1
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Jonak CR, Assad SA, Garcia TA, Sandhu MS, Rumschlag JA, Razak KA, Binder DK. Phenotypic analysis of multielectrode array EEG biomarkers in developing and adult male Fmr1 KO mice. Neurobiol Dis 2024; 195:106496. [PMID: 38582333 DOI: 10.1016/j.nbd.2024.106496] [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: 02/03/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/08/2024] Open
Abstract
Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability with symptoms that include increased anxiety and social and sensory processing deficits. Recent electroencephalographic (EEG) studies in humans with FXS have identified neural oscillation deficits that include increased resting state gamma power, increased amplitude of auditory evoked potentials, and reduced phase locking of sound-evoked gamma oscillations. Similar EEG phenotypes are present in mouse models of FXS, but very little is known about the development of such abnormal responses. In the current study, we employed a 30-channel mouse multielectrode array (MEA) system to record and analyze resting and stimulus-evoked EEG signals in male P21 and P91 WT and Fmr1 KO mice. This led to several novel findings. First, P91, but not P21, Fmr1 KO mice have significantly increased resting EEG power in the low- and high-gamma frequency bands. Second, both P21 and P91 Fmr1 KO mice have markedly attenuated inter-trial phase coherence (ITPC) to spectrotemporally dynamic auditory stimuli as well as to 40 Hz and 80 Hz auditory steady-state response (ASSR) stimuli. This suggests abnormal temporal processing from early development that may lead to abnormal speech and language function in FXS. Third, we found hemispheric asymmetry of fast temporal processing in the mouse auditory cortex in WT but not Fmr1 KO mice. Together, these findings define a set of EEG phenotypes in young and adult mice that can serve as translational targets for genetic and pharmacological manipulation in phenotypic rescue studies.
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Affiliation(s)
- Carrie R Jonak
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States of America
| | - Samantha A Assad
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States of America
| | - Terese A Garcia
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States of America
| | - Manbir S Sandhu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States of America
| | - Jeffrey A Rumschlag
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, United States of America
| | - Khaleel A Razak
- Neuroscience Graduate Program, University of California, Riverside, CA, United States of America; Department of Psychology, University of California, Riverside, CA, United States of America
| | - Devin K Binder
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States of America; Neuroscience Graduate Program, University of California, Riverside, CA, United States of America.
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2
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Agusti I, Alvarez-Mora MI, Wijngaard R, Borras A, Barcos T, Peralta S, Guimera M, Goday A, Manau D, Rodriguez-Revenga L. Correlation of FMR4 expression levels to ovarian reserve markers in FMR1 premutation carriers. J Ovarian Res 2024; 17:103. [PMID: 38760837 PMCID: PMC11100203 DOI: 10.1186/s13048-024-01425-0] [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: 11/09/2023] [Accepted: 04/25/2024] [Indexed: 05/19/2024] Open
Abstract
BACKGROUND Fragile X-associated primary ovarian insufficiency (FXPOI), characterized by amenorrhea before age 40 years, occurs in 20% of female FMR1 premutation carriers. Presently, there are no molecular or biomarkers that can help predicting which FMR1 premutation women will develop FXPOI. We previously demonstrated that high FMR4 levels can discriminate between FMR1 premutation carriers with and without FXPOI. In the present study the relationship between the expression levels of FMR4 and the ovarian reserve markers was assessed in female FMR1 premutation carriers under age of 35 years. METHODS We examined the association between FMR4 transcript levels and the measures of total antral follicle count (AFC) and serum anti-müllerian hormone (AMH) levels as markers of ovarian follicle reserve. RESULTS Results revealed a negative association between FMR4 levels and AMH (r = 0.45) and AFC (r = 0.64). Statistically significant higher FMR4 transcript levels were found among those FMR1 premutation women with both, low AFCs and AMH levels. CONCLUSIONS These findings reinforce previous studies supporting the association between high levels of FMR4 and the risk of developing FXPOI in FMR1 premutation carriers.
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Affiliation(s)
- Ines Agusti
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Maria Isabel Alvarez-Mora
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona and FCRB- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), C/Villarroel, 170, Barcelona, 08036, Spain
- CIBER of Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Robin Wijngaard
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Aina Borras
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Tamara Barcos
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona and FCRB- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), C/Villarroel, 170, Barcelona, 08036, Spain
| | - Sara Peralta
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Marta Guimera
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Anna Goday
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Dolors Manau
- Clinical Institute of Gynecology, Obstetrics and Neonatology (ICGON), Hospital Clinic of Barcelona and FCRB-Institut de Investigacions Biomediques August Pi iSunyer (IDIBAPS), Barcelona, Spain
| | - Laia Rodriguez-Revenga
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona and FCRB- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), C/Villarroel, 170, Barcelona, 08036, Spain.
- CIBER of Rare Diseases, Instituto de Salud Carlos III, Madrid, Spain.
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Malachowski T, Chandradoss KR, Boya R, Zhou L, Cook AL, Su C, Pham K, Haws SA, Kim JH, Ryu HS, Ge C, Luppino JM, Nguyen SC, Titus KR, Gong W, Wallace O, Joyce EF, Wu H, Rojas LA, Phillips-Cremins JE. Spatially coordinated heterochromatinization of long synaptic genes in fragile X syndrome. Cell 2023; 186:5840-5858.e36. [PMID: 38134876 PMCID: PMC10794044 DOI: 10.1016/j.cell.2023.11.019] [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: 12/03/2022] [Revised: 07/31/2023] [Accepted: 11/16/2023] [Indexed: 12/24/2023]
Abstract
Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X chromosome in FXS patient-derived iPSCs, iPSC-derived neural progenitors, EBV-transformed lymphoblasts, and brain tissue with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication-stress-induced double-strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the mutation-length CGG to premutation length reverses H3K9me3 on the X chromosome and multiple autosomes, refolds TADs, and restores gene expression. H3K9me3 domains can also arise in normal-length iPSCs created with perturbations linked to genome instability, suggesting their relevance beyond FXS. Our results reveal Mb-scale heterochromatinization and trans interactions among loci susceptible to instability.
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Affiliation(s)
- Thomas Malachowski
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Keerthivasan Raanin Chandradoss
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Ravi Boya
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Linda Zhou
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Ashley L Cook
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Chuanbin Su
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Kenneth Pham
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Spencer A Haws
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Ji Hun Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Han-Seul Ryu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Chunmin Ge
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer M Luppino
- Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Son C Nguyen
- Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Katelyn R Titus
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Wanfeng Gong
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Owen Wallace
- Fulcrum Therapeutics Incorporated, Cambridge, MA, USA
| | - Eric F Joyce
- Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Hao Wu
- Fulcrum Therapeutics Incorporated, Cambridge, MA, USA
| | | | - Jennifer E Phillips-Cremins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA.
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4
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Persico T, Tranquillo ML, Seracchioli R, Zuccarello D, Sorrentino U. PGT-M for Premature Ovarian Failure Related to CGG Repeat Expansion of the FMR1 Gene. Genes (Basel) 2023; 15:6. [PMID: 38275588 PMCID: PMC10815814 DOI: 10.3390/genes15010006] [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: 10/25/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024] Open
Abstract
Primary ovarian failure (POF) is caused by follicle exhaustion and is associated with menstrual irregularities and elevated gonadotropin levels, which lead to infertility before the age of 40 years. The etiology of POI is mostly unknown, but a heterogeneous genetic and familial background can be identified in a subset of cases. Abnormalities in the fragile X mental retardation 1 gene (FMR1) are among the most prevalent monogenic causes of POI. These abnormalities are caused by the expansion of an unstable CGG repeat in the 5' untranslated region of FMR1. Expansions over 200 repeats cause fragile X syndrome (FXS), whereas expansions between 55 and 200 CGG repeats, which are defined as a fragile X premutation, have been associated with premature ovarian failure type 1 (POF1) in heterozygous females. Preimplantation genetic testing for monogenic diseases (PGT-M) can be proposed when the female carries a premutation or a full mutation. In this narrative review, we aim to recapitulate the clinical and molecular features of POF1 and their implications in the context of PGT-M.
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Affiliation(s)
- Tiziana Persico
- Medically Assisted Procreation Center, Maternal and Child Department, Beauregard Hospital, Valle D’Aosta Local Public Health, 11100 Aoste, Italy
| | - Maria Lucrezia Tranquillo
- Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy; (M.L.T.); (R.S.)
| | - Renato Seracchioli
- Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy; (M.L.T.); (R.S.)
- Division of Gynaecology and Human Reproduction Physiopathology, IRCCS Azienda Ospedaliero, University of Bologna, 40138 Bologna, Italy
| | - Daniela Zuccarello
- Clinical Genetics and Epidemiology Unit, University of Padova, 35128 Padova, Italy; (D.Z.); (U.S.)
| | - Ugo Sorrentino
- Clinical Genetics and Epidemiology Unit, University of Padova, 35128 Padova, Italy; (D.Z.); (U.S.)
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5
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Annear DJ, Kooy RF. Unravelling the link between neurodevelopmental disorders and short tandem CGG-repeat expansions. Emerg Top Life Sci 2023; 7:265-275. [PMID: 37768318 PMCID: PMC10754333 DOI: 10.1042/etls20230021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/23/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
Neurodevelopmental disorders (NDDs) encompass a diverse group of disorders characterised by impaired cognitive abilities and developmental challenges. Short tandem repeats (STRs), repetitive DNA sequences found throughout the human genome, have emerged as potential contributors to NDDs. Specifically, the CGG trinucleotide repeat has been implicated in a wide range of NDDs, including Fragile X Syndrome (FXS), the most common inherited form of intellectual disability and autism. This review focuses on CGG STR expansions associated with NDDs and their impact on gene expression through repeat expansion-mediated epigenetic silencing. We explore the molecular mechanisms underlying CGG-repeat expansion and the resulting epigenetic modifications, such as DNA hypermethylation and gene silencing. Additionally, we discuss the involvement of other CGG STRs in neurodevelopmental diseases. Several examples, including FMR1, AFF2, AFF3, XYLT1, FRA10AC1, CBL, and DIP2B, highlight the complex relationship between CGG STR expansions and NDDs. Furthermore, recent advancements in this field are highlighted, shedding light on potential future research directions. Understanding the role of STRs, particularly CGG-repeats, in NDDs has the potential to uncover novel diagnostic and therapeutic strategies for these challenging disorders.
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Affiliation(s)
- Dale J Annear
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - R Frank Kooy
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
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6
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Chojnacka M, Beroun A, Magnowska M, Stawikowska A, Cysewski D, Milek J, Dziembowska M, Kuzniewska B. Impaired synaptic incorporation of AMPA receptors in a mouse model of fragile X syndrome. Front Mol Neurosci 2023; 16:1258615. [PMID: 38025260 PMCID: PMC10665894 DOI: 10.3389/fnmol.2023.1258615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common monogenetic cause of inherited intellectual disability and autism in humans. One of the well-characterized molecular phenotypes of Fmr1 KO mice, a model of FXS, is increased translation of synaptic proteins. Although this upregulation stabilizes in adulthood, abnormalities during the critical period of plasticity have long-term effects on circuit formation and synaptic properties. Using high-resolution quantitative proteomics of synaptoneurosomes isolated from the adult, developed brains of Fmr1 KO mice, we show a differential abundance of proteins regulating the postsynaptic receptor activity of glutamatergic synapses. We investigated the AMPA receptor composition and shuttling in adult Fmr1 KO and WT mice using a variety of complementary experimental strategies such as surface protein crosslinking, immunostaining of surface receptors, and electrophysiology. We discovered that the activity-dependent synaptic delivery of AMPARs is impaired in adult Fmr1 KO mice. Furthermore, we show that Fmr1 KO synaptic AMPARs contain more GluA2 subunits that can be interpreted as a switch in the synaptic AMPAR subtype toward an increased number of Ca2+-impermeable receptors in adult Fmr1 KO synapses.
