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Fang X, Baggett LM, Caylor RC, Percy AK, Neul JL, Lane JB, Glaze DG, Benke TA, Marsh ED, Motil KJ, Barrish JO, Annese FE, Skinner SA. Parental age effects and Rett syndrome. Am J Med Genet A 2024; 194:160-173. [PMID: 37768187 DOI: 10.1002/ajmg.a.63396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 08/18/2023] [Indexed: 09/29/2023]
Abstract
Rett syndrome (RTT) is a progressive neurodevelopmental disorder, and pathogenic Methyl-CpG-binding Protein 2 (MECP2) variants are identified in >95% of individuals with typical RTT. Most of RTT-causing variants in MECP2 are de novo and usually on the paternally inherited X chromosome. While paternal age has been reported to be associated with increased risk of genetic disorders, it is unknown whether parental age contributes to the risk of the development of RTT. Clinical data including parental age, RTT diagnostic status, and clinical severity are collected from 1226 participants with RTT and confirmed MECP2 variants. Statistical analyses are performed using Student t-test, single factor analysis of variance (ANOVA), and multi-factor regression. No significant difference is observed in parental ages of RTT probands compared to that of the general population. A small increase in parental ages is observed in participants with missense variants compared to those with nonsense variants. When we evaluate the association between clinical severity and parental ages by multiple regression analysis, there is no clear association between clinical severity and parental ages. Advanced parental ages do not appear to be a risk factor for RTT, and do not contribute to the clinical severity in individuals with RTT.
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Affiliation(s)
- Xiaolan Fang
- Greenwood Genetic Center, Greenwood, South Carolina, USA
| | | | | | - Alan K Percy
- The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey L Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jane B Lane
- The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | - Tim A Benke
- University of Colorado School of Medicine, Children's Hospital Colorado-Aurora, Denver, Colorado, USA
| | - Eric D Marsh
- Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kathleen J Motil
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Fran E Annese
- Greenwood Genetic Center, Greenwood, South Carolina, USA
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2
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Fang X, Fee T, Davis J, Stolerman E, Caylor RC. Clinical Case Report: Mosaic Genetic Variants in the ANK3 Gene are Associated with Neurodevelopmental Delays. Cold Spring Harb Mol Case Stud 2023:mcs.a006233. [PMID: 37263801 PMCID: PMC10393183 DOI: 10.1101/mcs.a006233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 05/26/2023] [Indexed: 06/03/2023] Open
Abstract
Ankyrins are a family of proteins that link integral membrane proteins to the underlying spectrin-actin cytoskeleton and play a key role in activities such as cell motility, activation, proliferation, cell-cell contact, and the maintenance of specialized membrane domains. Ankyrin G, which is encoded by ANK3 gene, is one of the three major subtypes of the ankyrin protein family. Ankryin genes are ubiquitously expressed, but their expression is highest in the brain. In the central nervous system, ankyrins have critical roles at the axonal initial segment, the nodes of Ranvier, and at synapses. To date, pathogenic variants in ANK3 have been reported in individuals with neuropsychiatric, cognitive, and neurodevelopmental disorders. The clinical severity is variable in these individuals with both autosomal recessive and autosomal dominant patterns of inheritance observed. These findings have suggested genotype-phenotype correlations and even isoform-specific implications for individuals with ANK3 pathogenic variants. Here we report a patient with speech delay, autism spectrum disorder and a language disorder in which a de novo nonsense ANK3 alteration was discovered by exome sequencing. Interestingly, the next-generation sequencing data suggested the change was mosaic in the affected child, and it was confirmed by digital PCR at 22% allelic fraction. To our knowledge, this is the first case of an individual with a pathogenic mosaic ANK3 variant. This finding expands upon the existing genotype-phenotype information available for the ANK3 gene while also highlighting potential gene expression correlations with phenotype.
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3
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Caylor RC. Nonrandom X Chromosome Inactivation Detection. Curr Protoc 2023; 3:e748. [PMID: 37074091 DOI: 10.1002/cpz1.748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
X chromosome inactivation patterns may be clinically useful in assessing tumor clonality, determining carrier status for certain X-linked disorders, and evaluating the pathogenicity of a genetic variant identified in an X-linked gene. The protocols in this article utilize the highly polymorphic trinucleotide repeat within the first exon of the human androgen receptor gene (AR) and the methylation-sensitive restriction enzyme HpaII to distinguish between the maternal and paternal alleles and simultaneously determine their methylation status. The data obtained from these protocols can be used to calculate the ratio of inactivation between the two alleles that ultimately reflects whether a female has a random or nonrandom pattern of X chromosome inactivation. © 2023 Wiley Periodicals LLC. Basic Protocol 1: X chromosome inactivation assay Basic Protocol 2: PCR amplification and labeling of digested and undigested DNA templates.
