101
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Iourov IY, Vorsanova SG, Yurov YB, Bertrand T. VIII World Rett Syndrome Congress & Symposium of rare diseases, Kazan, Russia. Mol Cytogenet 2018; 11:61. [PMID: 30603047 PMCID: PMC6304760 DOI: 10.1186/s13039-018-0412-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 12/11/2018] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND VIII World Rett Syndrome Congress & Symposium of Rare Diseases was held in Kazan, Russia from 13 to 17 May 2016. Although it has been a while since the event, specific problems highlighted by the contributors to the scientific program have stood the test of time. The Symposium of Rare Diseases has shown that studying Rett syndrome provides clues on molecular and cellular mechanisms for a variety of rare genetic/genomic disorders. Moreover, rare diseases associated with Rett-syndrome-like phenotype or MECP2 mutations/copy number variations have been thoroughly covered by a number of contributors. In this respect, we have found that a review dedicated to the scientific program of the VIII World Rett Syndrome Congress & Symposium of Rare Diseases could be an important addition to current literature. CONCLUSION Taking the opportunity to review the World Rett Syndrome Congress & Symposium of Rare Diseases at Kazan, we have made an attempt to describe a number of achievements and developments in the field of studying Rett syndrome and rare diseases in Russia. Furthermore, chromosomal abnormalities/disorders have been considered in the rare disease context. Such approach to chromosomal abnormalities/disorders has been found to be rather new for an appreciable part of international researchers and health care providers. We do hope that this congress review may be helpful not only for those who are interested in local development of research and management of rare genetic disorders, but also for international researchers and clinical community of rare disease specialists.
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Affiliation(s)
- Ivan Y. Iourov
- Mental Health Research Center, 117152 Moscow, Russia
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University, Ministry of Health of Russian Federation, 125412 Moscow, Russia
- Department of Medical Genetics, Russian Medical Academy of Continuous Professional Education, Moscow, 125993 Russia
| | - Svetlana G. Vorsanova
- Mental Health Research Center, 117152 Moscow, Russia
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University, Ministry of Health of Russian Federation, 125412 Moscow, Russia
| | - Yuri B. Yurov
- Mental Health Research Center, 117152 Moscow, Russia
- Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University, Ministry of Health of Russian Federation, 125412 Moscow, Russia
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102
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McLachlan F, Sires AM, Abbott CM. The role of translation elongation factor eEF1 subunits in neurodevelopmental disorders. Hum Mutat 2018; 40:131-141. [PMID: 30370994 DOI: 10.1002/humu.23677] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/16/2018] [Accepted: 10/23/2018] [Indexed: 11/06/2022]
Abstract
The multi-subunit eEF1 complex plays a crucial role in de novo protein synthesis. The central functional component of the complex is eEF1A, which occurs as two independently encoded variants with reciprocal expression patterns: whilst eEF1A1 is widely expressed, eEF1A2 is found only in neurons and muscle. Heterozygous mutations in the gene encoding eEF1A2, EEF1A2, have recently been shown to cause epilepsy, autism, and intellectual disability. The remaining subunits of the eEF1 complex, eEF1Bα, eEF1Bδ, eEF1Bγ, and valyl-tRNA synthetase (VARS), together form the GTP exchange factor for eEF1A and are ubiquitously expressed, in keeping with their housekeeping role. However, mutations in the genes encoding these subunits EEF1B2 (eEF1Bα), EEF1D (eEF1Bδ), and VARS (valyl-tRNA synthetase) have also now been identified as causes of neurodevelopmental disorders. In this review, we describe the mutations identified so far in comparison with the degree of normal variation in each gene, and the predicted consequences of the mutations on the functions of the proteins and their isoforms. We discuss the likely effects of the mutations in the context of the role of protein synthesis in neuronal development.
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Affiliation(s)
- Fiona McLachlan
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
| | - Anna Martinez Sires
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
| | - Catherine M Abbott
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, UK
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103
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Cargnin F, Kwon JS, Katzman S, Chen B, Lee JW, Lee SK. FOXG1 Orchestrates Neocortical Organization and Cortico-Cortical Connections. Neuron 2018; 100:1083-1096.e5. [PMID: 30392794 DOI: 10.1016/j.neuron.2018.10.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/16/2018] [Accepted: 10/05/2018] [Indexed: 12/31/2022]
Abstract
The hallmarks of FOXG1 syndrome, which results from mutations in a single FOXG1 allele, include cortical atrophy and corpus callosum agenesis. However, the etiology for these structural deficits and the role of FOXG1 in cortical projection neurons remain unclear. Here we demonstrate that Foxg1 in pyramidal neurons plays essential roles in establishing cortical layers and the identity and axon trajectory of callosal projection neurons. The neuron-specific actions of Foxg1 are achieved by forming a transcription complex with Rp58. The Foxg1-Rp58 complex directly binds and represses Robo1, Slit3, and Reelin genes, the key regulators of callosal axon guidance and neuronal migration. We also found that inactivation of one Foxg1 allele specifically in cortical neurons was sufficient to cause cerebral cortical hypoplasia and corpus callosum agenesis. Together, this study reveals a novel gene regulatory pathway that specifies neuronal characteristics during cerebral cortex development and sheds light on the etiology of FOXG1 syndrome. VIDEO ABSTRACT.
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Affiliation(s)
- Francesca Cargnin
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ji-Sun Kwon
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Sol Katzman
- Genomics Institute, University of California, Santa Cruz, CA 95064, USA
| | - Bin Chen
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Jae W Lee
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Soo-Kyung Lee
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA.
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104
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Yates TM, Suri M, Desurkar A, Lesca G, Wallgren-Pettersson C, Hammer TB, Raghavan A, Poulat AL, Møller RS, Thuresson AC, Balasubramanian M. SLC35A2-related congenital disorder of glycosylation: Defining the phenotype. Eur J Paediatr Neurol 2018; 22:1095-1102. [PMID: 30194038 DOI: 10.1016/j.ejpn.2018.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/10/2018] [Accepted: 08/19/2018] [Indexed: 12/01/2022]
Abstract
We aim to further delineate the phenotype associated with pathogenic variants in the SLC35A2 gene, and review all published literature to-date. This gene is located on the X chromosome and encodes a UDP-galactose transporter. Pathogenic variants in SLC35A2 cause a congenital disorder of glycosylation. The condition is rare, and less than twenty patients have been reported to-date. The phenotype is complex and has not been fully defined. Here, we present a series of five patients with de novo pathogenic variants in SLC35A2. The patients' phenotype includes developmental and epileptic encephalopathy with hypsarrhythmia, facial dysmorphism, severe intellectual disability, skeletal abnormalities, congenital cardiac disease and cortical visual impairment. Developmental and epileptic encephalopathy with hypsarrhythmia is present in most patients with SLC35A2 variants, and is drug-resistant in the majority of cases. Adrenocorticotropic hormone therapy may achieve partial or complete remission of seizures, but the effect is usually temporary. Isoelectric focusing of transferrins may be normal after infancy, therefore a congenital disorder of glycosylation should still be considered as a diagnosis in the presence of a suggestive phenotype. We also provide evidence that cortical visual impairment is part of the phenotypic spectrum.
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Affiliation(s)
- T Michael Yates
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, UK
| | - Archana Desurkar
- Department of Paediatric Neurology, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Gaetan Lesca
- Hospices Civils de Lyon, Service de Génétique, CHU de Lyon, Lyon, France
| | - Carina Wallgren-Pettersson
- Department of Medical and Clinical Genetics, University of Helsinki and the Folkhaelsan Institute of Genetics, Helsinki, Finland
| | - Trine B Hammer
- The Danish Epilepsy Center Filadelfia, Dianalund, Denmark
| | - Ashok Raghavan
- Department of Radiology, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Anne-Lise Poulat
- Hospices Civils de Lyon, Service de Génétique, CHU de Lyon, Lyon, France
| | - Rikke S Møller
- The Danish Epilepsy Center Filadelfia, Dianalund, Denmark; Institute for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Ann-Charlotte Thuresson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory Uppsala, Uppsala University, Uppsala, Sweden
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK; Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, UK.
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105
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Schirwani S, McConnell V, Willoughby J, Balasubramanian M. Exploring the association between SRPX2 variants and neurodevelopment: How causal is it? Gene 2018; 685:50-54. [PMID: 30393191 DOI: 10.1016/j.gene.2018.10.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 09/15/2018] [Accepted: 10/24/2018] [Indexed: 12/23/2022]
Abstract
The SRPX2 gene (Sushi-repeat-containing protein, X-linked, 2, OMIM*300642), located on Xq22.1, encodes a secreted protein that is highly expressed in neurons of cerebral cortex. SRPX2 was first implicated in neurodevelopment, learning and rolandic seizure when two patients with potentially pathogenic variants, c.980A>G (p.Asn327Ser) and c.215A>C (p.Tyr72Ser), in SRPX2 gene were identified. Subsequent experimental studies demonstrated that SRPX2 is needed for vocalization and synapse formation in mice, and that both silencing SRPX2 and injecting (p.Asn327Ser) in mouse models results in alteration in neuronal migration in cerebral cortex and epilepsy. A number of studies demonstrated that SRPX2 interacts with FOXP2 (Foxhead box protein P2), a gene responsible for speech and language disorder, and that FoxP2 controls timing and level of expression of SRPX2. Despite the supportive evidence for the role of SRPX2 in speech and language development and disorders, there are questions over its definitive association with neurodevelopmental disorders and epilepsy. In this paper, the role of SRPX2 as one in a network of many genes involved in speech and language is discussed. The goal of this paper is to examine the role of SRPX2 variants through describing two patients with potentially pathogenic variants in SRPX2, c.751G>C (p.Ala251Pro) and c.762G>T (p.Lys254Asn) presenting with language and motor delay, intellectual disability as well as congenital anomalies. We explore the contribution of SRPX2 variants to clinical phenotype in our patients and conclude that these variants at least partially explain the phenotype. Further studies are necessary to establish and confirm the association between SRPX2 and neurodevelopment particularly speech and language development.