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Affiliation(s)
- Magdalena Chojnacka
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Anna Beroun
- Laboratory of Neuronal Plasticity, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Marta Magnowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Aleksandra Stawikowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Dominik Cysewski
- Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland
| | - Jacek Milek
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Magdalena Dziembowska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Bozena Kuzniewska
- Laboratory of Molecular Basis of Synaptic Plasticity, Centre of New Technologies, University of Warsaw, Warsaw, Poland
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7
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Milla LA, Corral L, Rivera J, Zuñiga N, Pino G, Nunez-Parra A, Cea-Del Rio CA. Neurodevelopment and early pharmacological interventions in Fragile X Syndrome. Front Neurosci 2023; 17:1213410. [PMID: 37599992 PMCID: PMC10433175 DOI: 10.3389/fnins.2023.1213410] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Fragile X Syndrome (FXS) is a neurodevelopmental disorder and the leading monogenic cause of autism and intellectual disability. For years, several efforts have been made to develop an effective therapeutic approach to phenotypically rescue patients from the disorder, with some even advancing to late phases of clinical trials. Unfortunately, none of these attempts have completely succeeded, bringing urgency to further expand and refocus research on FXS therapeutics. FXS arises at early stages of postnatal development due to the mutation and transcriptional silencing of the Fragile X Messenger Ribonucleoprotein 1 gene (FMR1) and consequent loss of the Fragile X Messenger Ribonucleoprotein (FMRP) expression. Importantly, FMRP expression is critical for the normal adult nervous system function, particularly during specific windows of embryogenic and early postnatal development. Cellular proliferation, migration, morphology, axonal guidance, synapse formation, and in general, neuronal network establishment and maturation are abnormally regulated in FXS, underlying the cognitive and behavioral phenotypes of the disorder. In this review, we highlight the relevance of therapeutically intervening during critical time points of development, such as early postnatal periods in infants and young children and discuss past and current clinical trials in FXS and their potential to specifically target those periods. We also discuss potential benefits, limitations, and disadvantages of these pharmacological tools based on preclinical and clinical research.
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Affiliation(s)
- Luis A. Milla
- Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
| | - Lucia Corral
- Laboratorio de Neurofisiopatologia, Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
| | - Jhanpool Rivera
- Laboratorio de Neurofisiopatologia, Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
| | - Nolberto Zuñiga
- Laboratorio de Neurofisiopatologia, Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
| | - Gabriela Pino
- Laboratorio de Neurofisiopatologia, Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
| | - Alexia Nunez-Parra
- Physiology Laboratory, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile
- Cell Physiology Center, Universidad de Chile, Santiago, Chile
| | - Christian A. Cea-Del Rio
- Laboratorio de Neurofisiopatologia, Centro de Investigacion Biomedica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Medicas, Universidad de Santiago de Chile, Santiago, Chile
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8
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Laufer VA, Glover TW, Wilson TE. Applications of advanced technologies for detecting genomic structural variation. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2023; 792:108475. [PMID: 37931775 PMCID: PMC10792551 DOI: 10.1016/j.mrrev.2023.108475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/07/2023] [Accepted: 11/02/2023] [Indexed: 11/08/2023]
Abstract
Chromosomal structural variation (SV) encompasses a heterogenous class of genetic variants that exerts strong influences on human health and disease. Despite their importance, many structural variants (SVs) have remained poorly characterized at even a basic level, a discrepancy predicated upon the technical limitations of prior genomic assays. However, recent advances in genomic technology can identify and localize SVs accurately, opening new questions regarding SV risk factors and their impacts in humans. Here, we first define and classify human SVs and their generative mechanisms, highlighting characteristics leveraged by various SV assays. We next examine the first-ever gapless assembly of the human genome and the technical process of assembling it, which required third-generation sequencing technologies to resolve structurally complex loci. The new portions of that "telomere-to-telomere" and subsequent pangenome assemblies highlight aspects of SV biology likely to develop in the near-term. We consider the strengths and limitations of the most promising new SV technologies and when they or longstanding approaches are best suited to meeting salient goals in the study of human SV in population-scale genomics research, clinical, and public health contexts. It is a watershed time in our understanding of human SV when new approaches are expected to fundamentally change genomic applications.
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Affiliation(s)
- Vincent A Laufer
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Thomas W Glover
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Thomas E Wilson
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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Lee HG, Imaichi S, Kraeutler E, Aguilar R, Lee YW, Sheridan SD, Lee JT. Site-specific R-loops induce CGG repeat contraction and fragile X gene reactivation. Cell 2023; 186:2593-2609.e18. [PMID: 37209683 DOI: 10.1016/j.cell.2023.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/15/2023] [Accepted: 04/26/2023] [Indexed: 05/22/2023]
Abstract
Here, we describe an approach to correct the genetic defect in fragile X syndrome (FXS) via recruitment of endogenous repair mechanisms. A leading cause of autism spectrum disorders, FXS results from epigenetic silencing of FMR1 due to a congenital trinucleotide (CGG) repeat expansion. By investigating conditions favorable to FMR1 reactivation, we find MEK and BRAF inhibitors that induce a strong repeat contraction and full FMR1 reactivation in cellular models. We trace the mechanism to DNA demethylation and site-specific R-loops, which are necessary and sufficient for repeat contraction. A positive feedback cycle comprising demethylation, de novo FMR1 transcription, and R-loop formation results in the recruitment of endogenous DNA repair mechanisms that then drive excision of the long CGG repeat. Repeat contraction is specific to FMR1 and restores the production of FMRP protein. Our study therefore identifies a potential method of treating FXS in the future.
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Affiliation(s)
- Hun-Goo Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Sachiko Imaichi
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth Kraeutler
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Rodrigo Aguilar
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Yong-Woo Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Steven D Sheridan
- Center for Quantitative Health Center for Genomic Medicine and Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02114, USA
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA.
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10
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Shi Y, Niu Y, Zhang P, Luo H, Liu S, Zhang S, Wang J, Li Y, Liu X, Song T, Xu T, He S. Characterization of genome-wide STR variation in 6487 human genomes. Nat Commun 2023; 14:2092. [PMID: 37045857 PMCID: PMC10097659 DOI: 10.1038/s41467-023-37690-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 03/27/2023] [Indexed: 04/14/2023] Open
Abstract
Short tandem repeats (STRs) are abundant and highly mutagenic in the human genome. Many STR loci have been associated with a range of human genetic disorders. However, most population-scale studies on STR variation in humans have focused on European ancestry cohorts or are limited by sequencing depth. Here, we depicted a comprehensive map of 366,013 polymorphic STRs (pSTRs) constructed from 6487 deeply sequenced genomes, comprising 3983 Chinese samples (~31.5x, NyuWa) and 2504 samples from the 1000 Genomes Project (~33.3x, 1KGP). We found that STR mutations were affected by motif length, chromosome context and epigenetic features. We identified 3273 and 1117 pSTRs whose repeat numbers were associated with gene expression and 3'UTR alternative polyadenylation, respectively. We also implemented population analysis, investigated population differentiated signatures, and genotyped 60 known disease-causing STRs. Overall, this study further extends the scale of STR variation in humans and propels our understanding of the semantics of STRs.
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Affiliation(s)
- Yirong Shi
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yiwei Niu
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Peng Zhang
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Huaxia Luo
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuai Liu
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Sijia Zhang
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiajia Wang
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanyan Li
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xinyue Liu
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tingrui Song
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China.
| | - Shunmin He
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Wright SE, Todd PK. Native functions of short tandem repeats. eLife 2023; 12:e84043. [PMID: 36940239 PMCID: PMC10027321 DOI: 10.7554/elife.84043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/08/2023] [Indexed: 03/21/2023] Open
Abstract
Over a third of the human genome is comprised of repetitive sequences, including more than a million short tandem repeats (STRs). While studies of the pathologic consequences of repeat expansions that cause syndromic human diseases are extensive, the potential native functions of STRs are often ignored. Here, we summarize a growing body of research into the normal biological functions for repetitive elements across the genome, with a particular focus on the roles of STRs in regulating gene expression. We propose reconceptualizing the pathogenic consequences of repeat expansions as aberrancies in normal gene regulation. From this altered viewpoint, we predict that future work will reveal broader roles for STRs in neuronal function and as risk alleles for more common human neurological diseases.
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Affiliation(s)
- Shannon E Wright
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- Neuroscience Graduate Program, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Neuroscience, Picower InstituteCambridgeUnited States
| | - Peter K Todd
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- VA Ann Arbor Healthcare SystemAnn ArborUnited States
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12
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Wang X, Sela-Donenfeld D, Wang Y. Axonal and presynaptic FMRP: Localization, signal, and functional implications. Hear Res 2023; 430:108720. [PMID: 36809742 PMCID: PMC9998378 DOI: 10.1016/j.heares.2023.108720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/22/2023] [Accepted: 02/09/2023] [Indexed: 02/12/2023]
Abstract
Fragile X mental retardation protein (FMRP) binds a selected set of mRNAs and proteins to guide neural circuit assembly and regulate synaptic plasticity. Loss of FMRP is responsible for Fragile X syndrome, a neuropsychiatric disorder characterized with auditory processing problems and social difficulty. FMRP actions in synaptic formation, maturation, and plasticity are site-specific among the four compartments of a synapse: presynaptic and postsynaptic neurons, astrocytes, and extracellular matrix. This review summarizes advancements in understanding FMRP localization, signals, and functional roles in axons and presynaptic terminals.
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Affiliation(s)
- Xiaoyu Wang
- Division of Histology & Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou 510632, China
| | - Dalit Sela-Donenfeld
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Yuan Wang
- Department of Biomedical Sciences, Program in Neuroscience, Florida State University College of Medicine, Tallahassee, FL 32306, USA.
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13
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Norris JE, Schmitt LM, De Stefano LA, Pedapati EV, Erickson CA, Sweeney JA, Ethridge LE. Neuropsychiatric feature-based subgrouping reveals neural sensory processing spectrum in female FMR1 premutation carriers: A pilot study. Front Integr Neurosci 2023; 17:898215. [PMID: 36816716 PMCID: PMC9936150 DOI: 10.3389/fnint.2023.898215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction Fragile X Syndrome (FXS) is rare genetic condition characterized by a repeat expansion (CGG) in the Fragile X messenger ribonucleoprotein 1 (FMR1) gene where individuals with greater than 200 repeats are defined as full mutation. FXS clinical presentation often includes intellectual disability, and autism-like symptoms, including anxiety and sensory hypersensitivities. Individuals with 55 to <200 CGG repeats are said to have the FMR1 premutation, which is not associated with primary characteristics of the full mutation, but with an increased risk for anxiety, depression, and other affective conditions, as well as and impaired cognitive processing differences that vary in severity. Defining subgroups of premutation carriers based on distinct biological features may identify subgroups with varying levels of psychiatric, cognitive, and behavioral alterations. Methods The current pilot study utilized 3 cluster subgroupings defined by previous k means cluster analysis on neuropsychiatric, cognitive, and resting EEG variables in order to examine basic sensory auditory chirp task-based EEG parameters from 33 females with the FMR1 premutation (ages 17-78). Results Based on the predefined, neuropsychiatric three-cluster solution, premutation carriers with increased neuropsychiatric features and higher CGG repeat counts (cluster 1) showed decreased stimulus onset response, similar to previous ERP findings across a number of psychiatric disorders but opposite to findings in individuals with full mutation FXS. Premutation carriers with increased executive dysfunction and resting gamma power (cluster 2) exhibited decreased gamma phase locking to a chirp stimulus, similar to individuals with full mutation FXS. Cluster 3 members, who were relatively unaffected by psychiatric or cognitive symptoms, showed the most normative task-based EEG metrics. Discussion Our findings suggest a spectrum of sensory processing characteristics present in subgroups of premutation carriers that have been previously understudied due to lack of overall group differences. Our findings also further validate the pre-defined clinical subgroups by supporting links between disturbances in well-defined neural pathways and behavioral alterations that may be informative for identifying the mechanisms supporting specific risk factors and divergent therapeutic needs in individuals with the FMR1 premutation.
