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Akefe IO, Saber SH, Matthews B, Venkatesh BG, Gormal RS, Blackmore DG, Alexander S, Sieriecki E, Gambin Y, Bertran-Gonzalez J, Vitale N, Humeau Y, Gaudin A, Ellis SA, Michaels AA, Xue M, Cravatt B, Joensuu M, Wallis TP, Meunier FA. The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids. EMBO J 2024; 43:533-567. [PMID: 38316990 PMCID: PMC10897203 DOI: 10.1038/s44318-024-00030-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 12/06/2023] [Accepted: 12/14/2023] [Indexed: 02/07/2024] Open
Abstract
The phospholipid and free fatty acid (FFA) composition of neuronal membranes plays a crucial role in learning and memory, but the mechanisms through which neuronal activity affects the brain's lipid landscape remain largely unexplored. The levels of saturated FFAs, particularly of myristic acid (C14:0), strongly increase during neuronal stimulation and memory acquisition, suggesting the involvement of phospholipase A1 (PLA1) activity in synaptic plasticity. Here, we show that genetic ablation of the PLA1 isoform DDHD2 in mice dramatically reduces saturated FFA responses to memory acquisition across the brain. Furthermore, DDHD2 loss also decreases memory performance in reward-based learning and spatial memory models prior to the development of neuromuscular deficits that mirror human spastic paraplegia. Via pulldown-mass spectrometry analyses, we find that DDHD2 binds to the key synaptic protein STXBP1. Using STXBP1/2 knockout neurosecretory cells and a haploinsufficient STXBP1+/- mouse model of human early infantile encephalopathy associated with intellectual disability and motor dysfunction, we show that STXBP1 controls targeting of DDHD2 to the plasma membrane and generation of saturated FFAs in the brain. These findings suggest key roles for DDHD2 and STXBP1 in lipid metabolism and in the processes of synaptic plasticity, learning, and memory.
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Affiliation(s)
- Isaac O Akefe
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
- Academy for Medical Education, Medical School, The University of Queensland, 288 Herston Road, 4006, Brisbane, QLD, Australia
| | - Saber H Saber
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, St Lucia, QLD, 4072, Australia
| | - Benjamin Matthews
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Bharat G Venkatesh
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Daniel G Blackmore
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Suzy Alexander
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Emma Sieriecki
- School of Medical Science, University of New South Wales, Randwick, NSW, 2052, Australia
- EMBL Australia, Single Molecule Node, University of New South Wales, Sydney, 2052, Australia
| | - Yann Gambin
- School of Medical Science, University of New South Wales, Randwick, NSW, 2052, Australia
- EMBL Australia, Single Molecule Node, University of New South Wales, Sydney, 2052, Australia
| | | | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, UPR-3212 CNRS - Université de Strasbourg, Strasbourg, France
| | - Yann Humeau
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Université de Bordeaux, Bordeaux, France
| | - Arnaud Gaudin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Sevannah A Ellis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Alysee A Michaels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Mingshan Xue
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Benjamin Cravatt
- The Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia.
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, St Lucia, QLD, 4072, Australia.
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia.
- The School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
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Kolesnikova TO, Demin KA, Costa FV, Zabegalov KN, de Abreu MS, Gerasimova EV, Kalueff AV. Towards Zebrafish Models of CNS Channelopathies. Int J Mol Sci 2022; 23:ijms232213979. [PMID: 36430455 PMCID: PMC9693542 DOI: 10.3390/ijms232213979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Channelopathies are a large group of systemic disorders whose pathogenesis is associated with dysfunctional ion channels. Aberrant transmembrane transport of K+, Na+, Ca2+ and Cl- by these channels in the brain induces central nervous system (CNS) channelopathies, most commonly including epilepsy, but also migraine, as well as various movement and psychiatric disorders. Animal models are a useful tool for studying pathogenesis of a wide range of brain disorders, including channelopathies. Complementing multiple well-established rodent models, the zebrafish (Danio rerio) has become a popular translational model organism for neurobiology, psychopharmacology and toxicology research, and for probing mechanisms underlying CNS pathogenesis. Here, we discuss current prospects and challenges of developing genetic, pharmacological and other experimental models of major CNS channelopathies based on zebrafish.
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Affiliation(s)
| | - Konstantin A. Demin
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
| | - Fabiano V. Costa
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | | | - Murilo S. de Abreu
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| | - Elena V. Gerasimova
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | - Allan V. Kalueff
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, 197758 St. Petersburg, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
- Scientific Research Institute of Neurosciences and Medicine, 630117 Novosibirsk, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
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3
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Burns W, Chaudhari BP, Haffner DN. Neurogenetic and Metabolic Mimics of Common Neonatal Neurological Disorders. Semin Pediatr Neurol 2022; 42:100972. [PMID: 35868729 DOI: 10.1016/j.spen.2022.100972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
Neurogenetic and metabolic diseases often present in the neonatal period, masquerading as other disorders, most commonly as neonatal encephalopathy and seizures. Advancements in our understanding of inborn errors of metabolism are leading to an increasing number of therapeutic options. Many of these treatments can improve long-term neurodevelopment and seizure control. However, the treatments are frequently condition-specific. A high index of suspicion is required for prompt identification and treatment. When suspected, simultaneous metabolic and molecular testing are recommended along with concurrent treatment.
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Affiliation(s)
- William Burns
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH.
| | - Bimal P Chaudhari
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neonatology, Nationwide Children's Hospital, Columbus, OH; Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Darrah N Haffner
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neurology, Nationwide Children's Hospital, Columbus, OH
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New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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Saleh M, Helmi M, Yacop B. A Novel Nonsense Gene Variant Responsible for Early Infantile Epileptic Encephalopathy Type 39: Case Report. Pak J Biol Sci 2020; 23:973-976. [PMID: 32700846 DOI: 10.3923/pjbs.2020.973.976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Early infantile epileptic encephalopathy (EIEE) is a severe form neurological disorder of age-related epileptic encephalopathy. Characteristically, it presents with tonic spasms within the first 3 months of life. The spasms can be generalized or focal and hemi-convulsions, it can be in clusters or singly which occur hundreds of times per day, not related to sleep cycle, leading to psychomotor impairment and death. Some cases of EIEE are due to metabolic disorders or brain malformations that may or not be genetic in origin. The genetic origin of EIEE are usually related to brain dysgenesis or neuronal dysfunction. Early infantile epileptic encephalopathy-39 (EIEE39) is a result of homozygous mutation in the SLC25A12 gene (603667) on chromosome 2q31. Here it was described a homozygous nonsense variant of the SLC25A12 gene in our 7 years old child, which was not reported in the literature so far.
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Radaelli G, de Souza Santos F, Borelli WV, Pisani L, Nunes ML, Scorza FA, da Costa JC. Causes of mortality in early infantile epileptic encephalopathy: A systematic review. Epilepsy Behav 2018; 85:32-36. [PMID: 29906699 DOI: 10.1016/j.yebeh.2018.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/25/2018] [Accepted: 05/05/2018] [Indexed: 10/14/2022]
Abstract
INTRODUCTION Early infantile epileptic encephalopathy syndrome (EIEE), also known as Ohtahara syndrome, is an age-dependent epileptic encephalopathy syndrome defined by clinical features and electroencephalographic findings. Epileptic disorders with refractory seizures beginning in the neonatal period and/or early infancy have a potential risk of premature mortality, including sudden death. We aimed to identify the causes of death in EIEE and conducted a literature survey of fatal outcomes. METHODS We performed a literature search in MEDLINE, EMBASE, and Web of Science for data from inception until September 2017. The terms "death sudden," "unexplained death," "SUDEP," "lethal," and "fatal" and the medical subject heading terms "epileptic encephalopathy," "mortality," "death," "sudden infant death syndrome," and "human" were used in the search strategy. The EIEE case report studies reporting mortality were included. RESULTS The search yielded 1360 articles. After screening for titles and abstracts and removing duplicate entries, full texts of 15 articles were reviewed. After reading full texts, 11 articles met the inclusion criteria (9 articles in English and 2 in Japanese, dated from 1976 to 2015). The review comprised 38 unique cases of EIEE, 17 of which had death as an outcome. In all cases, the suppression-burst pattern on electroencephalographies (EEGs) was common. Most cases (55%) involved male infants. The mean (standard deviation [SD]) age at onset of seizure was 19.6 ± 33 days. The mean (SD) age at death was 12.9 ± 14.1 months. Most infants (58.8%) survived less than one year. The cause of death was described only in eight (47%) patients; the cause was pneumonia/respiratory illness or sudden unexpected death in epilepsy (SUDEP). DISCUSSION The results show EIEE as a severe disease associated with a premature mortality, evidenced by a very young age at death. Increasing interest in the detection of new molecular bases of EIEE is leading us to a better understanding of this severe disease, but well-reported data are lacking to clarify EIEE-related causes of death.