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Affiliation(s)
- Schaida Schirwani
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Vivienne McConnell
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, Northern Ireland BT9 7AB, UK
| | - Josh Willoughby
- Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, UK
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- DDD Study, Welcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Meena Balasubramanian
- Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, UK; Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, UK.
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106
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Lance EI, Kronenbuerger M, Cohen JS, Furmanski O, Singer HS, Fatemi A. Successful treatment of choreo-athetotic movements in a patient with an EEF1A2 gene variant. SAGE Open Med Case Rep 2018; 6:2050313X18807622. [PMID: 30377530 PMCID: PMC6202747 DOI: 10.1177/2050313x18807622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/25/2018] [Indexed: 01/26/2023] Open
Abstract
Pathogenic variants in EEF1A2, a gene encoding a eukaryotic translation elongation factor, have been previously reported in pediatric cases of epileptic encephalopathy and intellectual disability. We report a case of a 17-year-old male with a prior history of epilepsy, autism, intellectual disability, and the abrupt onset of choreo-athetotic movements. The patient was diagnosed with an EEF1A2 variant by whole exome sequencing. His movement disorder responded dramatically to treatment with tetrabenazine. To the best of our knowledge, this is the first report of successful treatment of a hyperkinetic movement disorder in the setting of EEF1A2 mutation. A trial with tetrabenazine should be considered in cases with significant choreoathetosis.
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Affiliation(s)
- Eboni I Lance
- Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Martin Kronenbuerger
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology, University Medicine Greifswald, Greifswald, Germany
| | - Julie S Cohen
- Hugo W. Moser Research Institute at Kennedy Krieger, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Orion Furmanski
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University, Bethesda, MD, USA.,Department of Anatomy, Physiology and Genetics, School of Medicine, Uniformed Services University, Bethesda, MD, USA
| | - Harvey S Singer
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ali Fatemi
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.,Hugo W. Moser Research Institute at Kennedy Krieger, Kennedy Krieger Institute, Baltimore, MD, USA
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107
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Evers MM, Miniarikova J, Juhas S, Vallès A, Bohuslavova B, Juhasova J, Skalnikova HK, Vodicka P, Valekova I, Brouwers C, Blits B, Lubelski J, Kovarova H, Ellederova Z, van Deventer SJ, Petry H, Motlik J, Konstantinova P. AAV5-miHTT Gene Therapy Demonstrates Broad Distribution and Strong Human Mutant Huntingtin Lowering in a Huntington's Disease Minipig Model. Mol Ther 2018; 26:2163-2177. [PMID: 30007561 PMCID: PMC6127509 DOI: 10.1016/j.ymthe.2018.06.021] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 02/07/2023] Open
Abstract
Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin gene. Previously, we showed strong huntingtin reduction and prevention of neuronal dysfunction in HD rodents using an engineered microRNA targeting human huntingtin, delivered via adeno-associated virus (AAV) serotype 5 vector with a transgene encoding an engineered miRNA against HTT mRNA (AAV5-miHTT). One of the challenges of rodents as a model of neurodegenerative diseases is their relatively small brain, making successful translation to the HD patient difficult. This is particularly relevant for gene therapy approaches, where distribution achieved upon local administration into the parenchyma is likely dependent on brain size and structure. Here, we aimed to demonstrate the translation of huntingtin-lowering gene therapy to a large-animal brain. We investigated the feasibility, efficacy, and tolerability of one-time intracranial administration of AAV5-miHTT in the transgenic HD (tgHD) minipig model. We detected widespread dose-dependent distribution of AAV5-miHTT throughout the tgHD minipig brain that correlated with the engineered microRNA expression. Both human mutant huntingtin mRNA and protein were significantly reduced in all brain regions transduced by AAV5-miHTT. The combination of widespread vector distribution and extensive huntingtin lowering observed with AAV5-miHTT supports the translation of a huntingtin-lowering gene therapy for HD from preclinical studies into the clinic.
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Affiliation(s)
- Melvin M Evers
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands.
| | - Jana Miniarikova
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Stefan Juhas
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Astrid Vallès
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | | | - Jana Juhasova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | | | - Petr Vodicka
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Ivona Valekova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Cynthia Brouwers
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Bas Blits
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Jacek Lubelski
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Hana Kovarova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Zdenka Ellederova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Sander J van Deventer
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Harald Petry
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Pavlina Konstantinova
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
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108
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Wang X, Kery R, Xiong Q. Synaptopathology in autism spectrum disorders: Complex effects of synaptic genes on neural circuits. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:398-415. [PMID: 28986278 DOI: 10.1016/j.pnpbp.2017.09.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/05/2017] [Accepted: 09/26/2017] [Indexed: 01/03/2023]
Affiliation(s)
- Xinxing Wang
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA
| | - Rachel Kery
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA; Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794, USA
| | - Qiaojie Xiong
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
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109
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Yuge K, Iwama K, Yonee C, Matsufuji M, Sano N, Saikusa T, Yae Y, Yamashita Y, Mizuguchi T, Matsumoto N, Matsuishi T. A novel STXBP1 mutation causes typical Rett syndrome in a Japanese girl. Brain Dev 2018; 40:493-497. [PMID: 29544889 DOI: 10.1016/j.braindev.2018.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 11/18/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder mostly caused by mutations in Methyl-CpG-binding protein 2 (MECP2); however, mutations in various other genes may lead to RTT-like phenotypes. Here, we report the first case of a Japanese girl with RTT caused by a novel syntaxin-binding protein 1 (STXBP1) frameshift mutation (c.60delG, p.Lys21Argfs*16). She showed epilepsy at one year of age, regression of acquired psychomotor abilities thereafter, and exhibited stereotypic hand and limb movements at 3 years of age. Her epilepsy onset was earlier than is typical for RTT patients. However, she fully met the 2010 diagnostic criteria of typical RTT. STXBP1 mutations cause early infantile epileptic encephalopathy (EIEE), various intractable epilepsies, and neurodevelopmental disorders. However, the case described here presented a unique clinical presentation of typical RTT without EIEE and a novel STXBP1 mutation.
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Affiliation(s)
- Kotaro Yuge
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan
| | - Kazuhiro Iwama
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Kanagawa, Japan
| | - Chihiro Yonee
- Department of Pediatric Neurology, MinamiKyushu Hospital, Kagoshima, Japan
| | - Mayumi Matsufuji
- Department of Pediatric Neurology, MinamiKyushu Hospital, Kagoshima, Japan
| | - Nozomi Sano
- Department of Pediatric Neurology, MinamiKyushu Hospital, Kagoshima, Japan
| | - Tomoko Saikusa
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan
| | - Yukako Yae
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan
| | - Yushiro Yamashita
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Fukuoka, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Kanagawa, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Kanagawa, Japan
| | - Toyojiro Matsuishi
- Research Center for Children and Research Center for Rett syndrome, St. Mary's Hospital, Fukuoka, Japan.
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110
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Zaghlula M, Glaze DG, Enns GM, Potocki L, Schwabe AL, Suter B. Current clinical evidence does not support a link between TBL1XR1 and Rett syndrome: Description of one patient with Rett features and a novel mutation in TBL1XR1, and a review of TBL1XR1 phenotypes. Am J Med Genet A 2018; 176:1683-1687. [PMID: 29777588 DOI: 10.1002/ajmg.a.38689] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/28/2018] [Accepted: 03/04/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Manar Zaghlula
- Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Jan and Dan Duncan Neurological Research Institute, Houston, Texas
| | - Daniel G Glaze
- Department of Neurology, Baylor College of Medicine, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas
| | - Gregory M Enns
- Departments of Pediatrics and Pathology, Stanford University, Stanford, California
| | - Lorraine Potocki
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Aloysia L Schwabe
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Bernhard Suter
- Department of Neurology, Baylor College of Medicine, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas
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111
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Saikusa T, Hara M, Iwama K, Yuge K, Ohba C, Okada JI, Hisano T, Yamashita Y, Okamoto N, Saitsu H, Matsumoto N, Matsuishi T. De novo HDAC8 mutation causes Rett-related disorder with distinctive facial features and multiple congenital anomalies. Brain Dev 2018. [PMID: 29519750 DOI: 10.1016/j.braindev.2017.12.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We present a unique 11-year-old girl showing clinical features of Rett-related disorder with distinctive facial features and multiple congenital anomalies including ocular hypertelorism, arched eyebrows, a broad nose, dental anomalies, congenital heart disease, truncal obesity, and epilepsy. A novel de novo mutation in histone deacetylase 8 (HDAC8) (c.652G > T, p.Gly218Cys) was confirmed by whole exome sequencing and Sanger sequencing. X-chromosome inactivation analysis on DNA isolated from peripheral blood lymphocytes revealed a completely skewed pattern associated with an inactive maternal allele. Late clinical loss of acquired purposeful hand movements and psychomotor deterioration may be a feature of Rett-related disorder, while distinctive facial features and multiple congenital anomalies are reminiscent of Cornelia de Lange syndrome.
