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Bieder A, Yoshihara M, Katayama S, Krjutškov K, Falk A, Kere J, Tapia-Páez I. Dyslexia Candidate Gene and Ciliary Gene Expression Dynamics During Human Neuronal Differentiation. Mol Neurobiol 2020; 57:2944-2958. [PMID: 32445086 PMCID: PMC7320047 DOI: 10.1007/s12035-020-01905-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/19/2020] [Indexed: 11/30/2022]
Abstract
Developmental dyslexia (DD) is a neurodevelopmental condition with complex genetic mechanisms. A number of candidate genes have been identified, some of which are linked to neuronal development and migration and to ciliary functions. However, expression and regulation of these genes in human brain development and neuronal differentiation remain uncharted. Here, we used human long-term self-renewing neuroepithelial stem (lt-NES, here termed NES) cells derived from human induced pluripotent stem cells to study neuronal differentiation in vitro. We characterized gene expression changes during differentiation by using RNA sequencing and validated dynamics for selected genes by qRT-PCR. Interestingly, we found that genes related to cilia were significantly enriched among upregulated genes during differentiation, including genes linked to ciliopathies with neurodevelopmental phenotypes. We confirmed the presence of primary cilia throughout neuronal differentiation. Focusing on dyslexia candidate genes, 33 out of 50 DD candidate genes were detected in NES cells by RNA sequencing, and seven candidate genes were upregulated during differentiation to neurons, including DYX1C1 (DNAAF4), a highly replicated DD candidate gene. Our results suggest a role of ciliary genes in differentiating neuronal cells and show that NES cells provide a relevant human neuronal model to study ciliary and DD candidate genes.
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Affiliation(s)
- Andrea Bieder
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden.
| | - Masahito Yoshihara
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden
| | - Shintaro Katayama
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden
| | - Kaarel Krjutškov
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden.,Competence Centre on Health Technologies, Tartu, Estonia.,Research Program of Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Juha Kere
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden. .,Research Program of Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki, Finland. .,Folkhälsan Institute of Genetics, Helsinki, Finland. .,School of Basic and Medical Biosciences, King's College London, London, UK.
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Price KM, Wigg KG, Feng Y, Blokland K, Wilkinson M, He G, Kerr EN, Carter TC, Guger SL, Lovett MW, Strug LJ, Barr CL. Genome-wide association study of word reading: Overlap with risk genes for neurodevelopmental disorders. GENES BRAIN AND BEHAVIOR 2020; 19:e12648. [PMID: 32108986 DOI: 10.1111/gbb.12648] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 01/28/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
Reading disabilities (RD) are the most common neurocognitive disorder, affecting 5% to 17% of children in North America. These children often have comorbid neurodevelopmental/psychiatric disorders, such as attention deficit/hyperactivity disorder (ADHD). The genetics of RD and their overlap with other disorders is incompletely understood. To contribute to this, we performed a genome-wide association study (GWAS) for word reading. Then, using summary statistics from neurodevelopmental/psychiatric disorders, we computed polygenic risk scores (PRS) and used them to predict reading ability in our samples. This enabled us to test the shared aetiology between RD and other disorders. The GWAS consisted of 5.3 million single nucleotide polymorphisms (SNPs) and two samples; a family-based sample recruited for reading difficulties in Toronto (n = 624) and a population-based sample recruited in Philadelphia [Philadelphia Neurodevelopmental Cohort (PNC)] (n = 4430). The Toronto sample SNP-based analysis identified suggestive SNPs (P ~ 5 × 10-7 ) in the ARHGAP23 gene, which is implicated in neuronal migration/axon pathfinding. The PNC gene-based analysis identified significant associations (P < 2.72 × 10-6 ) for LINC00935 and CCNT1, located in the region of the KANSL2/CCNT1/LINC00935/SNORA2B/SNORA34/MIR4701/ADCY6 genes on chromosome 12q, with near significant SNP-based analysis. PRS identified significant overlap between word reading and intelligence (R2 = 0.18, P = 7.25 × 10-181 ), word reading and educational attainment (R2 = 0.07, P = 4.91 × 10-48 ) and word reading and ADHD (R2 = 0.02, P = 8.70 × 10-6 ; threshold for significance = 7.14 × 10-3 ). Overlap was also found between RD and autism spectrum disorder (ASD) as top-ranked genes were previously implicated in autism by rare and copy number variant analyses. These findings support shared risk between word reading, cognitive measures, educational outcomes and neurodevelopmental disorders, including ASD.
