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Patel PA, LaConte LEW, Liang C, Cecere T, Rajan D, Srivastava S, Mukherjee K. Genetic evidence for splicing-dependent structural and functional plasticity in CASK protein. J Med Genet 2024; 61:759-768. [PMID: 38670634 PMCID: PMC11290809 DOI: 10.1136/jmg-2023-109747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 04/14/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND Pontocerebellar hypoplasia (PCH) may present with supratentorial phenotypes and is often accompanied by microcephaly. Damaging mutations in the X-linked gene CASK produce self-limiting microcephaly with PCH in females but are often lethal in males. CASK deficiency leads to early degeneration of cerebellar granule cells but its role in other regions of the brain remains uncertain. METHOD We generated a conditional Cask knockout mice and deleted Cask ubiquitously after birth at different times. We examined the clinical features in several subjects with damaging mutations clustered in the central part of the CASK protein. We have performed phylogenetic analysis and RT-PCR to assess the splicing pattern within the same protein region and performed in silico structural analysis to examine the effect of splicing on the CASK's structure. RESULT We demonstrate that deletion of murine Cask after adulthood does not affect survival but leads to cerebellar degeneration and ataxia over time. Intriguingly, damaging hemizygous CASK mutations in boys who display microcephaly and cerebral dysfunction but without PCH are known. These mutations are present in two vertebrate-specific CASK exons. These exons are subject to alternative splicing both in forebrain and hindbrain. Inclusion of these exons differentially affects the molecular structure and hence possibly the function/s of the CASK C-terminus. CONCLUSION Loss of CASK function disproportionately affects the cerebellum. Clinical data, however, suggest that CASK may have additional vertebrate-specific function/s that play a role in the mammalian forebrain. Thus, CASK has an ancient function shared between invertebrates and vertebrates as well as novel vertebrate-specific function/s.
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Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Leslie E W LaConte
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Chen Liang
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Thomas Cecere
- Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Deepa Rajan
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
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2
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Tello JA, Jiang L, Zohar Y, Restifo LL. Drosophila CASK regulates brain size and neuronal morphogenesis, providing a genetic model of postnatal microcephaly suitable for drug discovery. Neural Dev 2023; 18:6. [PMID: 37805506 PMCID: PMC10559581 DOI: 10.1186/s13064-023-00174-y] [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: 08/20/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND CASK-related neurodevelopmental disorders are untreatable. Affected children show variable severity, with microcephaly, intellectual disability (ID), and short stature as common features. X-linked human CASK shows dosage sensitivity with haploinsufficiency in females. CASK protein has multiple domains, binding partners, and proposed functions at synapses and in the nucleus. Human and Drosophila CASK show high amino-acid-sequence similarity in all functional domains. Flies homozygous for a hypomorphic CASK mutation (∆18) have motor and cognitive deficits. A Drosophila genetic model of CASK-related disorders could have great scientific and translational value. METHODS We assessed the effects of CASK loss of function on morphological phenotypes in Drosophila using established genetic, histological, and primary neuronal culture approaches. NeuronMetrics software was used to quantify neurite-arbor morphology. Standard nonparametric statistics methods were supplemented by linear mixed effects modeling in some cases. Microfluidic devices of varied dimensions were fabricated and numerous fluid-flow parameters were used to induce oscillatory stress fields on CNS tissue. Dissociation into viable neurons and neurite outgrowth in vitro were assessed. RESULTS We demonstrated that ∆18 homozygous flies have small brains, small heads, and short bodies. When neurons from developing CASK-mutant CNS were cultured in vitro, they grew small neurite arbors with a distinctive, quantifiable "bushy" morphology that was significantly rescued by transgenic CASK+. As in humans, the bushy phenotype showed dosage-sensitive severity. To overcome the limitations of manual tissue trituration for neuronal culture, we optimized the design and operation of a microfluidic system for standardized, automated dissociation of CNS tissue into individual viable neurons. Neurons from CASK-mutant CNS dissociated in the microfluidic system recapitulate the bushy morphology. Moreover, for any given genotype, device-dissociated neurons grew larger arbors than did manually dissociated neurons. This automated dissociation method is also effective for rodent CNS. CONCLUSIONS These biological and engineering advances set the stage for drug discovery using the Drosophila model of CASK-related disorders. The bushy phenotype provides a cell-based assay for compound screening. Nearly a dozen genes encoding CASK-binding proteins or transcriptional targets also have brain-development mutant phenotypes, including ID. Hence, drugs that improve CASK phenotypes might also benefit children with disorders due to mutant CASK partners.
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Affiliation(s)
- Judith A Tello
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA
- Present address: Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, 10010, USA
| | - Linan Jiang
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
| | - Yitshak Zohar
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA
| | - Linda L Restifo
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA.
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Cellular & Molecular Medicine, University of Arizona Health Sciences, Tucson, AZ, 85724, USA.
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Mori T, Zhou M, Tabuchi K. Diverse Clinical Phenotypes of CASK-Related Disorders and Multiple Functional Domains of CASK Protein. Genes (Basel) 2023; 14:1656. [PMID: 37628707 PMCID: PMC10454856 DOI: 10.3390/genes14081656] [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: 08/07/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
CASK-related disorders are a form of rare X-linked neurological diseases and most of the patients are females. They are characterized by several symptoms, including microcephaly with pontine and cerebellar hypoplasia (MICPCH), epilepsy, congenital nystagmus, and neurodevelopmental disorders. Whole-genome sequencing has identified various mutations, including nonsense and missense mutations, from patients with CASK-related disorders, revealing correlations between specific mutations and clinical phenotypes. Notably, missense mutations associated with epilepsy and intellectual disability were found throughout the whole region of the CASK protein, while missense mutations related to microcephaly and MICPCH were restricted in certain domains. To investigate the pathophysiology of CASK-related disorders, research groups have employed diverse methods, including the generation of CASK knockout mice and the supplementation of CASK to rescue the phenotypes. These approaches have yielded valuable insights into the identification of functional domains of the CASK protein associated with a specific phenotype. Additionally, recent advancements in the AI-based prediction of protein structure, such as AlphaFold2, and the application of genome-editing techniques to generate CASK mutant mice carrying missense mutations from patients with CASK-related disorders, allow us to understand the pathophysiology of CASK-related disorders in more depth and to develop novel therapeutic methods for the fundamental treatment of CASK-related disorders.
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Affiliation(s)
- Takuma Mori
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Mengyun Zhou
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Katsuhiko Tabuchi
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
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Paliotti K, Dassi C, Berrahmoune S, Bejaran ML, Davila CEV, Martinez AB, Estupiñà MCF, Mancardi MM, Riva A, Giacomini T, Severino M, Romaniello R, Dubeau F, Srour M, Myers KA. The phenotypic spectrum of epilepsy associated with periventricular nodular heterotopia. J Neurol 2023:10.1007/s00415-023-11724-z. [PMID: 37119372 DOI: 10.1007/s00415-023-11724-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 05/01/2023]
Abstract
BACKGROUND Periventricular nodular heterotopia (PVNH) is a congenital brain malformation often associated with seizures. We aimed to clarify the spectrum of epilepsy phenotypes in PVNH and the significance of specific brain malformation patterns. METHODS In this retrospective cohort study, we recruited people with PVNH and a history of seizures, and collected data via medical record review and a standardized questionnaire. RESULTS One hundred individuals were included, aged 1 month to 61 years. Mean seizure onset age was 7.9 years. Ten patients had a self-limited epilepsy course and 35 more were pharmacoresponsive. Fifty-five had ongoing seizures, of whom 23 met criteria for drug resistance. Patients were subdivided as follows: isolated PVNH ("PVNH-Only") single nodule (18) or multiple nodules (21) and PVNH with additional brain malformations ("PVNH-Plus") single nodule (8) or multiple nodules (53). Of PVNH-Only single nodule, none had drug-resistant seizures. Amongst PVNH-Plus, 55% with multiple unilateral nodules were pharmacoresponsive, compared to only 21% with bilateral nodules. PVNH-Plus with bilateral nodules demonstrated the highest proportion of drug resistance (39%). A review of genetic testing results revealed eight patients with pathogenic or likely pathogenic single-gene variants, two of which were FLNA. Five had copy number variants, two of which were pathogenic. CONCLUSIONS The spectrum of epilepsy phenotypes in PVNH is broad, and seizure patterns are variable; however, epilepsy course may be predicted to an extent by the pattern of malformation. Overall, drug-resistant epilepsy occurs in approximately one quarter of affected individuals. When identified, genetic etiologies are very heterogeneous.
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Affiliation(s)
- Karina Paliotti
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Christelle Dassi
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | | | - Marlin Liz Bejaran
- Pediatric Neurology Department, Sant Joan de Déu Barcelona Children's Hospital, Sant Joan de Déu Research Institute, Member of the ERN EpiCARE, Barcelona, Spain
| | - Carlos Eduardo Valera Davila
- Pediatric Neurology Department, Sant Joan de Déu Barcelona Children's Hospital, Sant Joan de Déu Research Institute, Member of the ERN EpiCARE, Barcelona, Spain
| | - Ariadna Borràs Martinez
- Pediatric Neurology Department, Sant Joan de Déu Barcelona Children's Hospital, Sant Joan de Déu Research Institute, Member of the ERN EpiCARE, Barcelona, Spain
| | - Maria Carme Fons Estupiñà
- Pediatric Neurology Department, Sant Joan de Déu Barcelona Children's Hospital, Sant Joan de Déu Research Institute, Member of the ERN EpiCARE, Barcelona, Spain
| | - Maria Margherita Mancardi
- Epilepsy Center, Reference Center for Rare and Complex Epilepsies-EpiCARE, IRCCS Istituto Gaslini, Genoa, Italy
| | - Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Gaslini, University of Genoa, Genoa, Italy
| | - Thea Giacomini
- Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | | | - Romina Romaniello
- Child Neuropsychiatry and Neurorehabilitation Department, Scientific Institute Eugenio Medea, La Nostra Famiglia, Lecco, Italy
| | - François Dubeau
- Department of Neurology and Neurosurgery, McGill University Health Centre, Montreal, QC, Canada
| | - Myriam Srour
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Division of Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, MUHC Glen Site, 1001 Décarie Blvd, Montreal, QC, H4A 3J1, Canada
- Department of Neurology and Neurosurgery, McGill University Health Centre, Montreal, QC, Canada
| | - Kenneth A Myers
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.
- Division of Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, MUHC Glen Site, 1001 Décarie Blvd, Montreal, QC, H4A 3J1, Canada.
- Department of Neurology and Neurosurgery, McGill University Health Centre, Montreal, QC, Canada.
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Guo Q, Kouyama-Suzuki E, Shirai Y, Cao X, Yanagawa T, Mori T, Tabuchi K. Structural Analysis Implicates CASK-Liprin-α2 Interaction in Cerebellar Granular Cell Death in MICPCH Syndrome. Cells 2023; 12:cells12081177. [PMID: 37190086 DOI: 10.3390/cells12081177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 04/06/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Microcephaly with pontine and cerebellar hypoplasia (MICPCH) syndrome is a neurodevelopmental disorder caused by the deficiency of the X-chromosomal gene CASK. However, the molecular mechanisms by which CASK deficiency causes cerebellar hypoplasia in this syndrome remain elusive. In this study, we used CASK knockout (KO) mice as models for MICPCH syndrome and investigated the effect of CASK mutants. Female CASK heterozygote KO mice replicate the progressive cerebellar hypoplasia observed in MICPCH syndrome. CASK KO cultured cerebellar granule (CG) cells show progressive cell death that can be rescued by co-infection with lentivirus expressing wild-type CASK. Rescue experiments with CASK deletion mutants identify that the CaMK, PDZ, and SH3, but not L27 and guanylate kinase domains of CASK are required for the survival of CG cells. We identify missense mutations in the CaMK domain of CASK derived from human patients that fail to rescue the cell death of cultured CASK KO CG cells. Machine learning-based structural analysis using AlphaFold 2.2 predicts that these mutations disrupt the structure of the binding interface with Liprin-α2. These results suggest that the interaction with Liprin-α2 via the CaMK domain of CASK may be involved in the pathophysiology of cerebellar hypoplasia in MICPCH syndrome.