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Affiliation(s)
- Tomoko Saikusa
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Munetsugu Hara
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Kazuhiro Iwama
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kotaro Yuge
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Chihiro Ohba
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Jun-Ichiro Okada
- Department of Neonatology, Medical Center for Maternal and Child Health, St. Mary's Hospital, Kurume, Fukuoka 830-8543, Japan
| | - Tadashi Hisano
- Department of Neonatology, Medical Center for Maternal and Child Health, St. Mary's Hospital, Kurume, Fukuoka 830-8543, Japan
| | - Yushiro Yamashita
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, 840 Shitudou-machi, Izumi, Osaka 594-0011, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Toyojiro Matsuishi
- Department of Pediatrics, Research Center for Children, Research Center for Rett Syndrome, St. Mary's Hospital, Kurume, Fukuoka 830-8543, Japan.
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112
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Genomic Context Analysis of de Novo STXBP1 Mutations Identifies Evidence of Splice Site DNA-Motif Associated Hotspots. G3-GENES GENOMES GENETICS 2018; 8:1115-1118. [PMID: 29438995 PMCID: PMC5873902 DOI: 10.1534/g3.118.200080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mutations within STXBP1 have been associated with a range of neurodevelopmental disorders implicating the pleotropic impact of this gene. Although the frequency of de novo mutations within STXBP1 for selective cohorts with early onset epileptic encephalopathy is more than 1%, there is no evidence for a hotspot within the gene. In this study, we analyzed the genomic context of de novo STXBP1 mutations to examine whether certain motifs indicated a greater risk of mutation. Through a comprehensive context analysis of 136 de novo/rare mutation (SNV/Indels) sites in this gene, strikingly 26.92% of all SNV mutations occurred within 5bp upstream or downstream of a 'GTA' motif (P < 0.0005). This implies a genomic context modulated mutagenesis. Moreover, 51.85% (14 out of 27) of the 'GTA' mutations are splicing compared to 14.70% (20 out of 136) of all reported mutations within STXBP1 We also noted that 11 of these 14 'GTA' associated mutations are de novo in origin. Our analysis provides strong evidence of DNA motif modulated mutagenesis for STXBP1 de novo splicing mutations.
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113
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van der Schoot V, de Munnik S, Venselaar H, Elting M, Mancini GMS, Ravenswaaij-Arts CMA, Anderlid BM, Brunner HG, Stevens SJC. Toward clinical and molecular understanding of pathogenic variants in the ZBTB18 gene. Mol Genet Genomic Med 2018; 6:393-400. [PMID: 29573576 PMCID: PMC6014478 DOI: 10.1002/mgg3.387] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/23/2018] [Accepted: 02/27/2018] [Indexed: 12/25/2022] Open
Abstract
Background Patients with pathogenic variants in ZBTB18 present with Intellectual Disability (ID) with frequent co‐occurrence of corpus callosum (CC) anomalies, hypotonia, microcephaly, growth problems and variable facial dysmorphologies. These features illustrate a key role for ZBTB18 in brain development. Methods Patients with a pathogenic variant in ZBTB18 were detected by diagnostic whole exome sequencing (WES) performed in our center. We reviewed the literature and used GeneMatcher to include other cases. YASARA and WHAT IF were used to provide insight into the structural effect of missense variants located in the C2H2 zinc finger domains of the ZBTB18 protein. Results We give a complete overview of pathogenic variants in ZBTB18 detected to date, showing inconsistent presence of clinical features, including CC anomalies. We present four new cases with a de novo pathogenic variant in the ZBTB18 gene, including the fourth case in which a de novo p.Arg464His variant was found. Conclusion Homology modeling of protein structure points to a variable degree of impaired DNA binding caused by missense variants in these domains probably leading to Loss of Function (LoF). Putative partial LoF may present with a less distinctive phenotype than complete LoF, as seen in truncating variants, which presents with an extensive variability in the phenotypic spectrum. Our data do not support a clear genotype to phenotype correlation.
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Affiliation(s)
- Vyne van der Schoot
- Department of Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Sonja de Munnik
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, Nijmegen, the Netherlands
| | - Hanka Venselaar
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre Nijmegen, Nijmegen, the Netherlands
| | - Mariet Elting
- Department of Clinical Genetics, Vrije Universiteit, Amsterdam, the Netherlands
| | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus MC University Medical Centre, Rotterdam, the Netherlands
| | - Conny M A Ravenswaaij-Arts
- University of Groningen, University Medical Centre Groningen, Department of Genetics, Groningen, the Netherlands
| | - Britt-Marie Anderlid
- Department of Clinical Genetics, Karolinska Universitetssjukhuset, Solna, Sweden
| | - Han G Brunner
- Department of Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands.,Department of Human Genetics, Radboud University Medical Centre Nijmegen, Nijmegen, the Netherlands
| | - Servi J C Stevens
- Department of Clinical Genetics, Maastricht University Medical Centre, Maastricht, the Netherlands
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114
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Genetic aberrations in macroautophagy genes leading to diseases. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018. [PMID: 29524522 DOI: 10.1016/j.bbamcr.2018.03.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The catabolic process of macroautophagy, through the rapid degradation of unwanted cellular components, is involved in a multitude of cellular and organismal functions that are essential to maintain homeostasis. Those functions include adaptation to starvation, cell development and differentiation, innate and adaptive immunity, tumor suppression, autophagic cell death, and maintenance of stem cell stemness. Not surprisingly, an impairment or block of macroautophagy can lead to severe pathologies. A still increasing number of reports, in particular, have revealed that mutations in the autophagy-related (ATG) genes, encoding the key players of macroautophagy, are either the cause or represent a risk factor for the development of several illnesses. The aim of this review is to provide a comprehensive overview of the diseases and disorders currently known that are or could be caused by mutations in core ATG proteins but also in the so-called autophagy receptors, which provide specificity to the process of macroautophagy. Our compendium underlines the medical relevance of this pathway and underscores the importance of the eventual development of therapeutic approaches aimed at modulating macroautophagy.
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115
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Moccia A, Martin DM. Nervous system development and disease: A focus on trithorax related proteins and chromatin remodelers. Mol Cell Neurosci 2018; 87:46-54. [PMID: 29196188 PMCID: PMC5828982 DOI: 10.1016/j.mcn.2017.11.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/08/2017] [Accepted: 11/27/2017] [Indexed: 01/12/2023] Open
Abstract
The nervous system comprises many different cell types including neurons, glia, macrophages, and immune cells, each of which is defined by specific patterns of gene expression, morphology, function, and anatomical location. Establishment of these complex and highly regulated cell fates requires spatial and temporal coordination of gene transcription. Open chromatin (euchromatin) allows transcription factors to interact with gene promoters and activate lineage specific genes, whereas closed chromatin (heterochromatin) remains inaccessible to transcriptional activation. Changes in the genome-wide distribution of euchromatin accompany transcriptional plasticity that allows the diversity of mature cell fates to be generated during development. In the past 20years, many new genes and gene families have been identified to participate in regulation of chromatin accessibility. These genes include chromatin remodelers that interact with Trithorax group (TrxG) and Polycomb group (PcG) proteins to activate or repress transcription, respectively. Here we review the role of TrxG proteins in neurodevelopment and disease.
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Affiliation(s)
- Amanda Moccia
- Department of Human Genetics, The University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Donna M Martin
- Department of Human Genetics, The University of Michigan Medical School, Ann Arbor, MI 48109, United States; Department of Pediatrics and Communicable Diseases, The University of Michigan Medical School, Ann Arbor, MI 48109, United States.
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116
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Abstract
PURPOSE OF REVIEW This article reviews the current molecular genetic studies, which investigate the genetic causes of Rett syndrome or Rett-like phenotypes without a MECP2 mutation. RECENT FINDINGS As next generation sequencing becomes broadly available, especially whole exome sequencing is used in clinical diagnosis of the genetic causes of a wide spectrum of intellectual disability, autism, and encephalopathies. Patients who were diagnosed with Rett syndrome or Rett-like syndrome because of their phenotype but were negative for mutations in the MECP2, CDKL5 or FOXG1 genes were subjected to whole exome sequencing and the results of the last few years revealed yet 69 different genes. Many of these genes are involved in epigenetic gene regulation, chromatin shaping, neurotransmitter action or RNA transcription/translation. Genetic data also allows to investigate the individual genetic background of an individual patient, which can modify the severity of a genetic disorder. SUMMARY We conclude that the Rett syndrome phenotype has a much broader underlying genetic cause and the typical phenotype overlap with other genetic disorders. For proper genetic counselling, patient perspective and treatment it is important to include both phenotype and genetic information.
