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Martins Junior CR, Borba FCD, Martinez ARM, Rezende TJRD, Cendes IL, Pedroso JL, Barsottini OGP, França Júnior MC. Twenty-five years since the identification of the first SCA gene: history, clinical features and perspectives for SCA1. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 76:555-562. [PMID: 30231129 DOI: 10.1590/0004-282x20180080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022]
Abstract
Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.
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Affiliation(s)
| | - Fabrício Castro de Borba
- Universidade de Campinas, Faculdade de Ciências Médicas, Departamento de Neurologia, Campinas SP, Brasil
| | | | | | - Iscia Lopes Cendes
- Universidade de Campinas, Faculdade de Ciências Médicas, Departamento de Genética Médica, Campinas SP, Brasil
| | - José Luiz Pedroso
- Universidade Federal de São Paulo, Unidade de Ataxia, Departamento de Neurologia, São Paulo SP, Brasil
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2
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Kumari R, Kumar D, Brahmachari SK, Srivastava AK, Faruq M, Mukerji M. Paradigm for disease deconvolution in rare neurodegenerative disorders in Indian population: insights from studies in cerebellar ataxias. J Genet 2018. [DOI: 10.1007/s12041-018-0948-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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3
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Seong E, Insolera R, Dulovic M, Kamsteeg EJ, Trinh J, Brüggemann N, Sandford E, Li S, Ozel AB, Li JZ, Jewett T, Kievit AJ, Münchau A, Shakkottai V, Klein C, Collins C, Lohmann K, van de Warrenburg BP, Burmeister M. Mutations in VPS13D lead to a new recessive ataxia with spasticity and mitochondrial defects. Ann Neurol 2018; 83:1075-1088. [PMID: 29604224 PMCID: PMC6105379 DOI: 10.1002/ana.25220] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 03/11/2018] [Accepted: 03/19/2018] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To identify novel causes of recessive ataxias, including spinocerebellar ataxia with saccadic intrusions, spastic ataxias, and spastic paraplegia. METHODS In an international collaboration, we independently performed exome sequencing in 7 families with recessive ataxia and/or spastic paraplegia. To evaluate the role of VPS13D mutations, we evaluated a Drosophila knockout model and investigated mitochondrial function in patient-derived fibroblast cultures. RESULTS Exome sequencing identified compound heterozygous mutations in VPS13D on chromosome 1p36 in all 7 families. This included a large family with 5 affected siblings with spinocerebellar ataxia with saccadic intrusions (SCASI), or spinocerebellar ataxia, recessive, type 4 (SCAR4). Linkage to chromosome 1p36 was found in this family with a logarithm of odds score of 3.1. The phenotypic spectrum in our 12 patients was broad. Although most presented with ataxia, additional or predominant spasticity was present in 5 patients. Disease onset ranged from infancy to 39 years, and symptoms were slowly progressive and included loss of independent ambulation in 5. All but 2 patients carried a loss-of-function (nonsense or splice site) mutation on one and a missense mutation on the other allele. Knockdown or removal of Vps13D in Drosophila neurons led to changes in mitochondrial morphology and impairment in mitochondrial distribution along axons. Patient fibroblasts showed altered morphology and functionality including reduced energy production. INTERPRETATION Our study demonstrates that compound heterozygous mutations in VPS13D cause movement disorders along the ataxia-spasticity spectrum, making VPS13D the fourth VPS13 paralog involved in neurological disorders. Ann Neurol 2018.
