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Lennon J, zur Lage P, von Kriegsheim A, Jarman AP. Strongly Truncated Dnaaf4 Plays a Conserved Role in Drosophila Ciliary Dynein Assembly as Part of an R2TP-Like Co-Chaperone Complex With Dnaaf6. Front Genet 2022; 13:943197. [PMID: 35873488 PMCID: PMC9298768 DOI: 10.3389/fgene.2022.943197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/16/2022] [Indexed: 11/15/2022] Open
Abstract
Axonemal dynein motors are large multi-subunit complexes that drive ciliary movement. Cytoplasmic assembly of these motor complexes involves several co-chaperones, some of which are related to the R2TP co-chaperone complex. Mutations of these genes in humans cause the motile ciliopathy, Primary Ciliary Dyskinesia (PCD), but their different roles are not completely known. Two such dynein (axonemal) assembly factors (DNAAFs) that are thought to function together in an R2TP-like complex are DNAAF4 (DYX1C1) and DNAAF6 (PIH1D3). Here we investigate the Drosophila homologues, CG14921/Dnaaf4 and CG5048/Dnaaf6. Surprisingly, Drosophila Dnaaf4 is truncated such that it completely lacks a TPR domain, which in human DNAAF4 is likely required to recruit HSP90. Despite this, we provide evidence that Drosophila Dnaaf4 and Dnaaf6 proteins can associate in an R2TP-like complex that has a conserved role in dynein assembly. Both are specifically expressed and required during the development of the two Drosophila cell types with motile cilia: mechanosensory chordotonal neurons and sperm. Flies that lack Dnaaf4 or Dnaaf6 genes are viable but with impaired chordotonal neuron function and lack motile sperm. We provide molecular evidence that Dnaaf4 and Dnaaf6 are required for assembly of outer dynein arms (ODAs) and a subset of inner dynein arms (IDAs).
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Affiliation(s)
- Jennifer Lennon
- Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
| | - Petra zur Lage
- Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
| | - Alex von Kriegsheim
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew P. Jarman
- Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
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2
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The Influence of Dyslexia Candidate Genes on Reading Skill in Old Age. Behav Genet 2018; 48:351-360. [PMID: 29959602 PMCID: PMC6097729 DOI: 10.1007/s10519-018-9913-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/23/2018] [Indexed: 11/27/2022]
Abstract
A number of candidate genes for reading and language impairment have been replicated, primarily in samples of children with developmental disability or delay, although these genes are also supported in adolescent population samples. The present study used a systematic approach to test 14 of these candidate genes for association with reading assessed in late adulthood (two cohorts with mean ages of 70 and 79 years). Gene-sets (14 candidates, axon-guidance and neuron migration pathways) and individual SNPs within each gene of interest were tested for association using imputed data referenced to the 1000 genomes European panel. Using the results from the genome-wide association (GWA) meta-analysis of the two cohorts (N = 1217), a competitive gene-set analysis showed that the candidate gene-set was associated with the reading index (p = .016) at a family wise error rate corrected significance level. Neither axon guidance nor neuron migration pathways were significant. Whereas individual SNP associations within CYP19A1, DYX1C1, CNTNAP2 and DIP2A genes (p < .05) did not reach corrected significance their allelic effects were in the same direction as past available reports. These results suggest that reading skill in normal adults shares the same genetic substrate as reading in adolescents, and clinically disordered reading, and highlights the utility of adult samples to increase sample sizes in the genetic study of developmental disorders.
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3
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Ji ZY, Sha YW, Ding L, Li P. Genetic factors contributing to human primary ciliary dyskinesia and male infertility. Asian J Androl 2018; 19:515-520. [PMID: 27270341 PMCID: PMC5566842 DOI: 10.4103/1008-682x.181227] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is an autosomal-recessive disorder resulting from the loss of normal ciliary function. Symptoms include neonatal respiratory distress, chronic sinusitis, bronchiectasis, situs inversus, and infertility. However, only 15 PCD-associated genes have been identified to cause male infertility to date. Owing to the genetic heterogeneity of PCD, comprehensive molecular genetic testing is not considered the standard of care. Here, we provide an update of the progress on the identification of genetic factors related to PCD associated with male infertility, summarizing the underlying molecular mechanisms, and discuss the clinical implications of these findings. Further research in this field will impact the diagnostic strategy for male infertility, enabling clinicians to provide patients with informed genetic counseling, and help to adopt the best course of treatment for developing directly targeted personalized medicine.
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Affiliation(s)
- Zhi-Yong Ji
- The Center for Reproductive Medicine, Xiamen Maternity and Child Care Hospital, No. 10 Zhenhai Road, Xiamen, China
| | - Yan-Wei Sha
- The Center for Reproductive Medicine, Xiamen Maternity and Child Care Hospital, No. 10 Zhenhai Road, Xiamen, China
| | - Lu Ding
- The Center for Reproductive Medicine, Xiamen Maternity and Child Care Hospital, No. 10 Zhenhai Road, Xiamen, China
| | - Ping Li
- The Center for Reproductive Medicine, Xiamen Maternity and Child Care Hospital, No. 10 Zhenhai Road, Xiamen, China
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4
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Müller B, Schaadt G, Boltze J, Emmrich F, Skeide MA, Neef NE, Kraft I, Brauer J, Friederici AD, Kirsten H, Wilcke A. ATP2C2 and DYX1C1 are putative modulators of dyslexia-related MMR. Brain Behav 2017; 7:e00851. [PMID: 29201552 PMCID: PMC5698869 DOI: 10.1002/brb3.851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/23/2017] [Accepted: 09/01/2017] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Dyslexia is a specific learning disorder affecting reading and spelling abilities. Its prevalence is ~5% in German-speaking individuals. Although the etiology of dyslexia largely remains to be determined, comprehensive evidence supports deficient phonological processing as a major contributing factor. An important prerequisite for phonological processing is auditory discrimination and, thus, essential for acquiring reading and spelling skills. The event-related potential Mismatch Response (MMR) is an indicator for auditory discrimination capabilities with dyslexics showing an altered late component of MMR in response to auditory input. METHODS In this study, we comprehensively analyzed associations of dyslexia-specific late MMRs with genetic variants previously reported to be associated with dyslexia-related phenotypes in multiple studies comprising 25 independent single-nucleotide polymorphisms (SNPs) within 10 genes. RESULTS First, we demonstrated validity of these SNPs for dyslexia in our sample by showing that additional inclusion of a polygenic risk score improved prediction of impaired writing compared with a model that used MMR alone. Secondly, a multifactorial regression analysis was conducted to uncover the subset of the 25 SNPs that is associated with the dyslexia-specific late component of MMR. In total, four independent SNPs within DYX1C1 and ATP2C2 were found to be associated with MMR stronger than expected from multiple testing. To explore potential pathomechanisms, we annotated these variants with functional data including tissue-specific expression analysis and eQTLs. CONCLUSION Our findings corroborate the late component of MMR as a potential endophenotype for dyslexia and support tripartite relationships between dyslexia-related SNPs, the late component of MMR and dyslexia.
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Affiliation(s)
- Bent Müller
- Fraunhofer Institute for Cell Therapy and Immunology Leipzig Germany
| | - Gesa Schaadt
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany.,Department of Psychology Humboldt-Universität zu Berlin Berlin Germany
| | - Johannes Boltze
- Fraunhofer Institute for Cell Therapy and Immunology Leipzig Germany.,Department of Medical Cell Technology Fraunhofer Research Institution for Marine Biotechnology Lübeck Germany.,Institute for Medical and Marine Biotechnology University of Lübeck Lübeck Germany
| | - Frank Emmrich
- Fraunhofer Institute for Cell Therapy and Immunology Leipzig Germany
| | | | - Michael A Skeide
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Nicole E Neef
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Indra Kraft
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Jens Brauer
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Angela D Friederici
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Holger Kirsten
- Fraunhofer Institute for Cell Therapy and Immunology Leipzig Germany.,Institute for Medical Informatics Statistics and Epidemiology University of Leipzig Leipzig Germany.,LIFE-Leipzig Research Center for Civilization Diseases University of Leipzig Leipzig Germany
| | - Arndt Wilcke
- Fraunhofer Institute for Cell Therapy and Immunology Leipzig Germany
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5
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Becker N, Vasconcelos M, Oliveira V, Santos FCD, Bizarro L, Almeida RMMD, Salles JFD, Carvalho MRS. Genetic and environmental risk factors for developmental dyslexia in children: systematic review of the last decade. Dev Neuropsychol 2017; 42:423-445. [PMID: 29068706 DOI: 10.1080/87565641.2017.1374960] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Despite advances in the characterization of developmental dyslexia (DD), several questions regarding the interplay between DD-susceptibility genes and environmental risk factors remain open. This systematic review aimed at answering the following questions: What has been the impact of new resources on the knowledge about DD? Which questions remain open? What is the investigative agenda for the short term? Forty-six studies were analyzed. Despite the growing literature on DD candidate genes, most studies have not been replicated. We found large effects on causative genes and smaller environmental contributions, involving maternal smoking during pregnancy, SES and the DYX1C1-1259C/G marker. Implications are discussed.