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Affiliation(s)
- Graciane Radaelli
- Federal University of São Paulo (UNIFESP)/Paulista School of Medicine, São Paulo, Brazil; Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Francisco de Souza Santos
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Wyllians Vendramini Borelli
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Leonardo Pisani
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Magda Lahorgue Nunes
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil; CNPq, Brazil
| | - Fulvio Alexandre Scorza
- Laboratory of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo, São Paulo, SP, Brazil; CNPq, Brazil
| | - Jaderson Costa da Costa
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil; CNPq, Brazil.
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Kothur K, Holman K, Farnsworth E, Ho G, Lorentzos M, Troedson C, Gupta S, Webster R, Procopis PG, Menezes MP, Antony J, Ardern-Holmes S, Dale RC, Christodoulou J, Gill D, Bennetts B. Diagnostic yield of targeted massively parallel sequencing in children with epileptic encephalopathy. Seizure 2018; 59:132-140. [DOI: 10.1016/j.seizure.2018.05.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 02/20/2018] [Accepted: 05/08/2018] [Indexed: 12/28/2022] Open
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Wipfler K, Cornish AS, Guda C. Comparative molecular characterization of typical and exceptional responders in glioblastoma. Oncotarget 2018; 9:28421-28433. [PMID: 29983870 PMCID: PMC6033343 DOI: 10.18632/oncotarget.25420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 04/27/2018] [Indexed: 12/21/2022] Open
Abstract
Glioblastoma (GBM) is the most common and the deadliest type of primary brain tumor, with a median survival time of only 15 months despite aggressive treatment. Although most patients have an extremely poor prognosis, a relatively small number of patients survive far beyond the median survival time. Investigation of these exceptional responders has sparked a great deal of interest and is becoming an important focus in the field of cancer research. To investigate the molecular differences between typical and exceptional responders in GBM, comparative analyses of somatic mutations, copy number, methylation, and gene expression datasets from The Cancer Genome Atlas were performed, and the results of these analyses were integrated via gene ontology and pathway analyses to assess the functional significance of the differential aberrations. Less severe copy number loss of CDKN2A, lower expression of CXCL8, and FLG mutations are all associated with an exceptional response. Typical responders are characterized by upregulation of NF-κB signaling and of pro-inflammatory cytokines, while exceptional responders are characterized by upregulation of Alzheimer's and Parkinson's disease pathways as well as of genes involved in synaptic transmission. The upregulated pathways and processes in typical responders are consistently associated with more aggressive tumor phenotypes, while those in the exceptional responders suggest a retained ability in tumor cells to undergo cell death in response to treatment. With the upcoming launch of the National Cancer Institute's Exceptional Responders Initiative, similar studies with much larger sample sizes will likely become possible, hopefully providing even more insight into the molecular differences between typical and exceptional responders.
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Affiliation(s)
- Kristin Wipfler
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Adam S. Cornish
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Bioinformatics and Systems Biology Core, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
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A Recurrent De Novo PACS2 Heterozygous Missense Variant Causes Neonatal-Onset Developmental Epileptic Encephalopathy, Facial Dysmorphism, and Cerebellar Dysgenesis. Am J Hum Genet 2018; 102:995-1007. [PMID: 29656858 DOI: 10.1016/j.ajhg.2018.03.005] [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: 12/22/2017] [Accepted: 02/27/2018] [Indexed: 11/24/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) represent a large clinical and genetic heterogeneous group of neurodevelopmental diseases. The identification of pathogenic genetic variants in DEEs remains crucial for deciphering this complex group and for accurately caring for affected individuals (clinical diagnosis, genetic counseling, impacting medical, precision therapy, clinical trials, etc.). Whole-exome sequencing and intensive data sharing identified a recurrent de novo PACS2 heterozygous missense variant in 14 unrelated individuals. Their phenotype was characterized by epilepsy, global developmental delay with or without autism, common cerebellar dysgenesis, and facial dysmorphism. Mixed focal and generalized epilepsy occurred in the neonatal period, controlled with difficulty in the first year, but many improved in early childhood. PACS2 is an important PACS1 paralog and encodes a multifunctional sorting protein involved in nuclear gene expression and pathway traffic regulation. Both proteins harbor cargo(furin)-binding regions (FBRs) that bind cargo proteins, sorting adaptors, and cellular kinase. Compared to the defined PACS1 recurrent variant series, individuals with PACS2 variant have more consistently neonatal/early-infantile-onset epilepsy that can be challenging to control. Cerebellar abnormalities may be similar but PACS2 individuals exhibit a pattern of clear dysgenesis ranging from mild to severe. Functional studies demonstrated that the PACS2 recurrent variant reduces the ability of the predicted autoregulatory domain to modulate the interaction between the PACS2 FBR and client proteins, which may disturb cellular function. These findings support the causality of this recurrent de novo PACS2 heterozygous missense in DEEs with facial dysmorphim and cerebellar dysgenesis.
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Sowada N, Hashem MO, Yilmaz R, Hamad M, Kakar N, Thiele H, Arold ST, Bode H, Alkuraya FS, Borck G. Mutations of PTPN23 in developmental and epileptic encephalopathy. Hum Genet 2017; 136:1455-1461. [PMID: 29090338 DOI: 10.1007/s00439-017-1850-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 10/22/2017] [Indexed: 11/26/2022]
Abstract
Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of neurodevelopmental disorders with poor prognosis. Recent discoveries have greatly expanded the repertoire of genes that are mutated in epileptic encephalopathies and DEE, often in a de novo fashion, but in many patients, the disease remains molecularly uncharacterized. Here, we describe a new form of DEE in patients with likely deleterious biallelic variants in PTPN23. The phenotype is characterized by early onset drug-resistant epilepsy, severe and global developmental delay, microcephaly, and sometimes premature death. PTPN23 encodes a tyrosine phosphatase with strong brain expression, and its knockout in mouse is embryonically lethal. Structural modeling supports a deleterious effect of the identified alleles. Our data suggest that PTPN23 mutations cause a rare severe form of autosomal-recessive DEE in humans, a finding that requires confirmation.
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Affiliation(s)
- Nadine Sowada
- Institute of Human Genetics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Mais Omar Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rüstem Yilmaz
- Institute of Human Genetics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Muddathir Hamad
- Department of Pediatrics, King Khalid University Hospital, Riyadh, Saudi Arabia
| | - Naseebullah Kakar
- Institute of Human Genetics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Department of Biotechnology, BUITEMS, Quetta, Pakistan
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Stefan T Arold
- Division of Biological and Environmental Sciences and Engineering (BESE), Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Harald Bode
- Division of Pediatric Neurology, Children's Hospital, University of Ulm, Ulm, Germany
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Guntram Borck
- Institute of Human Genetics, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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11
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Bainbridge MN, Cooney E, Miller M, Kennedy AD, Wulff JE, Donti T, Jhangiani SN, Gibbs RA, Elsea SH, Porter BE, Graham BH. Analyses of SLC13A5-epilepsy patients reveal perturbations of TCA cycle. Mol Genet Metab 2017; 121:314-319. [PMID: 28673551 PMCID: PMC7539367 DOI: 10.1016/j.ymgme.2017.06.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 01/16/2023]
Abstract
OBJECTIVE To interrogate the metabolic profile of five subjects from three families with rare, nonsense and missense mutations in SLC13A5 and Early Infantile Epileptic Encephalopathies (EIEE) characterized by severe, neonatal onset seizures, psychomotor retardation and global developmental delay. METHODS Mass spectrometry of plasma, CSF and urine was used to identify consistently dysregulated analytes in our subjects. RESULTS Distinctive elevations of citrate and dysregulation of citric acid cycle intermediates, supporting the hypothesis that loss of SLC13A5 function alters tricarboxylic acid cycle (TCA) metabolism and may disrupt metabolic compartmentation in the brain. SIGNIFICANCE Our results indicate that analysis of plasma citrate and other TCA analytes in SLC13A5 deficient patients define a diagnostic metabolic signature that can aid in diagnosing children with this disease.