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Affiliation(s)
- Eunju Seong
- Molecular & Behavioral Neuroscience Institute, University of
Michigan, Ann Arbor, MI 48109, USA
| | - Ryan Insolera
- Department of Molecular, Cellular, and Developmental Biology,
University of Michigan, Ann Arbor, MI 48109, USA
| | - Marija Dulovic
- Institute of Neurogenetics, University of Lübeck,
Germany
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Centre,
Nijmegen, The Netherlands
| | - Joanne Trinh
- Institute of Neurogenetics, University of Lübeck,
Germany
| | | | - Erin Sandford
- Molecular & Behavioral Neuroscience Institute, University of
Michigan, Ann Arbor, MI 48109, USA
| | | | - Ayse Bilge Ozel
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
48109, USA
| | - Jun Z. Li
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
48109, USA
- Department of Computational Medicine & Bioinformatics,
University of Michigan, Ann Arbor, MI 48109, USA
| | - Tamison Jewett
- Department of Pediatrics, Section on Medical Genetics, Wake Forest
School of Medicine, Winston-Salem, North Carolina, USA
| | | | | | - Vikram Shakkottai
- Departments of Neurology and of Molecular and Integrative
Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Catherine Collins
- Department of Molecular, Cellular, and Developmental Biology,
University of Michigan, Ann Arbor, MI 48109, USA
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck,
Germany
| | - Bart P. van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition and
Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Margit Burmeister
- Molecular & Behavioral Neuroscience Institute, University of
Michigan, Ann Arbor, MI 48109, USA
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
48109, USA
- Department of Computational Medicine & Bioinformatics,
University of Michigan, Ann Arbor, MI 48109, USA
- Department of Psychiatry, University of Michigan, Ann Arbor, MI
48109, USA
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4
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Tarnutzer AA, Straumann D, Salman MS. Neuro-ophthalmologic assessment and investigations in children and adults with cerebellar diseases. THE CEREBELLUM: FROM EMBRYOLOGY TO DIAGNOSTIC INVESTIGATIONS 2018; 154:305-327. [DOI: 10.1016/b978-0-444-63956-1.00019-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Abstract
The autosomal-recessive cerebellar ataxias comprise more than half of the known genetic forms of ataxia and represent an extensive group of clinically heterogeneous disorders that can occur at any age but whose onset is typically prior to adulthood. In addition to ataxia, patients often present with polyneuropathy and clinical symptoms outside the nervous system. The most common of these diseases is Friedreich ataxia, caused by mutation of the frataxin gene, but recent advances in genetic analysis have greatly broadened the ever-expanding number of causative genes to over 50. In this review, the clinical neurogenetics of the recessive cerebellar ataxias will be discussed, including updates on recently identified novel ataxia genes, advancements in unraveling disease-specific molecular pathogenesis leading to ataxia, potential treatments under development, technologic improvements in diagnostic testing such as clinical exome sequencing, and what the future holds for clinicians and geneticists.
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Affiliation(s)
- Brent L Fogel
- Program in Neurogenetics, Departments of Neurology and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States.
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6
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Urkasemsin G, Nielsen DM, Singleton A, Arepalli S, Hernandez D, Agler C, Olby NJ. Genetics of Hereditary Ataxia in Scottish Terriers. J Vet Intern Med 2017; 31:1132-1139. [PMID: 28556454 PMCID: PMC5508367 DOI: 10.1111/jvim.14738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/05/2017] [Accepted: 04/19/2017] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction. OBJECTIVE To identify chromosomal regions associated with hereditary ataxia in Scottish Terriers. ANIMALS One hundred and fifty-three Scottish Terriers were recruited through the Scottish Terrier Club of America. MATERIALS AND METHODS Prospective study. Dogs were classified as affected if they had slowly progressive cerebellar signs. When possible, magnetic resonance imaging and histopathological evaluation of the brain were completed as diagnostic aids. To identify genomic regions connected with the disease, genome-wide mapping was performed using both linkage- and association-based approaches. Pedigree evaluation and homozygosity mapping were also performed to examine mode of inheritance and to investigate the region of interest, respectively. RESULTS Linkage and genome-wide association studies in a cohort of Scottish Terriers both identified a region on CFA X strongly associated with the disease trait. Homozygosity mapping revealed a 4 Mb region of interest. Pedigree evaluation failed to identify the possible mode of inheritance due to the lack of complete litter information. CONCLUSION AND CLINICAL IMPORTANCE This finding suggests that further genetic investigation of the potential region of interest on CFA X should be considered in order to identify the causal mutation as well as develop a genetic test to eliminate the disease from this breed.
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Affiliation(s)
- G Urkasemsin
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - D M Nielsen
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC
| | - A Singleton
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD
| | - S Arepalli
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD
| | - D Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD
| | - C Agler
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - N J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC
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Elsayed LEO, Mohammed IN, Hamed AAA, Elseed MA, Johnson A, Mairey M, Mohamed HESA, Idris MN, Salih MAM, El-Sadig SM, Koko ME, Mohamed AYO, Raymond L, Coutelier M, Darios F, Siddig RA, Ahmed AKMA, Babai AMA, Malik HMO, Omer ZMBM, Mohamed EOE, Eltahir HB, Magboul NAA, Bushara EE, Elnour A, Rahim SMA, Alattaya A, Elbashir MI, Ibrahim ME, Durr A, Audhya A, Brice A, Ahmed AE, Stevanin G. Hereditary spastic paraplegias: identification of a novel SPG57 variant affecting TFG oligomerization and description of HSP subtypes in Sudan. Eur J Hum Genet 2016; 25:100-110. [PMID: 27601211 DOI: 10.1038/ejhg.2016.108] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 05/31/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022] Open
Abstract
Hereditary spastic paraplegias (HSP) are the second most common type of motor neuron disease recognized worldwide. We investigated a total of 25 consanguineous families from Sudan. We used next-generation sequencing to screen 74 HSP-related genes in 23 families. Linkage analysis and candidate gene sequencing was performed in two other families. We established a genetic diagnosis in six families with autosomal recessive HSP (SPG11 in three families and TFG/SPG57, SACS and ALS2 in one family each). A heterozygous mutation in a gene involved in an autosomal dominant HSP (ATL1/SPG3A) was also identified in one additional family. Six out of seven identified variants were novel. The c.64C>T (p.(Arg22Trp)) TFG/SPG57 variant (PB1 domain) is the second identified that underlies HSP, and we demonstrated its impact on TFG oligomerization in vitro. Patients did not present with visual impairment as observed in a previously reported SPG57 family (c.316C>T (p.(Arg106Cys)) in coiled-coil domain), suggesting unique contributions of the PB1 and coiled-coil domains in TFG complex formation/function and a possible phenotype correlation to variant location. Some families manifested marked phenotypic variations implying the possibility of modifier factors complicated by high inbreeding. Finally, additional genetic heterogeneity is expected in HSP Sudanese families. The remaining families might unravel new genes or uncommon modes of inheritance.