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Affiliation(s)
- Qi Guo
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Emi Kouyama-Suzuki
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Yoshinori Shirai
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Xueshan Cao
- College of Life Science and Oceanography, Shenzhen University, Shenzhen 518071, China
| | - Toru Yanagawa
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Takuma Mori
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
- Department of NeuroHealth Innovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan
| | - Katsuhiko Tabuchi
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
- Department of NeuroHealth Innovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan
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de Sainte Agathe JM, Filser M, Isidor B, Besnard T, Gueguen P, Perrin A, Van Goethem C, Verebi C, Masingue M, Rendu J, Cossée M, Bergougnoux A, Frobert L, Buratti J, Lejeune É, Le Guern É, Pasquier F, Clot F, Kalatzis V, Roux AF, Cogné B, Baux D. SpliceAI-visual: a free online tool to improve SpliceAI splicing variant interpretation. Hum Genomics 2023; 17:7. [PMID: 36765386 PMCID: PMC9912651 DOI: 10.1186/s40246-023-00451-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/18/2023] [Indexed: 02/12/2023] Open
Abstract
SpliceAI is an open-source deep learning splicing prediction algorithm that has demonstrated in the past few years its high ability to predict splicing defects caused by DNA variations. However, its outputs present several drawbacks: (1) although the numerical values are very convenient for batch filtering, their precise interpretation can be difficult, (2) the outputs are delta scores which can sometimes mask a severe consequence, and (3) complex delins are most often not handled. We present here SpliceAI-visual, a free online tool based on the SpliceAI algorithm, and show how it complements the traditional SpliceAI analysis. First, SpliceAI-visual manipulates raw scores and not delta scores, as the latter can be misleading in certain circumstances. Second, the outcome of SpliceAI-visual is user-friendly thanks to the graphical presentation. Third, SpliceAI-visual is currently one of the only SpliceAI-derived implementations able to annotate complex variants (e.g., complex delins). We report here the benefits of using SpliceAI-visual and demonstrate its relevance in the assessment/modulation of the PVS1 classification criteria. We also show how SpliceAI-visual can elucidate several complex splicing defects taken from the literature but also from unpublished cases. SpliceAI-visual is available as a Google Colab notebook and has also been fully integrated in a free online variant interpretation tool, MobiDetails ( https://mobidetails.iurc.montp.inserm.fr/MD ).
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Affiliation(s)
- Jean-Madeleine de Sainte Agathe
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France.
- Laboratoire de Biologie Médicale Multi-Sites SeqOIA (laboratoire-seqoia.fr/), Paris, France.
| | - Mathilde Filser
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France
| | - Bertrand Isidor
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000, Nantes, France
| | - Thomas Besnard
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000, Nantes, France
| | - Paul Gueguen
- Laboratoire de Biologie Médicale Multi-Sites SeqOIA (laboratoire-seqoia.fr/), Paris, France
- Service de Génétique, Inserm U1253, CHRU de Tours, Tours, France
| | - Aurélien Perrin
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Charles Van Goethem
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Camille Verebi
- Service de Médecine Génomique, Maladies de Système et d'Organe, Fédération de Génétique et de Médecine Génomique, DMU BioPhyGen, APHP Centre-Université Paris Cité, Hôpital Cochin, Paris, France
| | - Marion Masingue
- Centre de référence des maladies neuromusculaires Nord/Est/Ile de France, Hôpital Pitié-Salpêtrière, APHP, Paris, France
| | - John Rendu
- Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Mireille Cossée
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
- PhyMedExp, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Anne Bergougnoux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
- PhyMedExp, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Laurent Frobert
- Laboratoire de Biologie Médicale Multi-Sites SeqOIA (laboratoire-seqoia.fr/), Paris, France
| | - Julien Buratti
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France
| | - Élodie Lejeune
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France
| | - Éric Le Guern
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France
- Laboratoire de Biologie Médicale Multi-Sites SeqOIA (laboratoire-seqoia.fr/), Paris, France
| | - Florence Pasquier
- Centre mémoire, Inserm U1172 DistALZ, Licend, Univ Lille, CHU Lille, 59000, Lille, France
| | - Fabienne Clot
- Département de Génétique Médicale, Groupe Hospitalier Universitaire de la Pitié Salpêtrière, AP-HP.Sorbonne Université, Laboratoire de Médecine Génomique Sorbonne Université, Paris, France
| | | | - Anne-Françoise Roux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
- INM, Univ Montpellier, INSERM, CHU Montpellier, Montpellier, France
| | - Benjamin Cogné
- Laboratoire de Biologie Médicale Multi-Sites SeqOIA (laboratoire-seqoia.fr/), Paris, France
- Nantes Université, CHU Nantes, Service de Génétique Médicale, 44000, Nantes, France
| | - David Baux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
- INM, Univ Montpellier, INSERM, CHU Montpellier, Montpellier, France
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Lin PY, Chen LY, Jiang M, Trotter JH, Seigneur E, Südhof TC. Neurexin-2: An inhibitory neurexin that restricts excitatory synapse formation in the hippocampus. SCIENCE ADVANCES 2023; 9:eadd8856. [PMID: 36608123 PMCID: PMC9821874 DOI: 10.1126/sciadv.add8856] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Neurexins are widely thought to promote synapse formation and to organize synapse properties. Here we found that in contrast to neurexin-1 and neurexin-3, neurexin-2 unexpectedly restricts synapse formation. In the hippocampus, constitutive or neuron-specific deletions of neurexin-2 nearly doubled the strength of excitatory CA3➔CA1 region synaptic connections and markedly increased their release probability. No effect on inhibitory synapses was detected. Stochastic optical reconstruction microscopy (STORM) superresolution microscopy revealed that the neuron-specific neurexin-2 deletion elevated the density of excitatory CA1 region synapses nearly twofold. Moreover, hippocampal neurexin-2 deletions also increased synaptic connectivity in the CA1 region when induced in mature mice and impaired the cognitive flexibility of spatial memory. Thus, neurexin-2 controls the dynamics of hippocampal synaptic circuits by repressing synapse assembly throughout life, a restrictive function that markedly differs from that of neurexin-1 and neurexin-3 and of other synaptic adhesion molecules, suggesting that neurexins evolutionarily diverged into opposing pro- and antisynaptogenic organizers.
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Affiliation(s)
- Pei-Yi Lin
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
| | - Lulu Y. Chen
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
| | - Man Jiang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
| | - Justin H. Trotter
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
| | - Erica Seigneur
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 265 Campus Dr., Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
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8
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Yeo XY, Lim YT, Chae WR, Park C, Park H, Jung S. Alterations of presynaptic proteins in autism spectrum disorder. Front Mol Neurosci 2022; 15:1062878. [DOI: 10.3389/fnmol.2022.1062878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 10/31/2022] [Indexed: 11/19/2022] Open
Abstract
The expanded use of hypothesis-free gene analysis methods in autism research has significantly increased the number of genetic risk factors associated with the pathogenesis of autism. A further examination of the implicated genes directly revealed the involvement in processes pertinent to neuronal differentiation, development, and function, with a predominant contribution from the regulators of synaptic function. Despite the importance of presynaptic function in synaptic transmission, the regulation of neuronal network activity, and the final behavioral output, there is a relative lack of understanding of the presynaptic contribution to the pathology of autism. Here, we will review the close association among autism-related mutations, autism spectrum disorders (ASD) phenotypes, and the altered presynaptic protein functions through a systematic examination of the presynaptic risk genes relating to the critical stages of synaptogenesis and neurotransmission.
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Byun JC, Ha JS. CASK Mutation in an Infant with Microcephaly, Pontocerebellar Hypoplasia, and Hearing Loss. ANNALS OF CHILD NEUROLOGY 2022. [DOI: 10.26815/acn.2022.00283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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10
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Tibbe D, Ferle P, Krisp C, Nampoothiri S, Mirzaa G, Assaf M, Parikh S, Kutsche K, Kreienkamp HJ. Regulation of Liprin-α phase separation by CASK is disrupted by a mutation in its CaM kinase domain. Life Sci Alliance 2022; 5:5/10/e202201512. [PMID: 36137748 PMCID: PMC9500383 DOI: 10.26508/lsa.202201512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Mutations in the human CASK gene cause a neurodevelopmental disorder; we show that CASK regulates condensate formation of Liprin-alpha 2 and that patient mutations in the CaM kinase domain interfere with Liprin binding and regulation of condensate formation. CASK is a unique membrane-associated guanylate kinase (MAGUK) because of its Ca2+/calmodulin-dependent kinase (CaMK) domain. We describe four male patients with a severe neurodevelopmental disorder with microcephaly carrying missense variants affecting the CaMK domain. One boy who carried the p.E115K variant and died at an early age showed pontocerebellar hypoplasia (PCH) in addition to microcephaly, thus exhibiting the classical MICPCH phenotype observed in individuals with CASK loss-of-function variants. All four variants selectively weaken the interaction of CASK with Liprin-α2, a component of the presynaptic active zone. Liprin-α proteins form spherical phase-separated condensates, which we observe here in Liprin-α2 overexpressing HEK293T cells. Large Liprin-α2 clusters were also observed in transfected primary-cultured neurons. Cluster formation of Liprin-α2 is reversed in the presence of CASK; this is associated with altered phosphorylation of Liprin-α2. The p.E115K variant fails to interfere with condensate formation. As the individual carrying this variant had the severe MICPCH disorder, we suggest that regulation of Liprin-α2–mediated phase condensate formation is a new functional feature of CASK which must be maintained to prevent PCH.
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Affiliation(s)
- Debora Tibbe
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Pia Ferle
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Krisp
- Institute for Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Cochin, India
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, WA, USA.,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA
| | - Melissa Assaf
- Banner Children's Specialists Neurology Clinic, Glendale, AZ, USA
| | - Sumit Parikh
- Pediatric Neurology, Cleveland Clinic, Cleveland, OH, USA
| | - Kerstin Kutsche
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans-Jürgen Kreienkamp
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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11
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McSweeney D, Gabriel R, Jin K, Pang ZP, Aronow B, Pak C. CASK loss of function differentially regulates neuronal maturation and synaptic function in human induced cortical excitatory neurons. iScience 2022; 25:105187. [PMID: 36262316 PMCID: PMC9574418 DOI: 10.1016/j.isci.2022.105187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/30/2022] [Accepted: 09/20/2022] [Indexed: 12/14/2022] Open
Abstract
Loss-of-function (LOF) mutations in CASK cause severe developmental phenotypes, including microcephaly with pontine and cerebellar hypoplasia, X-linked intellectual disability, and autism. Unraveling the pathological mechanisms of CASK-related disorders has been challenging owing to limited human cellular models to study the dynamic roles of this molecule during neuronal maturation and synapse development. Here, we investigate cell-autonomous functions of CASK in cortical excitatory induced neurons (iNs) generated from CASK knockout (KO) isogenic human embryonic stem cells (hESCs) using gene expression, morphometrics, and electrophysiology. While immature CASK KO iNs show robust neuronal outgrowth, mature CASK KO iNs display severe defects in synaptic transmission and synchronized network activity without compromising neuronal morphology and synapse numbers. In the developing human cortical excitatory neurons, CASK functions to promote both structural integrity and establishment of cortical excitatory neuronal networks. These results lay the foundation for future studies identifying suppressors of such phenotypes relevant to human patients.
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Affiliation(s)
- Danny McSweeney
- Graduate Program in Molecular and Cellular Biology, UMass Amherst, Amherst, MA 01003, USA,Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA 01003, USA
| | - Rafael Gabriel
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA 01003, USA
| | - Kang Jin
- Departments of Biomedical Informatics, Pediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Zhiping P. Pang
- Child Health Institute of New Jersey and Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA
| | - Bruce Aronow
- Departments of Biomedical Informatics, Pediatrics, University of Cincinnati, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - ChangHui Pak
- Department of Biochemistry and Molecular Biology, UMass Amherst, Amherst, MA 01003, USA,Corresponding author
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12
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Xie G, Zhang Y, Yang W, Yang L, Wang R, Xu M, Sun L, Zhang B, Cui X. Case report: A novel CASK mutation in a Chinese female child with microcephaly with pontine and cerebellar hypoplasia. Front Genet 2022; 13:856636. [PMID: 36159992 PMCID: PMC9490368 DOI: 10.3389/fgene.2022.856636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Objective: Microcephaly with pontine and cerebellar hypoplasia (MICPCH) is a rare X-linked dominant genetic disease, and most MICPCHs are ascribed to CASK mutations, while few are revealed in Chinese patients. This study aims to identify the pathogenic mutation in a Chinese proband with MICPCH.Methods: A 3-year-old female Chinese proband with MICPCH and her parents were included. Clinical data were collected from the medical records and recalled by the proband’s mother. Whole genome sequencing and Sanger sequencing were used to find the pathogenic mutation of MICPCH.Results: The proband presented with postnatal progressive microcephaly, cerebellar hypoplasia, intellectual disability, motor and language development retardation and limb hypertonia. Genetic analysis indicated that there was a novel compound heterozygote nonsynonymous mutation, c.755T>C(p.Leu252Pro) in exon8 of CASK gene in the proband, but not in her parents. This CASK mutation has not been reported in other databases.Conclusion: This study broadens the mutation spectrum of the CASK gene and is of great value for precise prenatal diagnosis and genetic counseling.