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117
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Gold WA, Krishnarajy R, Ellaway C, Christodoulou J. Rett Syndrome: A Genetic Update and Clinical Review Focusing on Comorbidities. ACS Chem Neurosci 2018; 9:167-176. [PMID: 29185709 DOI: 10.1021/acschemneuro.7b00346] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Rett syndrome (RTT) is a unique neurodevelopmental disorder that primarily affects females resulting in severe cognitive and physical disabilities. Despite the commendable collective efforts of the research community to better understand the genetics and underlying biology of RTT, there is still no cure. However, in the past 50 years, since the first report of RTT, steady progress has been made in the accumulation of clinical and molecular information resulting in the identification of a number of genes associated with RTT and associated phenotypes, improved diagnostic criteria, natural history studies, curation of a number of databases capturing genotypic and phenotypic data, a number of promising clinical trials and exciting novel therapeutic options which are currently being tested in laboratory and clinical settings. This Review focuses on the current knowledge of the clinical aspects of RTT, with particular attention being paid to clinical trials and the comorbidities of the disorder as well as the genetic etiology and the recognition of new diseases genes.
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Affiliation(s)
- Wendy A Gold
- Genetic
Metabolic Disorders Research Unit, Western Sydney Genetics Program, The Children’s Hospital at Westmead, Sydney, NSW 2145, Australia
| | - Rahul Krishnarajy
- Genetic
Metabolic Disorders Research Unit, Western Sydney Genetics Program, The Children’s Hospital at Westmead, Sydney, NSW 2145, Australia
| | - Carolyn Ellaway
- Genetic
Metabolic Disorders Service, Western Sydney Genetics Program, The Children’s Hospital at Westmead, Sydney, NSW 2145, Australia
| | - John Christodoulou
- Genetic
Metabolic Disorders Research Unit, Western Sydney Genetics Program, The Children’s Hospital at Westmead, Sydney, NSW 2145, Australia
- Neurodevelopmental
Genomics Research Group, Murdoch Children’s Research Institute,
and Department of Paediatrics, Melbourne Medical School, University of Melbourne, Melbourne, VIC 3010, Australia
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118
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Vuillaume ML, Jeanne M, Xue L, Blesson S, Denommé-Pichon AS, Alirol S, Brulard C, Colin E, Isidor B, Gilbert-Dussardier B, Odent S, Parent P, Donnart A, Redon R, Bézieau S, Rondard P, Laumonnier F, Toutain A. A novel mutation in the transmembrane 6 domain of GABBR2 leads to a Rett-like phenotype. Ann Neurol 2018; 83:437-439. [PMID: 29369404 DOI: 10.1002/ana.25155] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 01/23/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Marie-Laure Vuillaume
- Genetics Department, University Hospital Center, Tours.,UMR 1253, iBrain, University of Tours, Inserm, Tours, France
| | - Médéric Jeanne
- Genetics Department, University Hospital Center, Tours.,UMR 1253, iBrain, University of Tours, Inserm, Tours, France
| | - Li Xue
- Institute of Functional Genomics, CNRS UMR5203, INSERM U1191, Montpellier University, Montpellier
| | | | - Anne-Sophie Denommé-Pichon
- Genetics Department.,UMR INSERM 1083 - CNRS 6015, Faculty of Medicine, Angers University, Angers, France
| | - Servane Alirol
- UMR 1253, iBrain, University of Tours, Inserm, Tours, France
| | - Céline Brulard
- UMR 1253, iBrain, University of Tours, Inserm, Tours, France.,Platform for Cancer Molecular Biology, University Hospital Center, Tours, France
| | - Estelle Colin
- Genetics Department.,UMR INSERM 1083 - CNRS 6015, Faculty of Medicine, Angers University, Angers, France
| | - Bertrand Isidor
- Genetics Department, University Hospital Center, Nantes, France.,INSERM, UMR-S 1238, Nantes University, Nantes, France
| | | | - Sylvie Odent
- Genetics Department, University Hospital Center, Rennes, France.,CNRS UMR 6290 Institute of Genetics and Development of Rennes, Faculty of Medicine, Rennes 1 University, Rennes
| | - Philippe Parent
- Genetics Department, University Hospital Center, Brest, France
| | - Audrey Donnart
- INSERM, CNRS, Nantes University, University Hospital Center, Thorax Institute, Nantes, France
| | - Richard Redon
- INSERM, CNRS, Nantes University, University Hospital Center, Thorax Institute, Nantes, France
| | - Stéphane Bézieau
- Genetics Department, University Hospital Center, Nantes, France.,Center for Research in Cancer and Immunology, INSERM, Angers University, Nantes University, Nantes, France
| | - Philippe Rondard
- Institute of Functional Genomics, CNRS UMR5203, INSERM U1191, Montpellier University, Montpellier
| | - Frédéric Laumonnier
- Genetics Department, University Hospital Center, Tours.,UMR 1253, iBrain, University of Tours, Inserm, Tours, France
| | - Annick Toutain
- Genetics Department, University Hospital Center, Tours.,UMR 1253, iBrain, University of Tours, Inserm, Tours, France
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119
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Yoo Y, Cho J, Choi M. Reply to “a novel mutation in the transmembrane 6 domain of GABBR2
leads to a rett-like phenotype”. Ann Neurol 2018; 83:439. [DOI: 10.1002/ana.25154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 01/21/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Yongjin Yoo
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Jaeso Cho
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Murim Choi
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
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120
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Schönewolf-Greulich B, Bisgaard AM, Møller R, Dunø M, Brøndum-Nielsen K, Kaur S, Van Bergen N, Lunke S, Eggers S, Jespersgaard C, Christodoulou J, Tümer Z. Clinician’s guide to genes associated with Rett-like phenotypes-Investigation of a Danish cohort and review of the literature. Clin Genet 2018; 95:221-230. [DOI: 10.1111/cge.13153] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 12/16/2022]
Affiliation(s)
- B. Schönewolf-Greulich
- Center for Rett Syndrome, Kennedy Center, Department of Paediatrics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
| | - A-M. Bisgaard
- Center for Rett Syndrome, Kennedy Center, Department of Paediatrics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
| | - R.S. Møller
- Danish Epilepsy Centre; Dianalund Denmark
- Institute for Regional Health Services; University of Southern Denmark; Odense Denmark
| | - M. Dunø
- Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
| | - K. Brøndum-Nielsen
- Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
| | - S. Kaur
- Neurodevelopmental Genomics Research Group; Murdoch Children's Research Institute; Melbourne Australia
- Department of Paediatrics; Melbourne Medical School, University of Melbourne; Melbourne Australia
| | - N.J. Van Bergen
- Neurodevelopmental Genomics Research Group; Murdoch Children's Research Institute; Melbourne Australia
- Department of Paediatrics; Melbourne Medical School, University of Melbourne; Melbourne Australia
| | - S. Lunke
- Translational Genomics Unit; Murdoch Children’s Research Institute; Melbourne Australia
| | - S. Eggers
- Translational Genomics Unit; Murdoch Children’s Research Institute; Melbourne Australia
| | - C. Jespersgaard
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
| | - J. Christodoulou
- Neurodevelopmental Genomics Research Group; Murdoch Children's Research Institute; Melbourne Australia
- Department of Paediatrics; Melbourne Medical School, University of Melbourne; Melbourne Australia
| | - Z. Tümer
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics; Copenhagen University Hospital, Rigshospitalet; Copenhagen Denmark
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121
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Kapur M, Ackerman SL. mRNA Translation Gone Awry: Translation Fidelity and Neurological Disease. Trends Genet 2018; 34:218-231. [PMID: 29352613 DOI: 10.1016/j.tig.2017.12.007] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
Errors during mRNA translation can lead to a reduction in the levels of functional proteins and an increase in deleterious molecules. Advances in next-generation sequencing have led to the discovery of rare genetic disorders, many caused by mutations in genes encoding the mRNA translation machinery, as well as to a better understanding of translational dynamics through ribosome profiling. We discuss here multiple neurological disorders that are linked to errors in tRNA aminoacylation and ribosome decoding. We draw on studies from genetic models, including yeast and mice, to enhance our understanding of the translational defects observed in these diseases. Finally, we emphasize the importance of tRNA, their associated enzymes, and the inextricable link between accuracy and efficiency in the maintenance of translational fidelity.