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Affiliation(s)
- Jordan E. Norris
- Department of Psychology, The University of Oklahoma, Norman, OK, United States
| | - Lauren M. Schmitt
- Behavioral Medicine and Clinical Psychology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States,Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
| | - Lisa A. De Stefano
- Behavioral Medicine and Clinical Psychology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Ernest V. Pedapati
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States,Division of Child Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States
| | - Craig A. Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States
| | - John A. Sweeney
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States
| | - Lauren E. Ethridge
- Department of Psychology, The University of Oklahoma, Norman, OK, United States,Department of Pediatrics, Section on Developmental and Behavioral Pediatrics, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States,*Correspondence: Lauren E. Ethridge,
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14
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Primary Cilia Dysfunction in Neurodevelopmental Disorders beyond Ciliopathies. J Dev Biol 2022; 10:jdb10040054. [PMID: 36547476 PMCID: PMC9782889 DOI: 10.3390/jdb10040054] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/04/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Primary cilia are specialized, microtubule-based structures projecting from the surface of most mammalian cells. These organelles are thought to primarily act as signaling hubs and sensors, receiving and integrating extracellular cues. Several important signaling pathways are regulated through the primary cilium including Sonic Hedgehog (Shh) and Wnt signaling. Therefore, it is no surprise that mutated genes encoding defective proteins that affect primary cilia function or structure are responsible for a group of disorders collectively termed ciliopathies. The severe neurologic abnormalities observed in several ciliopathies have prompted examination of primary cilia structure and function in other brain disorders. Recently, neuronal primary cilia defects were observed in monogenic neurodevelopmental disorders that were not traditionally considered ciliopathies. The molecular mechanisms of how these genetic mutations cause primary cilia defects and how these defects contribute to the neurologic manifestations of these disorders remain poorly understood. In this review we will discuss monogenic neurodevelopmental disorders that exhibit cilia deficits and summarize findings from studies exploring the role of primary cilia in the brain to shed light into how these deficits could contribute to neurologic abnormalities.
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15
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Norris JE, DeStefano LA, Schmitt LM, Pedapati EV, Erickson CA, Sweeney JA, Ethridge LE. Hemispheric Utilization of Alpha Oscillatory Dynamics as a Unique Biomarker of Neural Compensation in Females with Fragile X Syndrome. ACS Chem Neurosci 2022; 13:3389-3402. [PMID: 36411085 DOI: 10.1021/acschemneuro.2c00404] [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] [Indexed: 11/23/2022] Open
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by a trinucleotide expansion on the FMR1 gene and characterized by intellectual disability, sensory hypersensitivity, executive function difficulties, and social anxiety. Recently, efforts to define neural biomarkers for FXS have highlighted disruptions to power in the alpha frequency band; however the dynamic mechanisms supporting these findings are poorly understood. The current study aimed to explore the temporal and hemispheric dynamics supporting alpha phenotypes in FXS and their relationship with neural phenotypes related to auditory processing using electroencephalography during an auditory evoked task. Adolescents and adults (N = 36) with FXS and age/sex matched typically developing controls (N = 40) completed an auditory chirp task. Frontal alpha power in the prestimulus period was decomposed into "bursts" using percentile thresholding, then assessed for number of bursts per second (burst count) and burst length. Data were compared across left and right hemispheres to assess lateralization of neural activity. Individuals with FXS showed more differences in alpha power compared to TDC primarily in the right hemisphere. Notably, alpha hemisphere outcomes in males with FXS were driven by the number of times they entered a dynamically relevant period of alpha (burst count) rather than length of time spent in alpha. Females with FXS showed reduced burst counts but remained in sustained high alpha states for longer periods of time. Length of time spent in alpha may reflect a modulatory or compensatory mechanism capable of recovering sensory processing abilities in females with FXS resulting in a less severe clinical presentation. Right hemisphere abnormalities may impact sensory processing differences between males and females with FXS. The relationship between alpha burst length, count, sex, and hemisphere may shed light on underlying mechanisms for previously observed alpha power abnormalities in FXS and their variation by sex.
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Affiliation(s)
- Jordan E Norris
- Department of Psychology, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Lisa A DeStefano
- Division of Developmental and Behavioral Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, United States
| | - Lauren M Schmitt
- Division of Developmental and Behavioral Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, United States.,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Ernest V Pedapati
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, United States.,Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, United States.,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Craig A Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, United States.,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - John A Sweeney
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Lauren E Ethridge
- Department of Psychology, University of Oklahoma, Norman, Oklahoma 73019, United States.,Department of Pediatrics, Section on Developmental and Behavioral Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
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16
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Mirceta M, Shum N, Schmidt MHM, Pearson CE. Fragile sites, chromosomal lesions, tandem repeats, and disease. Front Genet 2022; 13:985975. [PMID: 36468036 PMCID: PMC9714581 DOI: 10.3389/fgene.2022.985975] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/02/2022] [Indexed: 09/16/2023] Open
Abstract
Expanded tandem repeat DNAs are associated with various unusual chromosomal lesions, despiralizations, multi-branched inter-chromosomal associations, and fragile sites. Fragile sites cytogenetically manifest as localized gaps or discontinuities in chromosome structure and are an important genetic, biological, and health-related phenomena. Common fragile sites (∼230), present in most individuals, are induced by aphidicolin and can be associated with cancer; of the 27 molecularly-mapped common sites, none are associated with a particular DNA sequence motif. Rare fragile sites ( ≳ 40 known), ≤ 5% of the population (may be as few as a single individual), can be associated with neurodevelopmental disease. All 10 molecularly-mapped folate-sensitive fragile sites, the largest category of rare fragile sites, are caused by gene-specific CGG/CCG tandem repeat expansions that are aberrantly CpG methylated and include FRAXA, FRAXE, FRAXF, FRA2A, FRA7A, FRA10A, FRA11A, FRA11B, FRA12A, and FRA16A. The minisatellite-associated rare fragile sites, FRA10B, FRA16B, can be induced by AT-rich DNA-ligands or nucleotide analogs. Despiralized lesions and multi-branched inter-chromosomal associations at the heterochromatic satellite repeats of chromosomes 1, 9, 16 are inducible by de-methylating agents like 5-azadeoxycytidine and can spontaneously arise in patients with ICF syndrome (Immunodeficiency Centromeric instability and Facial anomalies) with mutations in genes regulating DNA methylation. ICF individuals have hypomethylated satellites I-III, alpha-satellites, and subtelomeric repeats. Ribosomal repeats and subtelomeric D4Z4 megasatellites/macrosatellites, are associated with chromosome location, fragility, and disease. Telomere repeats can also assume fragile sites. Dietary deficiencies of folate or vitamin B12, or drug insults are associated with megaloblastic and/or pernicious anemia, that display chromosomes with fragile sites. The recent discovery of many new tandem repeat expansion loci, with varied repeat motifs, where motif lengths can range from mono-nucleotides to megabase units, could be the molecular cause of new fragile sites, or other chromosomal lesions. This review focuses on repeat-associated fragility, covering their induction, cytogenetics, epigenetics, cell type specificity, genetic instability (repeat instability, micronuclei, deletions/rearrangements, and sister chromatid exchange), unusual heritability, disease association, and penetrance. Understanding tandem repeat-associated chromosomal fragile sites provides insight to chromosome structure, genome packaging, genetic instability, and disease.
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Affiliation(s)
- Mila Mirceta
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Natalie Shum
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Monika H. M. Schmidt
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Christopher E. Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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17
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Zhang J, Fakharzadeh A, Roland C, Sagui C. RNA as a Major-Groove Ligand: RNA-RNA and RNA-DNA Triplexes Formed by GAA and UUC or TTC Sequences. ACS OMEGA 2022; 7:38728-38743. [PMID: 36340174 PMCID: PMC9631886 DOI: 10.1021/acsomega.2c04358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Friedreich's ataxia is associated with noncanonical nucleic acid structures that emerge when GAA:TTC repeats in the first intron of the FXN gene expand beyond a critical number of repeats. Specifically, the noncanonical repeats are associated with both triplexes and R-loops. Here, we present an in silico investigation of all possible triplexes that form by attaching a third RNA strand to an RNA:RNA or DNA:DNA duplex, complementing previous DNA-based triplex studies. For both new triplexes results are similar. For a pyridimine UUC+ third strand, the parallel orientation is stable while its antiparallel counterpart is unstable. For a neutral GAA third strand, the parallel conformation is stable. A protonated GA+A third strand is stable in both parallel and antiparallel orientations. We have also investigated Na+ and Mg2+ ion distributions around the triplexes. The presence of Mg2+ ions helps stabilize neutral, antiparallel GAA triplexes. These results (along with previous DNA-based studies) allow for the emergence of a complete picture of the stability and structural characteristics of triplexes based on the GAA and TTC/UUC sequences, thereby contributing to the field of trinucleotide repeats and the associated unusual structures that trigger expansion.
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18
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Scarpitti MR, Warrick JE, Yoder EL, Kearse MG. A noncanonical RNA-binding domain of the fragile X protein, FMRP, elicits translational repression independent of mRNA G-quadruplexes. J Biol Chem 2022; 298:102660. [PMID: 36328245 PMCID: PMC9712993 DOI: 10.1016/j.jbc.2022.102660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/12/2022] [Accepted: 10/21/2022] [Indexed: 11/07/2022] Open
Abstract
Loss of functional fragile X mental retardation protein (FMRP) causes fragile X syndrome, the leading form of inherited intellectual disability and the most common monogenic cause of autism spectrum disorders. FMRP is an RNA-binding protein that controls neuronal mRNA localization and translation. FMRP is thought to inhibit translation elongation after being recruited to target transcripts via binding RNA G-quadruplexes (G4s) within the coding sequence. Here, we directly test this model and report that FMRP inhibits translation independent of mRNA G4s. Furthermore, we found that the RGG box motif together with its natural C-terminal domain forms a noncanonical RNA-binding domain (ncRBD) that is essential for translational repression. The ncRBD elicits broad RNA-binding ability and binds to multiple reporter mRNAs and all four homopolymeric RNAs. Serial deletion analysis of the ncRBD identified that the regions required for mRNA binding and translational repression overlap but are not identical. Consistent with FMRP stalling elongating ribosomes and causing the accumulation of slowed 80S ribosomes, transcripts bound by FMRP via the ncRBD cosediment with heavier polysomes and were present in puromycin-resistant ribosome complexes. Together, this work identifies a ncRBD and translational repression domain that shifts our understanding of how FMRP inhibits translation independent of mRNA G4s.
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Affiliation(s)
- MaKenzie R. Scarpitti
- The Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, USA,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, USA,Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Julia E. Warrick
- The Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, USA,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, USA,Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Evelyn L. Yoder
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, USA,Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Michael G. Kearse
- The Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, USA,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, USA,Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA,For correspondence: Michael G. Kearse
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19
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Jonak CR, Pedapati EV, Schmitt LM, Assad SA, Sandhu MS, DeStefano L, Ethridge L, Razak KA, Sweeney JA, Binder DK, Erickson CA. Baclofen-associated neurophysiologic target engagement across species in fragile X syndrome. J Neurodev Disord 2022; 14:52. [PMID: 36167501 PMCID: PMC9513876 DOI: 10.1186/s11689-022-09455-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 08/03/2022] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is the most common inherited form of neurodevelopmental disability. It is often characterized, especially in males, by intellectual disability, anxiety, repetitive behavior, social communication deficits, delayed language development, and abnormal sensory processing. Recently, we identified electroencephalographic (EEG) biomarkers that are conserved between the mouse model of FXS (Fmr1 KO mice) and humans with FXS. METHODS In this report, we evaluate small molecule target engagement utilizing multielectrode array electrophysiology in the Fmr1 KO mouse and in humans with FXS. Neurophysiologic target engagement was evaluated using single doses of the GABAB selective agonist racemic baclofen (RBAC). RESULTS In Fmr1 KO mice and in humans with FXS, baclofen use was associated with suppression of elevated gamma power and increase in low-frequency power at rest. In the Fmr1 KO mice, a baclofen-associated improvement in auditory chirp synchronization was also noted. CONCLUSIONS Overall, we noted synchronized target engagement of RBAC on resting state electrophysiology, in particular the reduction of aberrant high frequency gamma activity, across species in FXS. This finding holds promise for translational medicine approaches to drug development for FXS, synchronizing treatment study across species using well-established EEG biological markers in this field. TRIAL REGISTRATION The human experiments are registered under NCT02998151.
