, and all patients were wheelchair bound after 15 years old. We performed a genome-wide screen including 25 affected individuals and 49 of their unaffected relatives. Linkage was detected at 11q13 region with a maximum logarithm of odds score of +14.43, obtained with marker D11S1883. The candidate region, which lies between D11S1908 and D11S1889, encompasses approximately 4.8Mb and has more than 100 genes and expressed sequences. We propose the acronym SPOAN (spastic paraplegia, optic atrophy, and neuropathy) for this complex syndrome.
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Affiliation(s)
- Lucia I Macedo-Souza
- Department of Biology, Institute of Biological Sciences and Center for Study of Human Genome, University of São Paulo, Brazil
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Abstract
AIMS To provide a clinical update on the hereditary optic neuropathies. METHODS Review of the literature. RESULTS The hereditary optic neuropathies comprise a group of disorders in which the cause of optic nerve dysfunction appears to be hereditable, based on familial expression or genetic analysis. In some hereditary optic neuropathies, optic nerve dysfunction is typically the only manifestation of the disease. In others, various neurologic and systemic abnormalities are regularly observed. CONCLUSION The most common hereditary optic neuropathies are autosomal dominant optic atrophy (Kjer's disease) and maternally inherited Leber's hereditary optic neuropathy. We review the clinical phenotypes of these and other inherited disorders with optic nerve involvement.
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MESH Headings
- Dysautonomia, Familial/complications
- Dysautonomia, Familial/genetics
- Female
- Friedreich Ataxia/complications
- Friedreich Ataxia/genetics
- Humans
- Male
- Muscular Dystrophies/complications
- Muscular Dystrophies/genetics
- Optic Atrophies, Hereditary/complications
- Optic Atrophies, Hereditary/genetics
- Optic Atrophies, Hereditary/physiopathology
- Optic Atrophy, Autosomal Dominant/complications
- Optic Atrophy, Autosomal Dominant/genetics
- Optic Atrophy, Autosomal Dominant/physiopathology
- Optic Atrophy, Hereditary, Leber/complications
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/physiopathology
- Pedigree
- Spinocerebellar Ataxias/complications
- Spinocerebellar Ataxias/genetics
- Vision Disorders/etiology
- Vision Disorders/genetics
- Vision Disorders/physiopathology
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Affiliation(s)
- N J Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30022, USA.
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Schollen E, Grünewald S, Keldermans L, Albrecht B, Körner C, Matthijs G. CDG-Id caused by homozygosity for an ALG3 mutation due to segmental maternal isodisomy UPD3(q21.3-qter). Eur J Med Genet 2005; 48:153-8. [PMID: 16053906 DOI: 10.1016/j.ejmg.2005.01.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Indexed: 11/17/2022]
Abstract
We report on a patient with a congenital disorder of glycosylation type Id (CDG-Id) caused by a homozygous mutation in the ALG3 gene, which results from a de novo mutation in combination with a segmental maternal uniparental isodisomy (UPD). The patient presented with severe psychomotor delay, primary microcephaly, and opticus atrophy, compatible with a severe form of CDG. Isoelectric focusing of transferrin showed a type I pattern and lipid-linked oligosaccharide analysis showed an accumulation of dol-PP-GlcNAc2Man5 in patient's fibroblasts suggesting a defect in the ALG3 gene. A homozygous ALG3 missense mutation p.R266C (c.796C > T) was identified. Further evaluation revealed that neither the mother nor the father were carrier of the p.R266C mutation. Marker analysis revealed a segmental maternal isodisomy for the chromosomal region 3q21.3-3qter. UPD for this region has not been described before. More important, the combination of UPD with a de novo mutation is an exceptional coincidence and an extraordinary observation.
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Affiliation(s)
- E Schollen
- Center for Human Genetics, UZ Leuven, Leuven, Belgium.
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38
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Abstract
AIM To review the molecular genetic basis of primary inherited optic neuropathies. METHODS Medline and Embase search. RESULTS Inherited optic neuropathies are a genetically diverse group of disorders that present with reduced visual acuity and the clinical appearance of optic atrophy. The inherited optic neuropathies may be sporadic or familial, in which case the mode of inheritance may be Mendelian (autosomal dominant, autosomal recessive, X-linked recessive) or non-Mendelian (mitochondrial). Two genes for dominantly inherited optic atrophy have been mapped (OPA1 and OPA4), of which the gene has been identified in one (OPA1). A gene for recessive optic atrophy (OPA3) has also been identified. X-linked optic atrophy (OPA2) has been mapped but to date no gene has been identified. Mutations in mitochondrial DNA have been identified in Leber's hereditary optic neuropathy. CONCLUSIONS Mutations in genes from both the nuclear and mitochondrial genomes appear to be responsible. Mitochondrial dysfunction, in the broadest sense, is emerging as central to the pathogenesis of this group of conditions.