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Affiliation(s)
- Mridu Kapur
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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122
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Monogenic disorders that mimic the phenotype of Rett syndrome. Neurogenetics 2018; 19:41-47. [PMID: 29322350 DOI: 10.1007/s10048-017-0535-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/17/2017] [Accepted: 12/21/2017] [Indexed: 10/18/2022]
Abstract
Rett syndrome (RTT) is caused by mutations in methyl-CpG-binding protein 2 (MECP2), but defects in a handful of other genes (e.g., CDKL5, FOXG1, MEF2C) can lead to presentations that resemble, but do not completely mirror, classical RTT. In this study, we attempted to identify other monogenic disorders that share features with RTT. We performed a retrospective chart review on n = 319 patients who had undergone clinical whole exome sequencing (WES) for further etiological evaluation of neurodevelopmental diagnoses that remained unexplained despite extensive prior workup. From this group, we characterized those who (1) possessed features that were compatible with RTT based on clinical judgment, (2) subsequently underwent MECP2 sequencing and/or MECP2 deletion/duplication analysis with negative results, and (3) ultimately arrived at a diagnosis other than RTT with WES. n = 7 patients had clinical features overlapping RTT with negative MECP2 analysis but positive WES providing a diagnosis. These seven patients collectively possessed pathogenic variants in six different genes: two in KCNB1 and one each in FOXG1, IQSEC2, MEIS2, TCF4, and WDR45. n = 2 (both with KCNB1 variants) fulfilled criteria for atypical RTT. RTT-associated features included the following: loss of hand or language skills (n = 3; IQSEC2, KCNB1 x 2); disrupted sleep (n = 4; KNCB1, MEIS2, TCF4, WDR45); stereotyped hand movements (n = 5; FOXG1, KNCB1 x 2, MEIS2, TCF4); bruxism (n = 3; KCNB1 x 2; TCF4); and hypotonia (n = 7). Clinically based diagnoses can be misleading, evident by the increasing number of genetic conditions associated with features of RTT with negative MECP2 mutations.
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123
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Missense Variants in RHOBTB2 Cause a Developmental and Epileptic Encephalopathy in Humans, and Altered Levels Cause Neurological Defects in Drosophila. Am J Hum Genet 2018; 102:44-57. [PMID: 29276004 DOI: 10.1016/j.ajhg.2017.11.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/16/2017] [Indexed: 01/08/2023] Open
Abstract
Although the role of typical Rho GTPases and other Rho-linked proteins in synaptic plasticity and cognitive function and dysfunction is widely acknowledged, the role of atypical Rho GTPases (such as RHOBTB2) in neurodevelopment has barely been characterized. We have now identified de novo missense variants clustering in the BTB-domain-encoding region of RHOBTB2 in ten individuals with a similar phenotype, including early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorders. Three of the variants were recurrent. Upon transfection of HEK293 cells, we found that mutant RHOBTB2 was more abundant than the wild-type, most likely because of impaired degradation in the proteasome. Similarly, elevated amounts of the Drosophila ortholog RhoBTB in vivo were associated with seizure susceptibility and severe locomotor defects. Knockdown of RhoBTB in the Drosophila dendritic arborization neurons resulted in a decreased number of dendrites, thus suggesting a role of RhoBTB in dendritic development. We have established missense variants in the BTB-domain-encoding region of RHOBTB2 as causative for a developmental and epileptic encephalopathy and have elucidated the role of atypical Rho GTPase RhoBTB in Drosophila neurological function and possibly dendrite development.
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124
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Goodwin LR, Picketts DJ. The role of ISWI chromatin remodeling complexes in brain development and neurodevelopmental disorders. Mol Cell Neurosci 2017; 87:55-64. [PMID: 29249292 DOI: 10.1016/j.mcn.2017.10.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/04/2017] [Accepted: 10/26/2017] [Indexed: 10/18/2022] Open
Abstract
The mammalian ISWI (Imitation Switch) genes SMARCA1 and SMARCA5 encode the ATP-dependent chromatin remodeling proteins SNF2L and SNF2H. The ISWI proteins interact with BAZ (bromodomain adjacent to PHD zinc finger) domain containing proteins to generate eight distinct remodeling complexes. ISWI complex-mediated nucleosome positioning within genes and gene regulatory elements is proving important for the transition from a committed progenitor state to a differentiated cell state. Genetic studies have implicated the involvement of many ATP-dependent chromatin remodeling proteins in neurodevelopmental disorders (NDDs), including SMARCA1. Here we review the characterization of mice inactivated for ISWI and their interacting proteins, as it pertains to brain development and disease. A better understanding of chromatin dynamics during neural development is a prerequisite to understanding disease pathologies and the development of therapeutics for these complex disorders.
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Affiliation(s)
- Laura R Goodwin
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology & Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology & Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
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125
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Kapur M, Monaghan CE, Ackerman SL. Regulation of mRNA Translation in Neurons-A Matter of Life and Death. Neuron 2017; 96:616-637. [PMID: 29096076 DOI: 10.1016/j.neuron.2017.09.057] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 09/20/2017] [Accepted: 09/28/2017] [Indexed: 12/14/2022]
Abstract
Dynamic regulation of mRNA translation initiation and elongation is essential for the survival and function of neural cells. Global reductions in translation initiation resulting from mutations in the translational machinery or inappropriate activation of the integrated stress response may contribute to pathogenesis in a subset of neurodegenerative disorders. Aberrant proteins generated by non-canonical translation initiation may be a factor in the neuron death observed in the nucleotide repeat expansion diseases. Dysfunction of central components of the elongation machinery, such as the tRNAs and their associated enzymes, can cause translational infidelity and ribosome stalling, resulting in neurodegeneration. Taken together, dysregulation of mRNA translation is emerging as a unifying mechanism underlying the pathogenesis of many neurodegenerative disorders.
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Affiliation(s)
- Mridu Kapur
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Caitlin E Monaghan
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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126
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Hamdan FF, Myers CT, Cossette P, Lemay P, Spiegelman D, Laporte AD, Nassif C, Diallo O, Monlong J, Cadieux-Dion M, Dobrzeniecka S, Meloche C, Retterer K, Cho MT, Rosenfeld JA, Bi W, Massicotte C, Miguet M, Brunga L, Regan BM, Mo K, Tam C, Schneider A, Hollingsworth G, FitzPatrick DR, Donaldson A, Canham N, Blair E, Kerr B, Fry AE, Thomas RH, Shelagh J, Hurst JA, Brittain H, Blyth M, Lebel RR, Gerkes EH, Davis-Keppen L, Stein Q, Chung WK, Dorison SJ, Benke PJ, Fassi E, Corsten-Janssen N, Kamsteeg EJ, Mau-Them FT, Bruel AL, Verloes A, Õunap K, Wojcik MH, Albert DV, Venkateswaran S, Ware T, Jones D, Liu YC, Mohammad SS, Bizargity P, Bacino CA, Leuzzi V, Martinelli S, Dallapiccola B, Tartaglia M, Blumkin L, Wierenga KJ, Purcarin G, O’Byrne JJ, Stockler S, Lehman A, Keren B, Nougues MC, Mignot C, Auvin S, Nava C, Hiatt SM, Bebin M, Shao Y, Scaglia F, Lalani SR, Frye RE, Jarjour IT, Jacques S, Boucher RM, Riou E, Srour M, Carmant L, Lortie A, Major P, Diadori P, Dubeau F, D’Anjou G, Bourque G, Berkovic SF, Sadleir LG, Campeau PM, Kibar Z, Lafrenière RG, Girard SL, Mercimek-Mahmutoglu S, Boelman C, Rouleau GA, Scheffer IE, Mefford HC, Andrade DM, Rossignol E, Minassian BA, Michaud JL, Michaud JL. High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies. Am J Hum Genet 2017; 101:664-685. [PMID: 29100083 DOI: 10.1016/j.ajhg.2017.09.008] [Citation(s) in RCA: 300] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/11/2017] [Indexed: 12/30/2022] Open
Abstract
Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequencing in another series of individuals with DEE and by mining various sequencing datasets. We also performed meta-analyses to document enrichment of DNMs in candidate genes by leveraging our WGS dataset with those of several DEE and ID series. By combining these strategies, we were able to provide a causal link between DEE and the following genes: NTRK2, GABRB2, CLTC, DHDDS, NUS1, RAB11A, GABBR2, and SNAP25. Overall, we established a molecular diagnosis in 63/197 (32%) individuals in our WGS series. The main cause of DEE in these individuals was de novo point mutations (53/63 solved cases), followed by inherited mutations (6/63 solved cases) and de novo CNVs (4/63 solved cases). De novo missense variants explained a larger proportion of individuals in our series than in other series that were primarily ascertained because of ID. Moreover, these DNMs were more frequently recurrent than those identified in ID series. These observations indicate that the genetic landscape of DEE might be different from that of ID without epilepsy.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Jacques L Michaud
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T1C5, Canada; Department of Neurosciences, Université de Montréal, Montreal, QC H3T1J4, Canada; Department of Pediatrics, Université de Montréal, Montreal, QC H3T1C5, Canada.
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127
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Vidal S, Brandi N, Pacheco P, Gerotina E, Blasco L, Trotta JR, Derdak S, Del Mar O'Callaghan M, Garcia-Cazorla À, Pineda M, Armstrong J. The utility of Next Generation Sequencing for molecular diagnostics in Rett syndrome. Sci Rep 2017; 7:12288. [PMID: 28947817 PMCID: PMC5613000 DOI: 10.1038/s41598-017-11620-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/29/2017] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that almost exclusively affects girls and is totally disabling. Three genes have been identified that cause RTT: MECP2, CDKL5 and FOXG1. However, the etiology of some of RTT patients still remains unknown. Recently, next generation sequencing (NGS) has promoted genetic diagnoses because of the quickness and affordability of the method. To evaluate the usefulness of NGS in genetic diagnosis, we present the genetic study of RTT-like patients using different techniques based on this technology. We studied 1577 patients with RTT-like clinical diagnoses and reviewed patients who were previously studied and thought to have RTT genes by Sanger sequencing. Genetically, 477 of 1577 patients with a RTT-like suspicion have been diagnosed. Positive results were found in 30% by Sanger sequencing, 23% with a custom panel, 24% with a commercial panel and 32% with whole exome sequencing. A genetic study using NGS allows the study of a larger number of genes associated with RTT-like symptoms simultaneously, providing genetic study of a wider group of patients as well as significantly reducing the response time and cost of the study.