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Affiliation(s)
- Natalia Becker
- a Cognitive Neuropsychology Research Center (Neurocog), Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Mailton Vasconcelos
- b Experimental Psychology, Neuroscience and Behavior Lab, Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Vanessa Oliveira
- b Experimental Psychology, Neuroscience and Behavior Lab, Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Fernanda Caroline Dos Santos
- c Departamento de Biologia Geral , Post-Graduation Program in Genetics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG) , Pampulha, Belo Horizonte , Minas Gerais , Brazil
| | - Lisiane Bizarro
- b Experimental Psychology, Neuroscience and Behavior Lab, Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Rosa M M De Almeida
- b Experimental Psychology, Neuroscience and Behavior Lab, Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Jerusa Fumagalli De Salles
- a Cognitive Neuropsychology Research Center (Neurocog), Department of Developmental and Personality Psychology , Post-Graduation Program in Psychology, Institute of Psychology, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre , Rio Grande do Sul , Brazil
| | - Maria Raquel Santos Carvalho
- c Departamento de Biologia Geral , Post-Graduation Program in Genetics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG) , Pampulha, Belo Horizonte , Minas Gerais , Brazil
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6
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Yamamoto R, Obbineni JM, Alford LM, Ide T, Owa M, Hwang J, Kon T, Inaba K, James N, King SM, Ishikawa T, Sale WS, Dutcher SK. Chlamydomonas DYX1C1/PF23 is essential for axonemal assembly and proper morphology of inner dynein arms. PLoS Genet 2017; 13:e1006996. [PMID: 28892495 PMCID: PMC5608425 DOI: 10.1371/journal.pgen.1006996] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/21/2017] [Accepted: 08/22/2017] [Indexed: 12/26/2022] Open
Abstract
Cytoplasmic assembly of ciliary dyneins, a process known as preassembly, requires numerous non-dynein proteins, but the identities and functions of these proteins are not fully elucidated. Here, we show that the classical Chlamydomonas motility mutant pf23 is defective in the Chlamydomonas homolog of DYX1C1. The pf23 mutant has a 494 bp deletion in the DYX1C1 gene and expresses a shorter DYX1C1 protein in the cytoplasm. Structural analyses, using cryo-ET, reveal that pf23 axonemes lack most of the inner dynein arms. Spectral counting confirms that DYX1C1 is essential for the assembly of the majority of ciliary inner dynein arms (IDA) as well as a fraction of the outer dynein arms (ODA). A C-terminal truncation of DYX1C1 shows a reduction in a subset of these ciliary IDAs. Sucrose gradients of cytoplasmic extracts show that preassembled ciliary dyneins are reduced compared to wild-type, which suggests an important role in dynein complex stability. The role of PF23/DYX1C1 remains unknown, but we suggest that DYX1C1 could provide a scaffold for macromolecular assembly. Most animal cells have antenna-like organelles called “cilia”. These organelles have various important functions both in motility and sensing the environment. Motile cilia are essential for moving cells as well as moving fluids across a surface. The waveform of motile cilia requires large macromolecular motors; these are the ciliary dyneins. These dynein complexes are assembled in the cytoplasm in a pathway called preassembly, and then transported into cilia. Defects in this process cause a heterogeneous human disease called primary ciliary dyskinesia that results, for example, in the disruption of the motility of respiratory tract cilia, sperm and nodal cilia during development. The mechanisms of the preassembly pathway are not fully understood. In this study, we use a mutation in the well-conserved DYX1C1/PF23 gene of the green alga, Chlamydomonas reinhardtii. Loss of a conserved domain (DYX) reveals a failure to assemble most ciliary dyneins. Preassembly of inner arm dyneins is particularly affected. We find that if dynein arms are not assembled, dynein subunits in the cytoplasm are unstable. We suggest that DYX1C1 may play a role as a scaffold for other preassembly factors and the dynein subunits.
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Affiliation(s)
- Ryosuke Yamamoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| | - Jagan M. Obbineni
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Lea M. Alford
- Department of Biology, Oglethorpe University, Atlanta, Georgia, United States of America
| | - Takahiro Ide
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - Mikito Owa
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - Juyeon Hwang
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Takahide Kon
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Noliyanda James
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Stephen M. King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Takashi Ishikawa
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen PSI, Switzerland
- * E-mail: (TI); (WSS); (SKD)
| | - Winfield S. Sale
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail: (TI); (WSS); (SKD)
| | - Susan K. Dutcher
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail: (TI); (WSS); (SKD)
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7
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Rendall AR, Tarkar A, Contreras-Mora HM, LoTurco JJ, Fitch RH. Deficits in learning and memory in mice with a mutation of the candidate dyslexia susceptibility gene Dyx1c1. BRAIN AND LANGUAGE 2017; 172:30-38. [PMID: 25989970 PMCID: PMC4646737 DOI: 10.1016/j.bandl.2015.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/15/2015] [Accepted: 04/28/2015] [Indexed: 06/04/2023]
Abstract
Dyslexia is a learning disability characterized by difficulty learning to read and write. The underlying biological and genetic etiology remains poorly understood. One candidate gene, dyslexia susceptibility 1 candidate 1 (DYX1C1), has been shown to be associated with deficits in short-term memory in dyslexic populations. The purpose of the current study was to examine the behavioral phenotype of a mouse model with a homozygous conditional (forebrain) knockout of the rodent homolog Dyx1c1. Twelve Dyx1c1 conditional homozygous knockouts, 7 Dyx1c1 conditional heterozygous knockouts and 6 wild-type controls were behaviorally assessed. Mice with the homozygous Dyx1c1 knockout showed deficits on memory and learning, but not on auditory or motor tasks. These findings affirm existing evidence that DYX1C1 may play an underlying role in the development of neural systems important to learning and memory, and disruption of this function could contribute to the learning deficits seen in individuals with dyslexia.
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Affiliation(s)
- Amanda R Rendall
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, United States.
| | - Aarti Tarkar
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, Unit 3156, Storrs, CT 06269, United States
| | - Hector M Contreras-Mora
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, United States
| | - Joseph J LoTurco
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, Unit 3156, Storrs, CT 06269, United States
| | - R Holly Fitch
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, United States
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8
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The role of READ1 and KIAA0319 genetic variations in developmental dyslexia: testing main and interactive effects. J Hum Genet 2017; 62:949-955. [DOI: 10.1038/jhg.2017.80] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/30/2017] [Accepted: 07/02/2017] [Indexed: 12/23/2022]
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9
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Xia Z, Hancock R, Hoeft F. Neurobiological bases of reading disorder Part I: Etiological investigations. LANGUAGE AND LINGUISTICS COMPASS 2017; 11:e12239. [PMID: 28785303 PMCID: PMC5543813 DOI: 10.1111/lnc3.12239] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 03/22/2017] [Indexed: 05/29/2023]
Abstract
While many studies have focused on identifying the neural and behavioral characteristics of decoding-based reading disorder (RD, aka developmental dyslexia), the etiology of RD remains largely unknown and understudied. Because the brain plays an intermediate role between genetic factors and behavioral outcomes, it is promising to address causality from a neural perspective. In the current, Part I of the two-part review, we discuss neuroimaging approaches to addressing the causality issue and review the results of studies that have employed these approaches. We assume that if a neural signature were associated with RD etiology, it would (a) manifest across comparisons in different languages, (b) be experience independent and appear in comparisons between RD and reading-matched controls, (c) be present both pre- and post-intervention, (d) be found in at-risk, pre-reading children and (e) be associated with genetic risk. We discuss each of these five characteristics in turn and summarize the studies that have examined each of them. The available literature provides evidence that anomalies in left temporo-parietal cortex, and possibly occipito-temporal cortex, may be closely related to the etiology of RD. Improved understanding of the etiology of RD can help improve the accuracy of early detection and enable targeted intervention of cognitive processes that are amenable to change, leading to improved outcomes in at-risk or affected populations.
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Affiliation(s)
- Zhichao Xia
- Department of Psychiatry and Weill Institute for Neurosciences, University of California San Francisco, USA
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, China
| | - Roeland Hancock
- Department of Psychiatry and Weill Institute for Neurosciences, University of California San Francisco, USA
| | - Fumiko Hoeft
- Department of Psychiatry and Weill Institute for Neurosciences, University of California San Francisco, USA
- Haskins Laboratories, USA
- Department of Neuropsychiatry, Keio University School of Medicine, Japan
- Dyslexia Center, University of California San Francisco, USA
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10
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Mascheretti S, Trezzi V, Giorda R, Boivin M, Plourde V, Vitaro F, Brendgen M, Dionne G, Marino C. Complex effects of dyslexia risk factors account for ADHD traits: evidence from two independent samples. J Child Psychol Psychiatry 2017; 58:75-82. [PMID: 27501527 DOI: 10.1111/jcpp.12612] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/13/2016] [Indexed: 01/01/2023]
Abstract
BACKGROUND Developmental dyslexia (DD) and attention deficit/hyperactivity disorder (ADHD) are among the most common neurodevelopmental disorders, whose etiology involves multiple risk factors. DD and ADHD co-occur in the same individuals much more often than would be expected by chance. Several studies have found significant bivariate heritability, and specific genes associated with either DD or ADHD have been investigated for association in the other disorder. Moreover, there are likely to be gene-by-gene and gene-by-environment interaction effects (G × G and G × E, respectively) underlying the comorbidity between DD and ADHD. We investigated the pleiotropic effects of 19 SNPs spanning five DD genes (DYX1C1, DCDC2, KIAA0319, ROBO1, and GRIN2B) and seven DD environmental factors (smoke, miscarriage, birth weight, breastfeeding, parental age, socioeconomic status, and parental education) for main, either (a) genetic or (b) environmental, (c) G × G, and (d) G × E upon inattention and hyperactivity/impulsivity. We then attempted replication of these findings in an independent twin cohort. METHODS Marker-trait association was analyzed by implementing the Quantitative Transmission Disequilibrium Test (QTDT). Environmental associations were tested by partial correlations. G × G were investigated by a general linear model equation and a family-based association test. G × E were analyzed through a general test for G × E in sib pair-based association analysis of quantitative traits. RESULTS DCDC2-rs793862 was associated with hyperactivity/impulsivity via G × G (KIAA0319) and G × E (miscarriage). Smoke was significantly correlated with hyperactivity/impulsivity. We replicated the DCDC2 × KIAA0319 interaction upon hyperactivity/impulsivity in the twin cohort. CONCLUSIONS DD genetic (DCDC2) and environmental factors (smoke and miscarriage) underlie ADHD traits supporting a potential pleiotropic effect.