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Affiliation(s)
- M Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
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Abstract
Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by early onset diabetes mellitus and progressive optic atrophy in the first decade of life. Other clinical features such as diabetes insipidus, deafness, renal tract abnormalities or psychiatric illnesses are often present. The sequence of the Wolfram syndrome gene (WFS1) was described in 1998, and mutations in the gene have been reported in many populations. To date, the function of the putative protein remains unknown. Here we report prenatal diagnosis by analysing the WFS1 gene, in a foetus belonging to a family with a child diagnosed for Wolfram syndrome. The parents are carriers of the c.2206G > C (G736R) mutation. To our knowledge this is the first description of prenatal diagnosis for Wolfram syndrome, based on the molecular analysis of the WFS1 gene.
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Affiliation(s)
- Enric Domènech
- Centre de Genètica Mèdica i Molecular, Institut de Recerca Oncològica, L'Hospitalet de Llobregat, Barcelona, Spain
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Udar N, Yelchits S, Chalukya M, Yellore V, Nusinowitz S, Silva-Garcia R, Vrabec T, Hussles Maumenee I, Donoso L, Small KW. Identification of GUCY2D gene mutations in CORD5 families and evidence of incomplete penetrance. Hum Mutat 2003; 21:170-1. [PMID: 12552567 DOI: 10.1002/humu.9109] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cone rod dystrophy 5 (CORD5) is an autosomal dominant retinal disease that primarily affects cone function. The locus has previously been mapped to human chromosome 17p12-p13 between the markers D17S926/D17S849 and D17S945/D17S804. One of our "unaffected" recombinant individual from family 1175 was subsequently found to cross through this interval. Reexamination revealed that he was in fact mildly affected. This expanded the minimum candidate region. Direct sequencing of the GUCY2D and other candidate genes within this interval was carried out on 2 American families affected with CORD5. There was an R838C missense mutation within the GUCY2D gene in one and a R838H missense mutation in another families. The previously reported mutations for CORD6 are clustered at the same position within the gene. These results indicate that both CORD5 (MIM# 600977) and CORD6 (MIM# 601777) are actually the same disease. We conclude that significant variability in expression and incomplete penetrance exists even within one family.
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Affiliation(s)
- Nitin Udar
- Jules Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA
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Abstract
The primary inherited optic neuropathies are a heterogeneous group of disorders that result in loss of retinal ganglion cells, leading to the clinical appearance of optic atrophy. They affect between 1:10,000 to 1:50,000 people. The main clinical features are a reduction in visual acuity, colour vision abnormalities, centro-caecal visual field defects and pallor of the optic nerve head. Electrophysiological testing shows a normal flash electroretinogram, absent or delayed pattern visually evoked potentials suggestive of a conduction deficit and N95 waveform reduction on the pattern electroretinogram, consistent with a primary ganglion cell pathology. The primary inherited optic neuropathies may be sporadic or familial. The mode of inheritance may be autosomal dominant, autosomal recessive, X-linked recessive or mitochondrial. Within each of these groups, the phenotypic characteristics vary in such features as the mode and age of onset, the severity of the visual loss, the colour deficit and the overall prognosis. A number of different genes (most as yet unidentified) in both nuclear and mitochondrial genomes, underlie these disorders. The elucidation of the role of the encoded proteins will improve our understanding of basic mechanisms of ganglion cell development, physiology and metabolism and further our understanding of the pathophysiology of optic nerve disease. It will also improve diagnosis, counselling and management of patients, and eventually lead to the development of new therapeutic modalities.
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Affiliation(s)
- M Votruba
- Department of Molecular Genetics, Institute of Ophthalmology, London, UK.