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Affiliation(s)
- Matthew N Bainbridge
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States; Codified Genomics LLC, Houston, TX, United States; Institute for Genomic Medicine, Rady Children's Hospital, San Diego, CA, United States
| | - Erin Cooney
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Marcus Miller
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | | | | | - Taraka Donti
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Sarah H Elsea
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Brenda E Porter
- Department of Neurology, Stanford University Medical School, Palo Alto, CA, United States
| | - Brett H Graham
- Dept. of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.
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12
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Lalani SR. Current Genetic Testing Tools in Neonatal Medicine. Pediatr Neonatol 2017; 58:111-121. [PMID: 28277305 DOI: 10.1016/j.pedneo.2016.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/13/2016] [Accepted: 07/08/2016] [Indexed: 12/31/2022] Open
Abstract
With the growing understanding of the magnitude of genetic diseases in newborns and equally rapid advancement of tools used for genetic diagnoses, healthcare providers must have a sufficient knowledge base to both recognize and evaluate genetic diseases in the neonatal period. Genetic assessment has become an essential aspect of medicine, and professionals need to know when genetic evaluation is indispensable. Much progress has been made in recent years in utilizing massively parallel sequencing for rapid diagnosis of genetic conditions in neonates. Next-generation sequencing is increasingly being used for noninvasive prenatal diagnosis, and it may become an essential component of newborn screening. This review will define some basic genetic terms and concepts, explain the gamut of genetic testing available for early diagnosis of genetic diseases, and describe some common chromosomal abnormalities, genomic disorders, and single-gene diseases relevant to neonatal medicine.
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Affiliation(s)
- Seema R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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Chai YJ, Sierecki E, Tomatis VM, Gormal RS, Giles N, Morrow IC, Xia D, Götz J, Parton RG, Collins BM, Gambin Y, Meunier FA. Munc18-1 is a molecular chaperone for α-synuclein, controlling its self-replicating aggregation. J Cell Biol 2016; 214:705-18. [PMID: 27597756 PMCID: PMC5021092 DOI: 10.1083/jcb.201512016] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 08/03/2016] [Indexed: 01/06/2023] Open
Abstract
Munc18-1 heterozygous mutations are associated with developmental diseases, including early infantile epileptic encephalopathy (EIEE). Chai et al. report that Munc18-1 acts as a chaperone for α-synuclein and controls its aggregative propensity. Munc18-1 EIEE-associated mutations promote the aggregation of endogenous α-synuclein in neurons, leading to a neurodegenerative phenotype. Munc18-1 is a key component of the exocytic machinery that controls neurotransmitter release. Munc18-1 heterozygous mutations cause developmental defects and epileptic phenotypes, including infantile epileptic encephalopathy (EIEE), suggestive of a gain of pathological function. Here, we used single-molecule analysis, gene-edited cells, and neurons to demonstrate that Munc18-1 EIEE-causing mutants form large polymers that coaggregate wild-type Munc18-1 in vitro and in cells. Surprisingly, Munc18-1 EIEE mutants also form Lewy body–like structures that contain α-synuclein (α-Syn). We reveal that Munc18-1 binds α-Syn, and its EIEE mutants coaggregate α-Syn. Likewise, removal of endogenous Munc18-1 increases the aggregative propensity of α-SynWT and that of the Parkinson’s disease–causing α-SynA30P mutant, an effect rescued by Munc18-1WT expression, indicative of chaperone activity. Coexpression of the α-SynA30P mutant with Munc18-1 reduced the number of α-SynA30P aggregates. Munc18-1 mutations and haploinsufficiency may therefore trigger a pathogenic gain of function through both the corruption of native Munc18-1 and a perturbed chaperone activity for α-Syn leading to aggregation-induced neurodegeneration.
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Affiliation(s)
- Ye Jin Chai
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Emma Sierecki
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia Single Molecule Sciences Centre, European Molecular Biology Laboratory Australia, The University of New South Wales, Sydney 2052, Australia
| | - Vanesa M Tomatis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nichole Giles
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia Single Molecule Sciences Centre, European Molecular Biology Laboratory Australia, The University of New South Wales, Sydney 2052, Australia
| | - Isabel C Morrow
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Di Xia
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Yann Gambin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia Single Molecule Sciences Centre, European Molecular Biology Laboratory Australia, The University of New South Wales, Sydney 2052, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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14
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Siekierska A, Isrie M, Liu Y, Scheldeman C, Vanthillo N, Lagae L, de Witte PAM, Van Esch H, Goldfarb M, Buyse GM. Gain-of-function FHF1 mutation causes early-onset epileptic encephalopathy with cerebellar atrophy. Neurology 2016; 86:2162-70. [PMID: 27164707 DOI: 10.1212/wnl.0000000000002752] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/12/2016] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE Voltage-gated sodium channel (Nav)-encoding genes are among early-onset epileptic encephalopathies (EOEE) targets, suggesting that other genes encoding Nav-binding proteins, such as fibroblast growth factor homologous factors (FHFs), may also play roles in these disorders. METHODS To identify additional genes for EOEE, we performed whole-exome sequencing in a family quintet with 2 siblings with a lethal disease characterized by EOEE and cerebellar atrophy. The pathogenic nature and functional consequences of the identified sequence alteration were determined by electrophysiologic studies in vitro and in vivo. RESULTS A de novo heterozygous missense mutation was identified in the FHF1 gene (FHF1AR114H, FHF1BR52H) in the 2 affected siblings. The mutant FHF1 proteins had a strong gain-of-function phenotype in transfected Neuro2A cells, enhancing the depolarizing shifts in Nav1.6 voltage-dependent fast inactivation, predicting increased neuronal excitability. Surprisingly, the gain-of-function effect is predicted to result from weaker interaction of mutant FHF1 with the Nav cytoplasmic tail. Transgenic overexpression of mutant FHF1B in zebrafish larvae enhanced epileptiform discharges, demonstrating the epileptic potential of this FHF1 mutation in the affected children. CONCLUSIONS Our data demonstrate that gain-of-function FHF mutations can cause neurologic disorder, and expand the repertoire of genetic causes (FHF1) and mechanisms (altered Nav gating) underlying EOEE and cerebellar atrophy.
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Affiliation(s)
- Aleksandra Siekierska
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Mala Isrie
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Yue Liu
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Chloë Scheldeman
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Niels Vanthillo
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Lieven Lagae
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Peter A M de Witte
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Hilde Van Esch
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Mitchell Goldfarb
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY
| | - Gunnar M Buyse
- From the Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences (A.S., C.S., N.V., P.A.M.d.W.), and Laboratory for the Genetics of Cognition (M.I.), University of Leuven; Center for Human Genetics (M.I., H.V.E.) and Child Neurology (L.L., G.M.B.), University Hospitals Leuven; Department of Biological Sciences (Y.L., M.G.), Hunter College of City University, New York; and Graduate Program in Biology/Neuroscience at City University (Y.L.), New York, NY.
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15
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Trump N, McTague A, Brittain H, Papandreou A, Meyer E, Ngoh A, Palmer R, Morrogh D, Boustred C, Hurst JA, Jenkins L, Kurian MA, Scott RH. Improving diagnosis and broadening the phenotypes in early-onset seizure and severe developmental delay disorders through gene panel analysis. J Med Genet 2016; 53:310-7. [PMID: 26993267 PMCID: PMC4862068 DOI: 10.1136/jmedgenet-2015-103263] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 11/22/2015] [Indexed: 11/17/2022]
Abstract
Background We sought to investigate the diagnostic yield and mutation spectrum in previously reported genes for early-onset epilepsy and disorders of severe developmental delay. Methods In 400 patients with these disorders with no known underlying aetiology and no major structural brain anomaly, we analysed 46 genes using a combination of targeted sequencing on an Illumina MiSeq platform and targeted, exon-level microarray copy number analysis. Results We identified causative mutations in 71/400 patients (18%). The diagnostic rate was highest among those with seizure onset within the first two months of life (39%), although overall it was similar in those with and without seizures. The most frequently mutated gene was SCN2A (11 patients, 3%). Other recurrently mutated genes included CDKL5, KCNQ2, SCN8A (six patients each), FOXG1, MECP2, SCN1A, STXBP1 (five patients each), KCNT1, PCDH19, TCF4 (three patients each) and ATP1A3, PRRT2 and SLC9A6 (two patients each). Mutations in EHMT1, GABRB3, LGI1, MBD5, PIGA, UBE3A and ZEB2 were each found in single patients. We found mutations in a number of genes in patients where either the electroclinical features or dysmorphic phenotypes were atypical for the identified gene. In only 11 cases (15%) had the clinician sufficient certainty to specify the mutated gene as the likely cause before testing. Conclusions Our data demonstrate the considerable utility of a gene panel approach in the diagnosis of patients with early-onset epilepsy and severe developmental delay disorders., They provide further insights into the phenotypic spectrum and genotype–phenotype correlations for a number of the causative genes and emphasise the value of exon-level copy number testing in their analysis.