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Affiliation(s)
- Liena E O Elsayed
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL université, Paris, France.,University of Khartoum, Khartoum, Sudan
| | | | | | | | - Adam Johnson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Mathilde Mairey
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL université, Paris, France
| | | | - Mohamed N Idris
- University of Khartoum, Khartoum, Sudan.,Sudan Medical Council, Neurology, Sudan
| | - Mustafa A M Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Sarah M El-Sadig
- University of Khartoum, Khartoum, Sudan.,Department of Neurology, Soba University Hospital, Khartoum, Sudan
| | - Mahmoud E Koko
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Ashraf Y O Mohamed
- Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan
| | - Laure Raymond
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL université, Paris, France.,Department of genetics, APHP Pitié-Salpêtrière Hospital, Paris, France
| | - Marie Coutelier
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL université, Paris, France
| | - Frédéric Darios
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France
| | | | | | | | | | | | | | - Hanan B Eltahir
- Department of Biochemistry, El Imam EL Mahdi University, Kosti, Sudan
| | | | | | | | | | | | | | - Muntaser E Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Alexandra Durr
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France.,Department of genetics, APHP Pitié-Salpêtrière Hospital, Paris, France
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Alexis Brice
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France. .,Department of genetics, APHP Pitié-Salpêtrière Hospital, Paris, France.
| | - Ammar E Ahmed
- University of Khartoum, Khartoum, Sudan.,Sudan Medical Council, Neurology, Sudan
| | - Giovanni Stevanin
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Sorbonne Universités, UPMC Université Paris VI UMR_S1127, Paris, France. .,Ecole Pratique des Hautes Etudes, EPHE, PSL université, Paris, France. .,Department of genetics, APHP Pitié-Salpêtrière Hospital, Paris, France.
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Burns R, Majczenko K, Xu J, Peng W, Yapici Z, Dowling JJ, Li JZ, Burmeister M. Homozygous splice mutation in CWF19L1 in a Turkish family with recessive ataxia syndrome. Neurology 2014; 83:2175-82. [PMID: 25361784 PMCID: PMC4276403 DOI: 10.1212/wnl.0000000000001053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 09/02/2014] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To elucidate the genetic cause of a rare recessive ataxia presented by 2 siblings from a consanguineous Turkish family with a nonprogressive, congenital ataxia with mental retardation of unknown etiology. METHODS Whole-exome sequencing was combined with homozygosity mapping, linkage, and expression analysis to identify candidate genes, confirmed by Sanger sequencing. Reverse transcription-PCR and immunoblotting were used to determine the functional consequences of the gene variant. A zebrafish model was developed using morpholino-mediated knockdown. RESULTS We identified a homozygous mutation at the invariant +1 position (c.964+1G>A) in intron 9 of the CWF19L1 (complexed with cdc5 protein 19-like 1) gene. This mutation is absent in >6,500 European and African American individuals and 200 Turkish control DNAs. The mutation causes exon skipping, reduction in messenger RNA levels, and protein loss in cell lines of affected individuals. Morpholino-mediated knockdown in a zebrafish model demonstrates that loss of the evolutionarily highly conserved CWF19L1, whose normal biological function is unknown, alters cerebellar morphology and causes movement abnormalities. CONCLUSIONS Our results suggest that CWF19L1 mutations may be a novel cause of recessive ataxia with developmental delay. Our research may help with diagnosis, especially in Turkey, identify causes of other ataxias, and may lead to novel therapies.
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Affiliation(s)
- Randi Burns
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Karen Majczenko
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Jishu Xu
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Weiping Peng
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Zuhal Yapici
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - James J Dowling
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Jun Z Li
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada
| | - Margit Burmeister
- From the Program in Cellular and Molecular Biology (R.B., M.B.), Molecular & Behavioral Neuroscience Institute (R.B., K.M., M.B.), Departments of Human Genetics (J.X., W.P., J.Z.L., M.B.), Neurology (J.J.D.), Pediatrics (J.J.D.), and Psychiatry (M.B.), University of Michigan Medical Center, Ann Arbor; and Department of Neurology (Z.Y.), Division of Child Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey. J.J.D. is currently affiliated with the Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Departments of Pediatrics and Molecular Genetics, University of Toronto, Canada.