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Hanein S, Perrault I, Olsen P, Lopponen T, Hietala M, Gerber S, Jeanpierre M, Barbet F, Ducroq D, Hakiki S, Munnich A, Rozet JM, Kaplan J. Evidence of a founder effect for the RETGC1 (GUCY2D) 2943DelG mutation in Leber congenital amaurosis pedigrees of Finnish origin. Hum Mutat 2002; 20:322-3. [PMID: 12325031 DOI: 10.1002/humu.9067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Leber congenital amaurosis (LCA) is the earliest and most severe form of all inherited retinal dystrophies. It is a genetically heterogeneous condition as six disease-causing genes have been hitherto identified. Among them, RETGC1 (GUCY2D), is more frequently implicated in our series of LCA patients. Interestingly, 70 % of the families with RETGC1 mutations are originating from Mediterranean countries, the remaining families (30%) being originating from various countries across the world. Here, we report, the identification of the same homozygous RETGC1 nonsense mutation in three unrelated and non-consanguineous LCA families of Finnish origin, suggesting a founder effect. Interestingly, no linkage desequilibrium was found using polymorphic markers flanking the RETGC1 gene, supporting the view that the mutation is very ancient. Haplotype studies and Bayesian calculation point the founder mutation to 150 generations (95% credible interval 80-240 generations), i.e., 3000 years ago.
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Affiliation(s)
- Sylvain Hanein
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant. Hôpital Necker - Enfants Malades, 149 rue de Sèvres, 75743 Paris Cedex 15, France
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Gerbitz KD, Paprotta A, Obermaier-Kusser B, Rietschel M, Zerres K. No genetic differences between affected and unaffected members of a German family with Leber's hereditary optic neuropathy (LHON) with respect to ten mtDNA point mutations associated with LHON. FEBS Lett 2001; 314:251-5. [PMID: 1361456 DOI: 10.1016/0014-5793(92)81482-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In order to investigate possible synergistic influences of different mtDNA mutations on penetrance and severity of Leber's hereditary optic neuropathy (LHON), a large German LHON pedigree is characterized with respect to 10 different mutations associated with LHON. All members of the family carry three different mtDNA mutations (at nucleotide 4,216, 11,778 and 13,708) in a homoplasmic form, regardless of whether or not they are clinically affected. Testing for another 7 mutations reveals negative results in all family members. Hence, the variable disease expression of the family members cannot be explained by varying combinations of LHON-associated mtDNA mutations.
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Affiliation(s)
- K D Gerbitz
- Institute für Klinische Chemie, Krankenhaus München-Schwabing, Germany
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Anikster Y, Kleta R, Shaag A, Gahl WA, Elpeleg O. Type III 3-methylglutaconic aciduria (optic atrophy plus syndrome, or Costeff optic atrophy syndrome): identification of the OPA3 gene and its founder mutation in Iraqi Jews. Am J Hum Genet 2001; 69:1218-24. [PMID: 11668429 PMCID: PMC1235533 DOI: 10.1086/324651] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2001] [Accepted: 09/28/2001] [Indexed: 11/03/2022] Open
Abstract
Type III 3-methylglutaconic aciduria (MGA) (MIM 258501) is a neuro-ophthalmologic syndrome that consists of early-onset bilateral optic atrophy and later-onset spasticity, extrapyramidal dysfunction, and cognitive deficit. Urinary excretion of 3-methylglutaconic acid and of 3-methylglutaric acid is increased. The disorder has been reported in approximately 40 patients of Iraqi Jewish origin, allowing the mapping of the disease to chromosome 19q13.2-q13.3, by linkage analysis. To isolate the causative gene, OPA3, we sequenced four genes within the critical interval and identified, in the intronic sequence of a gene corresponding to cDNA clone FLJ22187, a point mutation that segregated with the type III MGA phenotype. The FLJ22187-cDNA clone, which we identified as the OPA3 gene, consists of two exons and encodes a peptide of 179 amino acid residues. Northern blot analysis revealed a primary transcript of approximately 5.0 kb that was ubiquitously expressed, most prominently in skeletal muscle and kidney. Within the brain, the cerebral cortex, the medulla, the cerebellum, and the frontal lobe, compared to other parts of the brain, had slightly increased expression. The intronic G-->C mutation abolished mRNA expression in fibroblasts from affected patients and was detected in 8 of 85 anonymous Israeli individuals of Iraqi Jewish origin. Milder mutations in OPA3 should be sought in patients with optic atrophy with later onset, even in the absence of additional neurological abnormalities.