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Affiliation(s)
- Raymond C Caylor
- Molecular Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, South Carolina
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4
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Haghshenas S, Foroutan A, Bhai P, Levy MA, Relator R, Kerkhof J, McConkey H, Skinner CD, Caylor RC, Tedder ML, Stevenson RE, Sadikovic B, Schwartz CE. Identification of a DNA methylation signature for Renpenning syndrome (RENS1), a spliceopathy. Eur J Hum Genet 2023:10.1038/s41431-023-01313-z. [PMID: 36797465 PMCID: PMC10400603 DOI: 10.1038/s41431-023-01313-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/18/2023] Open
Abstract
The challenges and ambiguities in providing an accurate diagnosis for patients with neurodevelopmental disorders have led researchers to apply epigenetics as a technique to validate the diagnosis provided based on the clinical examination and genetic testing results. Genome-wide DNA methylation analysis has recently been adapted for clinical testing of patients with genetic neurodevelopmental disorders. In this paper, preliminary data demonstrating a DNA methylation signature for Renpenning syndrome (RENS1 - OMIM 309500), which is an X-linked recessive neurodevelopmental disorder caused by variants in polyglutamine-binding protein 1 (PQBP1) is reported. The identified episignature was then utilized to construct a highly sensitive and specific binary classification model. Besides providing evidence for the existence of a DNA methylation episignature for Renpenning syndrome, this study increases the knowledge of the molecular mechanisms related to the disease. Moreover, the availability of more subjects in future may facilitate the establishment of an episignature that can be utilized for diagnosis in a clinical setting and for reclassification of variants of unknown clinical significance.
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Affiliation(s)
- Sadegheh Haghshenas
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 3K7, Canada.,Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Aidin Foroutan
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 3K7, Canada
| | - Pratibha Bhai
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Michael A Levy
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Raissa Relator
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Jennifer Kerkhof
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Haley McConkey
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 3K7, Canada.,Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | | | | | | | | | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University, London, ON, N6A 3K7, Canada. .,Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada.
| | - Charles E Schwartz
- Greenwood Genetic Center, Greenwood, SC, 29646, USA. .,Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, Grand Rapids, MI, 49503, USA.
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McGee SR, Rajamanickam S, Adhikari S, Falayi OC, Wilson TA, Shayota BJ, Cooley Coleman JA, Skinner C, Caylor RC, Stevenson RE, Quaio CRDAC, Wilke BC, Bain JM, Anyane-Yeboa K, Brown K, Greally JM, Bijlsma EK, Ruivenkamp CAL, Politi K, Arbogast LA, Collard MW, Huggenvik JI, Elsea SH, Jensik PJ. Expansion and mechanistic insights into de novo DEAF1 variants in DEAF1-associated neurodevelopmental disorders. Hum Mol Genet 2023; 32:386-401. [PMID: 35981081 PMCID: PMC10310974 DOI: 10.1093/hmg/ddac200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/11/2022] [Accepted: 08/08/2022] [Indexed: 01/24/2023] Open
Abstract
De novo deleterious and heritable biallelic mutations in the DNA binding domain (DBD) of the transcription factor deformed epidermal autoregulatory factor 1 (DEAF1) result in a phenotypic spectrum of disorders termed DEAF1-associated neurodevelopmental disorders (DAND). RNA-sequencing using hippocampal RNA from mice with conditional deletion of Deaf1 in the central nervous system indicate that loss of Deaf1 activity results in the altered expression of genes involved in neuronal function, dendritic spine maintenance, development, and activity, with reduced dendritic spines in hippocampal regions. Since DEAF1 is not a dosage-sensitive gene, we assessed the dominant negative activity of previously identified de novo variants and a heritable recessive DEAF1 variant on selected DEAF1-regulated genes in 2 different cell models. While no altered gene expression was observed in cells over-expressing the recessive heritable variant, the gene expression profiles of cells over-expressing de novo variants resulted in similar gene expression changes as observed in CRISPR-Cas9-mediated DEAF1-deleted cells. Altered expression of DEAF1-regulated genes was rescued by exogenous expression of WT-DEAF1 but not by de novo variants in cells lacking endogenous DEAF1. De novo heterozygous variants within the DBD of DEAF1 were identified in 10 individuals with a phenotypic spectrum including autism spectrum disorder, developmental delays, sleep disturbance, high pain tolerance, and mild dysmorphic features. Functional assays demonstrate these variants alter DEAF1 transcriptional activity. Taken together, this study expands the clinical phenotypic spectrum of individuals with DAND, furthers our understanding of potential roles of DEAF1 on neuronal function, and demonstrates dominant negative activity of identified de novo variants.