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Koutsis G, Kladi A, Karadima G, Houlden H, Wood NW, Christodoulou K, Panas M. Friedreich's ataxia and other hereditary ataxias in Greece: An 18-year perspective. J Neurol Sci 2014; 336:87-92. [DOI: 10.1016/j.jns.2013.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/18/2013] [Accepted: 10/07/2013] [Indexed: 12/20/2022]
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10
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Eksi R, Li HD, Menon R, Wen Y, Omenn GS, Kretzler M, Guan Y. Systematically differentiating functions for alternatively spliced isoforms through integrating RNA-seq data. PLoS Comput Biol 2013; 9:e1003314. [PMID: 24244129 PMCID: PMC3820534 DOI: 10.1371/journal.pcbi.1003314] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 09/19/2013] [Indexed: 12/13/2022] Open
Abstract
Integrating large-scale functional genomic data has significantly accelerated our understanding of gene functions. However, no algorithm has been developed to differentiate functions for isoforms of the same gene using high-throughput genomic data. This is because standard supervised learning requires ‘ground-truth’ functional annotations, which are lacking at the isoform level. To address this challenge, we developed a generic framework that interrogates public RNA-seq data at the transcript level to differentiate functions for alternatively spliced isoforms. For a specific function, our algorithm identifies the ‘responsible’ isoform(s) of a gene and generates classifying models at the isoform level instead of at the gene level. Through cross-validation, we demonstrated that our algorithm is effective in assigning functions to genes, especially the ones with multiple isoforms, and robust to gene expression levels and removal of homologous gene pairs. We identified genes in the mouse whose isoforms are predicted to have disparate functionalities and experimentally validated the ‘responsible’ isoforms using data from mammary tissue. With protein structure modeling and experimental evidence, we further validated the predicted isoform functional differences for the genes Cdkn2a and Anxa6. Our generic framework is the first to predict and differentiate functions for alternatively spliced isoforms, instead of genes, using genomic data. It is extendable to any base machine learner and other species with alternatively spliced isoforms, and shifts the current gene-centered function prediction to isoform-level predictions. In mammalian genomes, a single gene can be alternatively spliced into multiple isoforms which greatly increase the functional diversity of the genome. In the human, more than 95% of multi-exon genes undergo alternative splicing. It is hard to computationally differentiate the functions for the splice isoforms of the same gene, because they are almost always annotated with the same functions and share similar sequences. In this paper, we developed a generic framework to identify the ‘responsible’ isoform(s) for each function that the gene carries out, and therefore predict functional assignment on the isoform level instead of on the gene level. Within this generic framework, we implemented and evaluated several related algorithms for isoform function prediction. We tested these algorithms through both computational evaluation and experimental validation of the predicted ‘responsible’ isoform(s) and the predicted disparate functions of the isoforms of Cdkn2a and of Anxa6. Our algorithm represents the first effort to predict and differentiate isoforms through large-scale genomic data integration.
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Affiliation(s)
- Ridvan Eksi
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Hong-Dong Li
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Rajasree Menon
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yuchen Wen
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Gilbert S. Omenn
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (GSO); (MK); (YG)
| | - Matthias Kretzler
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (GSO); (MK); (YG)
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (GSO); (MK); (YG)
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Glicksman S, Borgen C, Blackstein M, Gordon A, Hanon I, Kusin D, Leibowitz B, Halle J. A thematic review of scientific and family interests in Canavan Disease: where are the developmentalists? JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2013; 57:815-825. [PMID: 22676184 DOI: 10.1111/j.1365-2788.2012.01576.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Canavan Disease is a degenerative neurological condition resulting in a spongy deterioration of the brain. Much research has been conducted by the medical community regarding this condition, but little research can be found in the psychological literature. METHOD A review of the scientific literature related to Canavan Disease using the Psychinfo and PubMed databases was conducted covering a 5-year span from 2006 through 2011. Concurrently, a review of parent initiated topics found on the most popular Canavan Disease Internet discussion board was conducted for comparison purposes. RESULTS When comparing the topics discussed and information sought among parents with the themes noted in the extant scientific literature, researchers found an exceedingly small overlap between the two communities of interest. In the scientific literature, published research on Canavan Disease focused on three areas: the biochemistry of Canavan Disease, diagnosis and genetic counselling, and clinical therapeutic approaches in Canavan Disease. Of the 42 unique topics raised on a popular Internet discussion board, however, only three (7%) fell into the category of diagnosis and genetic counselling, none (0%) fell into the category of the biochemistry of Canavan Disease, and four fell into the category of clinical therapeutic approaches in Canavan Disease (10%). Of the four posts addressing clinical therapeutic approaches to Canavan Disease, only one post truly overlapped with the topics addressed by the scientific community. Worded differently, while these three categories comprise 100% of the extant scientific literature regarding Canavan Disease, they comprise only 17% of the parent-raised topics. The remaining 83% of parent-raised topics addressed concerns not currently being focusing upon by the scientific community, namely, non-medical practical issues, information regarding specific characteristics of Canavan Disease, non-medical developmental and quality of life issues, and day-to-day developmental and medical concerns. CONCLUSION By comparing the extant literature on Canavan Disease with the topics of interest raised by parents and caregivers, it seems clear that there is a significant 'underlap' of topics raised by these two communities of interest, one that may reflect a lack of sensitivity on the part of the scientific community to meet the needs of this population of knowledge seekers. It is the suggestion of these authors that developmental psychology may be the appropriate scientific field within which to address this need and fill this gap in the current literature.