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Affiliation(s)
- Yair Anikster
- Section on Human Biochemical Genetics, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda; and Metabolic Disease Unit, Shaare-Zedek Medical Center, Faculty of Medicine of the Hebrew University, Jerusalem
| | - Robert Kleta
- Section on Human Biochemical Genetics, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda; and Metabolic Disease Unit, Shaare-Zedek Medical Center, Faculty of Medicine of the Hebrew University, Jerusalem
| | - Avraham Shaag
- Section on Human Biochemical Genetics, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda; and Metabolic Disease Unit, Shaare-Zedek Medical Center, Faculty of Medicine of the Hebrew University, Jerusalem
| | - William A. Gahl
- Section on Human Biochemical Genetics, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda; and Metabolic Disease Unit, Shaare-Zedek Medical Center, Faculty of Medicine of the Hebrew University, Jerusalem
| | - Orly Elpeleg
- Section on Human Biochemical Genetics, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda; and Metabolic Disease Unit, Shaare-Zedek Medical Center, Faculty of Medicine of the Hebrew University, Jerusalem
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45
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Abstract
In the past 13 years, a new chapter of human genetics, "mitochondrial genetics", has opened up and is becoming increasingly important in differential diagnosis. Although the clinical manifestations of disorders related to mitochondrial DNA (mtDNA) are extremely variable, recent advances in genetic testing aid in the identification of patients. Muscle morphology can give important clues for diagnosis, but histological features alone cannot define a specific disorder. Biochemical analysis may reveal a single enzyme defect, or when multiple activities are affected, suggest an mtDNA mutation. However, definitive diagnosis often requires DNA analysis and documentation of a specific mtDNA abnormality. Disorders associated with mtDNA mutations are associated with a wide variety of syndromes, and owing to the properties and characteristics of mtDNA, these are often transmitted by maternal inheritance. Although therapy for mitochondrial diseases is limited, identification of the molecular defect is important for genetic counseling.
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Affiliation(s)
- A L Shanske
- Center for Congenital Disorders, Montefiore Medical Center, 111 E 210th St, Bronx, NY 10467, USA.
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46
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Abstract
PURPOSE To report a case of Leber hereditary optic neuropathy with multiple-sclerosis-like symptoms. METHODS Observational case report. A 34-year-old man was found to have Leber hereditary optic neuropathy and a mutation at position 11778 of the mitochondrial genome. The progression of vision loss and onset of weakness in the right leg warranted neuroimaging. RESULTS Magnetic resonance imaging documented multiple lesions in the brain and spinal cord. CONCLUSION Although rarely reported, progression of optic neuropathy over months has been previously documented in Leber hereditary optic neuropathy. The emergence of multiple sclerosis-like symptoms and signs in our patient may be part of the spectrum of Leber hereditary optic neuropathy or a coincidental occurrence.
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Affiliation(s)
- M Tran
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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47
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Seeliger MW, Grimm C, Ståhlberg F, Friedburg C, Jaissle G, Zrenner E, Guo H, Remé CE, Humphries P, Hofmann F, Biel M, Fariss RN, Redmond TM, Wenzel A. New views on RPE65 deficiency: the rod system is the source of vision in a mouse model of Leber congenital amaurosis. Nat Genet 2001; 29:70-4. [PMID: 11528395 DOI: 10.1038/ng712] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Leber congenital amaurosis (LCA) is the most serious form of the autosomal recessive childhood-onset retinal dystrophies. Mutations in the gene encoding RPE65, a protein vital for regeneration of the visual pigment rhodopsin in the retinal pigment epithelium, account for 10-15% of LCA cases. Whereas previous studies of RPE65 deficiency in both animal models and patients attributed remaining visual function to cones, we show here that light-evoked retinal responses in fact originate from rods. For this purpose, we selectively impaired either rod or cone function in Rpe65-/- mice by generating double- mutant mice with models of pure cone function (rhodopsin-deficient mice; Rho-/-) and pure rod function (cyclic nucleotide-gated channel alpha3-deficient mice; Cnga3-/-). The electroretinograms (ERGs) of Rpe65-/- and Rpe65-/-Cnga3-/- mice were almost identical, whereas there was no assessable response in Rpe65-/-Rho-/- mice. Thus, we conclude that the rod system is the source of vision in RPE65 deficiency. Furthermore, we found that lack of RPE65 enables rods to mimic cone function by responding under normally cone-isolating lighting conditions. We propose as a mechanism decreased rod sensitivity due to a reduction in rhodopsin content to less than 1%. In general, the dissection of pathophysiological processes in animal models through the introduction of additional, selective mutations is a promising concept in functional genetics.
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Affiliation(s)
- M W Seeliger
- Retinal Electrodiagnostics Research Group, Department of Ophthalmology, University of Tübingen, Germany.
