Investigation of gene-environment interactions in relation to tic severity

Tourette syndrome (TS) is a neuropsychiatric disorder with involvement of genetic and environmental factors. We investigated genetic loci previously implicated in Tourette syndrome and associated disorders in interaction with pre- and perinatal adversity in relation to tic severity using a case-only (N = 518) design. We assessed 98 single-nucleotide polymorphisms (SNPs) selected from (I) top SNPs from genome-wide association studies (GWASs) of TS; (II) top SNPs from GWASs of obsessive–compulsive disorder (OCD), attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD); (III) SNPs previously implicated in candidate-gene studies of TS; (IV) SNPs previously implicated in OCD or ASD; and (V) tagging SNPs in neurotransmitter-related candidate genes. Linear regression models were used to examine the main effects of the SNPs on tic severity, and the interaction effect of these SNPs with a cumulative pre- and perinatal adversity score. Replication was sought for SNPs that met the threshold of significance (after correcting for multiple testing) in a replication sample (N = 678). One SNP (rs7123010), previously implicated in a TS meta-analysis, was significantly related to higher tic severity. We found a gene–environment interaction for rs6539267, another top TS GWAS SNP. These findings were not independently replicated. Our study highlights the future potential of TS GWAS top hits in gene–environment studies

Investigation of previously implicated genetic variants in chronic tic disorders: a transmission disequilibrium test approach

Genetic studies in Tourette syndrome (TS) are characterized by scattered and poorly replicated findings. We aimed to replicate findings from candidate gene and genome-wide association studies (GWAS). Our cohort included 465 probands with chronic tic disorder (93% TS) and both parents from 412 families (some probands were siblings). We assessed 75 single nucleotide polymorphisms (SNPs) in 465 parent–child trios; 117 additional SNPs in 211 trios; and 4 additional SNPs in 254 trios. We performed SNP and gene-based transmission disequilibrium tests and compared nominally significant SNP results with those from a large independent case–control cohort. After quality control 71 SNPs were available in 371 trios; 112 SNPs in 179 trios; and 3 SNPs in 192 trios. 17 were candidate SNPs implicated in TS and 2 were implicated in obsessive–compulsive disorder (OCD) or autism spectrum disorder (ASD); 142 were tagging SNPs from eight monoamine neurotransmitter-related genes (including dopamine and serotonin); 10 were top SNPs from TS GWAS; and 13 top SNPs from attention-deficit/hyperactivity disorder, OCD, or ASD GWAS. None of the SNPs or genes reached significance after adjustment for multiple testing. We observed nominal significance for the candidate SNPs rs3744161 (TBCD) and rs4565946 (TPH2) and for five tagging SNPs; none of these showed significance in the independent cohort. Also, SLC1A1 in our gene-based analysis and two TS GWAS SNPs showed nominal significance, rs11603305 (intergenic) and rs621942 (PICALM). We found no convincing support for previously implicated genetic polymorphisms. Targeted re-sequencing should fully appreciate the relevance of candidate genes

Synaptic processes and immune-related pathways implicated in Tourette syndrome.

Tourette syndrome (TS) is a neuropsychiatric disorder of complex genetic architecture involving multiple interacting genes. Here, we sought to elucidate the pathways that underlie the neurobiology of the disorder through genome-wide analysis. We analyzed genome-wide genotypic data of 3581 individuals with TS and 7682 ancestry-matched controls and investigated associations of TS with sets of genes that are expressed in particular cell types and operate in specific neuronal and glial functions. We employed a self-contained, set-based association method (SBA) as well as a competitive gene set method (MAGMA) using individual-level genotype data to perform a comprehensive investigation of the biological background of TS. Our SBA analysis identified three significant gene sets after Bonferroni correction, implicating ligand-gated ion channel signaling, lymphocytic, and cell adhesion and transsynaptic signaling processes. MAGMA analysis further supported the involvement of the cell adhesion and trans-synaptic signaling gene set. The lymphocytic gene set was driven by variants in FLT3, raising an intriguing hypothesis for the involvement of a neuroinflammatory element in TS pathogenesis. The indications of involvement of ligand-gated ion channel signaling reinforce the role of GABA in TS, while the association of cell adhesion and trans-synaptic signaling gene set provides additional support for the role of adhesion molecules in neuropsychiatric disorders. This study reinforces previous findings but also provides new insights into the neurobiology of TS