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Affiliation(s)
- Silvia Vidal
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Núria Brandi
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Paola Pacheco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Edgar Gerotina
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Laura Blasco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Jean-Rémi Trotta
- Centro Nacional de Análisis Genómica (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Sophia Derdak
- Centro Nacional de Análisis Genómica (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Maria Del Mar O'Callaghan
- Neurology Service, Hospital Sant Joan de Déu, Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain
| | - Àngels Garcia-Cazorla
- Neurology Service, Hospital Sant Joan de Déu, Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain
| | - Mercè Pineda
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - Judith Armstrong
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain.
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain.
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.
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Yoo Y, Jung J, Lee YN, Lee Y, Cho H, Na E, Hong J, Kim E, Lee JS, Lee JS, Hong C, Park SY, Wie J, Miller K, Shur N, Clow C, Ebel RS, DeBrosse SD, Henderson LB, Willaert R, Castaldi C, Tikhonova I, Bilgüvar K, Mane S, Kim KJ, Hwang YS, Lee SG, So I, Lim BC, Choi HJ, Seong JY, Shin YB, Jung H, Chae JH, Choi M. GABBR2mutations determine phenotype in rett syndrome and epileptic encephalopathy. Ann Neurol 2017; 82:466-478. [DOI: 10.1002/ana.25032] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 08/23/2017] [Accepted: 08/23/2017] [Indexed: 12/29/2022]
Affiliation(s)
- Yongjin Yoo
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Jane Jung
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine; Seoul Republic of Korea
| | - Yoo-Na Lee
- Graduate School of Medicine; Korea University; Seoul Republic of Korea
| | - Youngha Lee
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Hyosuk Cho
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Eunjung Na
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine; Seoul Republic of Korea
| | - JeaYeok Hong
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine; Seoul Republic of Korea
| | - Eunjin Kim
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine; Seoul Republic of Korea
| | - Jin Sook Lee
- Department of Pediatrics, Department of Genome Medicine and Science; Gachon University Gil Medical Center; Incheon Republic of Korea
| | - Je Sang Lee
- Department of Rehabilitation Medicine; Pusan National University College of Medicine; Pusan Republic of Korea
| | - Chansik Hong
- Department of Physiology; Chosun University School of Medicine; Kwangju Republic of Korea
| | - Sang-Yoon Park
- Department of Science in Korean Medicine, Cancer Preventive Material Developmental Research Center, College of Korean Medicine; Kyung Hee University; Seoul Republic of Korea
| | - Jinhong Wie
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
- Department of Physiology; Seoul National University College of Medicine; Seoul Republic of Korea
| | | | | | | | - Roseànne S. Ebel
- UH Cleveland Medical Center; Center for Human Genetics; Cleveland OH
| | | | | | | | | | | | - Kaya Bilgüvar
- Yale Center for Genome Analysis; West Haven CT
- Department of Genetics; Yale University School of Medicine; New Haven CT
| | - Shrikant Mane
- Yale Center for Genome Analysis; West Haven CT
- Department of Genetics; Yale University School of Medicine; New Haven CT
| | - Ki Joong Kim
- Department of Pediatrics, Seoul National University College of Medicine; Seoul National University Children's Hospital; Seoul Republic of Korea
| | - Yong Seung Hwang
- Department of Pediatrics, Seoul National University College of Medicine; Seoul National University Children's Hospital; Seoul Republic of Korea
| | - Seok-Geun Lee
- Department of Science in Korean Medicine, Cancer Preventive Material Developmental Research Center, College of Korean Medicine; Kyung Hee University; Seoul Republic of Korea
| | - Insuk So
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
- Department of Physiology; Seoul National University College of Medicine; Seoul Republic of Korea
| | - Byung Chan Lim
- Department of Pediatrics, Seoul National University College of Medicine; Seoul National University Children's Hospital; Seoul Republic of Korea
| | - Hee-Jung Choi
- Department of Biological Sciences; Seoul National University College of Natural Sciences; Seoul Republic of Korea
| | - Jae Young Seong
- Graduate School of Medicine; Korea University; Seoul Republic of Korea
| | - Yong Beom Shin
- Department of Rehabilitation Medicine; Pusan National University College of Medicine; Pusan Republic of Korea
| | - Hosung Jung
- Department of Anatomy, Brain Research Institute, and Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine; Seoul Republic of Korea
| | - Jong-Hee Chae
- Department of Pediatrics, Seoul National University College of Medicine; Seoul National University Children's Hospital; Seoul Republic of Korea
| | - Murim Choi
- Department of Biomedical Sciences; Seoul National University College of Medicine; Seoul Republic of Korea
- Department of Pediatrics, Seoul National University College of Medicine; Seoul National University Children's Hospital; Seoul Republic of Korea
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129
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Abstract
Epileptic encephalopathies represent a particularly severe form of epilepsy, associated with cognitive and behavioral deficits, including impaired social-communication and restricted, repetitive behaviors that are the hallmarks of autism spectrum disorder (ASD). With the advent of next-generation sequencing, the genetic landscape of epileptic encephalopathies is growing and demonstrates overlap with genes separately implicated in ASD. However, many questions remain about this connection, including whether epileptiform activity itself contributes to the development of ASD symptomatology. In this review, we compiled a database of genes associated with both epileptic encephalopathy and ASD, limiting our purview to Mendelian disorders not including inborn errors of metabolism, and we focused on the connection between ASD and epileptic encephalopathy rather than epilepsy broadly. Our review has four goals: to (1) discuss the overlapping presentations of ASD and monogenic epileptic encephalopathies; (2) examine the impact of the epilepsy itself on neurocognitive features, including ASD, in monogenic epileptic encephalopathies; (3) outline many of the genetic causes responsible for both ASD and epileptic encephalopathy; (4) provide an illustrative example of a final common pathway that may be implicated in both ASD and epileptic encephalopathy. We demonstrate that autistic features are a common association with monogenic epileptic encephalopathies. Certain epileptic encephalopathy syndromes, like infantile spasms, are especially linked to the development of ASD. The connection between seizures themselves and neurobehavioral deficits in these monogenic encephalopathies remains open to debate. Finally, advances in genetics have revealed many genes that overlap in ties to both ASD and epileptic encephalopathy and that play a role in diverse central nervous system processes. Increased attention to the autistic features of monogenic epileptic encephalopathies is warranted for both researchers and clinicians alike.
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Affiliation(s)
- Siddharth Srivastava
- Department of Neurology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115 USA
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115 USA
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130
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Associations between the clinical findings of cases having submicroscopic chromosomal imbalances at chromosomal breakpoints of apparently balanced structural rearrangements. GENE REPORTS 2017. [DOI: 10.1016/j.genrep.2017.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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131
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Mirza N, Appleton R, Burn S, du Plessis D, Duncan R, Farah JO, Feenstra B, Hviid A, Josan V, Mohanraj R, Shukralla A, Sills GJ, Marson AG, Pirmohamed M. Genetic regulation of gene expression in the epileptic human hippocampus. Hum Mol Genet 2017; 26:1759-1769. [PMID: 28334860 PMCID: PMC5411756 DOI: 10.1093/hmg/ddx061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/12/2016] [Accepted: 02/16/2017] [Indexed: 01/21/2023] Open
Abstract
Epilepsy is a serious and common neurological disorder. Expression quantitative loci (eQTL) analysis is a vital aid for the identification and interpretation of disease-risk loci. Many eQTLs operate in a tissue- and condition-specific manner. We have performed the first genome-wide cis-eQTL analysis of human hippocampal tissue to include not only normal (n = 22) but also epileptic (n = 22) samples. We demonstrate that disease-associated variants from an epilepsy GWAS meta-analysis and a febrile seizures (FS) GWAS are significantly more enriched with epilepsy-eQTLs than with normal hippocampal eQTLs from two larger independent published studies. In contrast, GWAS meta-analyses of two other brain diseases associated with hippocampal pathology (Alzheimer's disease and schizophrenia) are more enriched with normal hippocampal eQTLs than with epilepsy-eQTLs. These observations suggest that an eQTL analysis that includes disease-affected brain tissue is advantageous for detecting additional risk SNPs for the afflicting and closely related disorders, but not for distinct diseases affecting the same brain regions. We also show that epilepsy eQTLs are enriched within epilepsy-causing genes: an epilepsy cis-gene is significantly more likely to be a causal gene for a Mendelian epilepsy syndrome than to be a causal gene for another Mendelian disorder. Epilepsy cis-genes, compared to normal hippocampal cis-genes, are more enriched within epilepsy-causing genes. Hence, we utilize the epilepsy eQTL data for the functional interpretation of epilepsy disease-risk variants and, thereby, highlight novel potential causal genes for sporadic epilepsy. In conclusion, an epilepsy-eQTL analysis is superior to normal hippocampal tissue eQTL analyses for identifying the variants and genes underlying epilepsy.