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Affiliation(s)
- Kaitlyn M Price
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Karen G Wigg
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Yu Feng
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Kirsten Blokland
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Margaret Wilkinson
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Gengming He
- Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elizabeth N Kerr
- Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Tasha-Cate Carter
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Holland Bloorview Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Sharon L Guger
- Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Maureen W Lovett
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Lisa J Strug
- Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Cathy L Barr
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Mascheretti S, Gori S, Trezzi V, Ruffino M, Facoetti A, Marino C. Visual motion and rapid auditory processing are solid endophenotypes of developmental dyslexia. GENES BRAIN AND BEHAVIOR 2017; 17:70-81. [PMID: 28834383 DOI: 10.1111/gbb.12409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/19/2017] [Accepted: 08/14/2017] [Indexed: 12/18/2022]
Abstract
Although a genetic component is known to have an important role in the etiology of developmental dyslexia (DD), we are far from understanding the molecular etiopathogenetic pathways. Reduced measures of neurobiological functioning related to reading (dis)ability, i.e. endophenotypes (EPs), are promising targets for gene finding and the elucidation of the underlying mechanisms. In a sample of 100 nuclear families with DD (229 offspring) and 83 unrelated typical readers, we tested whether a set of well-established, cognitive phenotypes related to DD [i.e. rapid auditory processing (RAP), rapid automatized naming (RAN), multisensory nonspatial attention and visual motion processing] fulfilled the criteria of the EP construct. Visual motion and RAP satisfied all testable criteria (i.e. they are heritable, associate with the disorder, co-segregate with the disorder within a family and represent reproducible measures) and are therefore solid EPs of DD. Multisensory nonspatial attention satisfied three of four criteria (i.e. it associates with the disorder, co-segregates with the disorder within a family and represents a reproducible measure) and is therefore a potential EP for DD. Rapid automatized naming is heritable but does not meet other criteria of the EP construct. We provide the first evidence of a methodologically and statistically sound approach for identifying EPs for DD to be exploited as a solid alternative basis to clinical phenotypes in neuroscience.
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Affiliation(s)
- S. Mascheretti
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
| | - S. Gori
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
- Department of Human and Social Sciences; University of Bergamo; Bergamo Italy
| | - V. Trezzi
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
| | - M. Ruffino
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
| | - A. Facoetti
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
- Developmental Cognitive Neuroscience Lab, Department of General Psychology; University of Padua; Padua Italy
| | - C. Marino
- Child Psychopathology Unit; Scientific Institute, IRCCS Eugenio Medea; Bosisio Parini Italy
- Centre for Addiction and Mental Health; University of Toronto; ON Canada
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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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Carrion-Castillo A, van Bergen E, Vino A, van Zuijen T, de Jong PF, Francks C, Fisher SE. Evaluation of results from genome-wide studies of language and reading in a novel independent dataset. GENES BRAIN AND BEHAVIOR 2017; 15:531-41. [PMID: 27198479 DOI: 10.1111/gbb.12299] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/17/2016] [Accepted: 05/17/2016] [Indexed: 01/05/2023]
Abstract
Recent genome-wide association scans (GWAS) for reading and language abilities have pin-pointed promising new candidate loci. However, the potential contributions of these loci remain to be validated. In this study, we tested 17 of the most significantly associated single nucleotide polymorphisms (SNPs) from these GWAS studies (P < 10(-6) in the original studies) in a new independent population dataset from the Netherlands: known as Familial Influences on Literacy Abilities. This dataset comprised 483 children from 307 nuclear families and 505 adults (including parents of participating children), and provided adequate statistical power to detect the effects that were previously reported. The following measures of reading and language performance were collected: word reading fluency, nonword reading fluency, phonological awareness and rapid automatized naming. Two SNPs (rs12636438 and rs7187223) were associated with performance in multivariate and univariate testing, but these did not remain significant after correction for multiple testing. Another SNP (rs482700) was only nominally associated in the multivariate test. For the rest of the SNPs, we did not find supportive evidence of association. The findings may reflect differences between our study and the previous investigations with respect to the language of testing, the exact tests used and the recruitment criteria. Alternatively, most of the prior reported associations may have been false positives. A larger scale GWAS meta-analysis than those previously performed will likely be required to obtain robust insights into the genomic architecture underlying reading and language.