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Affiliation(s)
- Carrie R. Jonak
- grid.266097.c0000 0001 2222 1582Division of Biomedical Sciences, School of Medicine, University of California, Riverside, USA
| | - Ernest V. Pedapati
- grid.239573.90000 0000 9025 8099Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.239573.90000 0000 9025 8099Division of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.24827.3b0000 0001 2179 9593Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Lauren M. Schmitt
- grid.239573.90000 0000 9025 8099Division of Developmental and Behavioral Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.24827.3b0000 0001 2179 9593Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Samantha A. Assad
- grid.266097.c0000 0001 2222 1582Division of Biomedical Sciences, School of Medicine, University of California, Riverside, USA
| | - Manbir S. Sandhu
- grid.266097.c0000 0001 2222 1582Division of Biomedical Sciences, School of Medicine, University of California, Riverside, USA
| | - Lisa DeStefano
- grid.239573.90000 0000 9025 8099Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.266900.b0000 0004 0447 0018Department of Psychology, University of Oklahoma, Norman, OK USA
| | - Lauren Ethridge
- grid.266900.b0000 0004 0447 0018Department of Psychology, University of Oklahoma, Norman, OK USA ,grid.266902.90000 0001 2179 3618Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
| | - Khaleel A. Razak
- grid.266097.c0000 0001 2222 1582Neuroscience Graduate Program, University of California, Riverside, USA ,grid.266097.c0000 0001 2222 1582Psychology Graduate Program, University of California, Riverside, USA
| | - John A. Sweeney
- grid.24827.3b0000 0001 2179 9593Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Devin K. Binder
- grid.266097.c0000 0001 2222 1582Division of Biomedical Sciences, School of Medicine, University of California, Riverside, USA ,grid.266097.c0000 0001 2222 1582Neuroscience Graduate Program, University of California, Riverside, USA
| | - Craig A. Erickson
- grid.239573.90000 0000 9025 8099Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.24827.3b0000 0001 2179 9593Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH USA
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20
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Abstract
Roughly 3% of the human genome consists of microsatellites or tracts of short tandem repeats (STRs). These STRs are often unstable, undergoing high-frequency expansions (increases) or contractions (decreases) in the number of repeat units. Some microsatellite instability (MSI) is seen at multiple STRs within a single cell and is associated with certain types of cancer. A second form of MSI is characterised by expansion of a single gene-specific STR and such expansions are responsible for a group of 40+ human genetic disorders known as the repeat expansion diseases (REDs). While the mismatch repair (MMR) pathway prevents genome-wide MSI, emerging evidence suggests that some MMR factors are directly involved in generating expansions in the REDs. Thus, MMR suppresses some forms of expansion while some MMR factors promote expansion in other contexts. This review will cover what is known about the paradoxical effect of MMR on microsatellite expansion in mammalian cells.
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21
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Haws SA, Simandi Z, Barnett RJ, Phillips-Cremins JE. 3D genome, on repeat: Higher-order folding principles of the heterochromatinized repetitive genome. Cell 2022; 185:2690-2707. [PMID: 35868274 DOI: 10.1016/j.cell.2022.06.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 12/16/2022]
Abstract
Nearly half of the human genome is comprised of diverse repetitive sequences ranging from satellite repeats to retrotransposable elements. Such sequences are susceptible to stepwise expansions, duplications, inversions, and recombination events which can compromise genome function. In this review, we discuss the higher-order folding mechanisms of compartmentalization and loop extrusion and how they shape, and are shaped by, heterochromatin. Using primarily mammalian model systems, we contrast mechanisms governing H3K9me3-mediated heterochromatinization of the repetitive genome and highlight emerging links between repetitive elements and chromatin folding.
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Affiliation(s)
- Spencer A Haws
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zoltan Simandi
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - R Jordan Barnett
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer E Phillips-Cremins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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22
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Jiraanont P, Manor E, Tabatadze N, Zafarullah M, Mendoza G, Melikishvili G, Tassone F. De Novo Large Deletion Leading to Fragile X Syndrome. Front Genet 2022; 13:884424. [PMID: 35646065 PMCID: PMC9130735 DOI: 10.3389/fgene.2022.884424] [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: 02/26/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
Fragile X syndrome (FXS) is the most frequent cause of X-linked inherited intellectual disabilities (ID) and the most frequent monogenic form of autism spectrum disorders. It is caused by an expansion of a CGG trinucleotide repeat located in the 5'UTR of the FMR1 gene, resulting in the absence of the fragile X mental retardation protein, FMRP. Other mechanisms such as deletions or point mutations of the FMR1 gene have been described and account for approximately 1% of individuals with FXS. Here, we report a 7-year-old boy with FXS with a de novo deletion of approximately 1.1 Mb encompassing several genes, including the FMR1 and the ASFMR1 genes, and several miRNAs, whose lack of function could result in the observed proband phenotypes. In addition, we also demonstrate that FMR4 completely overlaps with ASFMR1, and there are no sequencing differences between both transcripts (i.e., ASFMR1/FMR4 throughout the article).
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Affiliation(s)
- Poonnada Jiraanont
- Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Esther Manor
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beersheba, Israel.,Genetics Institute, Soroka Medical Center, Beersheba, Israel
| | - Nazi Tabatadze
- Department of Pediatrics, MediClub Georgia Medical Center, Tbilisi, Georgia
| | - Marwa Zafarullah
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, United States
| | - Guadalupe Mendoza
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, United States
| | - Gia Melikishvili
- Department of Pediatrics, MediClub Georgia Medical Center, Tbilisi, Georgia
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, United States.,UC Davis MIND Institute, UC Davis Health, Sacramento, CA, United States
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23
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Fakharzadeh A, Zhang J, Roland C, Sagui C. Novel eGZ-motif formed by regularly extruded guanine bases in a left-handed Z-DNA helix as a major motif behind CGG trinucleotide repeats. Nucleic Acids Res 2022; 50:4860-4876. [PMID: 35536254 PMCID: PMC9122592 DOI: 10.1093/nar/gkac339] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/19/2022] [Accepted: 05/05/2022] [Indexed: 12/19/2022] Open
Abstract
The expansion of d(CGG) trinucleotide repeats (TRs) lies behind several important neurodegenerative diseases. Atypical DNA secondary structures have been shown to trigger TR expansion: their characterization is important for a molecular understanding of TR disease. CD spectroscopy experiments in the last decade have unequivocally demonstrated that CGG runs adopt a left-handed Z-DNA conformation, whose features remain uncertain because it entails accommodating GG mismatches. In order to find this missing motif, we have carried out molecular dynamics (MD) simulations to explore all the possible Z-DNA helices that potentially form after the transition from B- to Z-DNA. Such helices combine either CpG or GpC Watson-Crick steps in Z-DNA form with GG-mismatch conformations set as either intrahelical or extrahelical; and participating in BZ or ZZ junctions or in alternately extruded conformations. Characterization of the stability and structural features (especially overall left-handedness, higher-temperature and steered MD simulations) identified two novel Z-DNA helices: the most stable one displays alternately extruded Gs, and is followed by a helix with symmetrically extruded ZZ junctions. The G-extrusion favors a seamless stacking of the Watson-Crick base pairs; extruded Gs favor syn conformations and display hydrogen-bonding and stacking interactions. Such conformations could have the potential to hijack the MMR complex, thus triggering further expansion.
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Affiliation(s)
- Ashkan Fakharzadeh
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Jiahui Zhang
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Christopher Roland
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Celeste Sagui
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
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24
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Evaluation of FMR4, FMR5 and FMR6 Expression Levels as Non-Invasive Biomarkers for the Diagnosis of Fragile X-Associated Primary Ovarian Insufficiency (FXPOI). J Clin Med 2022; 11:jcm11082186. [PMID: 35456280 PMCID: PMC9025681 DOI: 10.3390/jcm11082186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/31/2022] [Accepted: 04/08/2022] [Indexed: 02/01/2023] Open
Abstract
Female FMR1 (Fragile X mental retardation 1) premutation carriers are at risk for developing fragile X-associated primary ovarian insufficiency (FXPOI), a condition characterized by amenorrhea before age 40 years. Not all women with a FMR1 premutation suffer from primary ovarian insufficiency and nowadays there are no molecular or other biomarkers that can help predict the occurrence of FXPOI. Long non-coding RNAs (lncRNAs) comprise a group of regulatory transcripts which have versatile molecular functions, making them important regulators in all aspects of gene expression. In recent medical studies, lncRNAs have been described as potential diagnostic biomarkers in many diseases. The present study was designed to determine the expression profile of three lncRNAs derived from the FMR1 locus, FMR4, FMR5 and FMR6, in female FMR1 premutation carriers in order: (i) to determine a possible role in the pathogenesis of FXPOI and (ii) to investigate whether they could serve as a biomarker for the diagnosis of FXPOI. FMR4, FMR5 and FMR6 transcripts levels were evaluated in total RNA extracted from peripheral blood by digital droplet PCR and compared between FMR1 premutation carriers with FXPOI and without FXPOI. The diagnostic value of lncRNAs was evaluated by receiver operating characteristic (ROC) analysis. Results revealed a significant association between FXPOI and high expression levels of FMR4. No association was obtained for FMR5 or FMR6. ROC curve analysis revealed that FMR4 can distinguish FMR1 premutation carrier with FXPOI with a diagnostic power of 0.67. These findings suggest a potential role of FMR4 as a possible biomarker for FXPOI.
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25
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Nelson DL, Clark J, Garber K, Glover T, Hassold T, Jin P, Orr HT, Sherman SL, Zoghbi H, Warren KL. Stephen T. Warren, Ph.D. (1953-2021): A remembrance. Am J Hum Genet 2022; 109:3-11. [PMID: 34995503 DOI: 10.1016/j.ajhg.2021.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- David L Nelson
- Jan and Dan Duncan Neurological Research Institute, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Janelle Clark
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kathryn Garber
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Thomas Glover
- Departments of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Terry Hassold
- School of Molecular Biosciences, Washington State University, Pullman, WA 99163, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Harry T Orr
- Institute of Translational Neuroscience, Department of Laboratory Medicine and Pathology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
| | - Stephanie L Sherman
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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26
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Gall-Duncan T, Sato N, Yuen RKC, Pearson CE. Advancing genomic technologies and clinical awareness accelerates discovery of disease-associated tandem repeat sequences. Genome Res 2022; 32:1-27. [PMID: 34965938 PMCID: PMC8744678 DOI: 10.1101/gr.269530.120] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/29/2021] [Indexed: 11/25/2022]
Abstract
Expansions of gene-specific DNA tandem repeats (TRs), first described in 1991 as a disease-causing mutation in humans, are now known to cause >60 phenotypes, not just disease, and not only in humans. TRs are a common form of genetic variation with biological consequences, observed, so far, in humans, dogs, plants, oysters, and yeast. Repeat diseases show atypical clinical features, genetic anticipation, and multiple and partially penetrant phenotypes among family members. Discovery of disease-causing repeat expansion loci accelerated through technological advances in DNA sequencing and computational analyses. Between 2019 and 2021, 17 new disease-causing TR expansions were reported, totaling 63 TR loci (>69 diseases), with a likelihood of more discoveries, and in more organisms. Recent and historical lessons reveal that properly assessed clinical presentations, coupled with genetic and biological awareness, can guide discovery of disease-causing unstable TRs. We highlight critical but underrecognized aspects of TR mutations. Repeat motifs may not be present in current reference genomes but will be in forthcoming gapless long-read references. Repeat motif size can be a single nucleotide to kilobases/unit. At a given locus, repeat motif sequence purity can vary with consequence. Pathogenic repeats can be "insertions" within nonpathogenic TRs. Expansions, contractions, and somatic length variations of TRs can have clinical/biological consequences. TR instabilities occur in humans and other organisms. TRs can be epigenetically modified and/or chromosomal fragile sites. We discuss the expanding field of disease-associated TR instabilities, highlighting prospects, clinical and genetic clues, tools, and challenges for further discoveries of disease-causing TR instabilities and understanding their biological and pathological impacts-a vista that is about to expand.