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Affiliation(s)
- Guilan Xie
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Yan Zhang
- Center for Translational Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Wenfang Yang
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- *Correspondence: Wenfang Yang,
| | - Liren Yang
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Ruiqi Wang
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Mengmeng Xu
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Landi Sun
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Boxing Zhang
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Xiaoyi Cui
- Department of Obstetrics and Gynecology, Maternal and Child Health Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Peking University Health Science Center, Beijing, China
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13
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Dubbs H, Ortiz-Gonzalez X, Marsh ED. Pathogenic variants in CASK: Expanding the genotype-phenotype correlations. Am J Med Genet A 2022; 188:2617-2626. [PMID: 35670295 DOI: 10.1002/ajmg.a.62863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 05/04/2022] [Accepted: 05/16/2022] [Indexed: 01/24/2023]
Abstract
Pathogenic variants in CASK, an X-linked gene that plays a role in brain development and synaptic function, are the cause of both microcephaly with pontine and cerebellar hypoplasia (MICPCH), and X-linked intellectual disability (XLID) with or without nystagmus. MICPCH is caused by loss of function variants in CASK, typically affects females, and is associated with moderate-to-severe intellectual disability (ID). Additional findings, present in about one-third of individuals, include feeding difficulties, ophthalmologic issues, hypertonicity, epilepsy, and sensorineural hearing loss. Only a few affected males with MICPCH phenotype have been reported and most have had profound developmental disability and intractable epilepsy. The XLID phenotype is typically caused by missense variants and most often manifests in males; carrier females are mildly affected or unaffected. Nystagmus is often present. In total, over 175 patients have been reported in the literature. We now report an additional 11 patients with pathogenic variants in CASK that expand these phenotypes and reported genotype-phenotype correlations.
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Affiliation(s)
- Holly Dubbs
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Xilma Ortiz-Gonzalez
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eric D Marsh
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Departments of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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14
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Zhang R, Jia P, Yao Y, Zhu F. Case Report: Identification of a novel CASK missense variant in a Chinese family with MICPCH. Front Genet 2022; 13:933785. [PMID: 36092876 PMCID: PMC9452731 DOI: 10.3389/fgene.2022.933785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Mental retardation and microcephaly with pontine and cerebellar hypoplasia (MICPCH) is a rare genetic disorder that results in varying levels of pontocerebellar hypoplasia, microcephaly, and severe intellectual disabilities. Prior genetic analyses have identified the CASK gene as a driver of MICPCH. Herein, we analyzed a Chinese family with MICPCH. The index patient was an 8-year-old male. He and his 3-year-old brother suffered from microcephaly, pontocerebellar hypoplasia, serious mental retardation, ataxia, gait disorder, and inability to speak. Through a combination of whole-exome sequencing and subsequent Sanger sequencing, a novel X-linked missense mutation, c.1882G>C (p.D628H) in the CASK gene, was identified in two siblings, as well as their mother and grandmother, who exhibited mild mental retardation. Other family members with negative genetic testing were normal. In silico analyses indicated that this missense mutation was predicted to reduce CASK protein stability, disrupt the SRC homology 3 (SH3) domain, and abolish its function. In summary, we identified a novel missense variate in CASK associated with MICPCH. Our work facilitates the diagnosis of the disease in this family and broadens the gene variant spectrum of the CASK in MICPCH patients.
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Affiliation(s)
- Runfeng Zhang
- College of Life Sciences, Hubei Normal University, Huangshi, China
| | - Peng Jia
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanyi Yao
- Medical Genetic Center, Maternal and Child Health Hospital of Hubei Province, Wuhan, China
- *Correspondence: Feng Zhu, ; Yanyi Yao,
| | - Feng Zhu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Clinic Center of Human Gene Research, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Feng Zhu, ; Yanyi Yao,
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15
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Phung TN, Olney KC, Pinto BJ, Silasi M, Perley L, O’Bryan J, Kliman HJ, Wilson MA. X chromosome inactivation in the human placenta is patchy and distinct from adult tissues. HGG ADVANCES 2022; 3:100121. [PMID: 35712697 PMCID: PMC9194956 DOI: 10.1016/j.xhgg.2022.100121] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
In humans, one of the X chromosomes in genetic females is inactivated by a process called X chromosome inactivation (XCI). Variation in XCI across the placenta may contribute to observed sex differences and variability in pregnancy outcomes. However, XCI has predominantly been studied in human adult tissues. Here, we sequenced and analyzed DNA and RNA from two locations from 30 full-term pregnancies. Implementing an allele-specific approach to examine XCI, we report evidence that XCI in the human placenta is patchy, with large patches of either maternal or paternal X chromosomes inactivated. Further, using similar measurements, we show that this is in contrast to adult tissues, which generally exhibit mosaic X inactivation, where bulk samples exhibit both maternal and paternal X chromosome expression. Further, by comparing skewed samples in placenta and adult tissues, we identify genes that are uniquely inactivated or expressed in the placenta compared with adult tissues, highlighting the need for tissue-specific maps of XCI.
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Affiliation(s)
- Tanya N. Phung
- Center for Evolution and Medicine, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
| | - Kimberly C. Olney
- Center for Evolution and Medicine, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
| | - Brendan J. Pinto
- Center for Evolution and Medicine, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI 53233, USA
| | - Michelle Silasi
- Department of Maternal-Fetal Medicine, Mercy Hospital St. Louis, St. Louis, MO 63141, USA
| | - Lauren Perley
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jane O’Bryan
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Harvey J. Kliman
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Melissa A. Wilson
- Center for Evolution and Medicine, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
- The Biodesign Center for Mechanisms of Evolution, Arizona State University, PO Box 874501, Tempe, AZ 85282, USA
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16
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Wu S, Jiang C, Li J, Zhang G, Shen Y, Wang J. A novel missense variant in the CASK gene causes intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia. BMC Med Genomics 2022; 15:127. [PMID: 35668446 PMCID: PMC9169347 DOI: 10.1186/s12920-022-01275-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 05/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Variants in the CASK gene result in a wide range of observed phenotypes in humans, such as FG Syndrome 4 and intellectual disabilities. Intellectual developmental disorder with microcephaly and pontine and cerebellar hypoplasia (MICPCH) is an X-linked disorder that affects females and is characterized by severely impaired intellectual development and variable degrees of pontocerebellar hypoplasia. Variants in CASK are the main genetic cause of MICPCH. Variants in CASK can explain most patients with MICPCH, but there are still some patients whose disease aetiology cannot be explained. CASE PRESENTATION An 11-month-old female diagnosed with MICPCH exhibited general developmental delays, microcephaly, and cerebellar hypoplasia. Whole-exome sequencing (WES) was used to find a novel heterozygous missense variant (NM_003688.3: c.638T>G) of CASK in this patient. Strikingly, this variant reduced the expression of CASK at the protein level but not at the mRNA level. By using protein structure prediction analysis, this study found that the amino acid change caused by the variant resulted in further changes in the stability of the protein structure, and these changes caused the downregulation of protein expression and loss of protein function. CONCLUSION In this study, we first reported a novel heterozygous pathogenic variant and a causative mechanism of MICPCH. The amino acid change cause by this variant led to changes in the protein structure and a decrease in its stability, which caused a loss of protein function. This study could be helpful to the genetic diagnosis of this disease.
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Affiliation(s)
- Sixian Wu
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China.,West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Chuan Jiang
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Jiaman Li
- West China School of Pharmacy, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Guohui Zhang
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Ying Shen
- Joint Laboratory of Reproductive Medicine, Gynaecology and Paediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China.
| | - Jing Wang
- Department of Obstetrics and Gynaecology, West China Second University Hospital of Sichuan University and Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, 610041, People's Republic of China.
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17
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Zhang Y, Nie Y, Mu Y, Zheng J, Xu X, Zhang F, Shu J, Liu Y. A de novo variant in CASK gene causing intellectual disability and brain hypoplasia: a case report and literature review. Ital J Pediatr 2022; 48:73. [PMID: 35550617 PMCID: PMC9097383 DOI: 10.1186/s13052-022-01248-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/17/2022] [Indexed: 12/02/2022] Open
Abstract
Background The pathogenic variation of CASK gene can cause CASK related mental disorders. The main clinical manifestations are microcephaly with pontine and cerebellar hypoplasia, X-linked mental disorders with or without nystagmus and FG syndrome. The main pathogenic mechanism is the loss of function of related protein caused by variant. We reported a Chinese male newborn with a de novo variant in CASK gene. Case presentation We present an 18-day-old baby with growth retardation and brain hypoplasia. Whole-exome sequencing was performed, which detected a hemizygous missense variant c.764G > A of CASK gene. The variant changed the 255th amino acid from Arg to His. Software based bioinformatics analyses were conducted to infer its functional effect. Conclusions In this paper, a de novo variant of CASK gene was reported. Moreover, a detailed description of all the cases described in the literature is reported. CASK variants cause a variety of clinical phenotypes. Its diagnosis is difficult due to the lack of typical clinical symptoms. Genetic testing should be performed as early as possible if this disease is suspected. This case provides an important reference for the diagnosis and treatment of future cases.
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Affiliation(s)
- Ying Zhang
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.,Graduate College of Tianjin Medical University, Tianjin, China
| | - Yanyan Nie
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Yu Mu
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Jie Zheng
- Graduate College of Tianjin Medical University, Tianjin, China
| | - Xiaowei Xu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China.,Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Fang Zhang
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Jianbo Shu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China. .,Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.
| | - Yang Liu
- Department of Neonatology, Tianjin Children's Hospital (Tianjin University Children's Hospital), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China.
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18
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Mukherjee K, LaConte LEW, Srivastava S. The Non-Linear Path from Gene Dysfunction to Genetic Disease: Lessons from the MICPCH Mouse Model. Cells 2022; 11:1131. [PMID: 35406695 PMCID: PMC8997851 DOI: 10.3390/cells11071131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/09/2022] [Accepted: 03/24/2022] [Indexed: 11/17/2022] Open
Abstract
Most human disease manifests as a result of tissue pathology, due to an underlying disease process (pathogenesis), rather than the acute loss of specific molecular function(s). Successful therapeutic strategies thus may either target the correction of a specific molecular function or halt the disease process. For the vast majority of brain diseases, clear etiologic and pathogenic mechanisms are still elusive, impeding the discovery or design of effective disease-modifying drugs. The development of valid animal models and their proper characterization is thus critical for uncovering the molecular basis of the underlying pathobiological processes of brain disorders. MICPCH (microcephaly and pontocerebellar hypoplasia) is a monogenic condition that results from variants of an X-linked gene, CASK (calcium/calmodulin-dependent serine protein kinase). CASK variants are associated with a wide range of clinical presentations, from lethality and epileptic encephalopathies to intellectual disabilities, microcephaly, and autistic traits. We have examined CASK loss-of-function mutations in model organisms to simultaneously understand the pathogenesis of MICPCH and the molecular function/s of CASK. Our studies point to a highly complex relationship between the potential molecular function/s of CASK and the phenotypes observed in model organisms and humans. Here we discuss the implications of our observations from the pathogenesis of MICPCH as a cautionary narrative against oversimplifying molecular interpretations of data obtained from genetically modified animal models of human diseases.
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Affiliation(s)
- Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, VA 24016, USA; (L.E.W.L.); (S.S.)
- Department of Psychiatry, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | - Leslie E. W. LaConte
- Fralin Biomedical Research Institute at VTC, Roanoke, VA 24016, USA; (L.E.W.L.); (S.S.)
- Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, VA 24016, USA; (L.E.W.L.); (S.S.)
- Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
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19
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Catino G, Genovese S, Di Tommaso S, Orlando V, Petti MT, De Bernardi ML, Dallapiccola B, Novelli A, Ulgheri L, Piscopo C, Alesi V. Reciprocal Xp11.4p11.3 microdeletion/microduplication spanning USP9X, DDX3X, and CASK genes in two patients with syndromic intellectual disability. Am J Med Genet A 2022; 188:1836-1847. [PMID: 35238482 DOI: 10.1002/ajmg.a.62694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 12/13/2022]
Abstract
Only a few patients with deletions or duplications at Xp11.4, bridging USP9X, DDX3X, and CASK genes, have been described so far. Here, we report on a female harboring a de novo Xp11.4p11.3 deletion and a male with an overlapping duplication inherited from an unaffected mother, presenting with syndromic intellectual disability. We discuss the role of USP9X, DDX3X, and CASK genes in human development and describe the effects of Xp11.4 deletion and duplications in female and male patients, respectively.