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48
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Abstract
The hereditary optic neuropathies comprise a group of disorders in which the cause of optic nerve dysfunction seems to be heritable as demonstrated or suggested by familial expression or genetic analysis. Clinical variability, both within and among families with the same disease, often makes recognition and classification difficult. Genetic analysis now permits diagnosis of some of the hereditary optic neuropathies in the absence of family history or in the setting of unusual clinical presentations. The hereditary optic neuropathies are classified into three major groups: those that occur primarily without associated neurologic or systemic signs, those that frequently have associated neurologic or systemic signs, and those where the optic neuropathy is secondary in the overall disease process. This article reviewed the different hereditary optic neuropathies and emphasized the most common types.
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Affiliation(s)
- V Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA.
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Gerber S, Perrault I, Hanein S, Barbet F, Ducroq D, Ghazi I, Martin-Coignard D, Leowski C, Homfray T, Dufier JL, Munnich A, Kaplan J, Rozet JM. Complete exon-intron structure of the RPGR-interacting protein (RPGRIP1) gene allows the identification of mutations underlying Leber congenital amaurosis. Eur J Hum Genet 2001; 9:561-71. [PMID: 11528500 DOI: 10.1038/sj.ejhg.5200689] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2001] [Revised: 05/17/2001] [Accepted: 05/22/2001] [Indexed: 11/09/2022] Open
Abstract
Leber congenital amaurosis (LCA) is a genetically heterogeneous autosomal recessive condition responsible for congenital blindness or greatly impaired vision since birth. So far, six LCA loci have been mapped but only 4 out of 6 genes have been identified. A genome-wide screen for homozygosity was conducted in seven consanguineous families unlinked to any of the six LCA loci. Evidence for homozygosity was found in two of these seven families at the 14q11 chromosomal region. Two retinal specific candidate genes were known to map to this region, namely the neural retina leucine zipper (NRL) and the retinitis pigmentosa GTPase regulator interacting protein (RPGRIP1). No mutation of the NRL gene was found in any of the two families. Thus, we determined the complete exon-intron structure of the RPGRIP1 gene. RPGRIP1 encompasses 24 coding exons, nine of which are first described here with their corresponding exon-intron boundaries. The screening of the gene in the two families consistent with linkage to chromosome 14q11 allowed the identification of a homozygous null mutation and a homozygous missense mutation, respectively. Further screening of LCA patients unlinked to any of the four already identified LCA genes (n=86) identified seven additional mutations in six of them. In total, eight distinct mutations (5 out of 8 truncating) in 8/93 patients were found. So far this gene accounts for eight out of 142 LCA cases in our series (5.6%).
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Affiliation(s)
- S Gerber
- Unité de Recherches sur les Handicaps Génétiques de l'Enfant, Hôpital Necker-Enfants Malades, Paris, France
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50
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Jacobi FK, Meyer J, Pusch CM, Wissinger B. Quantitation of heteroplasmy in mitochondrial DNA mutations by primer extension using Vent(R)(exo-) DNA polymerase and RFLP analysis. Mutat Res 2001; 478:141-51. [PMID: 11406178 DOI: 10.1016/s0027-5107(01)00134-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this report we describe a simple and rapid protocol for reliable quantitation of mitochondrial DNA (mtDNA) mutations, which is basically a modification of the traditional polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) analysis technique. Up to now, the PCR/RFLP method has been of limited use for the accurate determination of ratios of mutant and wild type molecules, largely owing to the formation of heteroduplex molecules by PCR and incompleteness of restriction digestion. In order to overcome this problem, we have introduced a single-step primer extension reaction using Vent(R)(exo-) DNA polymerase and a fluorescence-labeled primer to the standard assay. The labeled homoduplex molecules are then digested with a restriction endonuclease, and the nucleic acids fractionated on an automated DNA sequencer equipped with GENESCAN analysis software. The amount of mutant mtDNA is readily estimated from fluorescence intensities of the wild-type and mutant mtDNA fragments corrected for incomplete digestion as monitored by a homologous control fragment. The accuracy of the improved protocol was determined by constructing standard curves obtained from defined mixtures of genomic DNA containing homoplasmic wild-type and mutant mtDNA. The expected values were obtained, with an observed correlation coefficient of 0.997 and a typical variability of +/-5% between repeated measurements. Further validation of the protocol is provided by the screening of five patients and unaffected subjects carrying the guanine to adenine transition at the nucleotide 3460 of the mitochondrial genome responsible for the mitochondrial disorder of Leber's hereditary optic neuropathy.
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Affiliation(s)
- F K Jacobi
- Molekulargenetisches Labor, Universitäts-Augenklinik, Auf der Morgenstelle 15, 72076 Tübingen, Germany.
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