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Affiliation(s)
- Sara Mascheretti
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Vittoria Trezzi
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Roberto Giorda
- Molecular Biology Lab, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Michel Boivin
- Research Unit on Children's Psychosocial Maladjustment, Montréal, QC, Canada.,Ecole de Psychologie, Laval University, Québec, QC, Canada.,Institute of Genetic, Neurobiological, and Social Foundations of Child Development, Tomsk State University, Tomsk, Russian Federation
| | - Vickie Plourde
- Research Unit on Children's Psychosocial Maladjustment, Montréal, QC, Canada.,Ecole de Psychologie, Laval University, Québec, QC, Canada
| | - Frank Vitaro
- Research Unit on Children's Psychosocial Maladjustment, Montréal, QC, Canada.,Department of Psycho-Education, GRIP, University of Montreal, Montreal, QC, Canada
| | - Mara Brendgen
- Research Unit on Children's Psychosocial Maladjustment, Montréal, QC, Canada.,Department of Psychology, Université du Québec à Montréal, Montreal, QC, Canada
| | - Ginette Dionne
- Research Unit on Children's Psychosocial Maladjustment, Montréal, QC, Canada.,Ecole de Psychologie, Laval University, Québec, QC, Canada
| | - Cecilia Marino
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy.,Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
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11
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An assessment of gene-by-gene interactions as a tool to unfold missing heritability in dyslexia. Hum Genet 2015; 134:749-60. [DOI: 10.1007/s00439-015-1555-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 04/12/2015] [Indexed: 12/24/2022]
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12
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Mascheretti S, Marino C, Simone D, Quadrelli E, Riva V, Cellino MR, Maziade M, Brombin C, Battaglia M. Putative risk factors in developmental dyslexia: a case-control study of Italian children. JOURNAL OF LEARNING DISABILITIES 2015; 48:120-129. [PMID: 23757350 DOI: 10.1177/0022219413492853] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Although dyslexia runs in families, several putative risk factors that cannot be immediately identified as genetic predict reading disability. Published studies analyzed one or a few risk factors at a time, with relatively inconsistent results. To assess the contribution of several putative risk factors to the development of dyslexia, we conducted a case-control study of 403 Italian children, 155 with dyslexia, by implementing a stepwise logistic regression applied to the entire sample, and then to boys and girls separately. Younger parental age at child's birth, lower parental education, and risk of miscarriage significantly increased the odds of belonging to the dyslexia group (19.5% of the variation). These associations were confirmed in the analyses conducted separately by sex, except for parental education, which significantly affected only males. These findings support reading disabilities as a multifactorial disorder and may bear some importance for the prevention and/or early detection of children at heightened risk for dyslexia.
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Affiliation(s)
| | - Cecilia Marino
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada Université Laval, Québec, Canada
| | - Daniela Simone
- Scientific Institute Eugenio Medea, Bosisio Parini, Italy
| | | | | | - Maria Rosaria Cellino
- Centro Regionale di Riferimento per i Disturbi dell'Apprendimento - CRRDA, ULSS 20, Verona, Italy
| | - Michel Maziade
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada Université Laval, Québec, Canada
| | | | - Marco Battaglia
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada Université Laval, Québec, Canada
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Bohland JW, Myers EM, Kim E. An informatics approach to integrating genetic and neurological data in speech and language neuroscience. Neuroinformatics 2014; 12:39-62. [PMID: 23949335 DOI: 10.1007/s12021-013-9201-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A number of heritable disorders impair the normal development of speech and language processes and occur in large numbers within the general population. While candidate genes and loci have been identified, the gap between genotype and phenotype is vast, limiting current understanding of the biology of normal and disordered processes. This gap exists not only in our scientific knowledge, but also in our research communities, where genetics researchers and speech, language, and cognitive scientists tend to operate independently. Here we describe a web-based, domain-specific, curated database that represents information about genotype-phenotype relations specific to speech and language disorders, as well as neuroimaging results demonstrating focal brain differences in relevant patients versus controls. Bringing these two distinct data types into a common database ( http://neurospeech.org/sldb ) is a first step toward bringing molecular level information into cognitive and computational theories of speech and language function. One bridge between these data types is provided by densely sampled profiles of gene expression in the brain, such as those provided by the Allen Brain Atlases. Here we present results from exploratory analyses of human brain gene expression profiles for genes implicated in speech and language disorders, which are annotated in our database. We then discuss how such datasets can be useful in the development of computational models that bridge levels of analysis, necessary to provide a mechanistic understanding of heritable language disorders. We further describe our general approach to information integration, discuss important caveats and considerations, and offer a specific but speculative example based on genes implicated in stuttering and basal ganglia function in speech motor control.
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Affiliation(s)
- Jason W Bohland
- Departments of Health Sciences and Speech, Language, and Hearing Sciences, Boston University, 635 Commonwealth Ave, Room 403, Boston, MA, 02215, USA,
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Mascheretti S, Riva V, Giorda R, Beri S, Lanzoni LFE, Cellino MR, Marino C. KIAA0319 and ROBO1: evidence on association with reading and pleiotropic effects on language and mathematics abilities in developmental dyslexia. J Hum Genet 2014; 59:189-97. [PMID: 24430574 DOI: 10.1038/jhg.2013.141] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/13/2013] [Accepted: 12/22/2013] [Indexed: 01/17/2023]
Abstract
Substantial heritability has been reported for developmental dyslexia (DD), and KIAA0319 and ROBO1 appear as more than plausible candidate susceptibility genes for this developmental disorder. Converging evidence indicates that developmental difficulties in oral language and mathematics can predate or co-occur with DD, and substantial genetic correlations have been found between these abilities and reading traits. In this study, we explored the role of eight single-nucleotide polymorphisms spanning within KIAA0319 and ROBO1 genes, and DD as a dichotomic trait, related neuropsychological phenotypes and comorbid language and mathematical (dis)abilities in a large cohort of 493 Italian nuclear families ascertained through a proband with a diagnosis of DD. Marker-trait association was analyzed by implementing a general test of family-based association for quantitative traits (that is, the Quantitative Transmission Disequilibrium Test, version 2.5.1). By providing evidence for significant association with mathematics skills, our data add further result in support of ROBO1 contributing to the deficits in DD and its correlated phenotypes. Taken together, our findings shed further light into the etiologic basis and the phenotypic complexity of this developmental disorder.
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Affiliation(s)
- Sara Mascheretti
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Valentina Riva
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Roberto Giorda
- Molecular Biology Lab, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Silvana Beri
- Molecular Biology Lab, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | | | - Maria Rosaria Cellino
- Centro Regionale di Riferimento per i Disturbi dell'Apprendimento-CRRDA, ULSS 20, Verona, Italy
| | - Cecilia Marino
- 1] Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, QC, Canada [2] Département de Psychiatrie et Neurosciences, Faculté de Médecine, Université Laval, Québec, QC, Canada
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15
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Eicher JD, Gruen JR. Imaging-genetics in dyslexia: connecting risk genetic variants to brain neuroimaging and ultimately to reading impairments. Mol Genet Metab 2013; 110:201-12. [PMID: 23916419 PMCID: PMC3800223 DOI: 10.1016/j.ymgme.2013.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/02/2013] [Accepted: 07/02/2013] [Indexed: 12/19/2022]
Abstract
Dyslexia is a common pediatric disorder that affects 5-17% of schoolchildren in the United States. It is marked by unexpected difficulties in fluent reading despite adequate intelligence, opportunity, and instruction. Classically, neuropsychologists have studied dyslexia using a variety of neurocognitive batteries to gain insight into the specific deficits and impairments in affected children. Since dyslexia is a complex genetic trait with high heritability, analyses conditioned on performance on these neurocognitive batteries have been used to try to identify associated genes. This has led to some successes in identifying contributing genes, although much of the heritability remains unexplained. Additionally, the lack of relevant human brain tissue for analysis and the challenges of modeling a uniquely human trait in animals are barriers to advancing our knowledge of the underlying pathophysiology. In vivo imaging technologies, however, present new opportunities to examine dyslexia and reading skills in a clearly relevant context in human subjects. Recent investigations have started to integrate these imaging data with genetic data in attempts to gain a more complete and complex understanding of reading processes. In addition to bridging the gap from genetic risk variant to a discernible neuroimaging phenotype and ultimately to the clinical impairments in reading performance, the use of neuroimaging phenotypes will reveal novel risk genes and variants. In this article, we briefly discuss the genetic and imaging investigations and take an in-depth look at the recent imaging-genetics investigations of dyslexia.
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Affiliation(s)
- John D. Eicher
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520
| | - Jeffrey R. Gruen
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520
- Departments of Pediatrics and Investigative Medicine, Yale University School of Medicine, New Haven, CT 06520
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Tarkar A, Loges NT, Slagle CE, Francis R, Dougherty GW, Tamayo JV, Shook B, Cantino M, Schwartz D, Jahnke C, Olbrich H, Werner C, Raidt J, Pennekamp P, Abouhamed M, Hjeij R, Köhler G, Griese M, Li Y, Lemke K, Klena N, Liu X, Gabriel G, Tobita K, Jaspers M, Morgan LC, Shapiro AJ, Letteboer SJ, Mans DA, Carson JL, Leigh MW, Wolf WE, Chen S, Lucas JS, Onoufriadis A, Plagnol V, Schmidts M, Boldt K, Roepman R, Zariwala M, Lo CW, Mitchison HM, Knowles MR, Burdine RD, LoTurco JJ, Omran H. DYX1C1 is required for axonemal dynein assembly and ciliary motility. Nat Genet 2013; 45:995-1003. [PMID: 23872636 PMCID: PMC4000444 DOI: 10.1038/ng.2707] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/24/2013] [Indexed: 11/08/2022]
Abstract
DYX1C1 has been associated with dyslexia and neuronal migration in the developing neocortex. Unexpectedly, we found that deleting exons 2-4 of Dyx1c1 in mice caused a phenotype resembling primary ciliary dyskinesia (PCD), a disorder characterized by chronic airway disease, laterality defects and male infertility. This phenotype was confirmed independently in mice with a Dyx1c1 c.T2A start-codon mutation recovered from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. Morpholinos targeting dyx1c1 in zebrafish also caused laterality and ciliary motility defects. In humans, we identified recessive loss-of-function DYX1C1 mutations in 12 individuals with PCD. Ultrastructural and immunofluorescence analyses of DYX1C1-mutant motile cilia in mice and humans showed disruptions of outer and inner dynein arms (ODAs and IDAs, respectively). DYX1C1 localizes to the cytoplasm of respiratory epithelial cells, its interactome is enriched for molecular chaperones, and it interacts with the cytoplasmic ODA and IDA assembly factor DNAAF2 (KTU). Thus, we propose that DYX1C1 is a newly identified dynein axonemal assembly factor (DNAAF4).