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Affiliation(s)
- Giorgia Catino
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Silvia Genovese
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Silvia Di Tommaso
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Valeria Orlando
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Maria Teresa Petti
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy
| | | | - Bruno Dallapiccola
- Genetics and Rare Disease Research Division, Bambino Gesu Children Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Lucia Ulgheri
- Department of Biomedical Sciences, Clinical Genetics Service, Azienda Ospedaliero-Universitaria, Sassari, Italy
| | - Carmelo Piscopo
- Department of Molecular Medicine and Medical Biotechnology, University Federico II, Naples, Italy
| | - Viola Alesi
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
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Identification of Pathogenic Mutations in Primary Microcephaly- (MCPH-) Related Three Genes CENPJ, CASK, and MCPH1 in Consanguineous Pakistani Families. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3769948. [PMID: 35281599 PMCID: PMC8913137 DOI: 10.1155/2022/3769948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/20/2022] [Indexed: 12/19/2022]
Abstract
Microcephaly (MCPH) is a developmental anomaly of the brain known by reduced cerebral cortex and underdeveloped intellectual disability without additional clinical symptoms. It is a genetically and clinically heterogenous disorder. Twenty-five genes (involved in spindle positioning, Wnt signaling, centriole biogenesis, DNA repair, microtubule dynamics, cell cycle checkpoints, and transcriptional regulation) causing MCPH have been identified so far. Pakistani population has contributed in the identification of many MCPH genes. WES of three large consanguineous families revealed three pathogenic variants of MCPH1, CENPJ, and CASK. One novel (c.1254delT) deletion variant of MCPH1 and one known (c.18delC) deletion variant of CENPJ were identified in family 1 and 2, respectively. In addition to this, we also identified a missense variant (c.1289G>A) of CASK in males individuals in family 3. Missense mutation in the CASK gene is frequent in the boys with intellectual disability and autistic traits which are the common features that are associated with FG Syndrome 4. The study reports novel and reported mutant alleles disrupting the working of genes vital for normal brain functioning. The findings of this study enhance our understanding about the genetic architecture of primary microcephaly in our local pedigrees and add to the allelic heterogeneity of 3 known MCPH genes. The data generated will help to develop specific strategies to reduce the high incidence rate of MCPH in Pakistani population.
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21
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Patel PA, Hegert JV, Cristian I, Kerr A, LaConte LEW, Fox MA, Srivastava S, Mukherjee K. Complete loss of the X-linked gene CASK causes severe cerebellar degeneration. J Med Genet 2022; 59:1044-1057. [PMID: 35149592 DOI: 10.1136/jmedgenet-2021-108115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/13/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Heterozygous loss of X-linked genes like CASK and MeCP2 (Rett syndrome) causes developmental delay in girls, while in boys, loss of the only allele of these genes leads to epileptic encephalopathy. The mechanism for these disorders remains unknown. CASK-linked cerebellar hypoplasia is presumed to result from defects in Tbr1-reelin-mediated neuronal migration. METHOD Here we report clinical and histopathological analyses of a deceased 2-month-old boy with a CASK-null mutation. We next generated a mouse line where CASK is completely deleted (hemizygous and homozygous) from postmigratory neurons in the cerebellum. RESULT The CASK-null human brain was smaller in size but exhibited normal lamination without defective neuronal differentiation, migration or axonal guidance. The hypoplastic cerebellum instead displayed astrogliosis and microgliosis, which are markers for neuronal loss. We therefore hypothesise that CASK loss-induced cerebellar hypoplasia is the result of early neurodegeneration. Data from the murine model confirmed that in CASK loss, a small cerebellum results from postdevelopmental degeneration of cerebellar granule neurons. Furthermore, at least in the cerebellum, functional loss from CASK deletion is secondary to degeneration of granule cells and not due to an acute molecular functional loss of CASK. Intriguingly, female mice with heterozygous deletion of CASK in the cerebellum do not display neurodegeneration. CONCLUSION We suggest that X-linked neurodevelopmental disorders like CASK mutation and Rett syndrome are pathologically neurodegenerative; random X-chromosome inactivation in heterozygous mutant girls, however, results in 50% of cells expressing the functional gene, resulting in a non-progressive pathology, whereas complete loss of the only allele in boys leads to unconstrained degeneration and encephalopathy.
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Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Julia V Hegert
- Department of Pathology, Orlando Health, Orlando, Florida, USA
| | | | - Alicia Kerr
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | | | - Michael A Fox
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,School of Neuroscience, Blacksburg, Virginia, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA.,Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA .,Department of Psychiatry, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
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22
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Moon D, Park HW, Surl D, Won D, Lee ST, Shin S, Choi JR, Han J. Precision Medicine through Next-Generation Sequencing in Inherited Eye Diseases in a Korean Cohort. Genes (Basel) 2021; 13:genes13010027. [PMID: 35052368 PMCID: PMC8774510 DOI: 10.3390/genes13010027] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/13/2021] [Accepted: 12/20/2021] [Indexed: 12/14/2022] Open
Abstract
In this study, we investigated medically or surgically actionable genes in inherited eye disease, based on clinical phenotype and genomic data. This retrospective consecutive case series included 149 patients with inherited eye diseases, seen by a single pediatric ophthalmologist, who underwent genetic testing between 1 March 2017 and 28 February 2018. Variants were detected using a target enrichment panel of 429 genes and known deep intronic variants associated with inherited eye disease. Among 149 patients, 38 (25.5%) had a family history, and this cohort includes heterogeneous phenotype including anterior segment dysgenesis, congenital cataract, infantile nystagmus syndrome, optic atrophy, and retinal dystrophy. Overall, 90 patients (60.4%) received a definite molecular diagnosis. Overall, NGS-guided precision care was provided to 8 patients (5.4%). The precision care included cryotherapy to prevent retinal detachment in COL2A1 Stickler syndrome, osteoporosis management in patients with LRP5-associated familial exudative vitreoretinopathy, and avoidance of unnecessary phlebotomy in hyperferritinemia-cataract syndrome. A revision of the initial clinical diagnosis was made in 22 patients (14.8%). Unexpected multi-gene deletions and dual diagnosis were noted in 4 patients (2.7%). We found that precision medical or surgical managements were provided for 8 of 149 patients (5.4%), and multiple locus variants were found in 2.7% of cases. These findings are important because individualized management of inherited eye diseases can be achieved through genetic testing.
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Affiliation(s)
- Dabin Moon
- Department of Medicine, Yonsei University College of Medicine, Seoul 03722, Korea;
| | - Hye Won Park
- Department of Ophthalmology, Konyang University College of Medicine, Daejeon 35365, Korea;
| | - Dongheon Surl
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea;
| | - Dongju Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.); (S.S.); (J.R.C.)
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.); (S.S.); (J.R.C.)
| | - Saeam Shin
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.); (S.S.); (J.R.C.)
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea; (D.W.); (S.-T.L.); (S.S.); (J.R.C.)
| | - Jinu Han
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea;
- Department of Ophthalmology, Institute of Vision Research, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea
- Correspondence: ; Tel.: +82-2-2019-3445; Fax: +82-2-3463-1049
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23
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Cook CB, Armstrong L, Boerkoel CF, Clarke LA, du Souich C, Demos MK, Gibson WT, Gill H, Lopez E, Patel MS, Selby K, Abu-Sharar Z, Elliott AM, Friedman JM. Somatic mosaicism detected by genome-wide sequencing in 500 parent-child trios with suspected genetic disease: clinical and genetic counseling implications. Cold Spring Harb Mol Case Stud 2021; 7:mcs.a006125. [PMID: 34697084 PMCID: PMC8751411 DOI: 10.1101/mcs.a006125] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/13/2021] [Indexed: 01/28/2023] Open
Abstract
Identifying genetic mosaicism is important in establishing a diagnosis, assessing recurrence risk, and providing accurate genetic counseling. Next-generation sequencing has allowed for the identification of mosaicism at levels below those detectable by conventional Sanger sequencing or chromosomal microarray analysis. The CAUSES Clinic was a pediatric translational trio-based genome-wide (exome or genome) sequencing study of 500 families (531 children) with suspected genetic disease at BC Children's and Women's Hospitals. Here we present 12 cases of apparent mosaicism identified in the CAUSES cohort: nine cases of parental mosaicism for a disease-causing variant found in a child and three cases of mosaicism in the proband for a de novo variant. In six of these cases, there was no evidence of mosaicism on Sanger sequencing—the variant was not detected on Sanger sequencing in three cases, and it appeared to be heterozygous in three others. These cases are examples of six clinical manifestations of mosaicism: a proband with classical clinical features of mosaicism (e.g., segmental abnormalities of skin pigmentation or asymmetrical growth of bilateral body parts), a proband with unusually mild manifestations of a disease, a mosaic proband who is clinically indistinguishable from the constitutive phenotype, a mosaic parent with no clinical features of the disease, a mosaic parent with mild manifestations of the disease, and a family in which both parents are unaffected and two siblings have the same disease-causing constitutional mutation. Our data demonstrate the importance of considering the possibility of mosaicism whenever exome or genome sequencing is performed and that its detection via genome-wide sequencing can permit more accurate genetic counseling.
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Affiliation(s)
- Courtney B Cook
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Linlea Armstrong
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada V5Z 4H4
| | - Cornelius F Boerkoel
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Lorne A Clarke
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Christèle du Souich
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada V5Z 4H4
| | - Michelle K Demos
- Division of Neurology, Department of Pediatrics, BC Children's Hospital, Vancouver, British Columbia, Canada V6H 0B3
| | - William T Gibson
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada V5Z 4H4
| | - Harinder Gill
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Elena Lopez
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Millan S Patel
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1
| | - Kathryn Selby
- Division of Neurology, Department of Pediatrics, BC Children's Hospital, Vancouver, British Columbia, Canada V6H 0B3
| | - Ziad Abu-Sharar
- Division of Neurology, Department of Pediatrics, BC Children's Hospital, Vancouver, British Columbia, Canada V6H 0B3
| | | | - Alison M Elliott
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada V5Z 4H4.,Women's Health Research Institute, Vancouver, British Columbia, Canada V6H 2N9
| | - Jan M Friedman
- Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada V6H 3N1.,BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada V5Z 4H4
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24
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Chromosomal Microarray Analysis Has a Poor Diagnostic Yield in Children with Developmental Delay/Intellectual Disability When Concurrent Cerebellar Anomalies Are Present. THE CEREBELLUM 2021; 19:629-635. [PMID: 32472476 DOI: 10.1007/s12311-020-01145-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Chromosomal microarray analysis is commonly used as screening test for children with neurodevelopmental issues, also in case of complex neurological phenotypes. Developmental delay/intellectual disability is a common presentation sign in pediatric ataxias, diseases with high clinical and genetic heterogeneity. In order to determine the diagnostic yield of Array-CGH in such conditions, all the tests performed in the last 10-year activity of a single referral center in children who present, besides the neurodevelopmental impairment, cerebellar abnormalities have been systematically gathered. The study demonstrates that, except for Dandy-Walker malformation or poly-malformative phenotypes, chromosomal microarray analysis should be discouraged as first-line diagnostic test in pediatric ataxias with neurodevelopmental disability.
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25
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van Dijk T, Barth P, Baas F, Reneman L, Poll-The BT. Postnatal Brain Growth Patterns in Pontocerebellar Hypoplasia. Neuropediatrics 2021; 52:163-169. [PMID: 33111306 DOI: 10.1055/s-0040-1716900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Pontocerebellar hypoplasia (PCH) is a rare group of disorders mainly affecting the cerebellum and pons. Supratentorial structures are variably involved. We assessed brain growth patterns in patients with the most frequent forms of PCH, namely PCH1B (OMIM#614678) and PCH2A (OMIM#277470), since in these types of PCH, pre- and postnatal neurodegeneration is established by neuropathological profiling. To assess the influence of the different pathomechanisms on postnatal growth patterns, we included CASK-associated microcephaly and PCH (MICPCH, OMIM#300749) patients in our analyses, as MICPH mimics PCH on magnetic resonance imaging (MRI) but represents a developmental disorder including abnormal neuronal migration. METHODS A total of 66 patients were included: 9 patients with PCH1B, 18 patients with PCH2A, 6 patients with MICPCH, and 33 age- and gender-matched hospital-based controls. Segmentation of the vermis and cerebellum was performed manually, as were measurements of the thickness of the head of the caudate nucleus, the width of the anterior horn, and lateral ventricle size. RESULTS The cerebellum was severely hypoplastic at birth in all patients, and postnatal growth was nearly absent. In patients with PCH1B/2A, we found relative sparing of the vermis compared with the cerebellar hemispheres. In addition, PCH1B and PCH2A cases demonstrated thinning of the head of the caudate nucleus, an associated increase in anterior horn width, and an increase in lateral ventricle size. None of these features were seen in the MICPCH group. CONCLUSIONS Our findings confirm the progressive nature including caudate nucleus atrophy in PCH1B and PCH2A. In MICPCH, the relative sparing of supratentorial structures confirms its different pathomechanism.