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Affiliation(s)
- Terence Gall-Duncan
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Nozomu Sato
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
| | - Ryan K C Yuen
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christopher E Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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27
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Hurley MJ, Deacon RMJ, Chan AWE, Baker D, Selwood DL, Cogram P. Reversal of behavioural phenotype by the cannabinoid-like compound VSN16R in fragile X syndrome mice. Brain 2021; 145:76-82. [PMID: 34196695 DOI: 10.1093/brain/awab246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/27/2021] [Accepted: 06/06/2021] [Indexed: 11/14/2022] Open
Abstract
Fragile X Syndrome is the most common inherited intellectual disability and mono-genetic cause of autism spectrum disorder. It is a neurodevelopmental condition occurring due to a CGG trinucleotide expansion in the FMR1 gene. Polymorphisms and variants in large-conductance calcium-activated potassium channels are increasingly linked to intellectual disability and loss of FMR protein caused reduced large-conductance calcium-activated potassium channel activity leading to abnormalities in synapse function. Using the cannabinoid-like large-conductance calcium-activated potassium channel activator VSN16R we rescued behavioural deficits such as repetitive behaviour, hippocampal dependent tests of daily living, hyperactivity and memory in a mouse model of fragile X syndrome. VSN16R has been shown to be safe in a phase 1 study in healthy volunteers and in a phase 2 study in people with Multiple Sclerosis with high oral bioavailability and no serious adverse effects reported. VSN16R could therefore be directly utilised in a fragile X syndrome clinical study. Moreover, VSN16R showed no evidence of tolerance, which strongly suggests that chronic VSN16R may have great therapeutic value for fragile X syndrome and autism spectrum disorder. This study provides new insight into the pathophysiology of fragile X syndrome and identifies a new pathway for drug intervention for this debilitating disorder.
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Affiliation(s)
- Michael J Hurley
- Neuroimmunology, Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO16 6YD, UK.,Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London NW3 2PF, United Kingdom
| | - Robert M J Deacon
- Biomedicine Division, Fraunhofer Research Institute, Center for System Biotechnology, Santiago, Chile
| | - A W Edith Chan
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - David Baker
- Centre for Neuroscience and Trauma, Blizard Institute, Queen Mary University of London, London E1 2AT, UK
| | - David L Selwood
- Drug Discovery, UCL Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Patricia Cogram
- Biomedicine Division, Fraunhofer Research Institute, Center for System Biotechnology, Santiago, Chile.,Department of Ecological Sciences, Institute of Ecology and Biodiversity, Faculty of Sciences, Universidad de Chile, Santiago, Chile
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28
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Pan X, Zhao J, Zhou Z, Chen J, Yang Z, Wu Y, Bai M, Jiao Y, Yang Y, Hu X, Cheng T, Lu Q, Wang B, Li CL, Lu YJ, Diao L, Zhong YQ, Pan J, Zhu J, Xiao HS, Qiu ZL, Li J, Wang Z, Hui J, Bao L, Zhang X. 5'-UTR SNP of FGF13 causes translational defect and intellectual disability. eLife 2021; 10:63021. [PMID: 34184986 PMCID: PMC8241442 DOI: 10.7554/elife.63021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 06/17/2021] [Indexed: 12/15/2022] Open
Abstract
The congenital intellectual disability (ID)-causing gene mutations remain largely unclear, although many genetic variations might relate to ID. We screened gene mutations in Chinese Han children suffering from severe ID and found a single-nucleotide polymorphism (SNP) in the 5′-untranslated region (5′-UTR) of fibroblast growth factor 13 (FGF13) mRNA (NM_001139500.1:c.-32c>G) shared by three male children. In both HEK293 cells and patient-derived induced pluripotent stem cells, this SNP reduced the translation of FGF13, which stabilizes microtubules in developing neurons. Mice carrying the homologous point mutation in 5′-UTR of Fgf13 showed delayed neuronal migration during cortical development, and weakened learning and memory. Furthermore, this SNP reduced the interaction between FGF13 5′-UTR and polypyrimidine-tract-binding protein 2 (PTBP2), which was required for FGF13 translation in cortical neurons. Thus, this 5′-UTR SNP of FGF13 interferes with the translational process of FGF13 and causes deficits in brain development and cognitive functions.
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Affiliation(s)
- Xingyu Pan
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China.,Shanghai Brain-Intelligence Project Center, Shanghai, China
| | - Jingrong Zhao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhiying Zhou
- Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Jijun Chen
- Shanghai Brain-Intelligence Project Center, Shanghai, China
| | - Zhenxing Yang
- Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Yuxuan Wu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Meizhu Bai
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Yang Jiao
- School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Yun Yang
- CAS-MPG Partner Institute for Computational Biology, Chinese Academy of Sciences, Shanghai, China
| | - Xuye Hu
- Shanghai Brain-Intelligence Project Center, Shanghai, China.,Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Tianling Cheng
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Qianyun Lu
- CAS-MPG Partner Institute for Computational Biology, Chinese Academy of Sciences, Shanghai, China
| | - Bin Wang
- Shanghai Brain-Intelligence Project Center, Shanghai, China.,State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Chang-Lin Li
- Shanghai Brain-Intelligence Project Center, Shanghai, China.,Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Ying-Jin Lu
- Shanghai Brain-Intelligence Project Center, Shanghai, China.,Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Lei Diao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Yan-Qing Zhong
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing Pan
- Shanghai Brain-Intelligence Project Center, Shanghai, China
| | - Jianmin Zhu
- Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Hua-Sheng Xiao
- Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China
| | - Zi-Long Qiu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jinsong Li
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Zefeng Wang
- CAS-MPG Partner Institute for Computational Biology, Chinese Academy of Sciences, Shanghai, China
| | - Jingyi Hui
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Lan Bao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.,School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Xu Zhang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China.,Shanghai Brain-Intelligence Project Center, Shanghai, China.,Shanghai Clinical Center, Chinese Academy of Sciences/Xu-Hui Central Hospital, Shanghai, China.,School of Life Science and Technology, Shanghai Tech University, Shanghai, China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, China
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29
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Haify SN, Buijsen RAM, Verwegen L, Severijnen LAWFM, de Boer H, Boumeester V, Monshouwer R, Yang WY, Cameron MD, Willemsen R, Disney MD, Hukema RK. Small molecule 1a reduces FMRpolyG-mediated toxicity in in vitro and in vivo models for FMR1 premutation. Hum Mol Genet 2021; 30:1632-1648. [PMID: 34077515 PMCID: PMC8369842 DOI: 10.1093/hmg/ddab143] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 12/15/2022] Open
Abstract
Fragile X-associated tremor and ataxia syndrome (FXTAS) is a late-onset, progressive neurodegenerative disorder characterized by tremors, ataxia and neuropsychological problems. This disease is quite common in the general population with approximately 20 million carriers worldwide. The risk of developing FXTAS increases dramatically with age, with about 45% of male carriers over the age of 50 being affected. FXTAS is caused by a CGG-repeat expansion (CGGexp) in the fragile X mental retardation 1 (FMR1) gene. CGGexp RNA is translated into the FMRpolyG protein by a mechanism called RAN translation. Although both gene and pathogenic trigger are known, no therapeutic interventions are available at this moment. Here, we present, for the first time, primary hippocampal neurons derived from the ubiquitous inducible mouse model which is used as a screening tool for targeted interventions. A promising candidate is the repeat binding, RAN translation blocking, small molecule 1a. Small molecule 1a shields the disease-causing CGGexp from being translated into the toxic FMRpolyG protein. Primary hippocampal neurons formed FMRpolyG-positive inclusions, and upon treatment with 1a, the numbers of FMRpolyG-positive inclusions are reduced. We also describe for the first time the formation of FMRpolyG-positive inclusions in the liver of this mouse model. Treatment with 1a reduced the insoluble FMRpolyG protein fraction in the liver but not the number of inclusions. Moreover, 1a treatment had a reducing effect on the number of Rad23b-positive inclusions and insoluble Rad23b protein levels. These data suggest that targeted small molecule therapy is effective in an FXTAS mouse model and has the potential to treat CGGexp-mediated diseases, including FXTAS.
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Affiliation(s)
- Saif N Haify
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Ronald A M Buijsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Human Genetics, LUMC, Leiden, the Netherlands
| | - Lucas Verwegen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Cell Biology, Erasmus MC, Rotterdam, the Netherlands
| | | | - Helen de Boer
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | | | - Roos Monshouwer
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Wong Y Yang
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Michael D Cameron
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands
| | - Matthew D Disney
- Department of Chemistry, Scripps Research Institute, Florida, the United States
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, Rotterdam, the Netherlands.,Department of Health Care Studies, Rotterdam University of Applied Sciences, Rotterdam, the Netherlands
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30
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Usdin K, Rodriguez-Revenga L, Willemsen R, Hukema R, Giulivi C. Editorial: Proceedings of the "Fourth International Conference of the FMR1 Premutation: Basic Mechanisms, Clinical Involvement and Therapy". Front Mol Biosci 2021; 8:671875. [PMID: 33987206 PMCID: PMC8111284 DOI: 10.3389/fmolb.2021.671875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 03/29/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Karen Usdin
- Gene Structure and Disease Section, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Laia Rodriguez-Revenga
- Biochemistry and Molecular Genetics Department, Hospital Clinic of Barcelona and CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Renate Hukema
- Department of Clinical Genetics, Erasmus MC, Rotterdam, Netherlands
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States.,The MIND Institute, University of California, Davis Medical Center, Sacramento, CA, United States
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31
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Jonak CR, Sandhu MS, Assad SA, Barbosa JA, Makhija M, Binder DK. The PDE10A Inhibitor TAK-063 Reverses Sound-Evoked EEG Abnormalities in a Mouse Model of Fragile X Syndrome. Neurotherapeutics 2021; 18:1175-1187. [PMID: 33594533 PMCID: PMC8423959 DOI: 10.1007/s13311-021-01005-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2021] [Indexed: 10/22/2022] Open
Abstract
Fragile X syndrome (FXS) is a genetic neurodevelopmental syndrome characterized by increased anxiety, repetitive behaviors, social communication deficits, delayed language development, and abnormal sensory processing. Recently, we have identified electroencephalographic (EEG) biomarkers that are conserved between the mouse model of FXS (Fmr1 KO mice) and humans with FXS. In this study, we test a specific candidate mechanism for engagement of multielectrode array (MEA) EEG biomarkers in the FXS mouse model. We administered TAK-063, a potent, selective, and orally active phosphodiesterase 10A (PDE10A) inhibitor, to Fmr1 KO mice, and examined its effects on MEA EEG biomarkers. We demonstrate significant dose-related amelioration of inter-trial phase coherence (ITPC) to temporally modulated auditory stimuli by TAK-063 in Fmr1 KO mice. Our data suggest that TAK-063 improves cortical auditory stimulus processing in Fmr1 KO mice, without significantly depressing baseline EEG power or causing any noticeable sedation or behavioral side effects. Thus, the PDE10A inhibitor TAK-063 has salutary effects on normalizing EEG biomarkers in a mouse model of FXS and should be pursued in further translational treatment development.
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Affiliation(s)
- Carrie R Jonak
- Division of Biomedical Sciences, School of Medicine, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Manbir S Sandhu
- Division of Biomedical Sciences, School of Medicine, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Samantha A Assad
- Division of Biomedical Sciences, School of Medicine, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Jacqueline A Barbosa
- Division of Biomedical Sciences, School of Medicine, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Mahindra Makhija
- Takeda International - UK, Rare Diseases Therapeutic Area Unit, 1 Kingdom Street, London, W2 6BD, UK
| | - Devin K Binder
- Division of Biomedical Sciences, School of Medicine, University of California, 900 University Avenue, Riverside, CA, 92521, USA.