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Affiliation(s)
- Natalie Trump
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Amy McTague
- Molecular Neurosciences, Developmental Neurosciences Programme, University College London Institute of Child Health, London, UK Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Helen Brittain
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, University College London Institute of Child Health, London, UK Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Esther Meyer
- Molecular Neurosciences, Developmental Neurosciences Programme, University College London Institute of Child Health, London, UK Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Adeline Ngoh
- Molecular Neurosciences, Developmental Neurosciences Programme, University College London Institute of Child Health, London, UK Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Rodger Palmer
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Deborah Morrogh
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Christopher Boustred
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Jane A Hurst
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Lucy Jenkins
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, University College London Institute of Child Health, London, UK Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Richard H Scott
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, UK Genetics and Genomic Medicine Unit, University College London Institute of Child Health, London, UK
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16
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Yamamoto T, Shimojima K, Yano T, Ueda Y, Takayama R, Ikeda H, Imai K. Loss-of-function mutations of STXBP1 in patients with epileptic encephalopathy. Brain Dev 2016; 38:280-4. [PMID: 26384463 DOI: 10.1016/j.braindev.2015.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/25/2015] [Accepted: 09/07/2015] [Indexed: 11/30/2022]
Abstract
Epileptic encephalopathy, which commences during early infancy, is a severe epileptic syndrome that manifests as age-dependent seizures and severe developmental delay. The syntaxin-binding protein 1 gene (STXBP1) is one of the genes responsible for epileptic encephalopathy. We conducted a cohort study to analyze STXBP1 in 42 patients with epileptic encephalopathy. We identified four novel mutations: two splicing mutations, a frameshift mutation, and a nonsense mutation. All of these mutations were predicted to cause loss-of-function. This result suggests loss-of-function is a common mechanism underlying STXBP1-related epileptic encephalopathy. The four patients showed epileptic features consistent with STXBP1-related epileptic encephalopathy, but showed variable radiological findings, including brain volume loss and myelination delay.
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Affiliation(s)
- Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan.
| | - Keiko Shimojima
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan
| | - Tamami Yano
- Department of Pediatrics, Faculty of Medicine, Akita University, Akita, Japan
| | - Yuki Ueda
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan
| | - Rumiko Takayama
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan
| | - Hiroko Ikeda
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan
| | - Katsumi Imai
- National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan
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17
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Parker A. Genomics in early infantile epileptic encephalopathies - trials and tribulations. Dev Med Child Neurol 2016; 58:15. [PMID: 26365232 DOI: 10.1111/dmcn.12928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alasdair Parker
- Department of Paediatric Neuroscience, Addenbrooke's Hospital, Cambridge, UK
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18
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Babkina N, Deignan JL, Lee H, Vilain E, Sankar R, Giurgea I, Mowat D, Graham JM. Early Infantile Epileptic Encephalopathy with a de novo variant in ZEB2 identified by exome sequencing. Eur J Med Genet 2015; 59:70-4. [PMID: 26721324 DOI: 10.1016/j.ejmg.2015.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 11/08/2015] [Accepted: 12/19/2015] [Indexed: 12/12/2022]
Abstract
Early Infantile Epileptic Encephalopathy (EIEE) presents shortly after birth with frequent, severe seizures, a burst-suppression EEG pattern, and progressive disturbance of cerebral function. We present a case of EIEE associated with a de novo missense variant in ZEB2. Heterozygous truncating mutations or deletions in ZEB2 are known to cause Mowat-Wilson syndrome (MWS), which is characterized by seizures with onset in the second year of life, distinctive dysmorphic facial features and malformations that were absent in this patient. This unique case expands the range of phenotypes associated with variants in ZEB2 and indicates that this gene should be included in the molecular investigation of EIEE cases.
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Affiliation(s)
- Natalia Babkina
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Pediatrics, Division of Medical Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Joshua L Deignan
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Hane Lee
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Eric Vilain
- Department of Pediatrics, Division of Medical Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Raman Sankar
- Department of Neurology, Pediatrics and Children's Discovery and Innovation Institute at Mattel Children's Hospital, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Irina Giurgea
- Service de Biochimie Génétique, INSERM U955 Equipe 11, Hôpital Henri Mondor, 94000 Créteil, France
| | - David Mowat
- Department of Medical Genetics, Sydney Children's Hospital, School of Women's and Children's Health, University of New South Wales, Australia
| | - John M Graham
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Pediatrics, Division of Medical Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
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19
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Functional analysis of a de novo GRIN2A missense mutation associated with early-onset epileptic encephalopathy. Nat Commun 2015; 5:3251. [PMID: 24504326 PMCID: PMC3934797 DOI: 10.1038/ncomms4251] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/13/2014] [Indexed: 12/21/2022] Open
Abstract
NMDA receptors (NMDARs), ligand-gated ion channels, play important roles in various neurological disorders, including epilepsy. Here we show the functional analysis of a de novo missense mutation (L812M) in a gene encoding NMDAR subunit GluN2A (GRIN2A). The mutation, identified in a patient with early-onset epileptic encephalopathy and profound developmental delay, is located in the linker region between the ligand-binding and transmembrane domains. Electrophysiological recordings revealed that the mutation enhances agonist potency, decreases sensitivity to negative modulators including magnesium, protons and zinc, prolongs the synaptic response time course and increases single-channel open probability. The functional changes of this amino acid apply to all other NMDAR subunits, suggesting an important role of this residue on the function of NMDARs. Taken together, these data suggest that the L812M mutation causes overactivation of NMDARs and drives neuronal hyperexcitability. We hypothesize that this mechanism underlies the patient's epileptic phenotype as well as cerebral atrophy.
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20
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Recurrent occurrences of CDKL5 mutations in patients with epileptic encephalopathy. Hum Genome Var 2015; 2:15042. [PMID: 27081548 PMCID: PMC4785533 DOI: 10.1038/hgv.2015.42] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/02/2015] [Accepted: 09/23/2015] [Indexed: 11/08/2022] Open
Abstract
The cyclin-dependent kinase-like 5 gene (CDKL5) is recognized as one of the genes responsible for epileptic encephalopathy. We identified CDKL5 mutations in five Japanese patients (one male and four female) with epileptic encephalopathy. Although all mutations were of de novo origin, they were located in the same positions as previously reported pathogenic mutations. These recurrent occurrences of de novo mutations in the same loci may indicate hot spots of nucleotide alteration.
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21
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Bhatnagar M, Shorvon S. Genetic mutations associated with status epilepticus. Epilepsy Behav 2015; 49:104-10. [PMID: 25982265 DOI: 10.1016/j.yebeh.2015.04.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/06/2015] [Accepted: 04/07/2015] [Indexed: 01/28/2023]
Abstract
This paper reports the results of a preliminary search of the literature aimed at identifying the genetic mutations reported to be strongly associated with status epilepticus. Genetic mutations were selected for inclusion if status epilepticus was specifically mentioned as a consequence of the mutation in standard genetic databases or in a case report or review article. Mutations in 122 genes were identified. The genetic mutations identified were found in only rare conditions (sometimes vanishingly rare) and mostly in infants and young children with multiple other handicaps. Most of the genetic mutations can be subdivided into those associated with cortical dysplasias, inborn errors of metabolism, mitochondrial disease, or epileptic encephalopathies and childhood syndromes. There are no identified 'pure status epilepticus genes'. The range of genes underpinning status epilepticus differs in many ways from the range of genes underpinning epilepsy, which suggests that the processes underpinning status epilepticus differ from those underpinning epilepsy. It has been frequently postulated that status epilepticus is the result of a failure of 'seizure termination mechanisms', but the wide variety of genes affecting very diverse biochemical pathways identified in this survey makes any unitary cause unlikely. The genetic influences in status epilepticus are likely to involve a wide range of mechanisms, some related to development, some to cerebral energy production, some to diverse altered biochemical pathways, some to transmitter and membrane function, and some to defects in networks or systems. The fact that many of the identified genes are involved with cerebral development suggests that status epilepticus might often be a system or network phenomenon. To date, there are very few genes identified which are associated with adult-onset status epilepticus (except in those with preexisting neurological damage), and this is disappointing as the cause of many adult-onset status epilepticus cases remains obscure. It has been suggested that idiopathic adult-onset status epilepticus might often have an immunological cause but no gene mutations which relate to immunological mechanisms were identified. Overall, the clinical utility of what is currently known about the genetics of status epilepticus is slight and the findings have had little impact on clinical treatment despite what has been a very large investment in money and time. New genetic technologies may result in the identification of further genes, but if the identified genetic defects confer only minor susceptibility, this is unlikely to influence therapy. It is also important to recognize that genetics has social implications in a way that other areas of science do not. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- M Bhatnagar
- UCL Institute of Neurology, University College London, UK
| | - S Shorvon
- UCL Institute of Neurology, University College London, UK.