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Affiliation(s)
- Tessa van Dijk
- Department of Clinical Genetics, Academic Medical Center, Amsterdam University Medical Center, Amsterdam, The Netherlands.,Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter Barth
- Department of Pediatric Neurology, Academic Medical Center, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Frank Baas
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Liesbeth Reneman
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Bwee Tien Poll-The
- Department of Pediatric Neurology, Academic Medical Center, Amsterdam University Medical Center, Amsterdam, The Netherlands
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26
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Nuovo S, Micalizzi A, Romaniello R, Arrigoni F, Ginevrino M, Casella A, Serpieri V, D'Arrigo S, Briguglio M, Salerno GG, Rossato S, Sartori S, Leuzzi V, Battini R, Ben-Zeev B, Graziano C, Mirabelli Badenier M, Brankovic V, Nardocci N, Spiegel R, Petković Ramadža D, Vento G, Marti I, Simonati A, Dipresa S, Freri E, Mazza T, Bassi MT, Bosco L, Travaglini L, Zanni G, Bertini ES, Vanacore N, Borgatti R, Valente EM. Refining the mutational spectrum and gene-phenotype correlates in pontocerebellar hypoplasia: results of a multicentric study. J Med Genet 2021; 59:399-409. [PMID: 34085948 DOI: 10.1136/jmedgenet-2020-107497] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/27/2021] [Accepted: 02/09/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND Pontocerebellar hypoplasias (PCH) comprise a group of genetically heterogeneous disorders characterised by concurrent hypoplasia of the pons and the cerebellum and variable clinical and imaging features. The current classification includes 13 subtypes, with ~20 known causative genes. Attempts have been made to delineate the phenotypic spectrum associated to specific PCH genes, yet clinical and neuroradiological features are not consistent across studies, making it difficult to define gene-specific outcomes. METHODS We performed deep clinical and imaging phenotyping in 56 probands with a neuroradiological diagnosis of PCH, who underwent NGS-based panel sequencing of PCH genes and MLPA for CASK rearrangements. Next, we conducted a phenotype-based unsupervised hierarchical cluster analysis to investigate associations between genes and specific phenotypic clusters. RESULTS A genetic diagnosis was obtained in 43 probands (77%). The most common causative gene was CASK, which accounted for nearly half cases (45%) and was mutated in females and occasionally in males. The European founder mutation p.Ala307Ser in TSEN54 and pathogenic variants in EXOSC3 accounted for 18% and 9% of cases, respectively. VLDLR, TOE1 and RARS2 were mutated in single patients. We were able to confirm only few previously reported associations, including jitteriness and clonus with TSEN54 and lower motor neuron signs with EXOSC3. When considering multiple features simultaneously, a clear association with a phenotypic cluster only emerged for EXOSC3. CONCLUSION CASK represents the major PCH causative gene in Italy. Phenotypic variability associated with the most common genetic causes of PCH is wider than previously thought, with marked overlap between CASK and TSEN54-associated disorders.
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Affiliation(s)
- Sara Nuovo
- Department of Human Neuroscience, Sapienza University of Rome, Roma, Italy
| | - Alessia Micalizzi
- Laboratory of Medical Genetics, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Filippo Arrigoni
- Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Monia Ginevrino
- Laboratory of Medical Genetics, IRCCS Bambino Gesù Children's Hospital, Roma, Italy.,Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Roma, Italy
| | - Antonella Casella
- IRCCS Mondino Foundation, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Stefano D'Arrigo
- Department of Developmental Neurology, Fondazione IRCCS, Istituto Neurologico Carlo Besta, Milano, Italy
| | - Marilena Briguglio
- Interdepartmental Program "Autism 0-90", "G. Martino" University Hospital of Messina, Messina, Italy
| | - Grazia Gabriella Salerno
- Child Neurology Unit, Department of Paediatrics, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Sara Rossato
- U.O.C. Pediatria, Ospedale San Bortolo, Vicenza, Italy
| | - Stefano Sartori
- Paediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University Hospital of Padova, Padova, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Roma, Italy
| | - Roberta Battini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Bruria Ben-Zeev
- Pediatric Neurology Department, The Edmond and Lilly Safra Pediatric Hospital, Sheba Medical Center, Tel Hashomer, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Claudio Graziano
- Medical Genetics Unit, AOU Policlinico di S. Orsola, Bologna, Italy
| | - Marisol Mirabelli Badenier
- Fondazione Istituto David Chiossone Onlus, Genova, Italy.,Child Neuropsychiatry Unit, Department of Neurosciences and Rehabilitation, Istituto G. Gaslini, Genova, Italy
| | - Vesna Brankovic
- Clinic for Child Neurology and Psychiatry, University of Belgrade, Belgrade, Serbia
| | - Nardo Nardocci
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Ronen Spiegel
- Department of Pediatrics B, Emek Medical Center, Afula, Israel.,Rappaport School of Medicine, Technion, Haifa, Israel
| | | | - Giovanni Vento
- Division of Neonatology, Department of Woman and Child Health and Public Health, Child Health Area, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Itxaso Marti
- Pediatric Neurology, Hospital Universitario Donostia, Biodonostia, Universidad del País Vasco UPV-EHU, San Sebastian, Spain
| | - Alessandro Simonati
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona School of Medicine and Department of Clinical Neuroscience AOUI Verona, Verona, Italy
| | - Savina Dipresa
- Department of Medicine, Unit of Andrology and Reproductive Medicine, University of Padova, Padova, Italy
| | - Elena Freri
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Tommaso Mazza
- Bioinformatics Unit, IRCCS Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Italy
| | - Maria Teresa Bassi
- Laboratory of Molecular Biology, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Luca Bosco
- Unit of Neuromuscular and Neurodegenerative Diseases, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Lorena Travaglini
- Unit of Neuromuscular and Neurodegenerative Diseases, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Diseases, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Enrico Silvio Bertini
- Unit of Neuromuscular and Neurodegenerative Diseases, Department of Neuroscience and Neurorehabilitation, IRCCS Bambino Gesù Children's Hospital, Roma, Italy
| | - Nicola Vanacore
- National Center for Disease Prevention and Health Promotion, Italian National Institute of Health, Roma, Italy
| | - Renato Borgatti
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Enza Maria Valente
- IRCCS Mondino Foundation, Pavia, Italy .,Department of Molecular Medicine, University of Pavia, Pavia, Italy
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CASK related disorder: Epilepsy and developmental outcome. Eur J Paediatr Neurol 2021; 31:61-69. [PMID: 33640666 DOI: 10.1016/j.ejpn.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 02/09/2021] [Accepted: 02/15/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE CASK pathogenic variants are associated with variable features, as intellectual disability, optic atrophy, brainstem/cerebellar hypoplasia, and epileptic encephalopathy. Few studies describe the electroclinical features of epilepsy in patients with CASK pathogenic variants and their relationship with developmental delay. METHODS this national multicentre cohort included genetically confirmed patients with different CASK pathogenic variants. Our findings were compared with cohorts reported in the literature. RESULTS we collected 34 patients (29 females) showing from moderate (4 patients) to severe (22) and profound (8) developmental delay; all showed pontine and cerebellar hypoplasia, all except three with microcephaly. Seventeen out of 34 patients (50%) suffered from epileptic seizures, including spasms (11 patients, 32.3%), generalized (5) or focal seizures (1). In 8/17 individuals (47.1%), epilepsy started at or beyond the age of 24 months. Seven (3 males) out of the 11 children with spasms showed EEG features and a course supporting the diagnosis of a developmental and epileptic encephalopathy (DEE). Drug resistance was frequent in our cohort (52.9% of patients with epilepsy). EEG abnormalities included poorly organized background activity with diffuse or multifocal epileptiform abnormalities and sleep-activation, with possible appearance over the follow-up period. Developmental delay degree was not statistically different among patients with or without seizures but feeding difficulties were more frequent in patients with epilepsy. CONCLUSIONS epilepsy is a frequent comorbidity with a high incidence of spasms and drug resistance. Overall developmental disability does not seem to be more severe in the group of patients with epilepsy nor to be linked to specific epilepsy/EEG characteristics. A childhood onset of epilepsy is frequent, with possible worsening over time, so that serial and systematic monitoring is mandatory.
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28
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Nishio Y, Kidokoro H, Takeo T, Narita H, Sawamura F, Narita K, Kawano Y, Nakata T, Muramatsu H, Hara S, Kaname T, Natsume J. The eldest case of MICPCH with CASK mutation exhibiting gross motor regression. Brain Dev 2021; 43:459-463. [PMID: 33272775 DOI: 10.1016/j.braindev.2020.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/02/2020] [Accepted: 11/15/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND MICPCH is manifested as microcephaly associated with pontocerebellar hypoplasia and global developmental delay but developmental regression has never been reported. We describe the detailed clinical history of a woman with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH) with a CASK mutation who exhibited gross motor regression after adolescence. CASE The patient experienced severe motor and intellectual developmental delay with microcephaly from infancy. The initial diagnosis was Rett syndrome based on her clinical features, including hand stereotypes and the absence of structural abnormality on magnetic resonance imaging (MRI) performed at the age of 5 years. Although gross motor abilities developed slowly and she could walk independently, she never acquired speech or understanding of languages. After adolescence, her motor ability gradually regressed so that she was unable to stand without support and moved with a wheelchair. At the age of 31 years, because of her atypical clinical course for Rett syndrome, whole exome sequencing was performed, which revealed a de novo heterozygous c.2068 + 1G > A mutation in the CASK gene (NM_001126055). Brain MRI revealed mild pontocerebellar hypoplasia compatible with the clinical phenotype of MICPCH. DISCUSSION This case suggests that MICPCH with a CASK mutation might cause developmental regression after adolescence and might be regarded as a neurodegenerative disorder.
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Affiliation(s)
- Yosuke Nishio
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Pediatrics, TOYOTA Memorial Hospital, Toyota, Japan
| | - Hiroyuki Kidokoro
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| | - Toshiki Takeo
- Department of Pediatrics, TOYOTA Memorial Hospital, Toyota, Japan
| | - Hajime Narita
- Department of Pediatrics, TOYOTA Memorial Hospital, Toyota, Japan
| | - Fumi Sawamura
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kotaro Narita
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihiko Kawano
- Department of Pediatrics, TOYOTA Memorial Hospital, Toyota, Japan
| | - Tomohiko Nakata
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hideki Muramatsu
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinya Hara
- Department of Pediatrics, TOYOTA Memorial Hospital, Toyota, Japan
| | - Tadashi Kaname
- Department of Genome Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Jun Natsume
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Disability Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Zhao J, Hou M, Wang H, Liu Q, Sun D, Wei W. Microcephaly, disproportionate pontine, and cerebellar hypoplasia syndrome: Two novel mutations in the CASK gene were discovered in Chinese females. Int J Dev Neurosci 2021; 81:277-284. [PMID: 33629417 DOI: 10.1002/jdn.10100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/08/2021] [Accepted: 02/21/2021] [Indexed: 11/10/2022] Open
Abstract
Microcephaly, disproportionate pontine and cerebellar hypoplasia (MICPCH) syndrome is a rare and genetic disorder, which is mainly caused by mutations in the CASK gene. We described four variations in the CASK gene in Chinese female patients with MICPCH, who presented with microcephaly, developmental delay, and motor disorder. The CASK mutations were identified using NGS (the next-generation sequencing), copy number variation sequencing. Two novel variations in the CASK gene were revealed including a frameshift mutation c.1000_1001insG (p.Asp334GlyfsTer32) and a nonsense mutation c.2110A > T (p.Lys704Ter). Two other aberrations were c.316C > T (p.Arg106Ter) and Xp11.4-p11.3 (41,700,001-44,660,000) × 1 loss. We provided clinical manifestations and neuroimaging findings of the four patients. The genetic variation spectrum of MICPCH caused by CASK was updated. Furthermore, we expounded on the molecular mechanism of the disease and noticed that it was not possible to relate the magnitude of the genetic alteration to a particular phenotype.