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Affiliation(s)
- Stacey R McGee
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | - Shivakumar Rajamanickam
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | - Sandeep Adhikari
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | | | - Theresa A Wilson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Brian J Shayota
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
- Department of Pediatrics, Division of Genetics, University of Utah, Salt Lake City, UT
| | | | | | | | | | - Caio Robledo D' Angioli Costa Quaio
- Instituto da Criança (Children’s Hospital), Hospital das Clínicas (HCFMUSP), Faculdade de Medicina (FMUSP), Universidade de São Paulo, São Paulo, SP, Brazil
- Laboratório Clínico, Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
| | | | - Jennifer M Bain
- Department of Neurology, Division of Child Neurology, Columbia University Irving Medical Center, New York, USA
| | - Kwame Anyane-Yeboa
- Department of Pediatrics, Division of Clinical Genetics, Columbia University Irving Medical Center, New York, USA
| | - Kaitlyn Brown
- Departments of Pediatrics and Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - John M Greally
- Departments of Pediatrics and Genetics, Albert Einstein College of Medicine, Bronx, NY USA
- Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Centre, PO box 9600, 2300 RC, Leiden, The Netherlands
| | - Claudia A L Ruivenkamp
- Department of Clinical Genetics, Leiden University Medical Centre, PO box 9600, 2300 RC, Leiden, The Netherlands
| | | | - Lydia A Arbogast
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | - Michael W Collard
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | - Jodi I Huggenvik
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Philip J Jensik
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL USA
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6
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van Jaarsveld RH, Reilly J, Cornips MC, Hadders MA, Agolini E, Ahimaz P, Anyane-Yeboa K, Bellanger SA, van Binsbergen E, van den Boogaard MJ, Brischoux-Boucher E, Caylor RC, Ciolfi A, van Essen TAJ, Fontana P, Hopman S, Iascone M, Javier MM, Kamsteeg EJ, Kerkhof J, Kido J, Kim HG, Kleefstra T, Lonardo F, Lai A, Lev D, Levy MA, Lewis MES, Lichty A, Mannens MMAM, Matsumoto N, Maya I, McConkey H, Megarbane A, Michaud V, Miele E, Niceta M, Novelli A, Onesimo R, Pfundt R, Popp B, Prijoles E, Relator R, Redon S, Rots D, Rouault K, Saida K, Schieving J, Tartaglia M, Tenconi R, Uguen K, Verbeek N, Walsh CA, Yosovich K, Yuskaitis CJ, Zampino G, Sadikovic B, Alders M, Oegema R. Delineation of a KDM2B-related neurodevelopmental disorder and its associated DNA methylation signature. Genet Med 2023; 25:49-62. [PMID: 36322151 PMCID: PMC9825659 DOI: 10.1016/j.gim.2022.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/12/2022] [Accepted: 09/12/2022] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Pathogenic variants in genes involved in the epigenetic machinery are an emerging cause of neurodevelopment disorders (NDDs). Lysine-demethylase 2B (KDM2B) encodes an epigenetic regulator and mouse models suggest an important role during development. We set out to determine whether KDM2B variants are associated with NDD. METHODS Through international collaborations, we collected data on individuals with heterozygous KDM2B variants. We applied methylation arrays on peripheral blood DNA samples to determine a KDM2B associated epigenetic signature. RESULTS We recruited a total of 27 individuals with heterozygous variants in KDM2B. We present evidence, including a shared epigenetic signature, to support a pathogenic classification of 15 KDM2B variants and identify the CxxC domain as a mutational hotspot. Both loss-of-function and CxxC-domain missense variants present with a specific subepisignature. Moreover, the KDM2B episignature was identified in the context of a dual molecular diagnosis in multiple individuals. Our efforts resulted in a cohort of 21 individuals with heterozygous (likely) pathogenic variants. Individuals in this cohort present with developmental delay and/or intellectual disability; autism; attention deficit disorder/attention deficit hyperactivity disorder; congenital organ anomalies mainly of the heart, eyes, and urogenital system; and subtle facial dysmorphism. CONCLUSION Pathogenic heterozygous variants in KDM2B are associated with NDD and a specific epigenetic signature detectable in peripheral blood.