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Affiliation(s)
- Aarti Tarkar
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269-3156, USA
| | - Niki T. Loges
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | | | - Richard Francis
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Gerard W. Dougherty
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Joel V. Tamayo
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Brett Shook
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269-3156, USA
| | - Marie Cantino
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269-3156, USA
| | - Daniel Schwartz
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269-3156, USA
| | - Charlotte Jahnke
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Heike Olbrich
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Claudius Werner
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Johanna Raidt
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Petra Pennekamp
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Marouan Abouhamed
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Rim Hjeij
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
| | - Gabriele Köhler
- Department of Pathology, University Hospital Muenster, 48149 Muenster, Germany
| | - Matthias Griese
- Dr. von Haunersches Children‘s Hospital, Ludwig Maximilian University, 80337 Munich, Germany
| | - You Li
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Kristi Lemke
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Nikolas Klena
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Xiaoqin Liu
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - George Gabriel
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Kimimasa Tobita
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Martine Jaspers
- University Hospital Leuven, Campus Gasthuisberg, 3000 Leuven, Belgium
| | - Lucy C. Morgan
- Department of Respiratory Medicine, Concord Hospital, Concord 2139, Australia
| | - Adam J. Shapiro
- Department of Pediatrics, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Stef J.F. Letteboer
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Dorus A. Mans
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Johnny L. Carson
- Department of Pediatrics, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Margaret W. Leigh
- Department of Pediatrics, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Whitney E. Wolf
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Serafine Chen
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jane S. Lucas
- Primary Ciliary Dyskinesia Centre, NIHR Southampton Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, SO17 1BJ, UK
| | - Alexandros Onoufriadis
- Molecular Medicine Unit, Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Vincent Plagnol
- University College London, Genetics Institute, London, WC1E 6BT, UK
| | - Miriam Schmidts
- Molecular Medicine Unit, Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Karsten Boldt
- Institute for Ophthalmic Research, Division of Experimental Ophthalmology and Medical Proteome Center, University of Tuebingen, D-72076 Tuebingen, Germany
| | | | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Maimoona Zariwala
- Department of Pathology & Laboratory Medicine, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Cecilia W. Lo
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201
| | - Hannah M. Mitchison
- Molecular Medicine Unit, Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Michael R. Knowles
- Department of Medicine, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Rebecca D. Burdine
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Joseph J. LoTurco
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269-3156, USA
| | - Heymut Omran
- Department of Pediatrics, University Hospital Muenster, 48149 Muenster; Germany
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The zebrafish orthologue of the dyslexia candidate gene DYX1C1 is essential for cilia growth and function. PLoS One 2013; 8:e63123. [PMID: 23650548 PMCID: PMC3641089 DOI: 10.1371/journal.pone.0063123] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/28/2013] [Indexed: 11/19/2022] Open
Abstract
DYX1C1, a susceptibility gene for dyslexia, encodes a tetratricopeptide repeat domain containing protein that has been implicated in neuronal migration in rodent models. The developmental role of this gene remains unexplored. To understand the biological function(s) of zebrafish dyx1c1 during embryonic development, we cloned the zebrafish dyx1c1 and used morpholino-based knockdown strategy. Quantitative real-time PCR analysis revealed the presence of dyx1c1 transcripts in embryos, early larval stages and in a wide range of adult tissues. Using mRNA in situ hybridization, we show here that dyx1c1 is expressed in many ciliated tissues in zebrafish. Inhibition of dyx1c1 produced pleiotropic phenotypes characteristically associated with cilia defects such as body curvature, hydrocephalus, situs inversus and kidney cysts. We also demonstrate that in dyx1c1 morphants, cilia length is reduced in several organs including Kupffer’s vesicle, pronephros, spinal canal and olfactory placode. Furthermore, electron microscopic analysis of cilia in dyx1c1 morphants revealed loss of both outer (ODA) and inner dynein arms (IDA) that have been shown to be required for cilia motility. Considering all these results, we propose an essential role for dyx1c1 in cilia growth and function.
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Tran C, Gagnon F, Wigg K, Feng Y, Gomez L, Cate-Carter T, Kerr E, Field L, Kaplan B, Lovett M, Barr C. A family-based association analysis and meta-analysis of the reading disabilities candidate gene DYX1C1. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:146-56. [PMID: 23341075 PMCID: PMC5381964 DOI: 10.1002/ajmg.b.32123] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 11/07/2012] [Indexed: 11/11/2022]
Abstract
Reading disabilities (RD) have a significant genetic basis and have shown linkage to multiple regions including chromosome 15q. Dyslexia susceptibility 1 candidate gene 1 (DYX1C1) on chromosome 15q21 was originally proposed as a candidate gene with two potentially functional polymorphisms at the -3G/A and 1249G/T positions showing association with RD. However, subsequent studies have yielded mixed results. We performed a literature review and meta-analysis of the -3G/A and 1249G/T polymorphisms, including new unpublished data from two family-based samples. Ten markers in DYX1C1 were genotyped in the two independently ascertained samples. Single marker and -3G/A:1249G/T haplotype analyses were performed for RD in both samples, and quantitative trait analyses using standardized reading-related measures was performed in one of the samples. For the meta-analysis, we used a random-effects model to summarize studies that tested for association between -3G/A or 1249G/T and RD. No significant association was found between the DYX1C1 SNPs and RD or any of the reading-related measures tested after correction for the number of tests performed. The previously reported risk haplotype (-3A:1249T) was not biased in transmission. A total of 9 and 10 study samples were included in the meta-analysis of the -3G/A and 1249G/T polymorphisms, respectively. Neither polymorphism reached statistical significance, but the heterogeneity for the 1249G/T polymorphism was high. The results of this study do not provide evidence for association between the putatively functional SNPs -3G/A and 1249G/T and RD.
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Affiliation(s)
- C. Tran
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - F. Gagnon
- Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - K.G. Wigg
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Y. Feng
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - L. Gomez
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - T.D. Cate-Carter
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - E.N. Kerr
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - L.L. Field
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - B.J. Kaplan
- Alberta Children’s Hospital and Department of Paediatrics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - M.W. Lovett
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - C.L. Barr
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada,Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada,Correspondence to: Dr. C.L. Barr, Genetics and Development Division, The Toronto Western Hospital, 399 Bathurst St., Room MP14-302, Toronto, ON, Canada M5T 2S8.
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19
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Raskind WH, Peter B, Richards T, Eckert MM, Berninger VW. The genetics of reading disabilities: from phenotypes to candidate genes. Front Psychol 2013; 3:601. [PMID: 23308072 PMCID: PMC3538356 DOI: 10.3389/fpsyg.2012.00601] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 12/18/2012] [Indexed: 12/19/2022] Open
Abstract
This article provides an overview of (a) issues in definition and diagnosis of specific reading disabilities at the behavioral level that may occur in different constellations of developmental and phenotypic profiles (patterns); (b) rapidly expanding research on genetic heterogeneity and gene candidates for dyslexia and other reading disabilities; (c) emerging research on gene-brain relationships; and (d) current understanding of epigenetic mechanisms whereby environmental events may alter behavioral expression of genetic variations. A glossary of genetic terms (denoted by bold font) is provided for readers not familiar with the technical terms.
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Affiliation(s)
- Wendy H Raskind
- Department of Medicine, University of Washington Seattle, WA, USA ; Department of Psychiatry and Behavioral Sciences, University of Washington Seattle, WA, USA
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20
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Darki F, Peyrard-Janvid M, Matsson H, Kere J, Klingberg T. Three dyslexia susceptibility genes, DYX1C1, DCDC2, and KIAA0319, affect temporo-parietal white matter structure. Biol Psychiatry 2012; 72:671-6. [PMID: 22683091 DOI: 10.1016/j.biopsych.2012.05.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 04/27/2012] [Accepted: 05/04/2012] [Indexed: 01/12/2023]
Abstract
BACKGROUND Volume and integrity of white matter correlate with reading ability, but the underlying factors contributing to this variability are unknown. METHODS We investigated single nucleotide polymorphisms in three genes previously associated with dyslexia and implicated in neuronal migration (DYX1C1, DCDC2, KIAA0319) and white matter volume in a cohort of 76 children and young adults from the general population. RESULTS We found that all three genes contained polymorphisms that were significantly associated with white matter volume in the left temporo-parietal region and that white matter volume influenced reading ability. CONCLUSIONS The identified region contained white matter pathways connecting the middle temporal gyrus with the inferior parietal lobe. The finding links previous neuroimaging and genetic results and proposes a mechanism underlying variability in reading ability in both normal and impaired readers.
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Affiliation(s)
- Fahimeh Darki
- Neuroscience Department, Karolinska Institutet, Stockholm, Sweden
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21
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Zhang Y, Li J, Tardif T, Burmeister M, Villafuerte SM, McBride-Chang C, Li H, Shi B, Liang W, Zhang Z, Shu H. Association of the DYX1C1 dyslexia susceptibility gene with orthography in the Chinese population. PLoS One 2012; 7:e42969. [PMID: 23028439 PMCID: PMC3441603 DOI: 10.1371/journal.pone.0042969] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 07/16/2012] [Indexed: 11/19/2022] Open
Abstract
Several independent studies have supported the association of DYX1C1 with dyslexia, but its role in general reading development remains unclear. Here, we investigated the contribution of this gene to reading, with a focus on orthographic skills, in a sample of 284 unrelated Chinese children aged 5 to 11 years who were participating in the Chinese Longitudinal Study of Reading Development. We tested this association using a quantitative approach for Chinese character reading, Chinese character dictation, orthographic judgment, and visual skills. Significant or marginally significant associations were observed at the marker rs11629841 with children's orthographic judgments at ages 7 and 8 years (all P values<0.020). Significant associations with Chinese character dictation (all P values<0.013) were also observed for this single-nucleotide polymorphism (SNP) at ages 9, 10, and 11 years. Further analyses revealed that the association with orthographic skills was specific to the processing of specific components of characters (P values<0.046). No association was found at either SNP of rs3743205 or rs57809907. Our findings suggest that DYX1C1 influences reading development in the general Chinese population and supports a universal effect of this gene.