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Affiliation(s)
- Jianhui Zhao
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Mei Hou
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Haiqiao Wang
- Department of Traditional Chinese Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, P.R. China
| | - Qiuyan Liu
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Dianrong Sun
- Department of Neurology & Rehabilitation, Qingdao Women and Children's Hospital, Qingdao, P.R. China
| | - Wei Wei
- Kangso Medical Inspection Co, Ltd., Beijing, P.R. China
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Abstract
Cerebellar hypoplasia (CH) refers to a cerebellum of reduced volume with preserved shape. CH is associated with a broad heterogeneity in neuroradiologic features, etiologies, clinical characteristics, and neurodevelopmental outcomes, challenging physicians evaluating children with CH. Traditionally, neuroimaging has been a key tool to categorize CH based on the pattern of cerebellar involvement (e.g., hypoplasia of cerebellar vermis only vs. hypoplasia of both the vermis and cerebellar hemispheres) and the presence of associated brainstem and cerebral anomalies. With the advances in genetic technologies of the recent decade, many novel CH genes have been identified, and consequently, a constant updating of the literature and revision of the classification of cerebellar malformations are needed. Here, we review the current literature on CH. We propose a systematic approach to recognize specific neuroimaging patterns associated with CH, based on whether the CH is isolated or associated with posterior cerebrospinal fluid anomalies, specific brainstem or cerebellar malformations, brainstem hypoplasia with or without cortical migration anomalies, or dysplasia. The CH radiologic pattern and clinical assessment will allow the clinician to guide his investigations and genetic testing, give a more precise diagnosis, screen for associated comorbidities, and improve prognostication of associated neurodevelopmental outcomes.
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Andrew DR, Moe ME, Chen D, Tello JA, Doser RL, Conner WE, Ghuman JK, Restifo LL. Spontaneous motor-behavior abnormalities in two Drosophila models of neurodevelopmental disorders. J Neurogenet 2020; 35:1-22. [PMID: 33164597 DOI: 10.1080/01677063.2020.1833005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mutations in hundreds of genes cause neurodevelopmental disorders with abnormal motor behavior alongside cognitive deficits. Boys with fragile X syndrome (FXS), a leading monogenic cause of intellectual disability, often display repetitive behaviors, a core feature of autism. By direct observation and manual analysis, we characterized spontaneous-motor-behavior phenotypes of Drosophila dfmr1 mutants, an established model for FXS. We recorded individual 1-day-old adult flies, with mature nervous systems and prior to the onset of aging, in small arenas. We scored behavior using open-source video-annotation software to generate continuous activity timelines, which were represented graphically and quantitatively. Young dfmr1 mutants spent excessive time grooming, with increased bout number and duration; both were rescued by transgenic wild-type dfmr1+. By two grooming-pattern measures, dfmr1-mutant flies showed elevated repetitions consistent with perseveration, which is common in FXS. In addition, the mutant flies display a preference for grooming posterior body structures, and an increased rate of grooming transitions from one site to another. We raise the possibility that courtship and circadian rhythm defects, previously reported for dfmr1 mutants, are complicated by excessive grooming. We also observed significantly increased grooming in CASK mutants, despite their dramatically decreased walking phenotype. The mutant flies, a model for human CASK-related neurodevelopmental disorders, displayed consistently elevated grooming indices throughout the assay, but transient locomotory activation immediately after placement in the arena. Based on published data identifying FMRP-target transcripts and functional analyses of mutations causing human genetic neurodevelopmental disorders, we propose the following proteins as candidate mediators of excessive repetitive behaviors in FXS: CaMKIIα, NMDA receptor subunits 2A and 2B, NLGN3, and SHANK3. Together, these fly-mutant phenotypes and mechanistic insights provide starting points for drug discovery to identify compounds that reduce dysfunctional repetitive behaviors.
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Affiliation(s)
- David R Andrew
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Department of Biological Sciences, Lycoming College, Williamsport, PA, USA
| | - Mariah E Moe
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Dailu Chen
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Judith A Tello
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
| | - Rachel L Doser
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - William E Conner
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Jaswinder K Ghuman
- Department of Psychiatry, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Linda L Restifo
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA.,BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, USA
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Pan YE, Tibbe D, Harms FL, Reißner C, Becker K, Dingmann B, Mirzaa G, Kattentidt-Mouravieva AA, Shoukier M, Aggarwal S, Missler M, Kutsche K, Kreienkamp HJ. Missense mutations in CASK, coding for the calcium-/calmodulin-dependent serine protein kinase, interfere with neurexin binding and neurexin-induced oligomerization. J Neurochem 2020; 157:1331-1350. [PMID: 33090494 DOI: 10.1111/jnc.15215] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 10/01/2020] [Accepted: 10/07/2020] [Indexed: 12/19/2022]
Abstract
Mutations in the X-linked gene coding for the calcium-/calmodulin-dependent serine protein kinase (CASK) are associated with severe neurological disorders ranging from intellectual disability (in males) to mental retardation and microcephaly with pontine and cerebellar hypoplasia. CASK is involved in transcription control, in the regulation of trafficking of the post-synaptic NMDA and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, and acts as a presynaptic scaffolding protein. For CASK missense mutations, it is mostly unclear which of CASK's molecular interactions and cellular functions are altered and contribute to patient phenotypes. We identified five CASK missense mutations in male patients affected by neurodevelopmental disorders. These and five previously reported mutations were systematically analysed with respect to interaction with CASK interaction partners by co-expression and co-immunoprecipitation. We show that one mutation in the L27 domain interferes with binding to synapse-associated protein of 97 kDa. Two mutations in the guanylate kinase (GK) domain affect binding of CASK to the nuclear factors CASK-interacting nucleosome assembly protein (CINAP) and T-box, brain, 1 (Tbr1). A total of five mutations in GK as well as PSD-95/discs large/ZO-1 (PDZ) domains affect binding of CASK to the pre-synaptic cell adhesion molecule Neurexin. Upon expression in neurons, we observe that binding to Neurexin is not required for pre-synaptic localization of CASK. We show by bimolecular fluorescence complementation assay that Neurexin induces oligomerization of CASK, and that mutations in GK and PDZ domains interfere with the Neurexin-induced oligomerization of CASK. Our data are supported by molecular modelling, where we observe that the cooperative activity of PDZ, SH3 and GK domains is required for Neurexin binding and oligomerization of CASK.
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Affiliation(s)
- Yingzhou Edward Pan
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Debora Tibbe
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frederike Leonie Harms
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Reißner
- Institut für Anatomie und Molekulare Neurobiologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | | | - Bri Dingmann
- Medical Genetics Department, Seattle Children's Hospital, Seattle, Washington, DC, USA
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, DC, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, DC, USA.,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA
| | | | - Moneef Shoukier
- Pränatal-Medizin München, Frauenärzte und Humangenetiker MVZ, München, Germany
| | - Shagun Aggarwal
- Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Markus Missler
- Institut für Anatomie und Molekulare Neurobiologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Kerstin Kutsche
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans-Jürgen Kreienkamp
- Institute for Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Presynaptic dysfunction in CASK-related neurodevelopmental disorders. Transl Psychiatry 2020; 10:312. [PMID: 32929080 PMCID: PMC7490425 DOI: 10.1038/s41398-020-00994-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/13/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022] Open
Abstract
CASK-related disorders are genetically defined neurodevelopmental syndromes. There is limited information about the effects of CASK mutations in human neurons. Therefore, we sought to delineate CASK-mutation consequences and neuronal effects using induced pluripotent stem cell-derived neurons from two mutation carriers. One male case with autism spectrum disorder carried a novel splice-site mutation and a female case with intellectual disability carried an intragenic tandem duplication. We show reduction of CASK protein in maturing neurons from the mutation carriers, which leads to significant downregulation of genes involved in presynaptic development and of CASK protein interactors. Furthermore, CASK-deficient neurons showed decreased inhibitory presynapse size as indicated by VGAT staining, which may alter the excitatory-inhibitory (E/I) balance in developing neural circuitries. Using in vivo magnetic resonance spectroscopy quantification of GABA in the male mutation carrier, we further highlight the possibility to validate in vitro cellular data in the brain. Our data show that future pharmacological and clinical studies on targeting presynapses and E/I imbalance could lead to specific treatments for CASK-related disorders.
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Mukherjee K, Patel PA, Rajan DS, LaConte LEW, Srivastava S. Survival of a male patient harboring CASK Arg27Ter mutation to adolescence. Mol Genet Genomic Med 2020; 8:e1426. [PMID: 32696595 PMCID: PMC7549553 DOI: 10.1002/mgg3.1426] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/01/2020] [Accepted: 07/02/2020] [Indexed: 02/06/2023] Open
Abstract
Background CASK is an X‐linked gene in mammals and its deletion in males is incompatible with life. CASK heterozygous mutations in female patients associate with intellectual disability, microcephaly, pontocerebellar hypoplasia, and optic nerve hypoplasia, whereas CASK hemizygous mutations in males manifest as early infantile epileptic encephalopathy with a grim prognosis. Here, we report a rare case of survival of a male patient harboring a CASK null mutation to adolescent age. Methods Trio whole exome sequencing analysis was performed from blood genomic DNA. Magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and electroencephalogram (EEG) analyses were performed to determine anomalies in brain development, metabolite concentrations, and electrical activity, respectively. Results Trio‐WES analysis identified a de novo c.79C>T (p.Arginine27Ter) mutation in CASK causing a premature translation termination at the very N‐terminus of the protein. The 17‐years, and 11‐month‐old male patient displayed profound intellectual disability, microcephaly, dysmorphism, ponto‐cerebellar hypoplasia, and intractable epilepsy. His systemic symptoms included overall reduced somatic growth, dysautonomia, ventilator and G tube dependence, and severe osteopenia. Brain MRI revealed a severe cerebellar and brain stem hypoplasia with progressive cerebral atrophy. EEG spectral analysis revealed a global functional defect with generalized background slowing and delta waves dominating even in the awake state. Conclusion This case study is the first to report survival of a male patient carrying a CASK loss‐of‐function mutation to adolescence and highlights that improved palliative care could extend survival. Moreover, the genomic position encoding Arg27 in CASK may possess an increased susceptibility to mutations.
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Affiliation(s)
- Konark Mukherjee
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Paras A Patel
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Deepa S Rajan
- Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leslie E W LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA.,Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
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36
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Patel PA, Liang C, Arora A, Vijayan S, Ahuja S, Wagley PK, Settlage R, LaConte LEW, Goodkin HP, Lazar I, Srivastava S, Mukherjee K. Haploinsufficiency of X-linked intellectual disability gene CASK induces post-transcriptional changes in synaptic and cellular metabolic pathways. Exp Neurol 2020; 329:113319. [PMID: 32305418 DOI: 10.1016/j.expneurol.2020.113319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/04/2020] [Accepted: 04/15/2020] [Indexed: 12/17/2022]
Abstract
Heterozygous mutations in the X-linked gene CASK are associated with intellectual disability, microcephaly, pontocerebellar hypoplasia, optic nerve hypoplasia and partially penetrant seizures in girls. The Cask+/- heterozygous knockout female mouse phenocopies the human disorder and exhibits postnatal microencephaly, cerebellar hypoplasia and optic nerve hypoplasia. It is not known if Cask+/- mice also display seizures, nor is known the molecular mechanism by which CASK haploinsufficiency produces the numerous documented phenotypes. 24-h video electroencephalography demonstrates that despite sporadic seizure activity, the overall electrographic patterns remain unaltered in Cask+/- mice. Additionally, seizure threshold to the commonly used kindling agent, pentylenetetrazol, remains unaltered in Cask+/- mice, indicating that even in mice the seizure phenotype is only partially penetrant and may have an indirect mechanism. RNA sequencing experiments on Cask+/- mouse brain uncovers a very limited number of changes, with most differences arising in the transcripts of extracellular matrix proteins and the transcripts of a group of nuclear proteins. In contrast to limited changes at the transcript level, quantitative whole-brain proteomics using iTRAQ quantitative mass-spectrometry reveals major changes in synaptic, metabolic/mitochondrial, cytoskeletal, and protein metabolic pathways. Unbiased protein-protein interaction mapping using affinity chromatography demonstrates that CASK may form complexes with proteins belonging to the same functional groups in which altered protein levels are observed. We discuss the mechanism of the observed changes in the context of known molecular function/s of CASK. Overall, our data indicate that the phenotypic spectrum of female Cask+/- mice includes sporadic seizures and thus closely parallels that of CASK haploinsufficient girls; the Cask+/- mouse is thus a face-validated model for CASK-related pathologies. We therefore surmise that CASK haploinsufficiency is likely to affect brain structure and function due to dysregulation of several cellular pathways including synaptic signaling and cellular metabolism.