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Affiliation(s)
| | - Jack Reilly
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Marie-Claire Cornips
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Michael A Hadders
- Oncode Institute and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Emanuele Agolini
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Priyanka Ahimaz
- Division of Clinical Genetics, Department of Pediatrics, Columbia University, New York, NY
| | - Kwame Anyane-Yeboa
- Division of Clinical Genetics, Department of Pediatrics, Columbia University, New York, NY
| | - Severine Audebert Bellanger
- Service de Génétique Médicale et de Biologie de la Reproduction, Centre Hospitalier Regional Universitaire Brest, Brest, France
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Ton A J van Essen
- Department of Medical Genetics, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Paolo Fontana
- Medical Genetics Unit, A.O.R.N. San Pio, Benevento, Italy
| | - Saskia Hopman
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maria Iascone
- Laboratorio di Genetica Medica - ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Margaret M Javier
- Department of Medical Genetics, BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jennifer Kerkhof
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, Ontario, Canada
| | - Jun Kido
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hyung-Goo Kim
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Abbe Lai
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program and Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Dorit Lev
- The Rina Mor Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
| | - Michael A Levy
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, Ontario, Canada
| | - M E Suzanne Lewis
- Department of Medical Genetics, BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Marcel M A M Mannens
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Idit Maya
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach-Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Haley McConkey
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada; Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, Ontario, Canada
| | - Andre Megarbane
- Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon; Institut Jérôme Lejeune, Paris, France
| | - Vincent Michaud
- Department of Medical Genetics, CHU Bordeaux, Bordeaux, France
| | - Evelina Miele
- Department of Pediatric Hematology and Oncology and Cellular and Gene Therapy, Bambino Gesù Children's Hospital, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS), Rome, Italy
| | - Marcello Niceta
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Roberta Onesimo
- Center for Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bernt Popp
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany; Center of Functional Genomics, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Raissa Relator
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, Ontario, Canada
| | - Sylvia Redon
- Service de Génétique Médicale et de Biologie de la Reproduction, Centre Hospitalier Regional Universitaire Brest, Brest, France; Université de Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Dmitrijs Rots
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Karen Rouault
- Service de Génétique Médicale et de Biologie de la Reproduction, Centre Hospitalier Regional Universitaire Brest, Brest, France; Université de Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Ken Saida
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Jolanda Schieving
- Department of Pediatric Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Romano Tenconi
- Clinical Genetics Unit, Department of Women and Children's Health, University of Padova, Padova, Italy
| | - Kevin Uguen
- Service de Génétique Médicale et de Biologie de la Reproduction, Centre Hospitalier Regional Universitaire Brest, Brest, France
| | - Nienke Verbeek
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Christopher A Walsh
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA
| | - Keren Yosovich
- Molecular Genetic Laboratory, Edith Wolfson Medical Center, Holon, Israel
| | - Christopher J Yuskaitis
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Giuseppe Zampino
- Center for Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Faculty of Medicine and Surgery, Catholic University of Sacred Heart, Rome, Italy
| | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada; Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, Ontario, Canada.
| | - Mariëlle Alders
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands.
| | - Renske Oegema
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands.