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Affiliation(s)
- Yuping Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Jun Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Twila Tardif
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Margit Burmeister
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sandra M. Villafuerte
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, United States of America
| | | | - Hong Li
- Department of Psychology, Beijing Normal University, Beijing, China
| | - Bingjie Shi
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Weilan Liang
- Peking University First Hospital, Beijing, China
| | | | - Hua Shu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- * E-mail:
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Abstract
OBJECTIVE(S) Developmental dyslexia is a heritable condition, with genetic factors accounting for 44-75% of the variance in performance tests of reading component subphenotypes. Compelling genetic linkage and association evidence supports a quantitative trait locus in the 6p21.3 region that encodes a gene called DCDC2. In this study, we explored the contribution of two DCDC2 markers to dyslexia, related reading and memory phenotypes in nuclear families of Italian origin. METHODS The 303 nuclear families recruited on the basis of having a proband with developmental dyslexia have been studied with 6p21.3 markers, BV677278 and rs793862. Marker-trait association was investigated by the quantitative transmission disequilibrium test (version 2.5.1) that allows for the analyses of quantitative traits. Seven phenotypes were used in association analyses, that is, word and nonword reading, word and nonword spelling, orthographic choice, memory, and the affected status based on inclusion criteria. RESULTS Quantitative transmission disequilibrium test analyses yielded evidence for association between reading skills and the BV677278 deletion (empirical P-values=0.025-0.029) and between memory and BV677278 allele 10 (empirical P-value=0.0001). CONCLUSION Our result adds further evidence in support of DCDC2 contributing to the deficits in developmental dyslexia. More specifically, our data support the view that DCDC2 influences both reading and memory impairments thus shedding further light into the etiologic basis and the phenotypic complexity of developmental dyslexia.
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23
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Szalkowski CE, Fiondella CG, Galaburda AM, Rosen GD, Loturco JJ, Fitch RH. Neocortical disruption and behavioral impairments in rats following in utero RNAi of candidate dyslexia risk gene Kiaa0319. Int J Dev Neurosci 2012; 30:293-302. [PMID: 22326444 PMCID: PMC3516384 DOI: 10.1016/j.ijdevneu.2012.01.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/24/2012] [Accepted: 01/25/2012] [Indexed: 11/22/2022] Open
Abstract
Within the last decade several genes have been identified as candidate risk genes for developmental dyslexia. Recent research using animal models and embryonic RNA interference (RNAi) has shown that a subset of the candidate dyslexia risk genes--DYX1C1, ROBO1, DCDC2, KIAA0319--regulate critical parameters of neocortical development, such as neuronal migration. For example, embryonic disruption of the rodent homolog of DYX1C1 disrupts neuronal migration and produces deficits in rapid auditory processing (RAP) and working memory--phenotypes that have been reported to be associated with developmental dyslexia. In the current study we used a modified prepulse inhibition paradigm to assess acoustic discrimination abilities of male Wistar rats following in utero RNA interference targeting Kiaa0319. We also assessed spatial learning and working memory using a Morris water maze (MWM) and a radial arm water maze. We found that embryonic interference with this gene resulted in disrupted migration of neocortical neurons leading to formation of heterotopia in white matter, and to formation of hippocampal dysplasia in a subset of animals. These animals displayed deficits in processing complex acoustic stimuli, and those with hippocampal malformations exhibited impaired spatial learning abilities. No significant impairment in working memory was detected in the Kiaa0319 RNAi treated animals. Taken together, these results suggest that Kiaa0319 plays a role in neuronal migration during embryonic development, and that early interference with this gene results in an array of behavioral deficits including impairments in rapid auditory processing and simple spatial learning.
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Affiliation(s)
- Caitlin E Szalkowski
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
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24
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Abstract
Language and learning disorders such as reading disability and language impairment are recognized to be subject to substantial genetic influences, but few causal mutations have been identified in the coding regions of candidate genes. Association analyses of single nucleotide polymorphisms have suggested the involvement of regulatory regions of these genes, and a few mutations affecting gene expression levels have been identified, indicating that the quantity rather than the quality of the gene product may be most relevant for these disorders. In addition, several of the candidate genes appear to be involved in neuronal migration, confirming the importance of early developmental processes. Accordingly, alterations in epigenetic processes such as DNA methylation and histone modification are likely to be important in the causes of language and learning disorders based on their functions in gene regulation. Epigenetic processes direct the differentiation of cells in early development when neurological pathways are set down, and mutations in genes involved in epigenetic regulation are known to cause cognitive disorders in humans. Epigenetic processes also regulate the changes in gene expression in response to learning, and alterations in histone modification are associated with learning and memory deficits in animals. Genetic defects in histone modification have been reversed in animals through therapeutic interventions resulting in rescue of these deficits, making it particularly important to investigate their potential contribution to learning disorders in humans.
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Poelmans G, Buitelaar JK, Pauls DL, Franke B. A theoretical molecular network for dyslexia: integrating available genetic findings. Mol Psychiatry 2011; 16:365-82. [PMID: 20956978 DOI: 10.1038/mp.2010.105] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Developmental dyslexia is a common specific childhood learning disorder with a strong heritable component. Previous studies using different genetic approaches have identified several genetic loci and candidate genes for dyslexia. In this article, we have integrated the current knowledge on 14 dyslexia candidate genes suggested by cytogenetic findings, linkage and association studies. We found that 10 of the 14 dyslexia candidate genes (ROBO1, KIAA0319, KIAA0319L, S100B, DOCK4, FMR1, DIP2A, GTF2I, DYX1C1 and DCDC2) fit into a theoretical molecular network involved in neuronal migration and neurite outgrowth. Based on this, we also propose three novel dyslexia candidate genes (SLIT2, HMGB1 and VAPA) from known linkage regions, and we discuss the possible involvement of genes emerging from the two reported genome-wide association studies for reading impairment-related phenotypes in the identified network.
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Affiliation(s)
- G Poelmans
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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26
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Kere J. Molecular genetics and molecular biology of dyslexia. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2011; 2:441-448. [PMID: 26302203 DOI: 10.1002/wcs.138] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Developmental dyslexia has been recognized as a distinct entity among learning disabilities as early as the late 1800s and its partially genetic nature has been firmly established by family and twin studies. The application of genetic mapping and molecular cloning methods has revealed specific genes that contribute to the genetic risk, but those known now do not yet suffice for explaining all of it. More importantly, the first genes, some of them found by the study of rare families, have indicated specific neurodevelopmental processes important for the development of dyslexia, including control of neuronal migration for the DYX1C1, DCDC2, and KIAA0319 genes, and a role of axonal and dendritic guidance suggested by the ROBO1 gene. I anticipate that forthcoming research within only a few years will yield molecular networks with fundamental roles in the molecular biology of dyslexia, and may aid in resolving relationships between comorbid disorders. WIREs Cogni Sci 2011 2 441-448 DOI: 10.1002/wcs.138 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Juha Kere
- Department of Biosciences and Nutrition, and Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden.,Department of Medical Genetics, University of Helsinki, and Folkhälsan Institute of Genetics, Helsinki, Finland
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Venkatesh SK, Siddaiah A, Padakannaya P, Ramachandra NB. An Examination of Candidate Gene SNPs for Dyslexia in an Indian Sample. Behav Genet 2011; 41:105-9. [DOI: 10.1007/s10519-010-9441-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 12/23/2010] [Indexed: 11/24/2022]
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28
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Skiba T, Landi N, Wagner R, Grigorenko EL. In search of the perfect phenotype: an analysis of linkage and association studies of reading and reading-related processes. Behav Genet 2011; 41:6-30. [PMID: 21243420 PMCID: PMC3056345 DOI: 10.1007/s10519-011-9444-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 12/22/2010] [Indexed: 01/15/2023]
Abstract
Reading ability and specific reading disability (SRD) are complex traits involving several cognitive processes and are shaped by a complex interplay of genetic and environmental forces. Linkage studies of these traits have identified several susceptibility loci. Association studies have gone further in detecting candidate genes that might underlie these signals. These results have been obtained in samples of mainly European ancestry, which vary in their languages, inclusion criteria, and phenotype assessments. Such phenotypic heterogeneity across samples makes understanding the relationship between reading (dis)ability and reading-related processes and the genetic factors difficult; in addition, it may negatively influence attempts at replication. In moving forward, the identification of preferable phenotypes for future sample collection may improve the replicability of findings. This review of all published linkage and association results from the past 15 years was conducted to determine if certain phenotypes produce more replicable and consistent results than others.
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Affiliation(s)
| | - Nicole Landi
- Yale University & Haskins Laboratories, New Haven, CT, USA
| | | | - Elena L. Grigorenko
- Yale University, New Heaven, CT, USA
- Moscow State University, Moscow, Russia
- Columbia University, New York, NY, USA
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29
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Investigation of dyslexia and SLI risk variants in reading- and language-impaired subjects. Behav Genet 2010. [PMID: 21165691 DOI: 10.1007/s10519-010-9424-3"] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Dyslexia (or reading disability) and specific language impairment (or SLI) are common childhood disorders that show considerable co-morbidity and diagnostic overlaps and have been suggested to share some genetic aetiology. Recently, genetic risk variants have been identified for SLI and dyslexia enabling the direct evaluation of possible shared genetic influences between these disorders. In this study we investigate the role of variants in these genes (namely MRPL19/C20RF3, ROBO1, DCDC2, KIAA0319, DYX1C1, CNTNAP2, ATP2C2 and CMIP) in the aetiology of SLI and dyslexia. We perform case-control and quantitative association analyses using measures of oral and written language skills in samples of SLI and dyslexic families and cases. We replicate association between KIAA0319 and DCDC2 and dyslexia and provide evidence to support a role for KIAA0319 in oral language ability. In addition, we find association between reading-related measures and variants in CNTNAP2 and CMIP in the SLI families.