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Affiliation(s)
- P A Patel
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, United States
| | - C Liang
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - A Arora
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - S Vijayan
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
| | - S Ahuja
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - P K Wagley
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - R Settlage
- Advanced Research Computing, Virginia Tech, Blacksburg, VA, United States
| | - L E W LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - H P Goodkin
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - I Lazar
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - S Srivastava
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - K Mukherjee
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, United States.
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Kerr A, Patel PA, LaConte LEW, Liang C, Chen CK, Shah V, Fox MA, Mukherjee K. Non-Cell Autonomous Roles for CASK in Optic Nerve Hypoplasia. Invest Ophthalmol Vis Sci 2019; 60:3584-3594. [PMID: 31425583 PMCID: PMC6701874 DOI: 10.1167/iovs.19-27197] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose Heterozygous mutations in the essential X-linked gene CASK associate with optic nerve hypoplasia (ONH) and other retinal disorders in girls. CASK+/− heterozygous knockout mice with mosaic CASK expression exhibit ONH with a loss of retinal ganglion cells (RGCs) but no changes in retinal morphology. It remains unclear if CASK deficiency selectively affects RGCs or also affects other retinal cells. Furthermore, it is not known if CASK expression in RGCs is critical for optic nerve (ON) development and maintenance. Methods The visual behavior of CASK+/− mice was assessed and electroretinography (ERG) was performed. Using a mouse line with a floxed CASK gene that expresses approximately 40% CASK globally in all cells (hypomorph) under hemizygous and homozygous conditions, we investigated effects of CASK reduction on the retina and ON. CASK then was completely deleted from RGCs to examine its cell-autonomous role. Finally, for the first time to our knowledge, we describe a hemizygous CASK missense mutation in a boy with ONH. Results CASK+/− heterozygous mutant mice display reduced visual contrast sensitivity, but ERG is indistinguishable from wildtype. CASK hypomorph mice exhibit ONH, but deletion of CASK from RGCs in this background does not exacerbate the condition. The boy with ONH harbors a missense mutation (p.Pro673Leu) that destabilizes CASK and weakens the crucial CASK–neurexin interaction. Conclusions Our results demonstrate that mosaic or global reduction in CASK expression and/or function disproportionately affects RGCs. CASK expression in RGCs does not appear critical for cell survival, indicating a noncell autonomous role for CASK in the development of ON.
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Affiliation(s)
- Alicia Kerr
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Paras A Patel
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Leslie E W LaConte
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
| | - Chen Liang
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
| | - Ching-Kang Chen
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Veeral Shah
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Texas Children's Hospital, Houston, Texas, United States
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States.,Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
| | - Konark Mukherjee
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States.,Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
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Bencsik N, Pusztai S, Borbély S, Fekete A, Dülk M, Kis V, Pesti S, Vas V, Szűcs A, Buday L, Schlett K. Dendritic spine morphology and memory formation depend on postsynaptic Caskin proteins. Sci Rep 2019; 9:16843. [PMID: 31727973 PMCID: PMC6856520 DOI: 10.1038/s41598-019-53317-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022] Open
Abstract
CASK-interactive proteins, Caskin1 and Caskin2, are multidomain neuronal scaffold proteins. Recent data from Caskin1 knockout animals indicated only a mild role of Caskin1 in anxiety and pain perception. In this work, we show that deletion of both Caskins leads to severe deficits in novelty recognition and spatial memory. Ultrastructural analyses revealed a reduction in synaptic profiles and dendritic spine areas of CA1 hippocampal pyramidal neurons of double knockout mice. Loss of Caskin proteins impaired LTP induction in hippocampal slices, while miniature EPSCs in dissociated hippocampal cultures appeared to be unaffected. In cultured Caskin knockout hippocampal neurons, overexpressed Caskin1 was enriched in dendritic spine heads and increased the amount of mushroom-shaped dendritic spines. Chemically induced LTP (cLTP) mediated enlargement of spine heads was augmented in the knockout mice and was not influenced by Caskin1. Immunocytochemistry and immunoprecipitation confirmed that Shank2, a master scaffold of the postsynaptic density, and Caskin1 co-localized within the same complex. Phosphorylation of AMPA receptors was specifically altered by Caskin deficiency and was not elevated by cLTP treatment further. Taken together, our results prove a previously unnoticed postsynaptic role of Caskin scaffold proteins and indicate that Caskins influence learning abilities via regulating spine morphology and AMPA receptor localisation.
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Affiliation(s)
- Norbert Bencsik
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Szilvia Pusztai
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Sándor Borbély
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary.,Institute of Cognitive Neuroscience and Psychology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Anna Fekete
- Institute of Enzymology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Metta Dülk
- Institute of Enzymology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Viktor Kis
- Department Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Szabolcs Pesti
- Department Medical Chemistry, Semmelweis University, Budapest, Hungary
| | - Virág Vas
- Institute of Enzymology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Attila Szűcs
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - László Buday
- Institute of Enzymology, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.,Department Medical Chemistry, Semmelweis University, Budapest, Hungary
| | - Katalin Schlett
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary.
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Rama Devi AR, Lingappa L, Naushad SM. Identification and in Silico Characterization of a Novel CASK c.2546T>C (p.V849A) Mutation in a Male Infant with Pontocerebellar Hypoplasia. Ann Indian Acad Neurol 2019; 22:523-524. [PMID: 31736593 PMCID: PMC6839305 DOI: 10.4103/aian.aian_2_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 12/23/2022] Open
Affiliation(s)
- Akella Radha Rama Devi
- Department of Genetics, Rainbow Children's Hospital, Banjara Hills Road No: 2, Hyderabad, Andhra Pradesh, India.,Department of Biochemical Genetics and Pharmacogenomics, Sandor Speciality Diagnostics Pvt Ltd, Banjara Hills, Road No: 3, Hyderabad, Andhra Pradesh, India
| | - Lokesh Lingappa
- Department of Genetics, Rainbow Children's Hospital, Banjara Hills Road No: 2, Hyderabad, Andhra Pradesh, India
| | - Shaik Mohammad Naushad
- Department of Biochemical Genetics and Pharmacogenomics, Sandor Speciality Diagnostics Pvt Ltd, Banjara Hills, Road No: 3, Hyderabad, Andhra Pradesh, India
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Gao R, Zaccard CR, Shapiro LP, Dionisio LE, Martin-de-Saavedra MD, Piguel NH, Pratt CP, Horan KE, Penzes P. The CNTNAP2-CASK complex modulates GluA1 subcellular distribution in interneurons. Neurosci Lett 2019; 701:92-99. [PMID: 30779956 DOI: 10.1016/j.neulet.2019.02.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/11/2019] [Accepted: 02/16/2019] [Indexed: 01/03/2023]
Abstract
GABAergic interneurons are emerging as prominent substrates in the pathophysiology of multiple neurodevelopmental disorders, including autism spectrum disorders, schizophrenia, intellectual disability, and epilepsy. Interneuron excitatory activity is influenced by 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl) propanoic acid receptors (AMPARs), which in turn affects excitatory transmission in the central nervous system. Yet how dysregulation of interneuronal AMPARs distinctly contributes to the molecular underpinning of neurobiological disease is drastically underexplored. Contactin-associated protein-like 2 (CNTNAP2) is a neurexin-related adhesion molecule shown to mediate AMPAR subcellular distribution while calcium/calmodulin-dependent serine protein kinase (CASK) is a multi-functional scaffold involved with glutamate receptor trafficking. Mutations in both genes have overlapping disease associations, including autism spectrum disorders, intellectual disability, and epilepsy, thus suggesting converging perturbations of excitatory/inhibitory balance. Our lab has previously shown that CNTNAP2 stabilizes interneuron dendritic arbors through CASK and that CNTNAP2 regulates AMPAR subunit GluA1 trafficking in excitatory neurons. The interaction between these three proteins, however, has not been studied in interneurons. Using biochemical techniques, structured illumination microscopy (SIM) and shRNA technology, we first confirm that these three proteins interact in mouse brain, and then examined relationship between CNTNAP2, CASK and GluA1 in mature interneurons. Using SIM, we ascertain that a large fraction of endogenous CNTNAP2, CASK, and GluA1 molecules collectively colocalize together in a tripartite manner. Finally, individual knockdown of either CNTNAP2 or CASK similarly alter GluA1 levels and localization. These findings offer insight to molecular mechanisms underlying GluA1 regulation in interneurons.
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Affiliation(s)
- Ruoqi Gao
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Colleen R Zaccard
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Lauren P Shapiro
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Leonardo E Dionisio
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | | | - Nicolas H Piguel
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Christopher P Pratt
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Katherine E Horan
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA
| | - Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, 60611 IL, USA; Northwestern University Center for Autism and Neurodevelopment, Chicago, IL 60611, USA.
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41
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Kessi M, Xiong J, Wu L, Yang L, He F, Chen C, Pang N, Duan H, Zhang W, Arafat A, Yin F, Peng J. Rare Copy Number Variations and Predictors in Children With Intellectual Disability and Epilepsy. Front Neurol 2018; 9:947. [PMID: 30510536 PMCID: PMC6252327 DOI: 10.3389/fneur.2018.00947] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022] Open
Abstract
Introduction: The concurrence of intellectual disability/global developmental delay and epilepsy (ID/GDD-EP) is very common in the pediatric population. The etiologies for both conditions are complex and largely unknown. The predictors of significant copy number variations (CNVs) are known for the cases with ID/GDD, but unknown for those with exclusive ID/GDD-EP. Importantly, the known predictors are largely from the same ethnic group; hence, they lack replication. Purpose: We aimed to determine and investigate the diagnostic yield of CNV tests, new causative CNVs, and the independent predictors of significant CNVs in Chinese children with unexplained ID/GDD-EP. Materials and methods: A total of 100 pediatric patients with unexplained ID/GDD-EP and 1,000 healthy controls were recruited. The American College of Medical Genetics guideline was used to classify the CNVs. Additionally, clinical information was collected and compared between those with significant and non-significant CNVs. Results: Twenty-eight percent of the patients had significant CNVs, 16% had variants of unknown significance, and 56% had non-significant CNVs. In total, 31 CNVs were identified in 28% (28/100) of cases: 25 pathogenic and 6 likely pathogenic. Eighteen known syndromes were diagnosed in 17 cases. Thirteen rare CNVs (8 novel and 5 reported in literature) were identified, of which three spanned dosage-sensitive genes: 19q13.2 deletion (ATP1A3), Xp11.4-p11.3 deletion (CASK), and 6q25.3-q25.3 deletion (ARID1B). By comparing clinical features in patients with significant CNVs against those with non-significant CNVs, a statistically significant association was found between the presence of significant CNVs and speech and language delay for those aged above 2 years and for those with facial malformations, microcephaly, congenital heart disease, fair skin, eye malformations, and mega cisterna magna. Multivariate logistic regression analysis allowed the identification of two independent significant CNV predictors, which are eye malformations and facial malformations. Conclusion: Our study supports the performance of CNV tests in pediatric patients with unexplained ID/GDD-EP, as there is high diagnostic yield, which informs genetic counseling. It adds 13 rare CNVs (8 novel), which can be accountable for both conditions. Moreover, congenital eye and facial malformations are clinical markers that can aid clinicians to understand which patients can benefit from the CNV testing and which will not, thus helping patients to avoid unnecessary and expensive tests.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Liwen Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Haolin Duan
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Wen Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Ahmed Arafat
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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Johnson S, Wozniak DF, Imai S. CA1 Nampt knockdown recapitulates hippocampal cognitive phenotypes in old mice which nicotinamide mononucleotide improves. NPJ Aging Mech Dis 2018; 4:10. [PMID: 30416740 PMCID: PMC6224504 DOI: 10.1038/s41514-018-0029-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 10/12/2018] [Accepted: 10/16/2018] [Indexed: 02/07/2023] Open
Abstract
Cognitive dysfunction is one of the most concerning outcomes in global population aging. However, the mechanisms by which cognitive functions are impaired during aging remain elusive. It has been established that NAD+ levels are reduced in multiple tissues and organs, including the brain. We found that NAD+ levels declined in the hippocampus of mice during the course of aging, and whereas we observed minimal age-related effects on spatial learning/memory capabilities in old mice, we discovered that they developed cognitive hypersensitivity in response to aversive stimulation during contextual fear conditioning tests. This cognitive hypersensitivity appears to be associated with alterations in emotionality (fear/anxiety) and sensory processing (shock sensitivity), rather than reflect genuine conditioning/retention effects, during aging. Supplementation of nicotinamide mononucleotide (NMN) improved the sensory processing aspect of the hypersensitivity and possibly other related behaviors. Specific knockdown of nicotinamide phosphoribosyltransferase (Nampt) in the CA1 region, but not in the dentate gyrus, recapitulates this cognitive hypersensitivity observed in old mice. We identified calcium/calmodulin-dependent serine protein kinase (Cask) as a potential downstream effector in response to age-associated NAD+ reduction in the hippocampus. Cask expression is responsive to NAD+ changes and also reduced in the hippocampus during aging. Short-term NMN supplementation can enhance Cask expression in the hippocampus of old mice. Its promoter activity is regulated in a Sirt1-dependent manner. Taken together, NAD+ reduction in the CA1 region contributes to development of age-associated cognitive dysfunction, aspects of which may be prevented or treated by enhancing NAD+ availability through supplementation of NAD+ intermediates, such as NMN. Cognitive dysfunction is one of the most concerning outcomes in global population aging. However, the mechanisms of cognitive impairment during aging remain elusive. We found that in old mice, levels of nicotinamide adenine dinucleotide (NAD+), an essential chemical for all living organisms, declined in the hippocampus, a critical part of the brain for memory and learning. We also found that age-associated hypersensitivity in cognitive and behavioral functions (cognitive hypersensitivity) was induced by reduced NAD+ availability in the hippocampus. Supplementation of nicotinamide mononucleotide (NMN), a critical chemical that is converted to NAD+, is able to mitigate the cognitive hypersensitivity observed in old mice. Our findings provide new insights into how NAD+ decline affects age-associated anxiety/depression and how such impairments can be prevented or treated by enhancing NAD+.