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22
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Abstract
As the genetic etiologies of an expanding number of epilepsy syndromes are revealed, the complexity of the phenotype genotype correlation increases. As our review will show, multiple gene mutations cause different epilepsy syndromes, making identification of the specific mutation increasingly more important for prognostication and often more directed treatment. Examples of that include the need to avoid specific drugs in Dravet syndrome and the ongoing investigations of the potential use of new directed therapies such as retigabine in KCNQ2-related epilepsies, quinidine in KCNT1-related epilepsies, and memantine in GRIN2A-related epilepsies.
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Affiliation(s)
- Abeer J Hani
- Division of Pediatric Neurology, Department of Pediatrics, Duke Children's Hospital and Health Center, Suite T0913J, 2301 Erwin Road, Durham, NC 27710, USA
| | - Husam M Mikati
- Center of Human Genome Variation, LSRC, Duke University School of Medicine, 201 Trent Drive, Durham, NC 27710, USA
| | - Mohamad A Mikati
- Division of Pediatric Neurology, Department of Pediatrics, Duke Children's Hospital and Health Center, Suite T0913J, 2301 Erwin Road, Durham, NC 27710, USA.
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23
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Mertz J, Tan H, Pagala V, Bai B, Chen PC, Li Y, Cho JH, Shaw T, Wang X, Peng J. Sequential Elution Interactome Analysis of the Mind Bomb 1 Ubiquitin Ligase Reveals a Novel Role in Dendritic Spine Outgrowth. Mol Cell Proteomics 2015; 14:1898-910. [PMID: 25931508 DOI: 10.1074/mcp.m114.045898] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Indexed: 11/06/2022] Open
Abstract
The mind bomb 1 (Mib1) ubiquitin ligase is essential for controlling metazoan development by Notch signaling and possibly the Wnt pathway. It is also expressed in postmitotic neurons and regulates neuronal morphogenesis and synaptic activity by mechanisms that are largely unknown. We sought to comprehensively characterize the Mib1 interactome and study its potential function in neuron development utilizing a novel sequential elution strategy for affinity purification, in which Mib1 binding proteins were eluted under different stringency and then quantified by the isobaric labeling method. The strategy identified the Mib1 interactome with both deep coverage and the ability to distinguish high-affinity partners from low-affinity partners. A total of 817 proteins were identified during the Mib1 affinity purification, including 56 high-affinity partners and 335 low-affinity partners, whereas the remaining 426 proteins are likely copurified contaminants or extremely weak binding proteins. The analysis detected all previously known Mib1-interacting proteins and revealed a large number of novel components involved in Notch and Wnt pathways, endocytosis and vesicle transport, the ubiquitin-proteasome system, cellular morphogenesis, and synaptic activities. Immunofluorescence studies further showed colocalization of Mib1 with five selected proteins: the Usp9x (FAM) deubiquitinating enzyme, alpha-, beta-, and delta-catenins, and CDKL5. Mutations of CDKL5 are associated with early infantile epileptic encephalopathy-2 (EIEE2), a severe form of mental retardation. We found that the expression of Mib1 down-regulated the protein level of CDKL5 by ubiquitination, and antagonized CDKL5 function during the formation of dendritic spines. Thus, the sequential elution strategy enables biochemical characterization of protein interactomes; and Mib1 analysis provides a comprehensive interactome for investigating its role in signaling networks and neuronal development.
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Affiliation(s)
- Joseph Mertz
- From the ‡Departments of Structural Biology and Developmental Neurobiology
| | | | | | - Bing Bai
- From the ‡Departments of Structural Biology and Developmental Neurobiology
| | - Ping-Chung Chen
- From the ‡Departments of Structural Biology and Developmental Neurobiology
| | - Yuxin Li
- From the ‡Departments of Structural Biology and Developmental Neurobiology
| | | | - Timothy Shaw
- §St. Jude Proteomics Facility, ¶Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | | | - Junmin Peng
- From the ‡Departments of Structural Biology and Developmental Neurobiology, §St. Jude Proteomics Facility,
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24
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Mignot C, Lambert L, Pasquier L, Bienvenu T, Delahaye-Duriez A, Keren B, Lefranc J, Saunier A, Allou L, Roth V, Valduga M, Moustaïne A, Auvin S, Barrey C, Chantot-Bastaraud S, Lebrun N, Moutard ML, Nougues MC, Vermersch AI, Héron B, Pipiras E, Héron D, Olivier-Faivre L, Guéant JL, Jonveaux P, Philippe C. WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation. J Med Genet 2014; 52:61-70. [PMID: 25411445 DOI: 10.1136/jmedgenet-2014-102748] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Homozygous mutations in WWOX were reported in eight individuals of two families with autosomal recessive spinocerebellar ataxia type 12 and in two siblings with infantile epileptic encephalopathy (IEE), including one who deceased prior to DNA sampling. METHODS By combining array comparative genomic hybridisation, targeted Sanger sequencing and next generation sequencing, we identified five further patients from four families with IEE due to biallelic alterations of WWOX. RESULTS We identified eight deleterious WWOX alleles consisting in four deletions, a four base-pair frameshifting deletion, one missense and two nonsense mutations. Genotype-phenotype correlation emerges from the seven reported families. The phenotype in four patients carrying two predicted null alleles was characterised by (1) little if any psychomotor acquisitions, poor spontaneous motility and absent eye contact from birth, (2) pharmacoresistant epilepsy starting in the 1st weeks of life, (3) possible retinal degeneration, acquired microcephaly and premature death. This contrasted with the less severe autosomal recessive spinocerebellar ataxia type 12 phenotype due to hypomorphic alleles. In line with this correlation, the phenotype in two siblings carrying a null allele and a missense mutation was intermediate. CONCLUSIONS Our results obtained by a combination of different molecular techniques undoubtedly incriminate WWOX as a gene for recessive IEE and illustrate the usefulness of high throughput data mining for the identification of genes for rare autosomal recessive disorders. The structure of the WWOX locus encompassing the FRA16D fragile site might explain why constitutive deletions are recurrently reported in genetic databases, suggesting that WWOX-related encephalopathies, although likely rare, may not be exceptional.