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7
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Sleyp Y, Valenzuela I, Accogli A, Ballon K, Ben-Zeev B, Berkovic SF, Broly M, Callaerts P, Caylor RC, Charles P, Chatron N, Cohen L, Coppola A, Cordeiro D, Cuccurullo C, Cuscó I, Janette diMonda, Duran-Romaña R, Ekhilevitch N, Fernández-Alvarez P, Gordon CT, Isidor B, Keren B, Lesca G, Maljaars J, Mercimek-Andrews S, Morrow MM, Muir AM, Rousseau F, Salpietro V, Scheffer IE, Schnur RE, Schymkowitz J, Souche E, Steyaert J, Stolerman ES, Vengoechea J, Ville D, Washington C, Weiss K, Zaid R, Sadleir LG, Mefford HC, Peeters H. De novo missense variants in the E3 ubiquitin ligase adaptor KLHL20 cause a developmental disorder with intellectual disability, epilepsy, and autism spectrum disorder. Genet Med 2022; 24:2464-2474. [PMID: 36214804 DOI: 10.1016/j.gim.2022.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE KLHL20 is part of a CUL3-RING E3 ubiquitin ligase involved in protein ubiquitination. KLHL20 functions as the substrate adaptor that recognizes substrates and mediates the transfer of ubiquitin to the substrates. Although KLHL20 regulates neurite outgrowth and synaptic development in animal models, a role in human neurodevelopment has not yet been described. We report on a neurodevelopmental disorder caused by de novo missense variants in KLHL20. METHODS Patients were ascertained by the investigators through Matchmaker Exchange. Phenotyping of patients with de novo missense variants in KLHL20 was performed. RESULTS We studied 14 patients with de novo missense variants in KLHL20, delineating a genetic syndrome with patients having mild to severe intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, hyperactivity, and subtle dysmorphic facial features. We observed a recurrent de novo missense variant in 11 patients (NM_014458.4:c.1069G>A p.[Gly357Arg]). The recurrent missense and the 3 other missense variants all clustered in the Kelch-type β-propeller domain of the KLHL20 protein, which shapes the substrate binding surface. CONCLUSION Our findings implicate KLHL20 in a neurodevelopmental disorder characterized by intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, and hyperactivity.
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Affiliation(s)
- Yoeri Sleyp
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Irene Valenzuela
- Department of Clinical and Molecular Genetics, Vall d'Hebron University Hospital and Medicine Genetics Group, Vall d'Hebron Research Institute, Barcelona, Spain
| | - Andrea Accogli
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Katleen Ballon
- Centre for Developmental Disabilities, University Hospitals Leuven, Leuven, Belgium
| | - Bruria Ben-Zeev
- Pediatric Neurology Institute, The Edmond & Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Martin Broly
- Service de Génétique Médicale, Centre Hospitalier Universitaire (CHU) de Nantes, Nantes, France; Medigenome, Swiss Institute of Genomic Medicine, Geneva, Switzerland
| | | | | | - Perrine Charles
- Salpêtrière Hospital Genetic Department and Reference Center for Rare Intellectual Disabilities, APHP, Paris, France
| | - Nicolas Chatron
- Department of Medical Genetics, Hospices Civils de Lyon and NeuroMyogene Institute, CNRS UMR 5310 - INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Lior Cohen
- Genetic Institute, Barzilai University Medical Center, Ashkelon, Israel; Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel
| | - Antonietta Coppola
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy
| | - Dawn Cordeiro
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Claudia Cuccurullo
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy
| | - Ivon Cuscó
- Department of Clinical and Molecular Genetics, Vall d'Hebron University Hospital and Medicine Genetics Group, Vall d'Hebron Research Institute, Barcelona, Spain
| | - Janette diMonda
- Department of Human Genetics, Emory Clinic, Emory Healthcare, Atlanta, GA
| | - Ramon Duran-Romaña
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | | | - Paula Fernández-Alvarez
- Department of Clinical and Molecular Genetics, Vall d'Hebron University Hospital and Medicine Genetics Group, Vall d'Hebron Research Institute, Barcelona, Spain
| | - Christopher T Gordon
- Laboratory of Embryology and Genetics of Human Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Imagine, Université de Paris, Paris, France
| | - Bertrand Isidor
- Service de Génétique Médicale, Centre Hospitalier Universitaire (CHU) de Nantes, Nantes, France
| | - Boris Keren
- Département de Génétique, AP-HP.Sorbonne Université, Hôpital Pitié-Salpêtrière, Paris, France
| | - Gaetan Lesca
- Department of Medical Genetics, Hospices Civils de Lyon and NeuroMyogene Institute, CNRS UMR 5310 - INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Jarymke Maljaars
- Parenting and Special Education Research Unit, KU Leuven, Leuven, Belgium
| | - Saadet Mercimek-Andrews
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | | | - Alison M Muir
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA
| | | | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Vincenzo Salpietro
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy; Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia; Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Victoria, Australia; Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia
| | | | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Erika Souche
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Jean Steyaert
- Center for Developmental Psychiatry, KU Leuven, Leuven, Belgium
| | | | - Jaime Vengoechea
- Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA
| | - Dorothée Ville
- Pediatric Neurology Department, Lyon University Hospital, Lyon, France
| | | | - Karin Weiss
- Genetics Institute, Rambam Health Care Campus, Haifa, Israel; The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rinat Zaid
- Genetics Institute, Rambam Health Care Campus, Haifa, Israel
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA; Center for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN
| | - Hilde Peeters
- Department of Human Genetics, KU Leuven, Leuven, Belgium; Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium.