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Affiliation(s)
- Sean Johnson
- 1Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110 USA.,3Present Address: Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - David F Wozniak
- 2Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - S Imai
- 1Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110 USA
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43
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Bozarth X, Foss K, Mefford HC. A de novo in-frame deletion of CASK
gene causes early onset infantile spasms and supratentorial cerebral malformation in a female patient. Am J Med Genet A 2018; 176:2425-2429. [DOI: 10.1002/ajmg.a.40429] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/06/2018] [Accepted: 06/10/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Xiuhua Bozarth
- Department of Neurology; Seattle Children's Hospital, University of Washington; Seattle Washington
| | - Kimberly Foss
- Department of Genetics; Seattle Children's Hospital; Seattle Washington
| | - Heather C. Mefford
- Division of Genetic Medicine, Department of Pediatrics; University of Washington; Seattle Washington
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44
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Gao R, Piguel NH, Melendez-Zaidi AE, Martin-de-Saavedra MD, Yoon S, Forrest MP, Myczek K, Zhang G, Russell TA, Csernansky JG, Surmeier DJ, Penzes P. CNTNAP2 stabilizes interneuron dendritic arbors through CASK. Mol Psychiatry 2018; 23:1832-1850. [PMID: 29610457 PMCID: PMC6168441 DOI: 10.1038/s41380-018-0027-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 01/10/2018] [Accepted: 01/15/2018] [Indexed: 11/25/2022]
Abstract
Contactin associated protein-like 2 (CNTNAP2) has emerged as a prominent susceptibility gene implicated in multiple complex neurodevelopmental disorders, including autism spectrum disorders (ASD), intellectual disability (ID), and schizophrenia (SCZ). The presence of seizure comorbidity in many of these cases, as well as inhibitory neuron dysfunction in Cntnap2 knockout (KO) mice, suggests CNTNAP2 may be crucial for proper inhibitory network function. However, underlying cellular mechanisms are unclear. Here we show that cultured Cntnap2 KO mouse neurons exhibit an inhibitory neuron-specific simplification of the dendritic tree. These alterations can be replicated by acute knockdown of CNTNAP2 in mature wild-type (WT) neurons and are caused by faulty dendrite stabilization rather than outgrowth. Using structured illumination microscopy (SIM) and stimulated-emission depletion microscopy (STED), two super-resolution imaging techniques, we uncovered relationships between nanoscale CNTNAP2 protein localization and dendrite arborization patterns. Employing yeast two-hybrid screening, biochemical analysis, in situ proximity ligation assay (PLA), SIM, and phenotype rescue, we show that these effects are mediated at the membrane by the interaction of CNTNAP2's C-terminus with calcium/calmodulin-dependent serine protein kinase (CASK), another ASD/ID risk gene. Finally, we show that adult Cntnap2 KO mice have reduced interneuron dendritic length and branching in particular cortical regions, as well as decreased CASK levels in the cortical membrane fraction. Taken together, our data reveal an interneuron-specific mechanism for dendrite stabilization that may provide a cellular mechanism for inhibitory circuit dysfunction in CNTNAP2-related disorders.
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Affiliation(s)
- Ruoqi Gao
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Nicolas H Piguel
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | | | | | - Sehyoun Yoon
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Marc P Forrest
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Kristoffer Myczek
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Gefei Zhang
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Theron A Russell
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - John G Csernansky
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - D James Surmeier
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
- Northwestern University, Center for Autism and Neurodevelopment, Chicago, IL, 60611, USA.
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45
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Cristofoli F, Devriendt K, Davis EE, Van Esch H, Vermeesch JR. Novel CASK mutations in cases with syndromic microcephaly. Hum Mutat 2018; 39:993-1001. [PMID: 29691940 PMCID: PMC5995665 DOI: 10.1002/humu.23536] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 11/05/2022]
Abstract
Mutations in CASK cause a wide spectrum of phenotypes in humans ranging from mild X-linked intellectual disability to a severe microcephaly (MC) and pontocerebellar hypoplasia syndrome. Nevertheless, predicting pathogenicity and phenotypic consequences of novel CASK mutations through the exclusive consideration of genetic information and population-based data remains a challenge. Using whole exome sequencing, we identified four novel CASK mutations in individuals with syndromic MC. To understand the functional consequences of the different point mutations on the development of MC and cerebellar defects, we established a transient loss-of-function zebrafish model, and demonstrate recapitulation of relevant neuroanatomical phenotypes. Furthermore, we utilized in vivo complementation studies to demonstrate that the three point mutations confer a loss-of-function effect. This work endorses zebrafish as a tractable model to rapidly assess the effect of novel CASK variants on brain development.
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Affiliation(s)
- Francesca Cristofoli
- Laboratory for Cytogenetics and Genome Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Koen Devriendt
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina
| | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
- Laboratory for the Genetics of Cognition, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Joris R Vermeesch
- Laboratory for Cytogenetics and Genome Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
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46
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van Dijk T, Baas F, Barth PG, Poll-The BT. What's new in pontocerebellar hypoplasia? An update on genes and subtypes. Orphanet J Rare Dis 2018; 13:92. [PMID: 29903031 PMCID: PMC6003036 DOI: 10.1186/s13023-018-0826-2] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 05/16/2018] [Indexed: 12/25/2022] Open
Abstract
Background Pontocerebellar hypoplasia (PCH) describes a rare, heterogeneous group of neurodegenerative disorders mainly with a prenatal onset. Patients have severe hypoplasia or atrophy of cerebellum and pons, with variable involvement of supratentorial structures, motor and cognitive impairments. Based on distinct clinical features and genetic causes, current classification comprises 11 types of PCH. Main text In this review we describe the clinical, neuroradiological and genetic characteristics of the different PCH subtypes, summarize the differential diagnosis and reflect on potential disease mechanisms in PCH. Seventeen PCH-related genes are now listed in the OMIM database, most of them have a function in RNA processing or translation. It is unknown why defects in these apparently ubiquitous processes result in a brain-specific phenotype. Conclusions Many new PCH related genes and phenotypes have been described due to the appliance of next generation sequencing techniques. By including such a broad range of phenotypes, including non-degenerative and postnatal onset disorders, the current classification gives rise to confusion. Despite the discovery of new pathways involved in PCH, treatment is still symptomatic. However, correct diagnosis of PCH is important to provide suitable care and counseling regarding prognosis, and offer appropriate (prenatal) genetic testing to families.
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Affiliation(s)
- Tessa van Dijk
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands.,Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Frank Baas
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter G Barth
- Department of Pediatric Neurology, Academic Medical Center, Amsterdam, The Netherlands
| | - Bwee Tien Poll-The
- Department of Pediatric Neurology, Academic Medical Center, Amsterdam, The Netherlands.
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48
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Abstract
X-linked cerebellar ataxias (XLCA) are an expanding group of genetically heterogeneous and clinically variable conditions characterized by cerebellar dysgenesis (hypoplasia, atrophy, or dysplasia) caused by gene mutations or genomic imbalances on the X chromosome. The neurologic features of XLCA include hypotonia, developmental delay, intellectual disability, ataxia, and other cerebellar signs. Normal cognitive development has also been reported. Cerebellar defects may be isolated or associated with other brain malformations or extraneurologic involvement. More than 20 genes on the X chromosome, mainly encoding for proteins involved in brain development and synaptic function that have been constantly or occasionally associated with a pathologic cerebellar phenotype, and several families with X-linked inheritance have been reported. Given the excess of males with ataxia, this group of conditions is probably underestimated and families of patients with neuroradiologic and clinical evidence of a cerebellar disorder should be counseled for high risk of X-linked inheritance.
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Affiliation(s)
- Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu' Children's Research Hospital, Rome, Italy.
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu' Children's Research Hospital, Rome, Italy
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49
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Südhof TC. Synaptic Neurexin Complexes: A Molecular Code for the Logic of Neural Circuits. Cell 2017; 171:745-769. [PMID: 29100073 DOI: 10.1016/j.cell.2017.10.024] [Citation(s) in RCA: 485] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/04/2017] [Accepted: 10/15/2017] [Indexed: 10/18/2022]
Abstract
Synapses are specialized junctions between neurons in brain that transmit and compute information, thereby connecting neurons into millions of overlapping and interdigitated neural circuits. Here, we posit that the establishment, properties, and dynamics of synapses are governed by a molecular logic that is controlled by diverse trans-synaptic signaling molecules. Neurexins, expressed in thousands of alternatively spliced isoforms, are central components of this dynamic code. Presynaptic neurexins regulate synapse properties via differential binding to multifarious postsynaptic ligands, such as neuroligins, cerebellin/GluD complexes, and latrophilins, thereby shaping the input/output relations of their resident neural circuits. Mutations in genes encoding neurexins and their ligands are associated with diverse neuropsychiatric disorders, especially schizophrenia, autism, and Tourette syndrome. Thus, neurexins nucleate an overall trans-synaptic signaling network that controls synapse properties, which thereby determines the precise responses of synapses to spike patterns in a neuron and circuit and which is vulnerable to impairments in neuropsychiatric disorders.
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Affiliation(s)
- Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, CA 94305-5453, USA.
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50
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Liang C, Kerr A, Qiu Y, Cristofoli F, Van Esch H, Fox MA, Mukherjee K. Optic Nerve Hypoplasia Is a Pervasive Subcortical Pathology of Visual System in Neonates. Invest Ophthalmol Vis Sci 2017; 58:5485-5496. [PMID: 29067402 PMCID: PMC5656421 DOI: 10.1167/iovs.17-22399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose Optic nerve hypoplasia (ONH) is the most common cause of childhood congenital blindness in developed nations, yet the fundamental pathobiology of ONH remains unknown. The objective of this study was to employ a ‘face validated' murine model to determine the timing of onset and the pathologic characteristics of ONH. Methods Based on the robust linkage between X-linked CASK haploinsufficiency and clinically diagnosed ONH, we hypothesized that heterozygous deletion of CASK (CASK(+/−)) in rodents will produce an optic nerve pathology closely recapitulating ONH. We quantitatively analyzed the entire subcortical visual system in female CASK(+/−) mice using immunohistochemistry, anterograde axonal tracing, toluidine blue staining, transmission electron microscopy, and serial block-face scanning electron microscopy. Results CASK haploinsuffiency in mice phenocopies human ONH with complete penetrance, thus satisfying the ‘face validity'. We demonstrate that the optic nerve in CASK(+/−) mice is not only thin, but is comprised of atrophic retinal axons and displays reactive astrogliosis. Myelination of the optic nerve axons remains unchanged. Moreover, we demonstrate a significant decrease in retinal ganglion cell (RGC) numbers and perturbation in retinothalamic connectivity. Finally, we used this mouse model to define the onset and progression of ONH pathology, demonstrating for the first time that optic nerve defects arise at neonatally in CASK(+/−)mice. Conclusions Optic nerve hypoplasia is a complex neuropathology of the subcortical visual system involving RGC loss, axonopathy, and synaptopathy and originates at a developmental stage in mice that corresponds to the late third trimester development in humans.
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Affiliation(s)
- Chen Liang
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| | - Alicia Kerr
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Yangfengzhong Qiu
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States
| | | | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Michael A Fox
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| | - Konark Mukherjee
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
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