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Affiliation(s)
- Cyril Mignot
- Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP; Centre de Référence des Déficiences Intellectuelles de Causes Rares, UPMC Univ Paris 06 Groupe de Recherche Clinique "Déficience Intellectuelle et Autisme", Paris, France
| | - Laetitia Lambert
- Unité Fonctionnelle de Génétique Clinique, Service de Médecine Néonatale, Maternité Régionale Universitaire, Nancy, France
| | - Laurent Pasquier
- Service de Génétique Clinique, Hôpital Sud, CLAD Ouest, Rennes, France
| | - Thierry Bienvenu
- Laboratoire de Biochimie et Génétique Moléculaire, GH Cochin-Broca-Hôtel Dieu, APHP, Inserm U1016, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
| | | | - Boris Keren
- Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP; Centre de Référence des Déficiences Intellectuelles de Causes Rares, UPMC Univ Paris 06 Groupe de Recherche Clinique "Déficience Intellectuelle et Autisme", Paris, France
| | - Jérémie Lefranc
- Service de Pédiatrie, Centre Hospitalo-Universitaire Morvan, Brest, France
| | - Aline Saunier
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France
| | - Lila Allou
- Université de Lorraine, Inserm U954 Nutrition-Genetics-Environmental Risk Exposure, Medical Faculty, Vandoeuvre-les-Nancy, France
| | - Virginie Roth
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France
| | - Mylène Valduga
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France
| | - Aissa Moustaïne
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France
| | - Stéphane Auvin
- APHP, Hôpital Robert Debré, Service de Neurologie Pédiatrique; Univ Paris Diderot, Sorbonne Paris Cité, INSERM UMR1141, Paris, France
| | - Catherine Barrey
- Service de Pédiatrie, Hôpital Saint-Camille, Bry-sur-Marne, France
| | | | - Nicolas Lebrun
- Laboratoire de Biochimie et Génétique Moléculaire, GH Cochin-Broca-Hôtel Dieu, APHP, Inserm U1016, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
| | | | | | | | - Bénédicte Héron
- Service de Neuropédiatrie, APHP, Hôpital Armand Trousseau, Paris, France Service de Pédiatrie, APHP, Hôpital Jean Verdier, Bondy, France
| | - Eva Pipiras
- Unité de Cytogénétique, Hôpital Jean Verdier, APHP, CHU-Paris 13, Bondy, France
| | - Delphine Héron
- Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP; Centre de Référence des Déficiences Intellectuelles de Causes Rares, UPMC Univ Paris 06 Groupe de Recherche Clinique "Déficience Intellectuelle et Autisme", Paris, France
| | - Laurence Olivier-Faivre
- Medical Genetics Unit, Centre Hospitalier Universitaire de Dijon; Research Unit EA 4271 Génétique des Anomalies du Développement, Université de Bourgogne, PRES Bourgogne-Franche Comté, Dijon, France
| | - Jean-Louis Guéant
- Université de Lorraine, Inserm U954 Nutrition-Genetics-Environmental Risk Exposure, Medical Faculty, Vandoeuvre-les-Nancy, France
| | - Philippe Jonveaux
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France. Université de Lorraine, Inserm U954 Nutrition-Genetics-Environmental Risk Exposure, Medical Faculty, Vandoeuvre-les-Nancy, France
| | - Christophe Philippe
- Laboratoire de Génétique Médicale, Centre Hospitalier Régional et Universitaire, Vandoeuvre-les-Nancy, France. Université de Lorraine, Inserm U954 Nutrition-Genetics-Environmental Risk Exposure, Medical Faculty, Vandoeuvre-les-Nancy, France
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25
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Morelli E, Ghiglieri V, Pendolino V, Bagetta V, Pignataro A, Fejtova A, Costa C, Ammassari-Teule M, Gundelfinger ED, Picconi B, Calabresi P. Environmental enrichment restores CA1 hippocampal LTP and reduces severity of seizures in epileptic mice. Exp Neurol 2014; 261:320-7. [DOI: 10.1016/j.expneurol.2014.05.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/08/2014] [Indexed: 12/13/2022]
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26
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Martin S, Papadopulos A, Tomatis VM, Sierecki E, Malintan NT, Gormal RS, Giles N, Johnston WA, Alexandrov K, Gambin Y, Collins BM, Meunier FA. Increased polyubiquitination and proteasomal degradation of a Munc18-1 disease-linked mutant causes temperature-sensitive defect in exocytosis. Cell Rep 2014; 9:206-218. [PMID: 25284778 DOI: 10.1016/j.celrep.2014.08.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/31/2014] [Accepted: 08/23/2014] [Indexed: 12/23/2022] Open
Abstract
Munc18-1 is a critical component of the core machinery controlling neuroexocytosis. Recently, mutations in Munc18-1 leading to the development of early infantile epileptic encephalopathy have been discovered. However, which degradative pathway controls Munc18-1 levels and how it impacts on neuroexocytosis in this pathology is unknown. Using neurosecretory cells deficient in Munc18, we show that a disease-linked mutation, C180Y, renders the protein unstable at 37°C. Although the mutated protein retains its function as t-SNARE chaperone, neuroexocytosis is impaired, a defect that can be rescued at a lower permissive temperature. We reveal that Munc18-1 undergoes K48-linked polyubiquitination, which is highly increased by the mutation, leading to proteasomal, but not lysosomal, degradation. Our data demonstrate that functional Munc18-1 levels are controlled through polyubiquitination and proteasomal degradation. The C180Y disease-causing mutation greatly potentiates this degradative pathway, rendering Munc18-1 unable to facilitate neuroexocytosis, a phenotype that is reversed at a permissive temperature.
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Affiliation(s)
- Sally Martin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Vanesa M Tomatis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Emma Sierecki
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nancy T Malintan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nichole Giles
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wayne A Johnston
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Kirill Alexandrov
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Yann Gambin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Frederic A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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27
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Martin HC, Kim GE, Pagnamenta AT, Murakami Y, Carvill GL, Meyer E, Copley RR, Rimmer A, Barcia G, Fleming MR, Kronengold J, Brown MR, Hudspith KA, Broxholme J, Kanapin A, Cazier JB, Kinoshita T, Nabbout R, Bentley D, McVean G, Heavin S, Zaiwalla Z, McShane T, Mefford HC, Shears D, Stewart H, Kurian MA, Scheffer IE, Blair E, Donnelly P, Kaczmarek LK, Taylor JC. Clinical whole-genome sequencing in severe early-onset epilepsy reveals new genes and improves molecular diagnosis. Hum Mol Genet 2014; 23:3200-11. [PMID: 24463883 PMCID: PMC4030775 DOI: 10.1093/hmg/ddu030] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/20/2014] [Indexed: 11/13/2022] Open
Abstract
In severe early-onset epilepsy, precise clinical and molecular genetic diagnosis is complex, as many metabolic and electro-physiological processes have been implicated in disease causation. The clinical phenotypes share many features such as complex seizure types and developmental delay. Molecular diagnosis has historically been confined to sequential testing of candidate genes known to be associated with specific sub-phenotypes, but the diagnostic yield of this approach can be low. We conducted whole-genome sequencing (WGS) on six patients with severe early-onset epilepsy who had previously been refractory to molecular diagnosis, and their parents. Four of these patients had a clinical diagnosis of Ohtahara Syndrome (OS) and two patients had severe non-syndromic early-onset epilepsy (NSEOE). In two OS cases, we found de novo non-synonymous mutations in the genes KCNQ2 and SCN2A. In a third OS case, WGS revealed paternal isodisomy for chromosome 9, leading to identification of the causal homozygous missense variant in KCNT1, which produced a substantial increase in potassium channel current. The fourth OS patient had a recessive mutation in PIGQ that led to exon skipping and defective glycophosphatidyl inositol biosynthesis. The two patients with NSEOE had likely pathogenic de novo mutations in CBL and CSNK1G1, respectively. Mutations in these genes were not found among 500 additional individuals with epilepsy. This work reveals two novel genes for OS, KCNT1 and PIGQ. It also uncovers unexpected genetic mechanisms and emphasizes the power of WGS as a clinical tool for making molecular diagnoses, particularly for highly heterogeneous disorders.
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Affiliation(s)
- Hilary C Martin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Grace E Kim
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Alistair T Pagnamenta
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Gemma L Carvill
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Esther Meyer
- Neurosciences Unit, UCL-Institute of Child Health, London, UK, Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Richard R Copley
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Andrew Rimmer
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Giulia Barcia
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | - Matthew R Fleming
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jack Kronengold
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Maile R Brown
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Karl A Hudspith
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - John Broxholme
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alexander Kanapin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Rima Nabbout
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Gil McVean
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Sinéad Heavin
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Zenobia Zaiwalla
- Department of Clinical Neurophysiology, John Radcliffe Hospital, Oxford, UK
| | - Tony McShane
- Department of Paediatrics, Children's Hospital Oxford, John Radcliffe Hospital, Oxford, UK
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Deborah Shears
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Helen Stewart
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Manju A Kurian
- Neurosciences Unit, UCL-Institute of Child Health, London, UK
| | - Ingrid E Scheffer
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Edward Blair
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Peter Donnelly
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Leonard K Kaczmarek
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jenny C Taylor
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK,
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28
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Fukai R, Hiraki Y, Nishimura G, Nakashima M, Tsurusaki Y, Saitsu H, Matsumoto N, Miyake N. A de novo 1.4-Mb deletion at 21q22.11 in a boy with developmental delay. Am J Med Genet A 2014; 164A:1021-8. [PMID: 24458657 DOI: 10.1002/ajmg.a.36377] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/20/2013] [Indexed: 01/15/2023]
Abstract
Monosomy 21 is a very rare chromosomal abnormality. At least 45 patients with partial deletion involving 21q11 have been reported. Here, we report a Japanese boy who presented with pre- and postnatal growth delays, psychomotor developmental delay, microcephaly, and iris coloboma. Cytogenetic analysis revealed a de novo 1.4-Mb deletion at 21q22.11 containing 19 protein-coding RefSeq genes. We compared the clinical phenotypes between the present patient and 16 previously reported patients with a deleted region associated with postnatal growth delay and psychomotor developmental delay. Interestingly, ITSN1 was the only gene deleted or disrupted in all cases; this gene is known to be associated with intellectual disability. Microcephaly and brain structural abnormalities including polymicrogyria and agenesis/hypoplasia of the corpus callosum may also result from haploinsufficiency of ITSN1, highlighting its clinical significance for the neurological features of patients with monosomy 21.