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8
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Fang X, Butler KM, Abidi F, Gass J, Beisang A, Feyma T, Ryther RC, Standridge S, Heydemann P, Jones M, Haas R, Lieberman DN, Marsh E, Benke TA, Skinner S, Neul JL, Percy AK, Friez MJ, Caylor RC. Analysis of X-inactivation status in a Rett syndrome natural history study cohort. Mol Genet Genomic Med 2022; 10:e1917. [PMID: 35318820 PMCID: PMC9034674 DOI: 10.1002/mgg3.1917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a rare neurodevelopmental disorder associated with pathogenic MECP2 variants. Because the MECP2 gene is subject to X-chromosome inactivation (XCI), factors including MECP2 genotypic variation, tissue differences in XCI, and skewing of XCI all likely contribute to the clinical severity of individuals with RTT. METHODS We analyzed the XCI patterns from blood samples of 320 individuals and their mothers. It includes individuals with RTT (n = 287) and other syndromes sharing overlapping phenotypes with RTT (such as CDKL5 Deficiency Disorder [CDD, n = 16]). XCI status in each proband/mother duo and the parental origin of the preferentially inactivated X chromosome were analyzed. RESULTS The average XCI ratio in probands was slightly increased compared to their unaffected mothers (73% vs. 69%, p = .0006). Among the duos with informative XCI data, the majority of individuals with classic RTT had their paternal allele preferentially inactivated (n = 180/220, 82%). In sharp contrast, individuals with CDD had their maternal allele preferentially inactivated (n = 10/12, 83%). Our data indicate a weak positive correlation between XCI skewing ratio and clinical severity scale (CSS) scores in classic RTT patients with maternal allele preferentially inactivated XCI (rs = 0.35, n = 40), but not in those with paternal allele preferentially inactivated XCI (rs = -0.06, n = 180). The most frequent MECP2 pathogenic variants were enriched in individuals with highly/moderately skewed XCI patterns, suggesting an association with higher levels of XCI skewing. CONCLUSION These results extend our understanding of the pathogenesis of RTT and other syndromes with overlapping clinical features by providing insight into the both XCI and the preferential XCI of parental alleles.
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Affiliation(s)
- Xiaolan Fang
- Greenwood Genetic CenterGreenwoodSouth CarolinaUSA
| | | | - Fatima Abidi
- Greenwood Genetic CenterGreenwoodSouth CarolinaUSA
| | - Jennifer Gass
- Florida Cancer Specialists & Research InstituteFort MyersFLUSA,Present address:
Florida Cancer Specialists & Research InstituteFort MyersFloridaUSA
| | - Arthur Beisang
- Gillette Children’s Specialty HealthcareSt. PaulMinnesotaUSA
| | - Timothy Feyma
- Gillette Children’s Specialty HealthcareSt. PaulMinnesotaUSA
| | - Robin C. Ryther
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Shannon Standridge
- Division of NeurologyCincinnati Children’s Hospital Medical CenterCincinnatiOhioUSA,Department of Pediatrics, College of MedicineUniversity of CincinnatiCincinnatiOhioUSA
| | | | - Mary Jones
- Oakland Children’s Hospital, UCSFOaklandCaliforniaUSA
| | - Richard Haas
- University of California San DiegoSan DiegoCaliforniaUSA
| | - David N Lieberman
- Department of NeurologyBoston Children’s HospitalBostonMassachusettsUSA
| | - Eric D. Marsh
- Children’s Hospital of Philadelphia and University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Tim A. Benke
- University of Colorado School of Medicine, Children’s Hospital Colorado‐AuroraDenverColoradoUSA
| | | | - Jeffrey L. Neul
- Vanderbilt Kennedy CenterVanderbilt University Medical CenterNashville TN
| | - Alan K. Percy
- The University of Alabama at BirminghamBirminghamAlabamaUSA
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Upadia J, Walano N, Noh GS, Liu J, Li Y, Deputy S, Elliott LT, Wong J, Lee JA, Caylor RC, Andersson HC. HSD10 disease in a female: A case report and review of literature. JIMD Rep 2021; 62:35-43. [PMID: 34765396 PMCID: PMC8574182 DOI: 10.1002/jmd2.12250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 11/07/2022] Open
Abstract