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Affiliation(s)
- A Carrion-Castillo
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands
| | - E van Bergen
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - A Vino
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands
| | - T van Zuijen
- Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, the Netherlands
| | - P F de Jong
- Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, the Netherlands
| | - C Francks
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - S E Fisher
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
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Neurogenetics of developmental dyslexia: from genes to behavior through brain neuroimaging and cognitive and sensorial mechanisms. Transl Psychiatry 2017; 7:e987. [PMID: 28045463 PMCID: PMC5545717 DOI: 10.1038/tp.2016.240] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 10/15/2016] [Indexed: 01/18/2023] Open
Abstract
Developmental dyslexia (DD) is a complex neurodevelopmental deficit characterized by impaired reading acquisition, in spite of adequate neurological and sensorial conditions, educational opportunities and normal intelligence. Despite the successful characterization of DD-susceptibility genes, we are far from understanding the molecular etiological pathways underlying the development of reading (dis)ability. By focusing mainly on clinical phenotypes, the molecular genetics approach has yielded mixed results. More optimally reduced measures of functioning, that is, intermediate phenotypes (IPs), represent a target for researching disease-associated genetic variants and for elucidating the underlying mechanisms. Imaging data provide a viable IP for complex neurobehavioral disorders and have been extensively used to investigate both morphological, structural and functional brain abnormalities in DD. Performing joint genetic and neuroimaging studies in humans is an emerging strategy to link DD-candidate genes to the brain structure and function. A limited number of studies has already pursued the imaging-genetics integration in DD. However, the results are still not sufficient to unravel the complexity of the reading circuit due to heterogeneous study design and data processing. Here, we propose an interdisciplinary, multilevel, imaging-genetic approach to disentangle the pathways from genes to behavior. As the presence of putative functional genetic variants has been provided and as genetic associations with specific cognitive/sensorial mechanisms have been reported, new hypothesis-driven imaging-genetic studies must gain momentum. This approach would lead to the optimization of diagnostic criteria and to the early identification of 'biologically at-risk' children, supporting the definition of adequate and well-timed prevention strategies and the implementation of novel, specific remediation approach.
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Kong R, Song RR. [Research advances in susceptible genes for developmental dyslexia in children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2016; 18:1308-1312. [PMID: 27974128 PMCID: PMC7403085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 08/24/2016] [Indexed: 12/16/2023]
Abstract
Developmental dyslexia in children is one of the neurodevelopmental disorders and is affected by various susceptible genes. In recent years, researchers have found some susceptible genes for dyslexia via chromosome analysis, genome-wide association studies, association analysis, gene function research, neuroimaging, and neurophysiological techniques. This article reviews the research advances in susceptible genes for developmental dyslexia, and with the study on susceptible genes for dyslexia, it lays a foundation for in-depth studies on the "gene-brain-behavior" level and provides scientific clues for exploring etiology and pathogenesis of dyslexia.
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Affiliation(s)
- Rui Kong
- Department of Maternal and Child Health Care, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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Rüsseler J, Gerth I, Heldmann M, Münte T. Audiovisual perception of natural speech is impaired in adult dyslexics: An ERP study. Neuroscience 2015; 287:55-65. [DOI: 10.1016/j.neuroscience.2014.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 12/05/2014] [Accepted: 12/05/2014] [Indexed: 01/30/2023]
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Tran C, Wigg KG, Zhang K, Cate-Carter TD, Kerr E, Field LL, Kaplan BJ, Lovett MW, Barr CL. Association of the ROBO1 gene with reading disabilities in a family-based analysis. GENES, BRAIN, AND BEHAVIOR 2014; 13:430-8. [PMID: 24612512 PMCID: PMC4930671 DOI: 10.1111/gbb.12126] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 01/10/2014] [Accepted: 02/18/2014] [Indexed: 01/28/2023]
Abstract
Linkage studies have identified a locus on chromosome 3 as reading disabilities (RD) and speech and sound disorder (SSD) susceptibility region, with both RD and SSD sharing similar phonological processing and phonological memory difficulties. One gene in this region, roundabout homolog 1 (ROBO1), has been indicated as a RD candidate and has shown significant association with measures of phonological memory in a population-based sample. In this study, we conducted a family-based association analysis using two independent samples collected in Toronto and Calgary, Canada. Using the two samples, we tested for association between ROBO1 single nucleotide polymorphisms (SNPs) and RD, along with quantitative measures for reading, spelling and phonological memory. One SNP, rs331142, which was selected based on its correlation with ROBO1 expression in brain tissue, was found to be significantly associated with RD in the Toronto sample with over transmission of the minor C allele (P = 0.001), correlated with low expression. This SNP is located ~200 bp from a putative enhancer and results for a marker within the enhancer, rs12495133, showed evidence for association with the same allele in both the Toronto and Calgary samples (P = 0.005 and P = 0.007). These results support previous associations between ROBO1 and RD, as well as correlation with low gene expression, suggesting a possible mechanism of risk conferred by this gene.