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Affiliation(s)
- Nasir Mirza
- Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GL, UK
| | - Richard Appleton
- The Roald Dahl EEG Unit, Paediatric Neurosciences Foundation, Alder Hey Children's NHS Foundation Trust, Liverpool L12 2AP, UK
| | - Sasha Burn
- Department of Neurosurgery, Alder Hey Children's NHS Foundation Trust, Liverpool L12 2AP, UK
| | - Daniel du Plessis
- Department of Cellular Pathology, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK
| | - Roderick Duncan
- Department of Neurology, Christchurch Hospital, Christchurch 8140, New Zealand
| | - Jibril Osman Farah
- Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool L9 7LJ, UK
| | - Bjarke Feenstra
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Anders Hviid
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Vivek Josan
- Department of Neurosurgery, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK
| | - Rajiv Mohanraj
- Department of Neurology, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK
| | - Arif Shukralla
- Department of Neurology, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK
| | - Graeme J. Sills
- Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GL, UK
| | - Anthony G. Marson
- Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GL, UK
| | - Munir Pirmohamed
- Department of Molecular & Clinical Pharmacology, University of Liverpool, Liverpool L69 3GL, UK
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132
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Ehmke N, Karge S, Buchmann J, Korinth D, Horn D, Reis O, Häßler F. A de novo nonsense mutation in ZBTB18 plus a de novo 15q13.3 microdeletion in a 6-year-old female. Am J Med Genet A 2017; 173:1251-1256. [PMID: 28345786 DOI: 10.1002/ajmg.a.38145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 12/21/2016] [Accepted: 01/02/2017] [Indexed: 12/11/2022]
Abstract
ZBTB18 has been proposed as candidate gene for microcephaly and abnormalities of the corpus callosum based on overlapping microdeletions of 1q43q44. More recently, de novo mutations of ZBTB18 have been identified in patients with syndromic and non-syndromic intellectual disability. Heterozygous microdeletions of 15q13.3 encompassing the candidate gene CHRNA7 are associated with developmental delay or intellectual disability with speech problems, hypotonia, and seizures. They are characterized by significant variability and reduced penetrance. We report on a patient with a de novo ZBTB18 nonsense mutation and a de novo 15q13.3 microdeletion, both in a heterozygous state, identified by next generation sequencing and array-CGH. The 6-year-old girl showed global developmental delay, absent speech, therapy-refractory seizures, ataxia, muscular hypotonia, and discrete facial dysmorphisms. Almost all of these features have been reported for both genetic aberrations, but the severity could hardly been explained by the microdeletion 15q13.3 alone. We assume an additive effect of haploinsufficiency of ZBTB18 and CHRNA7 in our patient. Assembling the features of our patient and the published patients, we noted that only one of them showed mild anomalies of the corpus callosum. Moreover, we hypothesize that nonsense mutations of ZBTB18 are associated with a more severe phenotype than missense mutations. This report indicates that haploinsufficiency of additional genes beside ZBTB18 causes the high frequency of corpus callosum anomalies in patients with microdeletions of 1q43q44 and underlines the importance of an NGS-based molecular diagnostic in complex phenotypes.
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Affiliation(s)
- Nadja Ehmke
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Sylvio Karge
- Clinics for Child and Adolescent Psychiatry of the University of Rostock, Rostock, Germany
| | - Johannes Buchmann
- Clinics for Child and Adolescent Psychiatry of the University of Rostock, Rostock, Germany
| | | | - Denise Horn
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Olaf Reis
- Clinics for Child and Adolescent Psychiatry of the University of Rostock, Rostock, Germany
| | - Frank Häßler
- Clinics for Child and Adolescent Psychiatry of the University of Rostock, Rostock, Germany
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133
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Wang P, Mokhtari R, Pedrosa E, Kirschenbaum M, Bayrak C, Zheng D, Lachman HM. CRISPR/Cas9-mediated heterozygous knockout of the autism gene CHD8 and characterization of its transcriptional networks in cerebral organoids derived from iPS cells. Mol Autism 2017; 8:11. [PMID: 28321286 PMCID: PMC5357816 DOI: 10.1186/s13229-017-0124-1] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 02/15/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND CHD8 (chromodomain helicase DNA-binding protein 8), which codes for a member of the CHD family of ATP-dependent chromatin-remodeling factors, is one of the most commonly mutated genes in autism spectrum disorders (ASD) identified in exome-sequencing studies. Loss of function mutations in the gene have also been found in schizophrenia (SZ) and intellectual disabilities and influence cancer cell proliferation. We previously reported an RNA-seq analysis carried out on neural progenitor cells (NPCs) and monolayer neurons derived from induced pluripotent stem (iPS) cells that were heterozygous for CHD8 knockout (KO) alleles generated using CRISPR-Cas9 gene editing. A significant number of ASD and SZ candidate genes were among those that were differentially expressed in a comparison of heterozygous KO lines (CHD8+/-) vs isogenic controls (CHD8+/-), including the SZ and bipolar disorder (BD) candidate gene TCF4, which was markedly upregulated in CHD8+/- neuronal cells. METHODS In the current study, RNA-seq was carried out on CHD8+/- and isogenic control (CHD8+/+) cerebral organoids, which are 3-dimensional structures derived from iPS cells that model the developing human telencephalon. RESULTS TCF4 expression was, again, significantly upregulated. Pathway analysis carried out on differentially expressed genes (DEGs) revealed an enrichment of genes involved in neurogenesis, neuronal differentiation, forebrain development, Wnt/β-catenin signaling, and axonal guidance, similar to our previous study on NPCs and monolayer neurons. There was also significant overlap in our CHD8+/- DEGs with those found in a transcriptome analysis carried out by another group using cerebral organoids derived from a family with idiopathic ASD. Remarkably, the top DEG in our respective studies was the non-coding RNA DLX6-AS1, which was markedly upregulated in both studies; DLX6-AS1 regulates the expression of members of the DLX (distal-less homeobox) gene family. DLX1 was also upregulated in both studies. DLX genes code for transcription factors that play a key role in GABAergic interneuron differentiation. Significant overlap was also found in a transcriptome study carried out by another group using iPS cell-derived neurons from patients with BD, a condition characterized by dysregulated WNT/β-catenin signaling in a subgroup of affected individuals. CONCLUSIONS Overall, the findings show that distinct ASD, SZ, and BD candidate genes converge on common molecular targets-an important consideration for developing novel therapeutics in genetically heterogeneous complex traits.
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Affiliation(s)
- Ping Wang
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
| | - Ryan Mokhtari
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Michael Kirschenbaum
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
| | - Can Bayrak
- Erciyes University School of Medicine, Kayseri, Turkey
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Neurology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
| | - Herbert M. Lachman
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Psychiatry and Behavioral Sciences, Erciyes University School of Medicine, Kayseri, Turkey
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY USA
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134
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Genetic and phenotypic dissection of 1q43q44 microdeletion syndrome and neurodevelopmental phenotypes associated with mutations in ZBTB18 and HNRNPU. Hum Genet 2017; 136:463-479. [PMID: 28283832 PMCID: PMC5360844 DOI: 10.1007/s00439-017-1772-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 02/21/2017] [Indexed: 11/09/2022]
Abstract
Subtelomeric 1q43q44 microdeletions cause a syndrome associating intellectual disability, microcephaly, seizures and anomalies of the corpus callosum. Despite several previous studies assessing genotype-phenotype correlations, the contribution of genes located in this region to the specific features of this syndrome remains uncertain. Among those, three genes, AKT3, HNRNPU and ZBTB18 are highly expressed in the brain and point mutations in these genes have been recently identified in children with neurodevelopmental phenotypes. In this study, we report the clinical and molecular data from 17 patients with 1q43q44 microdeletions, four with ZBTB18 mutations and seven with HNRNPU mutations, and review additional data from 37 previously published patients with 1q43q44 microdeletions. We compare clinical data of patients with 1q43q44 microdeletions with those of patients with point mutations in HNRNPU and ZBTB18 to assess the contribution of each gene as well as the possibility of epistasis between genes. Our study demonstrates that AKT3 haploinsufficiency is the main driver for microcephaly, whereas HNRNPU alteration mostly drives epilepsy and determines the degree of intellectual disability. ZBTB18 deletions or mutations are associated with variable corpus callosum anomalies with an incomplete penetrance. ZBTB18 may also contribute to microcephaly and HNRNPU to thin corpus callosum, but with a lower penetrance. Co-deletion of contiguous genes has additive effects. Our results confirm and refine the complex genotype-phenotype correlations existing in the 1qter microdeletion syndrome and define more precisely the neurodevelopmental phenotypes associated with genetic alterations of AKT3, ZBTB18 and HNRNPU in humans.