HSD10 disease is a rare X-linked mitochondrial disorder caused by pathogenic variants in the HSD17B10 gene. The phenotype results from impaired 17β-hydroxysteroid dehydrogenase 10 (17β-HSD10) protein structure and function. HSD10 is a multifunctional protein involved in enzymatic degradation of isoleucine and branched-chain fatty acids, the metabolism of sex hormones and neurosteroids, as well as in regulating mitochondrial RNA maturation. HSD10 disease is characterised by progressive neurologic impairment. Disease onset is varied and includes neonatal-onset, infantile-onset and late-onset in males. Females can also be affected. Our index case is a 45-month-old female, who initially presented at 11 months of age with global developmental delay. She subsequently began to lose previously acquired cognitive and motor skills starting around 29 months of age. Brain MRI showed abnormalities in the basal ganglia indicative of possible mitochondrial disease. Urine organic acid analysis revealed elevations of 2-methyl-3-hydroxybutyric acid and tiglyglycine. HSD17B10 gene sequencing revealed a likely pathogenic variant, NM_001037811.2:c.439C>T (p.Arg147Cys) inherited from her mother, expected to be causative of HSD10 disease. Her X-chromosome inactivation study is consistent with a skewed X-inactivation pattern. We report a female patient with HSD10 disease caused by a missense pathogenic variant, Arg147Cys in the HSD17B10 gene. The patient is the fifth severely affected female with this disease. This case adds to the small number of known affected families with this highly variable disease in the literature. These findings support the possibility of X-inactivation patterns influencing the penetrance of HSD10 disease in females.
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Affiliation(s)
- Jariya Upadia
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
- Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
| | - Nicolette Walano
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
- Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
| | - Grace S. Noh
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
- Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
| | - Jiao Liu
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yuwen Li
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
- Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
| | - Stephen Deputy
- Division of Pediatric Neurology, Department of PediatricsLouisiana State University Health Sciences Center/Children's HospitalNew OrleansLouisianaUSA
| | - Lindsay T. Elliott
- Department of Pediatric Physical Medicine and RehabilitationLouisiana State University Health Sciences Center/Children's HospitalNew OrleansLouisianaUSA
| | - Joaquin Wong
- Division of Pediatric Neurology, Department of PediatricsLouisiana State University Health Sciences Center/Children's HospitalNew OrleansLouisianaUSA
| | | | | | - Hans C. Andersson
- Hayward Genetics Center, Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
- Department of PediatricsTulane University School of MedicineNew OrleansLouisianaUSA
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10
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Caylor RC, Grote L, Thiffault I, Farrow EG, Willig L, Soden S, Amudhavalli SM, Nopper AJ, Horii KA, Fleming E, Jenkins J, Welsh H, Ilyas M, Engleman K, Abdelmoity A, Saunders CJ. Incidental diagnosis of tuberous sclerosis complex by exome sequencing in three families with subclinical findings. Neurogenetics 2018; 19:205-213. [PMID: 29926239 DOI: 10.1007/s10048-018-0551-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 12/19/2022]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal-dominant neurocutaneous disorder characterized by lesions and benign tumors in multiple organ systems including the brain, skin, heart, eyes, kidneys, and lungs. The phenotype is highly variable, although penetrance is reportedly complete. We report the molecular diagnosis of TSC in individuals exhibiting extreme intra-familial variability, including the incidental diagnosis of asymptomatic family members. Exome sequencing was performed in three families, with probands referred for epilepsy, autism, and absent speech (Family 1); epileptic spasms (Family 2); and connective tissue disorders (Family 3.) Pathogenic variants in TSC1 or TSC2 were identified in nine individuals, including relatives with limited or no medical concerns at the time of testing. Of the nine individuals reported here, six had post-diagnosis examinations and three met clinical diagnostic criteria for TSC. One did not meet clinical criteria for a possible or definite diagnosis of TSC, and two had only a possible clinical diagnosis following post-diagnosis workup. These individuals as well as their mothers demonstrated limited features that would not raise concern for TSC in the absence of molecular results. In addition, three individuals exhibited epilepsy with normal brain MRIs, and two without seizures or intellectual disability had MRI findings fulfilling major criteria for TSC highlighting the difficulty providers face when relying on clinical criteria to guide genetic testing. Given the importance of a timely TSC diagnosis for clinical management, such cases demonstrate a potential benefit for clinical criteria to include seizures and an unbiased molecular approach to genetic testing.