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Abstract
The autosomal dominant spinocerebellar ataxias are a diverse and clinically heterogeneous group of disorders characterized by degeneration and dysfunction of the cerebellum and its associated pathways. Clinical and diagnostic evaluation can be challenging because of phenotypic overlap among causes, and a stratified and systematic approach is essential. Recent advances include the identification of additional genes causing dominant genetic ataxia, a better understanding of cellular pathogenesis in several disorders, the generation of new disease models that may stimulate development of new therapies, and the use of new DNA sequencing technologies, including whole-exome sequencing, to improve diagnosis.
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Fogel BL, Vickrey BG, Walton-Wetzel J, Lieber E, Browner CH. Utilization of genetic testing prior to subspecialist referral for cerebellar ataxia. Genet Test Mol Biomarkers 2013; 17:588-94. [PMID: 23725007 DOI: 10.1089/gtmb.2013.0005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE To evaluate the utilization of laboratory testing in the diagnosis of cerebellar ataxia, including the completeness of initial standard testing for acquired causes, the early use of genetic testing, and associated clinical and nonclinical factors, among a cohort referred for subspecialty consultation. METHODS Data were abstracted from records of 95 consecutive ataxia patients referred to one neurogenetics subspecialist from 2006-2010 and linked to publicly available data on characteristics of referral clinicians. Multivariable logistic and linear regression models were used to analyze unique associations of clinical and nonclinical factors with laboratory investigation of acquired causes and with early genetic testing prior to referral. RESULTS At referral, 27 of 95 patients lacked evidence of any of 14 laboratory studies suggested for initial work-up of an acquired cause for ataxia (average number of tests=4.5). In contrast, 92% of patients had undergone brain magnetic resonance imaging prior to referral. Overall, 41.1% (n=39) had genetic testing prior to referral; there was no association between family history of ataxia and obtaining genetic testing prior to referral (p=0.39). The level of early genetic testing was 31.6%, primarily due to genetic testing despite an incomplete laboratory evaluation for acquired causes and no family history. A positive family history was consistently associated with less extensive laboratory testing (p=0.004), and referral by a neurologist was associated with higher levels of early genetic testing. CONCLUSIONS Among consecutive referrals to a single center, a substantial proportion of sporadic cases had genetic testing without evidence of a work-up for acquired causes. Better strategies to guide decision making and subspecialty referrals in rare neurologic disorders are needed, given the cost and consequences of genetic testing.
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Affiliation(s)
- Brent L Fogel
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California 90095-1553, USA
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Vedolin L, Gonzalez G, Souza CF, Lourenço C, Barkovich AJ. Inherited cerebellar ataxia in childhood: a pattern-recognition approach using brain MRI. AJNR Am J Neuroradiol 2013; 34:925-34, S1-2. [PMID: 22595899 PMCID: PMC7964648 DOI: 10.3174/ajnr.a3055] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ataxia is the principal symptom of many common neurologic diseases in childhood. Ataxias caused by dysfunction of the cerebellum occur in acute, intermittent, and progressive disorders. Most of the chronic progressive processes are secondary to degenerative and metabolic diseases. In addition, congenital malformation of the midbrain and hindbrain can also be present, with posterior fossa symptoms related to ataxia. Brain MR imaging is the most accurate imaging technique to investigate these patients, and imaging abnormalities include size, shape, and/or signal of the brain stem and/or cerebellum. Supratentorial and cord lesions are also common. This review will discuss a pattern-recognition approach to inherited cerebellar ataxia in childhood. The purpose is to provide a comprehensive discussion that ultimately could help neuroradiologists better manage this important topic in pediatric neurology.
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Affiliation(s)
- L Vedolin
- Neuroradiology Section, Hospital Moinhos de Vento, Porto Alegre, Brazil.