- Neuroscience Graduate Program, University of California, Riverside, CA, USA.
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32
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Monckton DG. The Contribution of Somatic Expansion of the CAG Repeat to Symptomatic Development in Huntington's Disease: A Historical Perspective. J Huntingtons Dis 2021; 10:7-33. [PMID: 33579863 PMCID: PMC7990401 DOI: 10.3233/jhd-200429] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The discovery in the early 1990s of the expansion of unstable simple sequence repeats as the causative mutation for a number of inherited human disorders, including Huntington’s disease (HD), opened up a new era of human genetics and provided explanations for some old problems. In particular, an inverse association between the number of repeats inherited and age at onset, and unprecedented levels of germline instability, biased toward further expansion, provided an explanation for the wide symptomatic variability and anticipation observed in HD and many of these disorders. The repeats were also revealed to be somatically unstable in a process that is expansion-biased, age-dependent and tissue-specific, features that are now increasingly recognised as contributory to the age-dependence, progressive nature and tissue specificity of the symptoms of HD, and at least some related disorders. With much of the data deriving from affected individuals, and model systems, somatic expansions have been revealed to arise in a cell division-independent manner in critical target tissues via a mechanism involving key components of the DNA mismatch repair pathway. These insights have opened new approaches to thinking about how the disease could be treated by suppressing somatic expansion and revealed novel protein targets for intervention. Exciting times lie ahead in turning these insights into novel therapies for HD and related disorders.
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Affiliation(s)
- Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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33
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Nguyen U, Tinsley B, Sen Y, Stein J, Palacios Y, Ceballos A, Welch C, Nzenkue K, Penn A, Murphy L, Leodones K, Casiquin J, Ivory I, Ghenta K, Danziger K, Widman E, Newman J, Triplehorn M, Hindi Z, Mulligan K. Exposure to bisphenol A differentially impacts neurodevelopment and behavior in Drosophila melanogaster from distinct genetic backgrounds. Neurotoxicology 2020; 82:146-157. [PMID: 33309840 DOI: 10.1016/j.neuro.2020.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/30/2020] [Accepted: 12/06/2020] [Indexed: 12/13/2022]
Abstract
Bisphenol A (BPA) is a ubiquitous environmental chemical that has been linked to behavioral differences in children and shown to impact critical neurodevelopmental processes in animal models. Though data is emerging, we still have an incomplete picture of how BPA disrupts neurodevelopment; in particular, how its impacts may vary across different genetic backgrounds. Given the genetic tractability of Drosophila melanogaster, they present a valuable model to address this question. Fruit flies are increasingly being used for assessment of neurotoxicants because of their relatively simple brain structure and variety of measurable behaviors. Here we investigated the neurodevelopmental impacts of BPA across two genetic strains of Drosophila-w1118 (control) and the Fragile X Syndrome (FXS) model-by examining both behavioral and neuronal phenotypes. We show that BPA induces hyperactivity in larvae, increases repetitive grooming behavior in adults, reduces courtship behavior, impairs axon guidance in the mushroom body, and disrupts neural stem cell development in the w1118 genetic strain. Remarkably, for every behavioral and neuronal phenotype examined, the impact of BPA in FXS flies was either insignificant or contrasted with the phenotypes observed in the w1118 strain. This data indicates that the neurodevelopmental impacts of BPA can vary widely depending on genetic background and suggests BPA may elicit a gene-environment interaction with Drosophila fragile X mental retardation 1 (dFmr1)-the ortholog of human FMR1, which causes Fragile X Syndrome and is associated with autism spectrum disorder.
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Affiliation(s)
- U Nguyen
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - B Tinsley
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - Y Sen
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - J Stein
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - Y Palacios
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - A Ceballos
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - C Welch
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - K Nzenkue
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - A Penn
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - L Murphy
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - K Leodones
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - J Casiquin
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - I Ivory
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - K Ghenta
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - K Danziger
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - E Widman
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - J Newman
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - M Triplehorn
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - Z Hindi
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States
| | - K Mulligan
- Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA, 95819, United States.
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34
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Zhang J, Fakharzadeh A, Pan F, Roland C, Sagui C. Atypical structures of GAA/TTC trinucleotide repeats underlying Friedreich's ataxia: DNA triplexes and RNA/DNA hybrids. Nucleic Acids Res 2020; 48:9899-9917. [PMID: 32821947 PMCID: PMC7515735 DOI: 10.1093/nar/gkaa665] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/27/2020] [Accepted: 08/04/2020] [Indexed: 11/13/2022] Open
Abstract
Expansion of the GAA/TTC repeats in the first intron of the FXN gene causes Friedreich's ataxia. Non-canonical structures are linked to this expansion. DNA triplexes and R-loops are believed to arrest transcription, which results in frataxin deficiency and eventual neurodegeneration. We present a systematic in silico characterization of the possible DNA triplexes that could be assembled with GAA and TTC strands; the two hybrid duplexes [r(GAA):d(TTC) and d(GAA):r(UUC)] in an R-loop; and three hybrid triplexes that could form during bidirectional transcription when the non-template DNA strand bonds with the hybrid duplex (collapsed R-loops, where the two DNA strands remain antiparallel). For both Y·R:Y and R·R:Y DNA triplexes, the parallel third strand orientation is more stable; both parallel and antiparallel protonated d(GA+A)·d(GAA):d(TTC) triplexes are stable. Apparent contradictions in the literature about the R·R:Y triplex stability is probably due to lack of molecular resolution, since shifting the third strand by a single nucleotide alters the stability ranking. In the collapsed R-loops, antiparallel d(TTC+)·d(GAA):r(UUC) is unstable, while parallel d(GAA)·r(GAA):d(TTC) and d(GA+A)·r(GAA):d(TTC) are stable. In addition to providing new structural perspectives for specific therapeutic aims, our results contribute to a systematic structural basis for the emerging field of quantitative R-loop biology.
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Affiliation(s)
- Jiahui Zhang
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Ashkan Fakharzadeh
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Feng Pan
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.,Department of Statistics, Florida State University, Tallahassee, FL 32306, USA
| | - Christopher Roland
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Celeste Sagui
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
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35
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Hartley T, Lemire G, Kernohan KD, Howley HE, Adams DR, Boycott KM. New Diagnostic Approaches for Undiagnosed Rare Genetic Diseases. Annu Rev Genomics Hum Genet 2020; 21:351-372. [DOI: 10.1146/annurev-genom-083118-015345] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Accurate diagnosis is the cornerstone of medicine; it is essential for informed care and promoting patient and family well-being. However, families with a rare genetic disease (RGD) often spend more than five years on a diagnostic odyssey of specialist visits and invasive testing that is lengthy, costly, and often futile, as 50% of patients do not receive a molecular diagnosis. The current diagnostic paradigm is not well designed for RGDs, especially for patients who remain undiagnosed after the initial set of investigations, and thus requires an expansion of approaches in the clinic. Leveraging opportunities to participate in research programs that utilize new technologies to understand RGDs is an important path forward for patients seeking a diagnosis. Given recent advancements in such technologies and international initiatives, the prospect of identifying a molecular diagnosis for all patients with RGDs has never been so attainable, but achieving this goal will require global cooperation at an unprecedented scale.
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Affiliation(s)
- Taila Hartley
- CHEO Research Institute, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada;, , , ,
| | - Gabrielle Lemire
- CHEO Research Institute, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada;, , , ,
- Department of Genetics, CHEO, Ottawa, Ontario K1H 8L1, Canada
| | - Kristin D. Kernohan
- CHEO Research Institute, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada;, , , ,
- Newborn Screening Ontario, CHEO, Ottawa, Ontario K1H 9M8, Canada
| | - Heather E. Howley
- CHEO Research Institute, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada;, , , ,
| | - David R. Adams
- Office of the Clinical Director, National Human Genome Research Institute and Undiagnosed Diseases Program, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kym M. Boycott
- CHEO Research Institute, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada;, , , ,
- Department of Genetics, CHEO, Ottawa, Ontario K1H 8L1, Canada
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36
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Lovelace JW, Ethell IM, Binder DK, Razak KA. Minocycline Treatment Reverses Sound Evoked EEG Abnormalities in a Mouse Model of Fragile X Syndrome. Front Neurosci 2020; 14:771. [PMID: 32848552 PMCID: PMC7417521 DOI: 10.3389/fnins.2020.00771] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/30/2020] [Indexed: 01/19/2023] Open
Abstract
Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability. Many symptoms of FXS overlap with those in autism including repetitive behaviors, language delays, anxiety, social impairments and sensory processing deficits. Electroencephalogram (EEG) recordings from humans with FXS and an animal model, the Fmr1 knockout (KO) mouse, show remarkably similar phenotypes suggesting that EEG phenotypes can serve as biomarkers for developing treatments. This includes enhanced resting gamma band power and sound evoked total power, and reduced fidelity of temporal processing and habituation of responses to repeated sounds. Given the therapeutic potential of the antibiotic minocycline in humans with FXS and animal models, it is important to determine sensitivity and selectivity of EEG responses to minocycline. Therefore, in this study, we examined if a 10-day treatment of adult Fmr1 KO mice with minocycline (oral gavage, 30 mg/kg per day) would reduce EEG abnormalities. We tested if minocycline treatment has specific effects based on the EEG measurement type (e.g., resting versus sound-evoked) from the frontal and auditory cortex of the Fmr1 KO mice. We show increased resting EEG gamma power and reduced phase locking to time varying stimuli as well as the 40 Hz auditory steady state response in the Fmr1 KO mice in the pre-drug condition. Minocycline treatment increased gamma band phase locking in response to auditory stimuli, and reduced sound-evoked power of auditory event related potentials (ERP) in Fmr1 KO mice compared to vehicle treatment. Minocycline reduced resting EEG gamma power in Fmr1 KO mice, but this effect was similar to vehicle treatment. We also report frequency band-specific effects on EEG responses. Taken together, these data indicate that sound-evoked EEG responses may serve as more sensitive measures, compared to resting EEG measures, to isolate minocycline effects from placebo in humans with FXS. Given the use of minocycline and EEG recordings in a number of neurodegenerative and neurodevelopmental conditions, these findings may be more broadly applicable in translational neuroscience.
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Affiliation(s)
- Jonathan W Lovelace
- Department of Psychology and Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States
| | - Iryna M Ethell
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Devin K Binder
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Khaleel A Razak
- Department of Psychology and Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States.,Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, United States
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37
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Villate O, Ibarluzea N, Maortua H, de la Hoz AB, Rodriguez-Revenga L, Izquierdo-Álvarez S, Tejada MI. Effect of AGG Interruptions on FMR1 Maternal Transmissions. Front Mol Biosci 2020; 7:135. [PMID: 32766278 PMCID: PMC7381193 DOI: 10.3389/fmolb.2020.00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/05/2020] [Indexed: 12/30/2022] Open
Abstract
There are four classes of CGG repeat alleles in the FMR1 gene: normal alleles have up to 44 repeats; patients with Fragile X Syndrome have more than 200 repeats; those between 55 and 200 CGGs are considered FMR1 premutation alleles, because they are associated with maternal expansions of the number of CGGs in the next generation and finally, alleles between 45 and 54 CGGs are called intermediate or gray zone alleles. In these last categories, the stability depends on the presence of AGG interruptions, which usually occurs between 9 and 10 CGGs. In this context, we have studied retrospectively 66 women with CGG repeats between 45 and 65, and their offspring. In total 87 transmissions were analyzed with triplet repeat primed PCR using AmplideX® FMR1 PCR (Asuragen, Austin, TX, USA) and we found that alleles with CGG repeats between 45 and 58 do not expand in the next generation except two cases with 56 repeats and 0 AGG interruptions. Furthermore, we have found four females with alleles with more than 59 CGG repeats and 2 AGG interruptions that do not expand either. Alleles from 56 CGG repeats without AGGs expand in all cases. In light of these results and those of the literature, we consider that the risk of unstable transmissions should be based on the presence or absence of AGG interruptions and not on the classical cutoffs which define each category of FMR1 alleles. The application of these results in the genetic and reproductive counseling is essential and AGG interruptions should always be studied.