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135
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Epilepsy and intellectual disability linked protein Shrm4 interaction with GABA BRs shapes inhibitory neurotransmission. Nat Commun 2017; 8:14536. [PMID: 28262662 PMCID: PMC5343488 DOI: 10.1038/ncomms14536] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023] Open
Abstract
Shrm4, a protein expressed only in polarized tissues, is encoded by the KIAA1202 gene, whose mutations have been linked to epilepsy and intellectual disability. However, a physiological role for Shrm4 in the brain is yet to be established. Here, we report that Shrm4 is localized to synapses where it regulates dendritic spine morphology and interacts with the C terminus of GABAB receptors (GABABRs) to control their cell surface expression and intracellular trafficking via a dynein-dependent mechanism. Knockdown of Shrm4 in rat severely impairs GABABR activity causing increased anxiety-like behaviour and susceptibility to seizures. Moreover, Shrm4 influences hippocampal excitability by modulating tonic inhibition in dentate gyrus granule cells, in a process involving crosstalk between GABABRs and extrasynaptic δ-subunit-containing GABAARs. Our data highlights a role for Shrm4 in synaptogenesis and in maintaining GABABR-mediated inhibition, perturbation of which may be responsible for the involvement of Shrm4 in cognitive disorders and epilepsy. Mutations in the gene encoding Shrm4 are associated with epilepsy and intellectual disability. The authors show that Shrm4 interacts with GABAB receptors and regulates tonic inhibition in the hippocampus, and knockdown of Shrm4 in rats leads to anxiety-like behaviour and seizures.
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136
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Lucariello M, Vidal E, Vidal S, Saez M, Roa L, Huertas D, Pineda M, Dalfó E, Dopazo J, Jurado P, Armstrong J, Esteller M. Whole exome sequencing of Rett syndrome-like patients reveals the mutational diversity of the clinical phenotype. Hum Genet 2016; 135:1343-1354. [PMID: 27541642 PMCID: PMC5065581 DOI: 10.1007/s00439-016-1721-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 07/31/2016] [Indexed: 12/15/2022]
Abstract
Classical Rett syndrome (RTT) is a neurodevelopmental disorder where most of cases carry MECP2 mutations. Atypical RTT variants involve mutations in CDKL5 and FOXG1. However, a subset of RTT patients remains that do not carry any mutation in the described genes. Whole exome sequencing was carried out in a cohort of 21 female probands with clinical features overlapping with those of RTT, but without mutations in the customarily studied genes. Candidates were functionally validated by assessing the appearance of a neurological phenotype in Caenorhabditis elegans upon disruption of the corresponding ortholog gene. We detected pathogenic variants that accounted for the RTT-like phenotype in 14 (66.6 %) patients. Five patients were carriers of mutations in genes already known to be associated with other syndromic neurodevelopmental disorders. We determined that the other patients harbored mutations in genes that have not previously been linked to RTT or other neurodevelopmental syndromes, such as the ankyrin repeat containing protein ANKRD31 or the neuronal acetylcholine receptor subunit alpha-5 (CHRNA5). Furthermore, worm assays demonstrated that mutations in the studied candidate genes caused locomotion defects. Our findings indicate that mutations in a variety of genes contribute to the development of RTT-like phenotypes.
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Affiliation(s)
- Mario Lucariello
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain
| | - Enrique Vidal
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain
| | - Silvia Vidal
- Servei de Medicina Genètica i Molecular, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Esplugues De Llobregat, Catalonia, Spain
| | - Mauricio Saez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain
| | - Laura Roa
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain
| | - Dori Huertas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain
| | - Mercè Pineda
- Fundació Hospital Sant Joan de Déu (HSJD), Barcelona, Catalonia, Spain
| | - Esther Dalfó
- Genetics Department, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Joaquin Dopazo
- Computational Genomics Department, Centro de Investigación Príncipe Felipe (CIPF), 46012, Valencia, Spain
- Bioinformatics of Rare Diseases (BIER), CIBER de Enfermedades Raras (CIBERER), Valencia, Spain
- Functional Genomics Node (INB) at CIPF, 46012, Valencia, Spain
| | - Paola Jurado
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain.
| | - Judith Armstrong
- Servei de Medicina Genètica i Molecular, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Esplugues De Llobregat, Catalonia, Spain.
- CIBER Enfermedades Raras, Barcelona, Catalonia, Spain.
- Department of Neurology, Hospital Sant Joan de Déu (HSJD), Barcelona, Catalonia, Spain.
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet, 08908, Barcelona, Catalonia, Spain.
- Department of Physiological Sciences, School of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain.
- Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain.
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137
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Cohen JS, Srivastava S, Farwell Hagman KD, Shinde DN, Huether R, Darcy D, Wallerstein R, Houge G, Berland S, Monaghan KG, Poretti A, Wilson AL, Chung WK, Fatemi A. Further evidence that de novo missense and truncating variants in ZBTB18 cause intellectual disability with variable features. Clin Genet 2016; 91:697-707. [PMID: 27598823 DOI: 10.1111/cge.12861] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/12/2016] [Accepted: 09/01/2016] [Indexed: 01/21/2023]
Abstract
Identification of rare genetic variants in patients with intellectual disability (ID) has been greatly accelerated by advances in next generation sequencing technologies. However, due to small numbers of patients, the complete phenotypic spectrum associated with pathogenic variants in single genes is still emerging. Among these genes is ZBTB18 (ZNF238), which is deleted in patients with 1q43q44 microdeletions who typically present with ID, microcephaly, corpus callosum (CC) abnormalities, and seizures. Here we provide additional evidence for haploinsufficiency or dysfunction of the ZBTB18 gene as the cause of ID in five unrelated patients with variable syndromic features who underwent whole exome sequencing revealing separate de novo pathogenic or likely pathogenic variants in ZBTB18 (two missense alterations and three truncating alterations). The neuroimaging findings in our cohort (CC hypoplasia seen in 4/4 of our patients who underwent MRI) lend further support for ZBTB18 as a critical gene for CC abnormalities. A similar phenotype of microcephaly, CC agenesis, and cerebellar vermis hypoplasia has been reported in mice with central nervous system-specific knockout of Zbtb18. Our five patients, in addition to the previously described cases of de novo ZBTB18 variants, add to knowledge about the phenotypic spectrum associated with ZBTB18 haploinsufficiency/dysfunction.
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Affiliation(s)
- J S Cohen
- Division of Neurogenetics, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA
| | - S Srivastava
- Division of Neurogenetics, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Neurology, The Johns Hopkins Hospital, Baltimore, MD, USA.,Department of Pediatrics, The Johns Hopkins Hospital, Baltimore, MD, USA
| | | | - D N Shinde
- Division of Clinical Genomics, Ambry Genetics, Aliso Viejo, CA, USA
| | - R Huether
- Department of Bioinformatics, Ambry Genetics, Aliso Viejo, CA, USA
| | - D Darcy
- Silicon Valley Genetics Center, Santa Clara Valley Medical Center, San Jose, CA, USA
| | - R Wallerstein
- Hawaii Community Genetics, Kapiolani Medical Center for Women and Children, Honolulu, HI, USA
| | - G Houge
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Medical Genetics, St. Olav Hospital, Trondheim, Norway
| | - S Berland
- Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Medical Genetics, St. Olav Hospital, Trondheim, Norway
| | | | - A Poretti
- Section of Pediatric Neuroradiology, Division of Pediatric Radiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Hospital, Baltimore, MD, USA
| | - A L Wilson
- Department of Clinical Genetics, New York Presbyterian Hospital, New York, NY, USA
| | - W K Chung
- Department of Pediatrics, Columbia University, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA
| | - A Fatemi
- Division of Neurogenetics, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA.,Department of Neurology, The Johns Hopkins Hospital, Baltimore, MD, USA.,Department of Pediatrics, The Johns Hopkins Hospital, Baltimore, MD, USA
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138
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Rodan LH, Cohen J, Fatemi A, Gillis T, Lucente D, Gusella J, Picker JD. A novel neurodevelopmental disorder associated with compound heterozygous variants in the huntingtin gene. Eur J Hum Genet 2016; 24:1826-1827. [PMID: 27329733 DOI: 10.1038/ejhg.2016.74] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 04/28/2016] [Accepted: 05/26/2016] [Indexed: 11/09/2022] Open
Abstract
We report compound heterozygous variants in HTT, the gene encoding huntingtin, in association with an autosomal recessive neurodevelopmental disorder. Three siblings presented with severe global developmental delay since birth, central hypotonia progressing to spastic quadraparesis, feeding difficulties, dystonia (2/3 sibs), prominent midline stereotypies (2/3), bruxism (1/3), high myopia (2/3), and epilepsy (1/3). Whole exome sequencing identified compound heterozygous variants in HTT that co-segregated in the three affected sibs and were absent in an unaffected sib. There were no additional variants in other genes that could account for the reported phenotype. Molecular analysis of HTT should be considered, not just for Huntington's disease, but also in children with a Rett-like syndrome who test negative for known Rett and Rett-like syndrome genes.
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Affiliation(s)
- Lance H Rodan
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Julie Cohen
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Ali Fatemi
- Division of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Tammy Gillis
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
| | - Diane Lucente
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
| | - James Gusella
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Jonathan D Picker
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
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