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Affiliation(s)
- Ryoko Fukai
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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29
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Alazami AM, Hijazi H, Kentab AY, Alkuraya FS. NECAP1 loss of function leads to a severe infantile epileptic encephalopathy. J Med Genet 2014; 51:224-8. [PMID: 24399846 DOI: 10.1136/jmedgenet-2013-102030] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Epileptic encephalopathy is a broad clinical category that is highly heterogeneous genetically. OBJECTIVE To describe a multiplex extended consanguineous family that defines a molecularly novel subtype of early infantile epileptic encephalopathy. METHODS Autozygosity mapping and exome sequencing for the identification of the causal mutation. This was followed by expression analysis of the candidate gene. RESULTS In an extended multigenerational family with six affected individuals, a single novel disease locus was identified on chromosome 12p13.31-p13.2. Within that locus, the only deleterious novel exomic variant was a homozygous truncating mutation in NECAP1, encoding a clathrin-accessory protein. The mutation was confirmed to trigger nonsense-mediated decay. Consistent with previous reports, we show that NECAP1 is highly enriched in the central nervous system. CONCLUSIONS NECAP1 is known to regulate clathrin-mediated endocytosis in synapses. The mutation we report here links for the first time this trafficking pathway in early infantile epileptic encephalopathy.
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Affiliation(s)
- Anas M Alazami
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
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30
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Pippucci T, Parmeggiani A, Palombo F, Maresca A, Angius A, Crisponi L, Cucca F, Liguori R, Valentino ML, Seri M, Carelli V. A novel null homozygous mutation confirms CACNA2D2 as a gene mutated in epileptic encephalopathy. PLoS One 2013; 8:e82154. [PMID: 24358150 PMCID: PMC3864908 DOI: 10.1371/journal.pone.0082154] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/21/2013] [Indexed: 11/19/2022] Open
Abstract
Contribution to epileptic encephalopathy (EE) of mutations in CACNA2D2, encoding α2δ-2 subunit of Voltage Dependent Calcium Channels, is unclear. To date only one CACNA2D2 mutation altering channel functionality has been identified in a single family. In the same family, a rare CELSR3 polymorphism also segregated with disease. Involvement of CACNA2D2 in EE is therefore not confirmed, while that of CELSR3 is questionable. In a patient with epilepsy, dyskinesia, cerebellar atrophy, psychomotor delay and dysmorphic features, offspring to consanguineous parents, we performed whole exome sequencing (WES) for homozygosity mapping and mutation detection. WES identified extended autozygosity on chromosome 3, containing two novel homozygous candidate mutations: c.1295delA (p.Asn432fs) in CACNA2D2 and c.G6407A (p.Gly2136Asp) in CELSR3. Gene prioritization pointed to CACNA2D2 as the most prominent candidate gene. The WES finding in CACNA2D2 resulted to be statistically significant (p = 0.032), unlike that in CELSR3. CACNA2D2 homozygous c.1295delA essentially abolished α2δ-2 expression. In summary, we identified a novel null CACNA2D2 mutation associated to a clinical phenotype strikingly similar to the Cacna2d2 null mouse model. Molecular and statistical analyses together argued in favor of a causal contribution of CACNA2D2 mutations to EE, while suggested that finding in CELSR3, although potentially damaging, is likely incidental.
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Affiliation(s)
- Tommaso Pippucci
- U.O. Genetica Medica, Policlinico Sant’Orsola-Malpighi, University of Bologna, Bologna, Italy
| | - Antonia Parmeggiani
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Dipartimento di Scienze Mediche Chirurgiche, University of Bologna, Bologna, Italy
| | - Flavia Palombo
- U.O. Genetica Medica, Policlinico Sant’Orsola-Malpighi, University of Bologna, Bologna, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Andrea Angius
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
- Center for Advanced Studies, Research, and Development in Sardinia (CRS4), AGCT Program, Parco Scientifico e tecnologico della Sardegna, Pula, Italy
| | - Laura Crisponi
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
| | - Francesco Cucca
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
- Dipartimento di Scienze Biomediche, University of Sassari, Sassari, Italy
| | - Rocco Liguori
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Maria Lucia Valentino
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Marco Seri
- U.O. Genetica Medica, Policlinico Sant’Orsola-Malpighi, University of Bologna, Bologna, Italy
- Dipartimento di Scienze Mediche Chirurgiche, University of Bologna, Bologna, Italy
- * E-mail:
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
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31
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Campeau PM, Kasperaviciute D, Lu JT, Burrage LC, Kim C, Hori M, Powell BR, Stewart F, Félix TM, van den Ende J, Wisniewska M, Kayserili H, Rump P, Nampoothiri S, Aftimos S, Mey A, Nair LDV, Begleiter ML, De Bie I, Meenakshi G, Murray ML, Repetto GM, Golabi M, Blair E, Male A, Giuliano F, Kariminejad A, Newman WG, Bhaskar SS, Dickerson JE, Kerr B, Banka S, Giltay JC, Wieczorek D, Tostevin A, Wiszniewska J, Cheung SW, Hennekam RC, Gibbs RA, Lee BH, Sisodiya SM. The genetic basis of DOORS syndrome: an exome-sequencing study. Lancet Neurol 2013; 13:44-58. [PMID: 24291220 PMCID: PMC3895324 DOI: 10.1016/s1474-4422(13)70265-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background Deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals. Methods Through a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR. Findings 26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis. Interpretation Our findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24. Funding US National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.
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Affiliation(s)
- Philippe M Campeau
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Dalia Kasperaviciute
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - James T Lu
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA; Department of Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Choel Kim
- Department of Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Mutsuki Hori
- Department of Pediatrics, Toyohashi Municipal Hospital, Toyohashi, Aichi, Japan
| | | | - Fiona Stewart
- Genetics Service, Belfast City Hospital, Belfast, Ireland
| | - Têmis Maria Félix
- Medical Genetics Service, Clinical Hospital of Porto Alegre, Porto Alegre, Brazil
| | - Jenneke van den Ende
- Department of Medical Genetics, University Hospital Antwerp, 2650 Antwerp, Belgium
| | - Marzena Wisniewska
- Department of Medical Genetics, Poznañ University of Medical Sciences, Poznañ, Poland
| | - Hülya Kayserili
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Turkey
| | - Patrick Rump
- Department of Genetics, University of Groningen, Groningen, Netherlands
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Kerala, India
| | - Salim Aftimos
- Genetic Health Service New Zealand-Northern Hub, Auckland City Hospital, Auckland, New Zealand
| | - Antje Mey
- Pediatric Neurology, Braunschweig Hospital, Braunschweig, Germany
| | - Lal D V Nair
- Department of Pediatrics, Saveetha Medical College and Hospital, Saveetha University, Chennai, Tamil Nadu, 600077, India
| | - Michael L Begleiter
- Division of Genetics, Children's Mercy Hospitals and Clinics and the University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Isabelle De Bie
- Department of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Quebec, Canada
| | - Girish Meenakshi
- Department of Pediatrics, NKP Salve Institute of Medical Sciences and Lata Mangeshkar Hospital, Maharashtra, India
| | - Mitzi L Murray
- University of Washington Medical Center, Seattle, WA, USA
| | - Gabriela M Repetto
- Center for Human Genetics, Facultad de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - Mahin Golabi
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Edward Blair
- Department of Clinical Genetics, Churchill Hospital, Oxford, UK
| | - Alison Male
- Clinical Genetics Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Fabienne Giuliano
- Centre Référence Anomalie Développement et Syndromes Malformatifs, Centre Hospitalier Universitaire de Nice, France
| | | | - William G Newman
- Manchester Centre for Genomic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Manchester Centre for Genomic Centre for Genetic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; St Mary's Hospital, Manchester Academic Health Science Centre, Manchester, UK
| | - Sanjeev S Bhaskar
- Manchester Centre for Genomic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Manchester Centre for Genomic Centre for Genetic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; St Mary's Hospital, Manchester Academic Health Science Centre, Manchester, UK
| | - Jonathan E Dickerson
- Manchester Centre for Genomic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Manchester Centre for Genomic Centre for Genetic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; St Mary's Hospital, Manchester Academic Health Science Centre, Manchester, UK
| | - Bronwyn Kerr
- Manchester Centre for Genomic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Manchester Centre for Genomic Centre for Genetic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; St Mary's Hospital, Manchester Academic Health Science Centre, Manchester, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; Manchester Centre for Genomic Centre for Genetic Medicine, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK; St Mary's Hospital, Manchester Academic Health Science Centre, Manchester, UK
| | - Jacques C Giltay
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, Netherlands
| | - Dagmar Wieczorek
- Institut für Humangenetik, University of Duisburg-Essen, University Hospital Essen, Essen, Germany
| | - Anna Tostevin
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Joanna Wiszniewska
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sau Wai Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Raoul C Hennekam
- Department of Pediatrics and Translational Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Brendan H Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institutes, Houston, TX, USA.