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Affiliation(s)
- Olatz Villate
- Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.,Genetics Service, Cruces University Hospital, Osakidetza Basque Health Service, Barakaldo, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Nekane Ibarluzea
- Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Hiart Maortua
- Genetics Service, Cruces University Hospital, Osakidetza Basque Health Service, Barakaldo, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Ana Belén de la Hoz
- Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Laia Rodriguez-Revenga
- Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Biochemistry and Molecular Genetics Department, Hospital Clinic, Barcelona, Spain.,Institut d'Investigació Biomèdica August Pi i Sunyer IDIBAPS, Barcelona, Spain
| | - Silvia Izquierdo-Álvarez
- Genetics Department of Clinical Biochemistry, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - María Isabel Tejada
- Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.,Genetics Service, Cruces University Hospital, Osakidetza Basque Health Service, Barakaldo, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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38
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Are ovarian response and pregnancy rates similar in selected FMR1 premutated and mutated patients undergoing preimplantation genetic testing? J Assist Reprod Genet 2020; 37:1675-1683. [PMID: 32483686 DOI: 10.1007/s10815-020-01809-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/01/2020] [Indexed: 10/24/2022] Open
Abstract
PURPOSE To assess if the ovarian response of FMR1 premutated women undergoing preimplantation genetic testing (PGT) for Fragile X syndrome is lower compared with fully mutated patients, due to their frequent premature ovarian failure. METHODS In a retrospective cohort study from January 2009 to March 2019, we compared PGT outcomes in 18 FMR1 premutated women and 12 fully mutated women and aimed to identify predictive factors of stimulation outcomes. RESULTS Eighty-six IVF/PGT-M cycles for FMR1 PGT were analyzed. Premutation and full mutation patients were comparable in terms of age, body mass index (BMI), basal FSH, antral follicular count, and cycle length. However, premutation carriers had significantly lower AMH (1.9 versus 4.0 ng/mL, p = 0.0167). Premutated patients required higher doses of FSH (2740 versus 1944 IU, p = 0.0069) but had similar numbers of metaphase II oocytes (7.1 versus 6.6, p = 0.871) and embryos (5.6 versus 4.9, p = 0. 554). Pregnancy rates (37.1% versus 13.3%, p = 0.1076) were not statistically different in both groups. CONCLUSION In spite of lower ovarian reserve and thanks to an increased total dose of FSH, FMR1 premutated selected patients seem to have similar ovarian response as fully mutated patients. Neither the number of CGG repeats in FMR1 gene nor FMR1 mutation status was good predictors of the number of retrieved oocytes.
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39
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Razak KA, Dominick KC, Erickson CA. Developmental studies in fragile X syndrome. J Neurodev Disord 2020; 12:13. [PMID: 32359368 PMCID: PMC7196229 DOI: 10.1186/s11689-020-09310-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 02/13/2020] [Indexed: 01/27/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common single gene cause of autism and intellectual disabilities. Humans with FXS exhibit increased anxiety, sensory hypersensitivity, seizures, repetitive behaviors, cognitive inflexibility, and social behavioral impairments. The main purpose of this review is to summarize developmental studies of FXS in humans and in the mouse model, the Fmr1 knockout mouse. The literature presents considerable evidence that a number of early developmental deficits can be identified and that these early deficits chart a course of altered developmental experience leading to symptoms well characterized in adolescents and adults. Nevertheless, a number of critical issues remain unclear or untested regarding the development of symptomology and underlying mechanisms. First, what is the role of FMRP, the protein product of Fmr1 gene, during different developmental ages? Does the absence of FMRP during early development lead to irreversible changes, or could reintroduction of FMRP or therapeutics aimed at FMRP-interacting proteins/pathways hold promise when provided in adults? These questions have implications for clinical trial designs in terms of optimal treatment windows, but few studies have systematically addressed these issues in preclinical and clinical work. Published studies also point to complex trajectories of symptom development, leading to the conclusion that single developmental time point studies are unlikely to disambiguate effects of genetic mutation from effects of altered developmental experience and compensatory plasticity. We conclude by suggesting a number of experiments needed to address these major gaps in the field.
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Affiliation(s)
- Khaleel A Razak
- Department of Psychology and Graduate Neuroscience Program, University of California, Riverside, USA
| | - Kelli C Dominick
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA.,Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH, 45229, USA
| | - Craig A Erickson
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA. .,Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH, 45229, USA.
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40
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Khristich AN, Mirkin SM. On the wrong DNA track: Molecular mechanisms of repeat-mediated genome instability. J Biol Chem 2020; 295:4134-4170. [PMID: 32060097 PMCID: PMC7105313 DOI: 10.1074/jbc.rev119.007678] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Expansions of simple tandem repeats are responsible for almost 50 human diseases, the majority of which are severe, degenerative, and not currently treatable or preventable. In this review, we first describe the molecular mechanisms of repeat-induced toxicity, which is the connecting link between repeat expansions and pathology. We then survey alternative DNA structures that are formed by expandable repeats and review the evidence that formation of these structures is at the core of repeat instability. Next, we describe the consequences of the presence of long structure-forming repeats at the molecular level: somatic and intergenerational instability, fragility, and repeat-induced mutagenesis. We discuss the reasons for gender bias in intergenerational repeat instability and the tissue specificity of somatic repeat instability. We also review the known pathways in which DNA replication, transcription, DNA repair, and chromatin state interact and thereby promote repeat instability. We then discuss possible reasons for the persistence of disease-causing DNA repeats in the genome. We describe evidence suggesting that these repeats are a payoff for the advantages of having abundant simple-sequence repeats for eukaryotic genome function and evolvability. Finally, we discuss two unresolved fundamental questions: (i) why does repeat behavior differ between model systems and human pedigrees, and (ii) can we use current knowledge on repeat instability mechanisms to cure repeat expansion diseases?
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Affiliation(s)
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, Massachusetts 02155.
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41
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Jonak CR, Lovelace JW, Ethell IM, Razak KA, Binder DK. Multielectrode array analysis of EEG biomarkers in a mouse model of Fragile X Syndrome. Neurobiol Dis 2020; 138:104794. [PMID: 32036032 DOI: 10.1016/j.nbd.2020.104794] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/27/2020] [Accepted: 02/05/2020] [Indexed: 02/06/2023] Open
Abstract
Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability with symptoms that include increased anxiety and social and sensory processing deficits. Recent EEG studies in humans with FXS have identified neural oscillation deficits that include increased resting state gamma power, increased amplitude of auditory evoked potentials, and reduced inter-trial phase coherence of sound-evoked gamma oscillations. Identification of comparable EEG biomarkers in mouse models of FXS could facilitate the pre-clinical to clinical therapeutic pipeline. However, while human EEG studies have involved 128-channel scalp EEG acquisition, no mouse studies have been performed with more than three EEG channels. In the current study, we employed a recently developed 30-channel mouse multielectrode array (MEA) system to record and analyze resting and stimulus-evoked EEG signals in WT vs. Fmr1 KO mice. Using this system, we now report robust MEA-derived phenotypes including higher resting EEG power, altered event-related potentials (ERPs) and reduced inter-trial phase coherence to auditory chirp stimuli in Fmr1 KO mice that are remarkably similar to those reported in humans with FXS. We propose that the MEA system can be used for: (i) derivation of higher-level EEG parameters; (ii) EEG biomarkers for drug testing; and (ii) mechanistic studies of FXS pathophysiology.
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Affiliation(s)
- Carrie R Jonak
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States of America
| | - Jonathan W Lovelace
- Department of Psychology, University of California, Riverside, United States of America
| | - Iryna M Ethell
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States of America; Neuroscience Graduate Program, University of California, Riverside, United States of America
| | - Khaleel A Razak
- Neuroscience Graduate Program, University of California, Riverside, United States of America; Department of Psychology, University of California, Riverside, United States of America
| | - Devin K Binder
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States of America; Neuroscience Graduate Program, University of California, Riverside, United States of America.
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42
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Loss of fragile X mental retardation protein precedes Lewy pathology in Parkinson's disease. Acta Neuropathol 2020; 139:319-345. [PMID: 31768670 DOI: 10.1007/s00401-019-02099-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/10/2019] [Accepted: 11/11/2019] [Indexed: 12/11/2022]
Abstract
Parkinson's disease (PD) is the most common neurodegenerative movement disorder and is characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) and the gradual appearance of α-synuclein (α-syn)-containing neuronal protein aggregates. Although the exact mechanism of α-syn-mediated cell death remains elusive, recent research suggests that α-syn-induced alterations in neuronal excitability contribute to cell death in PD. Because the fragile X mental retardation protein (FMRP) controls the expression and function of numerous neuronal genes related to neuronal excitability and synaptic function, we here investigated the role of FMRP in α-syn-associated pathological changes in cell culture and mouse models of PD as well as in post-mortem human brain tissue from PD patients. We found FMRP to be decreased in cultured DA neurons and in the mouse brain in response to α-syn overexpression. FMRP was, furthermore, lost in the SNc of PD patients and in patients with early stages of incidental Lewy body disease (iLBD). Unlike fragile X syndrome (FXS), FMR1 expression in response to α-syn was regulated by a mechanism involving Protein Kinase C (PKC) and cAMP response element-binding protein (CREB). Reminiscent of FXS neurons, α-syn-overexpressing cells exhibited an increase in membrane N-type calcium channels, increased phosphorylation of ERK1/2, eIF4E and S6, increased overall protein synthesis, and increased expression of Matrix Metalloproteinase 9 (MMP9). FMRP affected neuronal function in a PD animal model, because FMRP-KO mice were resistant to the effect of α-syn on striatal dopamine release. In summary, our results thus reveal a new role of FMRP in PD and support the examination of FMRP-regulated genes in PD disease progression.
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43
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Wen TH, Afroz S, Reinhard SM, Palacios AR, Tapia K, Binder DK, Razak KA, Ethell IM. Genetic Reduction of Matrix Metalloproteinase-9 Promotes Formation of Perineuronal Nets Around Parvalbumin-Expressing Interneurons and Normalizes Auditory Cortex Responses in Developing Fmr1 Knock-Out Mice. Cereb Cortex 2019; 28:3951-3964. [PMID: 29040407 DOI: 10.1093/cercor/bhx258] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Indexed: 01/08/2023] Open
Abstract
Abnormal sensory responses associated with Fragile X Syndrome (FXS) and autism spectrum disorders include hypersensitivity and impaired habituation to repeated stimuli. Similar sensory deficits are also observed in adult Fmr1 knock-out (KO) mice and are reversed by genetic deletion of Matrix Metalloproteinase-9 (MMP-9) through yet unknown mechanisms. Here we present new evidence that impaired development of parvalbumin (PV)-expressing inhibitory interneurons may underlie hyper-responsiveness in auditory cortex of Fmr1 KO mice via MMP-9-dependent regulation of perineuronal nets (PNNs). First, we found that PV cell development and PNN formation around GABAergic interneurons were impaired in developing auditory cortex of Fmr1 KO mice. Second, MMP-9 levels were elevated in P12-P18 auditory cortex of Fmr1 KO mice and genetic reduction of MMP-9 to WT levels restored the formation of PNNs around PV cells. Third, in vivo single-unit recordings from auditory cortex neurons showed enhanced spontaneous and sound-driven responses in developing Fmr1 KO mice, which were normalized following genetic reduction of MMP-9. These findings indicate that elevated MMP-9 levels contribute to the development of sensory hypersensitivity by influencing formation of PNNs around PV interneurons suggesting MMP-9 as a new therapeutic target to reduce sensory deficits in FXS and potentially other autism spectrum disorders.