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15
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Genetic Variation in Ataxia Gene ATXN7 Influences Cerebellar Grey Matter Volume in Healthy Adults. THE CEREBELLUM 2012; 12:390-5. [DOI: 10.1007/s12311-012-0423-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Guan Y, Gorenshteyn D, Burmeister M, Wong AK, Schimenti JC, Handel MA, Bult CJ, Hibbs MA, Troyanskaya OG. Tissue-specific functional networks for prioritizing phenotype and disease genes. PLoS Comput Biol 2012; 8:e1002694. [PMID: 23028291 PMCID: PMC3459891 DOI: 10.1371/journal.pcbi.1002694] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 08/02/2012] [Indexed: 12/16/2022] Open
Abstract
Integrated analyses of functional genomics data have enormous potential for identifying phenotype-associated genes. Tissue-specificity is an important aspect of many genetic diseases, reflecting the potentially different roles of proteins and pathways in diverse cell lineages. Accounting for tissue specificity in global integration of functional genomics data is challenging, as “functionality” and “functional relationships” are often not resolved for specific tissue types. We address this challenge by generating tissue-specific functional networks, which can effectively represent the diversity of protein function for more accurate identification of phenotype-associated genes in the laboratory mouse. Specifically, we created 107 tissue-specific functional relationship networks through integration of genomic data utilizing knowledge of tissue-specific gene expression patterns. Cross-network comparison revealed significantly changed genes enriched for functions related to specific tissue development. We then utilized these tissue-specific networks to predict genes associated with different phenotypes. Our results demonstrate that prediction performance is significantly improved through using the tissue-specific networks as compared to the global functional network. We used a testis-specific functional relationship network to predict genes associated with male fertility and spermatogenesis phenotypes, and experimentally confirmed one top prediction, Mbyl1. We then focused on a less-common genetic disease, ataxia, and identified candidates uniquely predicted by the cerebellum network, which are supported by both literature and experimental evidence. Our systems-level, tissue-specific scheme advances over traditional global integration and analyses and establishes a prototype to address the tissue-specific effects of genetic perturbations, diseases and drugs. Tissue specificity is an important aspect of many genetic diseases, reflecting the potentially different roles of proteins and pathways in diverse cell lineages. We propose an effective strategy to model tissue-specific functional relationship networks in the laboratory mouse. We integrated large scale genomics datasets as well as low-throughput tissue-specific expression profiles to estimate the probability that two proteins are co-functioning in the tissue under study. These networks can accurately reflect the diversity of protein functions across different organs and tissue compartments. By computationally exploring the tissue-specific networks, we can accurately predict novel phenotype-related gene candidates. We experimentally confirmed a top candidate gene, Mybl1, to affect several male fertility phenotypes, predicted based on male-reproductive system-specific networks and we predicted candidates related to a rare genetic disease ataxia, which are supported by experimental and literature evidence. The above results demonstrate the power of modeling tissue-specific dynamics of co-functionality through computational approaches.
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Affiliation(s)
- Yuanfang Guan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Dmitriy Gorenshteyn
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Margit Burmeister
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Molecular & Behavioral Neuroscience Institution, Department of Psychiatry, and Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Aaron K. Wong
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - John C. Schimenti
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Mary Ann Handel
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Carol J. Bult
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Matthew A. Hibbs
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Trinity University, Computer Science Department, San Antonio, Texas, United States of America
- * E-mail: (MAH); (OGT)
| | - Olga G. Troyanskaya
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Computer Science, Princeton University, Princeton, New Jersey, United States of America
- * E-mail: (MAH); (OGT)
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Terracciano A, Renaldo F, Zanni G, D'Amico A, Pastore A, Barresi S, Valente EM, Piemonte F, Tozzi G, Carrozzo R, Valeriani M, Boldrini R, Mercuri E, Santorelli FM, Bertini E. The use of muscle biopsy in the diagnosis of undefined ataxia with cerebellar atrophy in children. Eur J Paediatr Neurol 2012; 16:248-56. [PMID: 21873089 PMCID: PMC3341568 DOI: 10.1016/j.ejpn.2011.07.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 07/21/2011] [Accepted: 07/24/2011] [Indexed: 01/07/2023]
Abstract
Childhood cerebellar ataxias, and particularly congenital ataxias, are heterogeneous disorders and several remain undefined. We performed a muscle biopsy in patients with congenital ataxia and children with later onset undefined ataxia having neuroimaging evidence of cerebellar atrophy. Significant reduced levels of Coenzyme Q10 (COQ10) were found in the skeletal muscle of 9 out of 34 patients that were consecutively screened. A mutation in the ADCK3/Coq8 gene (R347X) was identified in a female patient with ataxia, seizures and markedly reduced COQ10 levels. In a 2.5-years-old male patient with non syndromic congenital ataxia and autophagic vacuoles in the muscle biopsy we identified a homozygous nonsense mutation R111X mutation in SIL1 gene, leading to early diagnosis of Marinesco-Sjogren syndrome. We think that muscle biopsy is a valuable procedure to improve diagnostic assesement in children with congenital ataxia or other undefined forms of later onset childhood ataxia associated to cerebellar atrophy at MRI.