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK; Epilepsy Society, Buckinghamshire, UK.
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Basel-Vanagaite L, Hershkovitz T, Heyman E, Raspall-Chaure M, Kakar N, Smirin-Yosef P, Vila-Pueyo M, Kornreich L, Thiele H, Bode H, Lagovsky I, Dahary D, Haviv A, Hubshman MW, Pasmanik-Chor M, Nürnberg P, Gothelf D, Kubisch C, Shohat M, Macaya A, Borck G. Biallelic SZT2 mutations cause infantile encephalopathy with epilepsy and dysmorphic corpus callosum. Am J Hum Genet 2013; 93:524-9. [PMID: 23932106 DOI: 10.1016/j.ajhg.2013.07.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/07/2013] [Accepted: 07/01/2013] [Indexed: 11/18/2022] Open
Abstract
Epileptic encephalopathies are genetically heterogeneous severe disorders in which epileptic activity contributes to neurological deterioration. We studied two unrelated children presenting with a distinctive early-onset epileptic encephalopathy characterized by refractory epilepsy and absent developmental milestones, as well as thick and short corpus callosum and persistent cavum septum pellucidum on brain MRI. Using whole-exome sequencing, we identified biallelic mutations in seizure threshold 2 (SZT2) in both affected children. The causative mutations include a homozygous nonsense mutation and a nonsense mutation together with an exonic splice-site mutation in a compound-heterozygous state. The latter mutation leads to exon skipping and premature termination of translation, as shown by RT-PCR in blood RNA of the affected boy. Thus, all three mutations are predicted to result in nonsense-mediated mRNA decay and/or premature protein truncation and thereby loss of SZT2 function. Although the molecular role of the peroxisomal protein SZT2 in neuronal excitability and brain development remains to be defined, Szt2 has been shown to influence seizure threshold and epileptogenesis in mice, consistent with our findings in humans. We conclude that mutations in SZT2 cause a severe type of autosomal-recessive infantile encephalopathy with intractable seizures and distinct neuroradiological anomalies.
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Affiliation(s)
- Lina Basel-Vanagaite
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva 49100, Israel.
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Inoue T, Kawawaki H, Kuki I, Nabatame S, Tomonoh Y, Sukigara S, Horino A, Nukui M, Okazaki S, Tomiwa K, Kimura-Ohba S, Inoue T, Hirose S, Shiomi M, Itoh M. A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging. J Neurol Sci 2013; 327:65-72. [PMID: 23422026 DOI: 10.1016/j.jns.2013.01.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/26/2012] [Accepted: 01/29/2013] [Indexed: 11/17/2022]
Abstract
Early-onset epileptic encephalopathies include various diseases such as early-infantile epileptic encephalopathy with suppression burst. We experimentally investigated the unique clinicopathological features of a 28-month-old girl with early-onset epileptic encephalopathy. Her initial symptom was intractable epilepsy with a suppression-burst pattern of electroencephalography (EEG) from 7 days of age. The suppression-burst pattern was novel, appearing during sleep, but disappearing upon waking and after becoming 2 months old. The EEG showed multifocal spikes and altered with age. Her seizures demonstrated various clinical features and continued until death. She did not show any developmental features, including no social smiling or head control. Head MRI revealed progressive atrophy of the cerebral cortex and white matter after 1 month of age. (123)IMZ-SPECT demonstrated hypo-perfusion of the cerebral cortex, but normo-perfusion of the diencephalon and cerebellum. Such imaging information indicated GABA-A receptor dysfunction of the cerebral cortex. The genetic analyses of major neonatal epilepsies showed no mutation. The neuropathology revealed atrophy and severe edema of the cerebral cortex and white matter. GAD-immunohistochemistry exhibited imbalanced distribution of GABAergic interneurons between the striatum and cerebral cortex. The results were similar to those of focal cortical dysplasia with transmantle sign and X-linked lissencephaly with ARX mutation. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge, her clinical and pathological courses have never been described in the literature.
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Affiliation(s)
- T Inoue
- Department of Child Neurology, Osaka City General Hospital, Osaka, Japan
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Valli E, Trazzi S, Fuchs C, Erriquez D, Bartesaghi R, Perini G, Ciani E. CDKL5, a novel MYCN-repressed gene, blocks cell cycle and promotes differentiation of neuronal cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:1173-85. [PMID: 22921766 PMCID: PMC3787793 DOI: 10.1016/j.bbagrm.2012.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 07/20/2012] [Accepted: 08/13/2012] [Indexed: 01/08/2023]
Abstract
Mutations in the CDKL5 (cyclin-dependent kinase-like 5) gene are associated with a severe epileptic encephalopathy (early infantile epileptic encephalopathy type 2, EIEE2) characterized by early-onset intractable seizures, infantile spasms, severe developmental delay, intellectual disability, and Rett syndrome (RTT)-like features. Despite the clear involvement of CDKL5 mutations in intellectual disability, the function of this protein during brain development and the molecular mechanisms involved in its regulation are still unknown. Using human neuroblastoma cells as a model system we found that an increase in CDKL5 expression caused an arrest of the cell cycle in the G0/G1 phases and induced cellular differentiation. Interestingly, CDKL5 expression was inhibited by MYCN, a transcription factor that promotes cell proliferation during brain development and plays a relevant role in neuroblastoma biology. Through a combination of different and complementary molecular and cellular approaches we could show that MYCN acts as a direct repressor of the CDKL5 promoter. Overall our findings unveil a functional axis between MYCN and CDKL5 governing both neuron proliferation rate and differentiation. The fact that CDKL5 is involved in the control of both neuron proliferation and differentiation may help understand the early appearance of neurological symptoms in patients with mutations in CDKL5.
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Affiliation(s)
- Emanuele Valli
- Department of Pharmacy and Biotechnology, University of Bologna, Italy
| | - Stefania Trazzi
- Department of Human and General Physiology, University of Bologna, Italy
| | - Claudia Fuchs
- Department of Human and General Physiology, University of Bologna, Italy
| | - Daniela Erriquez
- Department of Pharmacy and Biotechnology, University of Bologna, Italy
| | - Renata Bartesaghi
- Department of Human and General Physiology, University of Bologna, Italy
| | - Giovanni Perini
- Department of Pharmacy and Biotechnology, University of Bologna, Italy
- Correspondence to: G. Perini, Department of Pharmacy and Biotechnology, University of Bologna, Via F. Selmi 3, I-40126 Bologna, Italy. Tel.: + 39 051 209 467; fax: + 39 051 209 4286.
| | - Elisabetta Ciani
- Department of Human and General Physiology, University of Bologna, Italy
- Correspondence to: E. Ciani, Department of Human and General Physiology, University of Bologna, Piazza di Porta San Donato 2, I-40126 Bologna, Italy. Tel.: + 39 051 2091726; fax: + 39 051 2091737.
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