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30
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Newbury DF, Paracchini S, Scerri TS, Winchester L, Addis L, Richardson AJ, Walter J, Stein JF, Talcott JB, Monaco AP. Investigation of dyslexia and SLI risk variants in reading- and language-impaired subjects. Behav Genet 2010; 41:90-104. [PMID: 21165691 PMCID: PMC3029677 DOI: 10.1007/s10519-010-9424-3] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 11/28/2010] [Indexed: 11/25/2022]
Abstract
Dyslexia (or reading disability) and specific language impairment (or SLI) are common childhood disorders that show considerable co-morbidity and diagnostic overlaps and have been suggested to share some genetic aetiology. Recently, genetic risk variants have been identified for SLI and dyslexia enabling the direct evaluation of possible shared genetic influences between these disorders. In this study we investigate the role of variants in these genes (namely MRPL19/C20RF3, ROBO1, DCDC2, KIAA0319, DYX1C1, CNTNAP2, ATP2C2 and CMIP) in the aetiology of SLI and dyslexia. We perform case-control and quantitative association analyses using measures of oral and written language skills in samples of SLI and dyslexic families and cases. We replicate association between KIAA0319 and DCDC2 and dyslexia and provide evidence to support a role for KIAA0319 in oral language ability. In addition, we find association between reading-related measures and variants in CNTNAP2 and CMIP in the SLI families.
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Affiliation(s)
- D. F. Newbury
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN UK
| | - S. Paracchini
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN UK
| | - T. S. Scerri
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN UK
| | - L. Winchester
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN UK
| | - L. Addis
- Department of Clinical Neurosciences, Institute of Psychiatry, King’s College, London, UK
| | - Alex J. Richardson
- Centre for Evidence-Based Intervention, Dept of Social Policy and Social Work, University of Oxford, Barnett House, 32 Wellington Square, Oxford, OX1 2ER UK
| | - J. Walter
- Department of Physiology, University of Oxford, Parks Road, Oxford, OX1 3PT UK
| | - J. F. Stein
- Department of Physiology, University of Oxford, Parks Road, Oxford, OX1 3PT UK
| | - J. B. Talcott
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET UK
| | - A. P. Monaco
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN UK
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31
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Abstract
The status of DYX1C1 (C15q21.3) as a susceptibility gene for dyslexia is unclear. We report the association of this gene with reading and spelling ability in a sample of adolescent twins and their siblings. Family-based association analyses were carried out on 13 single-nucleotide polymorphisms (SNPs) in DYX1C1, typed in 790 families with up to 5 offspring and tested on 6 validated measures of lexical processing (irregular word) and grapheme-phoneme decoding (pseudo-word) reading- and spelling-based measures of dyslexia, as well as a short-term memory measure. Significant association was observed at the misssense mutation rs17819126 for all reading measures and for spelling of lexical processing words, and at rs3743204 for both irregular and nonword reading. Verbal short-term memory was associated with rs685935. Support for association was not found at rs3743205 and rs61761345 as previously reported by Taipale et al., but these SNPs had very low (0.002 for rs3743205) minor allele frequencies in this sample. These results suggest that DYX1C1 influences reading and spelling ability with additional effects on short-term information storage or rehearsal. Missense mutation rs17819126 is a potential functional basis for the association of DYX1C1 with dyslexia.
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Szalkowski CE, Hinman JR, Threlkeld SW, Wang Y, LePack A, Rosen GD, Chrobak JJ, LoTurco JJ, Fitch RH. Persistent spatial working memory deficits in rats following in utero RNAi of Dyx1c1. GENES BRAIN AND BEHAVIOR 2010; 10:244-52. [PMID: 20977651 DOI: 10.1111/j.1601-183x.2010.00662.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Disruptions in the development of the neocortex are associated with cognitive deficits in humans and other mammals. Several genes contribute to neocortical development, and research into the behavioral phenotype associated with specific gene manipulations is advancing rapidly. Findings include evidence that variants in the human gene DYX1C1 may be associated with an increased risk of developmental dyslexia. Concurrent research has shown that the rat homolog for this gene modulates critical parameters of early cortical development, including neuronal migration. Moreover, recent studies have shown auditory processing and spatial learning deficits in rats following in utero transfection of an RNA interference (RNAi) vector of the rat homolog Dyx1c1 gene. The current study examined the effects of in utero RNAi of Dyx1c1 on working memory performance in Sprague-Dawley rats. This task was chosen based on the evidence of short-term memory deficits in dyslexic populations, as well as more recent evidence of an association between memory deficits and DYX1C1 anomalies in humans. Working memory performance was assessed using a novel match-to-place radial water maze task that allows the evaluation of memory for a single brief (∼4-10 seconds) swim to a new goal location each day. A 10-min retention interval was used, followed by a test trial. Histology revealed migrational abnormalities and laminar disruption in Dyx1c1 RNAi-treated rats. Dyx1c1 RNAi-treated rats exhibited a subtle, but significant and persistent impairment in working memory as compared to Shams. These results provide further support for the role of Dyx1c1 in neuronal migration and working memory.
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Affiliation(s)
- C E Szalkowski
- Department of Psychology/Behavioral Neuroscience, University of Connecticut, 406 Babbidge Road, Storrs, CT 06269, USA.
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33
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The effects of embryonic knockdown of the candidate dyslexia susceptibility gene homologue Dyx1c1 on the distribution of GABAergic neurons in the cerebral cortex. Neuroscience 2010; 172:535-46. [PMID: 21070838 DOI: 10.1016/j.neuroscience.2010.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 11/01/2010] [Accepted: 11/02/2010] [Indexed: 01/30/2023]
Abstract
Developmental dyslexia is a language-based learning disability, and a number of candidate dyslexia susceptibility genes have been identified, including DYX1C1, KIAA0319, and DCDC2. Knockdown of function by embryonic transfection of small hairpin RNA (shRNA) of rat homologues of these genes dramatically disrupts neuronal migration to the cerebral cortex by both cell autonomous and non-cell autonomous effects. Here we sought to investigate the extent of non-cell autonomous effects following in utero disruption of the candidate dyslexia susceptibility gene homolog Dyx1c1 by assessing the effects of this disruption on GABAergic neurons. We transfected the ventricular zone of embryonic day (E) 15.5 rat pups with either Dyx1c1 shRNA, DYX1C1 expression construct, both Dyx1c1 shRNA and DYX1C1 expression construct, or a scrambled version of Dyx1c1 shRNA, and sacrificed them at postnatal day 21. The mothers of these rats were injected with BrdU at either E13.5, E15.5, or E17.5. Neurons transfected with Dyx1c1 shRNA were bi-modally distributed in the cerebral cortex with one population in heterotopic locations at the white matter border and another migrating beyond their expected location in the cerebral cortex. In contrast, there was no disruption of migration following transfection with the DYX1C1 expression construct. We found untransfected GABAergic neurons (parvalbumin, calretinin, and neuropeptide Y) in the heterotopic collections of neurons in Dyx1c1 shRNA treated animals, supporting the hypothesis of non-cell autonomous effects. In contrast, we found no evidence that the position of the GABAergic neurons that made it to the cerebral cortex was disrupted by the embryonic transfection with any of the constructs. Taken together, these results support the notion that neurons within heterotopias caused by transfection with Dyx1c1 shRNA result from both cell autonomous and non-cell autonomous effects, but there is no evidence to support non-cell autonomous disruption of neuronal position in the cerebral cortex itself.
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Marino C, Mascheretti S, Riva V, Cattaneo F, Rigoletto C, Rusconi M, Gruen JR, Giorda R, Lazazzera C, Molteni M. Pleiotropic effects of DCDC2 and DYX1C1 genes on language and mathematics traits in nuclear families of developmental dyslexia. Behav Genet 2010; 41:67-76. [PMID: 21046216 DOI: 10.1007/s10519-010-9412-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 10/21/2010] [Indexed: 11/25/2022]
Abstract
Converging evidence indicates that developmental problems in oral language and mathematics can predate or co-occur with developmental dyslexia (DD). Substantial genetic correlations have been found between language, mathematics and reading traits, independent of the method of sampling. We tested for association of variants of two DD susceptibility genes, DCDC2 and DYX1C1, in nuclear families ascertained through a proband with DD using concurrent measurements of language and mathematics in both probands and siblings by the Quantitative Transmission Disequilibrium Test. Evidence for significant associations was found between DCDC2 and 'Numerical Facts' (p value = 0.02, with 85 informative families, genetic effect = 0.57) and between 'Mental Calculation' and DYX1C1 markers -3GA (p value = 0.05, with 40 informative families, genetic effect = -0.67) and 1249GT (p value = 0.02, with 49 informative families, genetic effect = -0.65). No statistically significant associations were found between DCDC2 or DYX1C1 and language phenotypes. Both DCDC2 and DYX1C1 DD susceptibility genes appear to have a pleiotropic role on mathematics but not language phenotypes.
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Affiliation(s)
- Cecilia Marino
- Department of Child Psychiatry, Scientific Institute Eugenio Medea, Via don Luigi Monza, 20, 23842 Bosisio Parini, LC, Italy.