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Affiliation(s)
- Teresa H Wen
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA.,Neuroscience Graduate Program, University of California Riverside, Riverside, CA, USA
| | - Sonia Afroz
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA
| | - Sarah M Reinhard
- Psychology Department and Psychology Graduate Program, University of California Riverside, Riverside, CA, USA
| | - Arnold R Palacios
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA
| | - Kendal Tapia
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA
| | - Devin K Binder
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA
| | - Khaleel A Razak
- Neuroscience Graduate Program, University of California Riverside, Riverside, CA, USA.,Psychology Department and Psychology Graduate Program, University of California Riverside, Riverside, CA, USA
| | - Iryna M Ethell
- Division of Biomedical Sciences, University of California Riverside School of Medicine, Riverside, CA, USA.,Neuroscience Graduate Program, University of California Riverside, Riverside, CA, USA
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44
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Satange R, Chuang CY, Neidle S, Hou MH. Polymorphic G:G mismatches act as hotspots for inducing right-handed Z DNA by DNA intercalation. Nucleic Acids Res 2019; 47:8899-8912. [PMID: 31361900 PMCID: PMC6895262 DOI: 10.1093/nar/gkz653] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/06/2019] [Accepted: 07/17/2019] [Indexed: 12/13/2022] Open
Abstract
DNA mismatches are highly polymorphic and dynamic in nature, albeit poorly characterized structurally. We utilized the antitumour antibiotic CoII(Chro)2 (Chro = chromomycin A3) to stabilize the palindromic duplex d(TTGGCGAA) DNA with two G:G mismatches, allowing X-ray crystallography-based monitoring of mismatch polymorphism. For the first time, the unusual geometry of several G:G mismatches including syn–syn, water mediated anti–syn and syn–syn-like conformations can be simultaneously observed in the crystal structure. The G:G mismatch sites of the d(TTGGCGAA) duplex can also act as a hotspot for the formation of alternative DNA structures with a GC/GA-5′ intercalation site for binding by the GC-selective intercalator actinomycin D (ActiD). Direct intercalation of two ActiD molecules to G:G mismatch sites causes DNA rearrangements, resulting in backbone distortion to form right-handed Z-DNA structures with a single-step sharp kink. Our study provides insights on intercalators-mismatch DNA interactions and a rationale for mismatch interrogation and detection via DNA intercalation.
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Affiliation(s)
- Roshan Satange
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, 402, Taiwan.,Ph.D. Program in Medical Biotechnology, National Chung Hsing University, Taichung, 402, Taiwan
| | - Chien-Ying Chuang
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, 402, Taiwan
| | - Stephen Neidle
- The School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Ming-Hon Hou
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, 402, Taiwan.,Ph.D. Program in Medical Biotechnology, National Chung Hsing University, Taichung, 402, Taiwan.,Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
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45
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Nussbacher JK, Tabet R, Yeo GW, Lagier-Tourenne C. Disruption of RNA Metabolism in Neurological Diseases and Emerging Therapeutic Interventions. Neuron 2019; 102:294-320. [PMID: 30998900 DOI: 10.1016/j.neuron.2019.03.014] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 01/24/2019] [Accepted: 03/12/2019] [Indexed: 02/06/2023]
Abstract
RNA binding proteins are critical to the maintenance of the transcriptome via controlled regulation of RNA processing and transport. Alterations of these proteins impact multiple steps of the RNA life cycle resulting in various molecular phenotypes such as aberrant RNA splicing, transport, and stability. Disruption of RNA binding proteins and widespread RNA processing defects are increasingly recognized as critical determinants of neurological diseases. Here, we describe distinct mechanisms by which the homeostasis of RNA binding proteins is compromised in neurological disorders through their reduced expression level, increased propensity to aggregate or sequestration by abnormal RNAs. These mechanisms all converge toward altered neuronal function highlighting the susceptibility of neurons to deleterious changes in RNA expression and the central role of RNA binding proteins in preserving neuronal integrity. Emerging therapeutic approaches to mitigate or reverse alterations of RNA binding proteins in neurological diseases are discussed.
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Affiliation(s)
- Julia K Nussbacher
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA, USA
| | - Ricardos Tabet
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, UCSD Stem Cell Program, University of California, San Diego, La Jolla, CA, USA.
| | - Clotilde Lagier-Tourenne
- Department of Neurology, The Sean M. Healey and AMG Center for ALS at Mass General, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA.
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46
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Geisler D. Educational Case: Fragile X Syndrome with Size Mosaicism. Acad Pathol 2019; 6:2374289519877550. [PMID: 31633014 PMCID: PMC6769227 DOI: 10.1177/2374289519877550] [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: 04/19/2019] [Revised: 08/18/2019] [Accepted: 08/22/2019] [Indexed: 11/27/2022] Open
Abstract
The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.
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Affiliation(s)
- Daniel Geisler
- Department of Pathology, University of Pittsburgh Medical Center, PA, USA
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47
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Manor E, Gonen R, Sarussi B, Keidar-Friedman D, Kumar J, Tang HT, Tassone F. The role of AGG interruptions in the FMR1 gene stability: A survey in ethnic groups with low and high rate of consanguinity. Mol Genet Genomic Med 2019; 7:e00946. [PMID: 31453660 PMCID: PMC6785435 DOI: 10.1002/mgg3.946] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/21/2019] [Accepted: 07/26/2019] [Indexed: 11/07/2022] Open
Abstract
Background The prevalence and the role of AGG interruptions within the FMR1 gene in the normal population is unknown. In this study, we investigated the frequent of AGG loss, in one or two alleles within the normal population. The role of AGG in the FMR1 stability has been assessed by correlating AGG loss to the prevalence of premutation/full mutation in two ethnic groups differing in their consanguinity rate: high versus low consanguinity rate (HCR vs. LCR). Methods The CGG repeat allele size and AGG presence were measured in 6,865 and 6,204 females belonging to the LCR (5%) and HCR (>45%) groups, respectively, by Tripled‐Primed‐PCR technique. Results A lower prevalence of the premutation was observed in the HCR (1:158) as compared to the LCR group (1:128). No full mutation was found in the HCR females while in the LCR group the prevalence found was 1:1,149. Homozygosity rate was higher in the HCR population compared to the LCR group.The overall AGG loss was higher in the HCR population than in the LCR and increased with increased CGG repeat number in both ethnic groups. Conclusions Although we observed a significantly higher rate of homozygosity and AGG loss in the HCR group, this did not affect the prevalence of the premutation and full mutation in this population. Their prevalence was significantly lower than in the LCR population. Finally, we discuss whether the loss of AGG could be also a polymorphic event but not only a stabilizing factor.
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Affiliation(s)
- Esther Manor
- Faculty of Health Science, Ben-Gurion University of the Negev Genetic Institute, Soroka University Medical Center, Beer Sheva, Israel
| | | | | | | | - Jay Kumar
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, USA
| | - Hiu-Tung Tang
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, USA
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, USA.,MIND Institute, Medical Center, University of California Davis, Sacramento, USA
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48
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Nolin SL, Glicksman A, Tortora N, Allen E, Macpherson J, Mila M, Vianna-Morgante AM, Sherman SL, Dobkin C, Latham GJ, Hadd AG. Expansions and contractions of the FMR1 CGG repeat in 5,508 transmissions of normal, intermediate, and premutation alleles. Am J Med Genet A 2019; 179:1148-1156. [PMID: 31050164 PMCID: PMC6619443 DOI: 10.1002/ajmg.a.61165] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/21/2019] [Accepted: 04/11/2019] [Indexed: 12/15/2022]
Abstract
Instability of the FMR1 repeat, commonly observed in transmissions of premutation alleles (55–200 repeats), is influenced by the size of the repeat, its internal structure and the sex of the transmitting parent. We assessed these three factors in unstable transmissions of 14/3,335 normal (~5 to 44 repeats), 54/293 intermediate (45–54 repeats), and 1561/1,880 premutation alleles. While most unstable transmissions led to expansions, contractions to smaller repeats were observed in all size classes. For normal alleles, instability was more frequent in paternal transmissions and in alleles with long 3′ uninterrupted repeat lengths. For premutation alleles, contractions also occurred more often in paternal than maternal transmissions and the frequency of paternal contractions increased linearly with repeat size. All paternal premutation allele contractions were transmitted as premutation alleles, but maternal premutation allele contractions were transmitted as premutation, intermediate, or normal alleles. The eight losses of AGG interruptions in the FMR1 repeat occurred exclusively in contractions of maternal premutation alleles. We propose a refined model of FMR1 repeat progression from normal to premutation size and suggest that most normal alleles without AGG interruptions are derived from contractions of maternal premutation alleles.
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Affiliation(s)
- Sarah L Nolin
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York
| | - Anne Glicksman
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York
| | - Nicole Tortora
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York
| | - Emily Allen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - James Macpherson
- Wessex Regional Genetics Laboratory, Salisbury NHS District Hospital, Salisbury, United Kingdom
| | - Montserrat Mila
- Biochemical and Molecular Genetics, Hospital Clinic de Barcelona, IDIBAPS and CIBERER, Barcelona, Spain
| | - Angela M Vianna-Morgante
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, Universidade de São Paulo, São Paulo, Brazil
| | - Stephanie L Sherman
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - Carl Dobkin
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York
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49
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Crowley JJ, Szatkiewicz J, Kähler AK, Giusti-Rodriguez P, Ancalade N, Booker JK, Carr MT JL, Crawford GE, Losh M, Stockmeier CA, Taylor AK, Piven J, Sullivan PF. Common-variant associations with fragile X syndrome. Mol Psychiatry 2019; 24:338-344. [PMID: 30531935 PMCID: PMC6457435 DOI: 10.1038/s41380-018-0290-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 10/07/2018] [Accepted: 10/09/2018] [Indexed: 12/15/2022]
Abstract
Fragile X syndrome is rare but a prominent cause of intellectual disability. It is usually caused by a de novo mutation that occurs on multiple haplotypes and thus would not be expected to be detectible using genome-wide association (GWA). We conducted GWA in 89 male FXS cases and 266 male controls, and detected multiple genome-wide significant signals near FMR1 (odds ratio = 8.10, P = 2.5 × 10-10). These findings withstood robust attempts at falsification. Fine-mapping yielded a minimum P = 1.13 × 10-14, but did not narrow the interval. Comprehensive functional genomic integration did not provide a mechanistic hypothesis. Controls carrying a risk haplotype had significantly longer FMR1 CGG repeats than controls with the protective haplotype (P = 4.75 × 10-5), which may predispose toward increases in CGG number to the premutation range over many generations. This is a salutary reminder of the complexity of even "simple" monogenetic disorders.
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Affiliation(s)
- James J Crowley
- Department of Genetics, University of North Carolina at Chapel Hill, NC, USA
| | - Jin Szatkiewicz
- Department of Genetics, University of North Carolina at Chapel Hill, NC, USA
| | - Anna K Kähler
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | | | - NaEshia Ancalade
- Department of Genetics, University of North Carolina at Chapel Hill, NC, USA
| | - Jessica K Booker
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Jennifer L Carr MT
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC, USA
| | | | - Molly Losh
- Department of Communication Sciences, Northwestern University, Evanston, IL, USA
| | | | | | - Joseph Piven
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. .,Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Patrick F Sullivan
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. .,Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. .,Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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50
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Bacrot S, Monnot S, Haddad G, Barcia G, Rachid M, Boisson M, Pasquier N, Rondeau S, Munnich A, Steffann J, Bonnefont JP, Raynaud M. Prenatal diagnosis of fragile X syndrome: Small meiotic recombination events at the FMR1 locus. Prenat Diagn 2019; 39:388-393. [PMID: 30779209 DOI: 10.1002/pd.5439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/11/2019] [Accepted: 02/16/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Séverine Bacrot
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Sophie Monnot
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Georges Haddad
- Service de gynécologie obstétrique, Centre hospitalier de Blois, Blois, France
| | - Giulia Barcia
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Myriam Rachid
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Marie Boisson
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Nathalie Pasquier
- Service de Génétique, CHRU de Tours, UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Sophie Rondeau
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Arnold Munnich
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Julie Steffann
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Jean-Paul Bonnefont
- Université Paris Descartes - Sorbonne Paris Cite, Institut Imagine UMR1163, Fédération de Génétique médicale, Hôpital universitaire Necker-Enfants Malades, AP-HP, Paris, France
| | - Martine Raynaud
- Service de Génétique, CHRU de Tours, UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
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