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Affiliation(s)
- Alessandra Terracciano
- Unit of Neuromuscular and Neurodegenerative Disorders, Lab of Molecular Medicine, Dept of Neuroscience, Bambino Gesù Childrens Hospital, Rome, Italy
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18
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Benini R, Ben Amor IM, Shevell MI. Clinical clues to differentiating inherited and noninherited etiologies of childhood ataxias. J Pediatr 2012; 160:152-7. [PMID: 21840535 DOI: 10.1016/j.jpeds.2011.06.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 04/18/2011] [Accepted: 06/22/2011] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To identify clinical features at presentation that differentiate inherited and noninherited etiologies of childhood ataxias. STUDY DESIGN A retrospective chart review analysis was conducted on 167 patients evaluated in neurology outpatient clinics for ataxia or ataxia-related symptoms. The frequency of clinical features, determined a priori, in the 2 groups was compared. RESULTS A larger proportion of patients were diagnosed with a nongenetic cause than with a genetic cause (89% [148 patients] vs 11% [19 patients]). The majority of patients in the nongenetic group (56% [83/148]) presented early for medical evaluation, compared with 31% (6/19) in the genetic group. Consanguinity (16% vs 4%) and positive family history (16% vs 2%) were more frequent in the genetic group. Presenting symptoms of abnormal gait (95% vs 57%) and muscle weakness (47% vs 8%), including physical findings of abnormal muscle tone (63% vs 32%), abnormal reflexes (63% vs 16%), clonus (26% vs 9%), dysmetria (32% vs 5%), pes cavus (21% vs 1%), sensory deficits (16% vs 0%), and nonneurologic musculoskeletal abnormalities (58% vs 19%), were more prevalent in the genetic group. CONCLUSION Certain clinical features can help delineate between inherited and noninherited causes of childhood ataxia and thus guide physicians in the targeted evaluation of patients.
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Affiliation(s)
- Ruba Benini
- Montreal Children's Hospital-McGill University Health Center, Montreal, Quebec, Canada
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Hypergonadotropic hypogonadism, progressive early-onset spinocerebellar ataxia, and late-onset sensorineural hearing loss: case report and literature review. Balkan J Med Genet 2011; 14:77-88. [PMID: 24052715 PMCID: PMC3776697 DOI: 10.2478/v10034-011-0050-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association of ataxia, hypergonadotropic hypogonadism and hearing loss is extremely rare. Considerable heterogeneity exists in the literature of the neurological manifestations, age of onset, clinical severity and associated abnormalities. We describe a 24-year-old woman with secondary hypergonadotropic amenorrhea, early-onset progressive spinocerebellar ataxia (SCA), late-onset sensorineural hearing loss and normal intelligence and compare it with reported cases.
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20
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Chamova T, Florez L, Guergueltcheva V, Raycheva M, Kaneva R, Lochmüller H, Kalaydjieva L, Tournev I. ANO10 c.1150_1151del is a founder mutation causing autosomal recessive cerebellar ataxia in Roma/Gypsies. J Neurol 2011; 259:906-11. [PMID: 22008874 DOI: 10.1007/s00415-011-6276-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Revised: 09/29/2011] [Accepted: 10/01/2011] [Indexed: 10/16/2022]
Abstract
A recent report (Vermeer et al. in Am J Hum Genet 87:813-819, 2010) implicated for the first time the ANO10 gene in the genetic basis of autosomal recessive cerebellar ataxias. One of the three described families were Roma/Gypsies from Serbia, where the affected individuals were homozygous for the truncating p.Leu384fs mutation and displayed distinct phenotypic features (Vermeer et al. in Am J Hum Genet 87:813-819, 2010). Based on the history and population genetics of the Roma/Gypsies, we hypothesised that p.Leu384fs could be another founder mutation in this population, whose identification in a larger number of genetically homogeneous patients will contribute to defining the phenotypic spectrum of the disorder. Here, we describe additional patients from neighbouring Bulgaria, outlining invariable ANO10-ataxia features and confirming global intellectual decline as part of the phenotype resulting from complete Anactomin 10 deficit.