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A Cohort of Balanced Reciprocal Translocations Associated with Dyslexia: Identification of Two Putative Candidate Genes at DYX1. Behav Genet 2010; 41:125-33. [PMID: 20798984 DOI: 10.1007/s10519-010-9389-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 08/11/2010] [Indexed: 01/22/2023]
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Abstract
Developmental dyslexia is a highly heritable disorder with a prevalence of at least 5% in school-aged children. Linkage studies have identified numerous loci throughout the genome that are likely to harbour candidate dyslexia susceptibility genes. Association studies and the refinement of chromosomal translocation break points in individuals with dyslexia have resulted in the discovery of candidate genes at some of these loci. A key function of many of these genes is their involvement in neuronal migration. This complements anatomical abnormalities discovered in dyslexic brains, such as ectopias, that may be the result of irregular neuronal migration.
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37
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Abstract
OBJECTIVE Dyslexia-susceptibility-1-candidate-1 (DYX1C1) was the first gene associated with dyslexia. Since the original report of 2003, eight replication attempts have been published reporting discordant results. As the dyslexia community still considers the role of DYX1C1 unsettled, we explored the contribution of this gene in a sample of 366 trios of German descent. METHODS To the common four markers used in previous studies, we added two new single nucleotide polymorphisms found by resequencing both the putative regulatory and coding region of the gene in randomly selected cases and controls. As linkage disequilibrium blocks of the region were not easy to define, we approached the association problem by running a transmission disequilibrium test over sliding windows of dimension 1 to 6 on consecutive markers. The significance of this test was calculated generating the empirical distribution of the global P value by simulating the data. As our study sample had a large female proband content, we also stratified our analysis by sex. RESULTS We found statistically significant association with global corrected P value of 0.036. The three-marker haplotype G/G/G spanning rs3743205/rs3743204/rs600753 was most associated with a P value of 0.006 and odds ratio 3.7 (95% confidence interval: 1.4-9.6) in female probands. A detailed haplotype-phenotype analysis revealed that the dyslexia subphenotype short-term memory contributed mainly to the observed findings. This is in accordance with a recent short-term memory-DYX1C1 association in an independent sample of dyslexia. CONCLUSION As significant association was proved in our sample, we could also conclude that denser maps, sex information, and well-defined subphenotypes are crucial to correctly determine the contribution of DYX1C1 to dyslexia.
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Gabel LA, Gibson CJ, Gruen JR, LoTurco JJ. Progress towards a cellular neurobiology of reading disability. Neurobiol Dis 2009; 38:173-80. [PMID: 19616627 DOI: 10.1016/j.nbd.2009.06.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Revised: 06/25/2009] [Accepted: 06/28/2009] [Indexed: 01/18/2023] Open
Abstract
Reading Disability (RD) is a significant impairment in reading accuracy, speed and/or comprehension despite adequate intelligence and educational opportunity. RD affects 5-12% of readers, has a well-established genetic risk, and is of unknown neurobiological cause or causes. In this review we discuss recent findings that revealed neuroanatomic anomalies in RD, studies that identified 3 candidate genes (KIAA0319, DYX1C1, and DCDC2), and compelling evidence that potentially link the function of candidate genes to the neuroanatomic anomalies. A hypothesis has emerged in which impaired neuronal migration is a cellular neurobiological antecedent to RD. We critically evaluate the evidence for this hypothesis, highlight missing evidence, and outline future research efforts that will be required to develop a more complete cellular neurobiology of RD.
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Affiliation(s)
- Lisa A Gabel
- Department of Psychology, Lafayette College, Easton, PA, USA
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39
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Chen Y, Zhao M, Wang S, Chen J, Wang Y, Cao Q, Zhou W, Liu J, Xu Z, Tong G, Li J. A novel role for DYX1C1, a chaperone protein for both Hsp70 and Hsp90, in breast cancer. J Cancer Res Clin Oncol 2009; 135:1265-76. [PMID: 19277710 DOI: 10.1007/s00432-009-0568-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 02/23/2009] [Indexed: 01/24/2023]
Abstract
AIMS With three consecutive tetratricopeptide repeat (TPR) motifs at its C-terminus essential for neuronal migration, and a p23 domain at its N-terminus, DYX1C1 was the first gene proposed to have a role in developmental dyslexia. In this study, we attempted to identify the potential interaction of DYX1C1 and heat shock protein, and the role of DYX1C1 in breast cancer. MAIN METHODS GST pull-down, a yeast two-hybrid system, RT-PCR, site-directed mutagenesis approach. KEY FINDINGS Our study initially confirmed DYX1C1, a dyslexia related protein, could interact with Hsp70 and Hsp90 via GST pull-down and a yeast two-hybrid system. And we verified that EEVD, the C-terminal residues of DYX1C1, is responsible for the identified association. Further, DYX1C1 mRNA was significantly overexpressed in malignant breast tumor, linking with the up-regulated expression of Hsp70 and Hsp90. SIGNIFICANCE These results suggest that DYX1C1 is a novel Hsp70 and Hsp90-interacting co-chaperone protein and its expression is associated with malignancy.
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Affiliation(s)
- Yuxin Chen
- Lab of Reproductive Medicine, Department of Cell Biology and Medical Genetics, Nanjing Medical University, 210029 Nanjing, Jiangsu, People's Republic of China
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Wigg KG, Feng Y, Crosbie J, Tannock R, Kennedy JL, Ickowicz A, Malone M, Schachar R, Barr CL. Association of ADHD and the Protogenin gene in the chromosome 15q21.3 reading disabilities linkage region. GENES BRAIN AND BEHAVIOR 2009; 7:877-86. [PMID: 19076634 DOI: 10.1111/j.1601-183x.2008.00425.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Twin studies indicate genetic overlap between symptoms of attention deficit hyperactivity disorder (ADHD) and reading disabilities (RD), and linkage studies identify several chromosomal regions possibly containing common susceptibility genes, including the 15q region. Based on a translocation finding and association to two specific alleles, the candidate gene, DYX1C1, has been proposed as the susceptibility gene for RD in 15q. Previously, we tested markers in DYX1C1 for association with ADHD. Although we identified association for haplotypes across the gene, we were unable to replicate the association to the specific alleles reported. Thus, the risk alleles for ADHD are yet to be identified. The susceptibility alleles may be in a remote regulatory element, or DYX1C1 may not be the risk gene. To continue study of 15q, we tested a coding region change in DYX1C1, followed by markers across the gene Protogenin (PRTG) in 253 ADHD nuclear families. PRTG was chosen based on its location and because it is closely related to DCC and Neogenin, two genes known to guide migratory cells and axons during development. The markers in DYX1C1 were not associated to ADHD when analyzed individually; however, six markers in PRTG showed significant association with ADHD as a categorical trait (P = 0.025-0.005). Haplotypes in both genes showed evidence for association. We identified association with ADHD symptoms measured as quantitative traits in PRTG, but no evidence for association with two key components of reading, word identification and decoding was observed. These findings, while preliminary, identify association of ADHD to a gene that potentially plays a role in cell migration and axon growth.
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Affiliation(s)
- K G Wigg
- Genetics and Development Division, The Toronto Western Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada
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41
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Poelmans G, Engelen JJM, Van Lent-Albrechts J, Smeets HJ, Schoenmakers E, Franke B, Buitelaar JK, Wuisman-Frerker M, Erens W, Steyaert J, Schrander-Stumpel C. Identification of novel dyslexia candidate genes through the analysis of a chromosomal deletion. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:140-7. [PMID: 18521840 DOI: 10.1002/ajmg.b.30787] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Dyslexia is the most common childhood learning disorder and it is a significantly heritable trait. At least nine chromosomal loci have been linked to dyslexia, and additional susceptibility loci on other chromosomes have been suggested. Within two of these loci, DYX1C1 (15q21) and ROBO1 (3p12) have recently been proposed as dyslexia candidate genes through the molecular analysis of translocation breakpoints in dyslexic individuals carrying balanced chromosomal translocations. Moreover, genetic association studies have indicated a cluster of five dyslexia candidate genes in another linkage region on chromosome 6p22, although there is currently no consensus about which of these five genes contributes to the genetic susceptibility for dyslexia. In this article, we report the identification of four new dyslexia candidate genes (PCNT, DIP2A, S100B, and PRMT2) on chromosome region 21q22.3 by FISH and SNP microarray analyses of a very small deletion in this region, which cosegregates with dyslexia in a father and his three sons.
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Affiliation(s)
- G Poelmans
- Department of Clinical Genetics, Academic Hospital Maastricht, The Netherlands.
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42
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Gibson CJ, Gruen JR. The human lexinome: genes of language and reading. JOURNAL OF COMMUNICATION DISORDERS 2008; 41:409-20. [PMID: 18466916 PMCID: PMC2488410 DOI: 10.1016/j.jcomdis.2008.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Accepted: 03/12/2008] [Indexed: 05/26/2023]
Abstract
UNLABELLED Within the human genome, genetic mapping studies have identified 10 regions of different chromosomes, known as DYX loci, in genetic linkage with dyslexia, and two, known as SLI loci, in genetic linkage with Specific Language Impairment (SLI). Further genetic studies have identified four dyslexia genes within the DYX loci: DYX1C1 on 15q, KIAA0319 and DCDC2 on 6p22, and ROBO1 on 13q. FOXP2 on 7q has been implicated in the development of Speech-Language Disorder. No genes for Specific Language Impairment have yet been identified within the two SLI loci. Functional studies have shown that all four dyslexia genes play roles in brain development, and ongoing molecular studies are attempting to elucidate how these genes exert their effects at a subcellular level. Taken together, these genes and loci likely represent only a fraction of the human lexinome, a term we introduce here to refer to the collection of all the genetic and protein elements involved in the development of human language, expression, and reading. LEARNING OUTCOMES The reader will become familiar with (i) methods for identifying genes for complex diseases, (ii) the application of these methods in the elucidation of genes underlying disorders of language and reading, and (iii) the cellular pathways through which polymorphisms in these genes may contribute to the development of the disorders.