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Affiliation(s)
- R C Caylor
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - L Grote
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - I Thiffault
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, 2420 Pershing Rd., Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
| | - E G Farrow
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, 2420 Pershing Rd., Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
| | - L Willig
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, 2420 Pershing Rd., Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
- Division of Nephrology, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - S Soden
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, 2420 Pershing Rd., Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
| | - S M Amudhavalli
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
| | - A J Nopper
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
- Division of Dermatology, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - K A Horii
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
- Division of Dermatology, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - E Fleming
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - J Jenkins
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - H Welsh
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - M Ilyas
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
- Division of Neurology, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - K Engleman
- Division of Clinical Genetics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - A Abdelmoity
- Department of Pediatrics, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA
- Division of Neurology, Children's Mercy Hospitals, Kansas City, MO, 64108, USA
| | - C J Saunders
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals, Kansas City, MO, 64108, USA.
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, 2420 Pershing Rd., Kansas City, MO, 64108, USA.
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, 64108, USA.
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11
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Caylor RC, Jin Y, Ackley BD. The Caenorhabditis elegans voltage-gated calcium channel subunits UNC-2 and UNC-36 and the calcium-dependent kinase UNC-43/CaMKII regulate neuromuscular junction morphology. Neural Dev 2013; 8:10. [PMID: 23663262 PMCID: PMC3661369 DOI: 10.1186/1749-8104-8-10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/25/2013] [Indexed: 11/30/2022] Open
Abstract
Background The conserved Caenorhabditis elegans proteins NID-1/nidogen and PTP-3A/LAR-RPTP function to efficiently localize the presynaptic scaffold protein SYD-2/α-liprin at active zones. Loss of function in these molecules results in defects in the size, morphology and spacing of neuromuscular junctions. Results Here we show that the Cav2-like voltage-gated calcium channel (VGCC) proteins, UNC-2 and UNC-36, and the calmodulin kinase II (CaMKII), UNC-43, function to regulate the size and morphology of presynaptic domains in C. elegans. Loss of function in unc-2, unc-36 or unc-43 resulted in slightly larger GABAergic neuromuscular junctions (NMJs), but could suppress the synaptic morphology defects found in nid-1/nidogen or ptp-3/LAR mutants. A gain-of-function mutation in unc-43 caused defects similar to those found in nid-1 mutants. Mutations in egl-19, Cav1-like, or cca-1, Cav3-like, α1 subunits, or the second α2/δ subunit, tag-180, did not suppress nid-1, suggesting a specific interaction between unc-2 and the synaptic extracellular matrix (ECM) component nidogen. Using a synaptic vesicle marker in time-lapse microscopy studies, we observed GABAergic motor neurons adding NMJ-like structures during late larval development. The synaptic bouton addition appeared to form in at least two ways: (1) de novo formation, where a cluster of vesicles appeared to coalesce, or (2) when a single punctum became enlarged and then divided to form two discrete fluorescent puncta. In comparison to wild type animals, we found unc-2 mutants exhibited reduced NMJ dynamics, with fewer observed divisions during a similar stage of development. Conclusions We identified UNC-2/UNC-36 VGCCs and UNC-43/CaMKII as regulators of C. elegans synaptogenesis. UNC-2 has a modest role in synapse formation, but a broader role in regulating dynamic changes in the size and morphology of synapses that occur during organismal development. During the late 4th larval stage (L4), wild type animals exhibit synaptic morphologies that are similar to those found in animals lacking NID-1/PTP-3 adhesion, as well as those with constitutive activation of UNC-43. Genetic evidence indicates that the VGCCs and the NID-1/PTP-3 adhesion complex provide opposing functions in synaptic development, suggesting that modulation of synaptic adhesion may underlie synapse development in C. elegans.
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Affiliation(s)
- Raymond C Caylor
- Department of Molecular Biosciences, University of Kansas, 5004 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045, USA
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