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Affiliation(s)
- C. Tran
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario
- Institute of Medical Science, University of Toronto, Toronto, Ontario
| | - K. G. Wigg
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario
| | - K. Zhang
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario
| | - T. D. Cate-Carter
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, Ontario
| | - E. Kerr
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, Ontario
| | - L. L. Field
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia
| | - B. J. Kaplan
- Department of Paediatrics, Faculty of Medicine, Alberta Children’s Hospital, University of Calgary, Calgary, Alberta, Canada
| | - M. W. Lovett
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, Ontario
| | - C. L. Barr
- Genetics and Development Division, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario
- Institute of Medical Science, University of Toronto, Toronto, Ontario
- Neurosciences & Mental Health Program, The Hospital for Sick Children, Toronto, Ontario
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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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Carrion-Castillo A, Franke B, Fisher SE. Molecular genetics of dyslexia: an overview. DYSLEXIA (CHICHESTER, ENGLAND) 2013; 19:214-240. [PMID: 24133036 DOI: 10.1002/dys.1464] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/02/2013] [Indexed: 05/28/2023]
Abstract
Dyslexia is a highly heritable learning disorder with a complex underlying genetic architecture. Over the past decade, researchers have pinpointed a number of candidate genes that may contribute to dyslexia susceptibility. Here, we provide an overview of the state of the art, describing how studies have moved from mapping potential risk loci, through identification of associated gene variants, to characterization of gene function in cellular and animal model systems. Work thus far has highlighted some intriguing mechanistic pathways, such as neuronal migration, axon guidance, and ciliary biology, but it is clear that we still have much to learn about the molecular networks that are involved. We end the review by highlighting the past, present, and future contributions of the Dutch Dyslexia Programme to studies of genetic factors. In particular, we emphasize the importance of relating genetic information to intermediate neurobiological measures, as well as the value of incorporating longitudinal and developmental data into molecular designs.
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Affiliation(s)
- Amaia Carrion-Castillo
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands
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12
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Luciano M, Evans DM, Hansell NK, Medland SE, Montgomery GW, Martin NG, Wright MJ, Bates TC. A genome-wide association study for reading and language abilities in two population cohorts. GENES BRAIN AND BEHAVIOR 2013; 12:645-52. [PMID: 23738518 PMCID: PMC3908370 DOI: 10.1111/gbb.12053] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 03/04/2013] [Accepted: 05/24/2013] [Indexed: 01/21/2023]
Abstract
Candidate genes have been identified for both reading and language, but most of the heritable variance in these traits remains unexplained. Here, we report a genome-wide association meta-analysis of two large cohorts: population samples of Australian twins and siblings aged 12–25 years (n = 1177 from 538 families), and a younger cohort of children of the UK Avon Longitudinal Study of Parents and their Children (aged 8 and 9 years; maximum n = 5472). Suggestive association was indicated for reading measures and non-word repetition (NWR), with the greatest support found for single nucleotide polymorphisms (SNPs) in the pseudogene, ABCC13 (P = 7.34 × 10−8), and the gene, DAZAP1 (P = 1.32 × 10−6). Gene-based analyses showed significant association (P < 2.8 × 10−6) for reading and spelling with genes CD2L1, CDC2L2 and RCAN3 in two loci on chromosome 1. Some support was found for the same SNPs having effects on both reading skill and NWR, which is compatible with behavior genetic evidence for influences of reading acquisition on phonological-task performance. The results implicate novel candidates for study in additional cohorts for reading and language abilities.
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Affiliation(s)
- M Luciano
- Centre for Cognitive Aging and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK.
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