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Affiliation(s)
- Christopher J. Gibson
- Department of Pediatrics, Yale Child Health Research Center, Yale University School of Medicine, New Haven, CT, USA
| | - Jeffrey R. Gruen
- Department of Genetics and Investigative Medicine Program, Yale University School of Medicine, New Haven, CT, USA
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Tapia-Páez I, Tammimies K, Massinen S, Roy AL, Kere J. The complex of TFII-I, PARP1, and SFPQ proteins regulates the DYX1C1 gene implicated in neuronal migration and dyslexia. FASEB J 2008; 22:3001-9. [PMID: 18445785 DOI: 10.1096/fj.07-104455] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
DYX1C1 was first identified as a candidate gene for dyslexia susceptibility, and its role in controlling neuronal migration during embryogenesis and effect on learning in rodents have been verified. In contrast, genetic association studies have been ambiguous in replicating its effects on dyslexia. To better understand the regulation of DYX1C1 and the possible functional role of genetic variation in the promoter of DYX1C1, we selected three single-nucleotide polymorphisms (SNPs) with predicted functional consequences or suggested associations to dyslexia for detailed study. Electrophoretic mobility shift assays suggested the allele-specific binding of the transcription factors TFII-I (to rs3743205) and Sp1 (to rs16787 and rs12899331) that could be verified by competition assays. In addition, we purified a complex of protein factors binding to the previously suggested dyslexia-related SNP, -3G/A (rs3743205). Three proteins, TFII-I, PARP1, and SFPQ, were unambiguously identified by mass spectrometry and protein sequencing. Two SNPs, rs16787 and rs3743205, showed significant allelic differences in luciferase assays. Our results show that TFII-I, PARP1, and SFPQ proteins, each previously implicated in gene regulation, form a complex controlling transcription of DYX1C1. Furthermore, allelic differences in the promoter or 5' untranslated region of DYX1C1 may affect factor binding and thus regulation of the gene.
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Affiliation(s)
- Isabel Tapia-Páez
- Department of Biosciences and Nutrition, 141 57 Huddinge, Karolinska Institute, Stockholm, Sweden
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de Kovel CGF, Franke B, Hol FA, Lebrec JJP, Maassen B, Brunner H, Padberg GW, Platko J, Pauls D. Confirmation of dyslexia susceptibility loci on chromosomes 1p and 2p, but not 6p in a Dutch sib-pair collection. Am J Med Genet B Neuropsychiatr Genet 2008; 147:294-300. [PMID: 17886254 DOI: 10.1002/ajmg.b.30598] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this study, we attempted to confirm genetic linkage to developmental dyslexia and reading-related quantitative traits of loci that have been shown to be associated with dyslexia in previous studies. In our sample of 108 Dutch nuclear families, the categorical trait showed strongest linkage to 1p36 (NPL-LOD = 2.1). LOD scores for quantitative traits word-reading, non-word reading, and rapid naming peaked near the same location as the categorical trait, as well as on chromosome 2. Non-word repetition showed little phenotypic correlation with dyslexia or with the other quantitative traits, and this trait showed linkage peaks on 11p and 15q. No evidence for linkage to 6p22-23 was found for this set of families. Comparison of our results and literature data shows that loci link to different phenotypes in different samples. The mutual connections of these traits and their relation to developmental dyslexia remain elusive.
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Affiliation(s)
- Carolien G F de Kovel
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Burbridge TJ, Wang Y, Volz AJ, Peschansky VJ, Lisann L, Galaburda AM, Lo Turco JJ, Rosen GD. Postnatal analysis of the effect of embryonic knockdown and overexpression of candidate dyslexia susceptibility gene homolog Dcdc2 in the rat. Neuroscience 2008; 152:723-33. [PMID: 18313856 DOI: 10.1016/j.neuroscience.2008.01.020] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 01/03/2008] [Accepted: 01/07/2008] [Indexed: 12/13/2022]
Abstract
Embryonic knockdown of candidate dyslexia susceptibility gene (CDSG) homologs in cerebral cortical progenitor cells in the rat results in acute disturbances of neocortical migration. In the current report we investigated the effects of embryonic knockdown and overexpression of the homolog of DCDC2, one of the CDSGs, on the postnatal organization of the cerebral cortex. Using a within-litter design, we transfected cells in rat embryo neocortical ventricular zone around embryonic day (E) 15 with either 1) small hairpin RNA (shRNA) vectors targeting Dcdc2, 2) a DCDC2 overexpression construct, 3) Dcdc2 shRNA along with DCDC2 overexpression construct, 4) an overexpression construct composed of the C terminal domain of DCDC2, or 5) an overexpression construct composed of the DCX terminal domain of DCDC2. RNAi of Dcdc2 resulted in pockets of heterotopic neurons in the periventricular region. Approximately 25% of the transfected brains had hippocampal pyramidal cell migration anomalies. Dcdc2 shRNA-transfected neurons migrated in a bimodal pattern, with approximately 7% of the neurons migrating a short distance from the ventricular zone, and another 30% migrating past their expected lamina. Rats transfected with Dcdc2 shRNA along with the DCDC2 overexpression construct rescued the periventricular heterotopia phenotype, but did not affect the percentage of transfected neurons that migrate past their expected laminar location. There were no malformations associated with any of the overexpression constructs, nor was there a significant laminar disruption of migration. These results support the claim that knockdown of Dcdc2 expression results in neuronal migration disorders similar to those seen in the brains of dyslexics.
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Affiliation(s)
- T J Burbridge
- The Dyslexia Research Laboratory, Division of Behavioral Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA
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Nebert DW, Zhang G, Vesell ES. From human genetics and genomics to pharmacogenetics and pharmacogenomics: past lessons, future directions. Drug Metab Rev 2008; 40:187-224. [PMID: 18464043 PMCID: PMC2752627 DOI: 10.1080/03602530801952864] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A brief history of human genetics and genomics is provided, comparing recent progress in those fields with that in pharmacogenetics and pharmacogenomics, which are subsets of genetics and genomics, respectively. Sequencing of the entire human genome, the mapping of common haplotypes of single-nucleotide polymorphisms (SNPs), and cost-effective genotyping technologies leading to genome-wide association (GWA) studies - have combined convincingly in the past several years to demonstrate the requirements needed to separate true associations from the plethora of false positives. While research in human genetics has moved from monogenic to oligogenic to complex diseases, its pharmacogenetics branch has followed, usually a few years behind. The continuous discoveries, even today, of new surprises about our genome cause us to question reviews declaring that "personalized medicine is almost here" or that "individualized drug therapy will soon be a reality." As summarized herein, numerous reasons exist to show that an "unequivocal genotype" or even an "unequivocal phenotype" is virtually impossible to achieve in current limited-size studies of human populations. This problem (of insufficiently stringent criteria) leads to a decrease in statistical power and, consequently, equivocal interpretation of most genotype-phenotype association studies. It remains unclear whether personalized medicine or individualized drug therapy will ever be achievable by means of DNA testing alone.
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Affiliation(s)
- Daniel W Nebert
- Division of Human Genetics, Department of Pediatrics & Molecular Developmental Biology, Cincinnati, Ohio 45267-0056, USA.
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Gene × Environment interactions in speech sound disorder predict language and preliteracy outcomes. Dev Psychopathol 2007; 19:1047-72. [PMID: 17931434 DOI: 10.1017/s0954579407000533] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractFew studies have investigated the role of gene × environment interactions (G × E) in speech, language, and literacy disorders. Currently, there are two theoretical models, the diathesis–stress model and the bioecological model, that make opposite predictions about the expected direction of G × E, because environmental risk factors may either strengthen or weaken the effect of genes on phenotypes. The purpose of the current study was to test for G × E at two speech sound disorder and reading disability linkage peaks using a sib-pair linkage design and continuous measures of socioeconomic status, home language/literacy environment, and number of ear infections. The interactions were tested using composite speech, language, and preliteracy phenotypes and previously identified linkage peaks on 6p22 and 15q21. Results showed five G × E at both the 6p22 and 15q21 locations across several phenotypes and environmental measures. Four of the five interactions were consistent with the bioecological model of G × E. Each of these four interactions involved environmental measures of the home language/literacy environment. The only interaction that was consistent with the diathesis–stress model was one involving the number of ear infections as the environmental risk variable. The direction of these interactions and possible interpretations are explored in the discussion.
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Caylak E. A review of association and linkage studies for genetical analyses of learning disorders. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:923-43. [PMID: 17510947 DOI: 10.1002/ajmg.b.30537] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Learning disorders (LD) commonly comprise of a heterogeneous group of disorders manifested by unexpected problems in some children's experiences in the academic performance arena. These problems especially comprise of a variety of disorders which may be subclassified to attention-deficit hyperactivity disorder (ADHD), reading disability (RD), specific language impairment (SLI), speech-sound disorder (SSD), and dyspraxia. The aim of this review is to summarize the current molecular studies and some of the most exciting recent developments in molecular genetic research on LD. The findings for the association and linkage of LD with candidate genes will help to set the research agendas for future studies to follow.
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Affiliation(s)
- Emrah Caylak
- Department of Biochemistry and Clinical Biochemistry, Firat University, School of Medicine, Elazig, Turkey.
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Peterson RL, McGrath LM, Smith SD, Pennington BF. Neuropsychology and genetics of speech, language, and literacy disorders. Pediatr Clin North Am 2007; 54:543-61, vii. [PMID: 17543909 DOI: 10.1016/j.pcl.2007.02.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The authors review the neuropsychology, brain bases, and genetics of three related disorders of language development: reading disability, or developmental dyslexia (RD); language impairment (LI); and speech sound disorder (SSD). Over the past three decades, cognitive analysis has demonstrated that the reading difficulties of most children who have RD result from phonologic impairments (difficulties processing the sound structure of language). Although understanding of LI and SSD is somewhat less developed, both disorders are also associated with phonologic impairments, which may account for their comorbidity with RD. Research across levels of analysis is progressing rapidly to promote understanding not only of each disorder by itself but also of the relationships of the three disorders to each other.
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Affiliation(s)
- Robin L Peterson
- Department of Psychology, University of Denver, 2155 South Race Street, Denver, CO 80208, USA.
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Genetik der Lese- und Rechtschreibstörung. Monatsschr Kinderheilkd 2007. [DOI: 10.1007/s00112-007-1479-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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