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Affiliation(s)
- Teodora Chamova
- Clinic of Neurology, University Hospital Alexandrovska, Sofia, Bulgaria
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21
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Affiliation(s)
- Leslie J Cloud
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
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22
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Cagnoli C, Stevanin G, Brussino A, Barberis M, Mancini C, Margolis RL, Holmes SE, Nobili M, Forlani S, Padovan S, Pappi P, Zaros C, Leber I, Ribai P, Pugliese L, Assalto C, Brice A, Migone N, Dürr A, Brusco A. Missense mutations in the AFG3L2 proteolytic domain account for ∼1.5% of European autosomal dominant cerebellar ataxias. Hum Mutat 2011; 31:1117-24. [PMID: 20725928 DOI: 10.1002/humu.21342] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Spinocerebellar ataxia type 28 is an autosomal dominant form of cerebellar ataxia (ADCA) caused by mutations in AFG3L2, a gene that encodes a subunit of the mitochondrial m-AAA protease. We screened 366 primarily Caucasian ADCA families, negative for the most common triplet expansions, for point mutations in AFG3L2 using DHPLC. Whole-gene deletions were excluded in 300 of the patients, and duplications were excluded in 129 patients. We found six missense mutations in nine unrelated index cases (9/366, 2.6%): c.1961C>T (p.Thr654Ile) in exon 15, c.1996A>G (p.Met666Val), c.1997T>G (p.Met666Arg), c.1997T>C (p.Met666Thr), c.2011G>A (p.Gly671Arg), and c.2012G>A (p.Gly671Glu) in exon 16. All mutated amino acids were located in the C-terminal proteolytic domain. In available cases, we demonstrated the mutations segregated with the disease. Mutated amino acids are highly conserved, and bioinformatic analysis indicates the substitutions are likely deleterious. This investigation demonstrates that SCA28 accounts for ∼3% of ADCA Caucasian cases negative for triplet expansions and, in extenso, to ∼1.5% of all ADCA. We further confirm both the involvement of AFG3L2 gene in SCA28 and the presence of a mutational hotspot in exons 15-16. Screening for SCA28, is warranted in patients who test negative for more common SCAs and present with a slowly progressive cerebellar ataxia accompanied by oculomotor signs.
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Affiliation(s)
- Claudia Cagnoli
- Department of Genetics, Biology and Biochemistry, University of Torino, Torino, Italy
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23
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Karalis A, Tischkowitz M, Millington G. Dermatological manifestations of inherited cancer syndromes in children. Br J Dermatol 2011; 164:245-56. [DOI: 10.1111/j.1365-2133.2010.10100.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Verhoeven WM, Egger JI, Kremer BP, de Pont BJ, Marcelis CL. Recurrent major depression, ataxia, and cardiomyopathy: association with a novel POLG mutation? Neuropsychiatr Dis Treat 2011; 7:293-6. [PMID: 21654874 PMCID: PMC3101889 DOI: 10.2147/ndt.s20153] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Indexed: 12/23/2022] Open
Abstract
At present, more than 100 disease mutations in mitochondrial DNA polymerase γ (POLG) have been indentified that are causally related to an array of neuropsychiatric diseases affecting multiple systems. Both autosomal recessive and autosomal dominant forms can be delineated, the latter being associated with Parkinsonism and depressive or psychotic syndromes. In this report, a middle-aged female patient with recurrent major depression with melancholic features, slowly progressive gait instability, and dilated cardiomyopathy is described. Detailed diagnostic evaluation was performed to elucidate the supposed relationship between ataxia, cardiomyopathy, and major depression with melancholia. After extensive genetic and metabolic investigation, a nucleotide substitution c.2207 A→G in the POLG gene resulting in amino acid change Asn 736Ser in exon 13 was demonstrated. This mutation was considered to be compatible with a mitochondrial disorder and implicated in the pathophysiology of the neuropsychiatric syndrome. It is concluded that this novel POLG mutation forms the most parsimonious etiological explanation for the here-described combination of ataxia, major depression, and cardiomyopathy. Therefore, in patients with a complex neuropsychiatric presentation, extensive diagnostic analysis is warranted, including the search for mitochondriopathies, in order to avoid unnecessary delay of adequate treatment.
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Affiliation(s)
- Willem Ma Verhoeven
- Vincent van Gogh Institute for Psychiatry, Centre of Excellence for Neuropsychiatry, Venray, The Netherlands
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Revuelta GJ, Wilmot GR. Therapeutic Interventions in the Primary Hereditary Ataxias. Curr Treat Options Neurol 2010; 12:257-73. [DOI: 10.1007/s11940-010-0075-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
Mitochondrial disorders (MIDs) are an increasingly recognized condition. The second most frequently affected organ in MIDs is the central nervous system. One of the most prevalent clinical CNS manifestations of MIDs is ataxia. Ataxia may be even the dominant manifestation of a MID. This is why certain MIDs should be included in the classification of heredoataxias or at least considered as differentials of classical heredoataxias. MIDs due to mutations of the mitochondrial DNA, which develop ataxia include the MERRF, NARP, MILS, or KSS syndrome. More rarely, ataxia may be a feature of MELAS, LHON, PS, MIDD, or MSL. MIDs due to mutations of the nuclear DNA, which develop ataxia include LS, SANDO, SCAE, AHS, XSLA/A, IOSCA, MIRAS, MEMSA, or LBSL syndrome. More rarely ataxia can be found in AD-CPEO, AR-CPEO, MNGIE, DIDMOAD, CoQ-deficiency, ADOAD, DCMA, or PDC-deficiency. MIDs most frequently associated with ataxia are the non-syndromic MIDs. Syndromic and non-syndromic MIDs with ataxia should be delineated from classical heredoataxias to initiate appropriate symptomatic or supportive treatment.
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