Synaptic processes and immune-related pathways implicated in Tourette syndrome

Tourette syndrome (TS) is a neuropsychiatric disorder of complex genetic architecture involving multiple interacting genes. Here, we sought to elucidate the pathways that underlie the neurobiology of the disorder through genome-wide analysis. We analyzed genome-wide genotypic data of 3581 individuals with TS and 7682 ancestry-matched controls and investigated associations of TS with sets of genes that are expressed in particular cell types and operate in specific neuronal and glial functions. We employed a self-contained, set-based association method (SBA) as well as a competitive gene set method (MAGMA) using individual-level genotype data to perform a comprehensive investigation of the biological background of TS. Our SBA analysis identified three significant gene sets after Bonferroni correction, implicating ligand-gated ion channel signaling, lymphocytic, and cell adhesion and transsynaptic signaling processes. MAGMA analysis further supported the involvement of the cell adhesion and trans-synaptic signaling gene set. The lymphocytic gene set was driven by variants in FLT3, raising an intriguing hypothesis for the involvement of a neuroinflammatory element in TS pathogenesis. The indications of involvement of ligand-gated ion channel signaling reinforce the role of GABA in TS, while the association of cell adhesion and trans-synaptic signaling gene set provides additional support for the role of adhesion molecules in neuropsychiatric disorders. This study reinforces previous findings but also provides new insights into the neurobiology of TS

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe

European Multicentre Tics in Children Studies (EMTICS): protocol for two cohort studies to assess risk factors for tic onset and exacerbation in children and adolescents

Genetic predisposition, autoimmunity and environmental factors [e.g. pre- and perinatal difficulties, Group A Streptococcal (GAS) and other infections, stress-inducing events] might interact to create a neurobiological vulnerability to the development of tics and associated behaviours. However, the existing evidence for this relies primarily on small prospective or larger retrospective population-based studies, and is therefore still inconclusive. This article describes the design and methodology of the EMTICS study, a longitudinal observational European multicentre study involving 16 clinical centres, with the following objectives: (1) to investigate the association of environmental factors (GAS exposure and psychosocial stress, primarily) with the onset and course of tics and/or obsessive-compulsive symptoms through the prospective observation of at-risk individuals (ONSET cohort: 260 children aged 3-10 years who are tic-free at study entry and have a first-degree relative with a chronic tic disorder) and affected individuals (COURSE cohort: 715 youth aged 3-16 years with a tic disorder); (2) to characterise the immune response to microbial antigens and the host's immune response regulation in association with onset and exacerbations of tics; (3) to increase knowledge of the human gene pathways influencing the pathogenesis of tic disorders; and (4) to develop prediction models for the risk of onset and exacerbations of tic disorders. The EMTICS study is, to our knowledge, the largest prospective cohort assessment of the contribution of different genetic and environmental factors to the risk of developing tics in putatively predisposed individuals and to the risk of exacerbating tics in young individuals with chronic tic disorders

Validation of the Spanish version of the Dimensional Yale-Brown Obsessive-Compulsive Scale (DYBOCS) in children and adolescents

Background: Obsessive compulsive disorder (OCD) is best understood as a complex overlap of obsessive compulsive (OC) symptom dimensions with specific clinical and etiological characteristics. The Dimensional Yale Brown Obsessive Compulsive Scale (DYBOCS) was developed to assess the presence and severity of each of these OC symptom dimensions. Despite showing excellent psychometric properties in adults, the psychometric properties of the DYBOCS have not been widely investigated in children and adolescents. Methods: We examined the psychometric properties of the DYBOCS Spanish version in a sample of 97 OCD children and adolescents. Results: The results of the psychometric analyses Were excellent overall. The internal consistency for each OC symptom dimension was high, although somewhat lower than in previous studies with adult samples. The DYBOCS showed overall good convergent and divergent validity. Factors obtained from a principal component analysis corresponded with the five DYBOCS dimensions (aggressive, sexual/religious, contamination symmetry and hoarding) and each one accounted for approximately 20% of the variance. Conclusions: The DYBOCS is a valid instrument for assessing the frequency and severity of OC symptom dimensions in children and adolescents with OCD. The principal component analysis supported the division of OC symptoms into five dimensions. OCD is a heterogeneous disorder, and a dimensional approach can help to understand its clinical, etiological and treatment response characteristics. (C) 2016 Elsevier Inc. All rights reserved.Catalonia Government, Comissionat per Universitats i Recerca del Departament d'Innovacio, Universitats I Empresa (DIVE)Hosp Clin Univ, Inst Neurosci, Dept Child & Adolescent Psychiat & Psychol, C Villarroel 170, Barcelona 08036, SpainIDIBAPS, Barcelona, SpainInst Carlos III, Ctr Invest Red Salud Mental CIBERSAM, Barcelona, SpainBellvitge Hosp, Dept Psychiat, Obsess Compuls Clin & Res Unit, Feixa Llarga S-N, Barcelona 08907, SpainUniv Barcelona, Bellvitge Biomed Res Inst IDIBELL, Bellvitge Campus, Barcelona, SpainUniv Barcelona, Dept Clin Sci, Bellvitge Campus, Barcelona, SpainFed Univ Sao Paulo UNIFESP, Dept Psychiat, Child & Adolescent Psychiat Unit UPIA, Rua Pedro Toledo 590, BR-04038020 Sao Paulo, BrazilUniv Barcelona, Dept Psychiat & Clin Psychobiol, C Casanova 143, E-08036 Barcelona, SpainFed Univ Sao Paulo UNIFESP, Dept Psychiat, Child & Adolescent Psychiat Unit UPIA, Rua Pedro Toledo 590, BR-04038020 Sao Paulo, BrazilCatalonia Government, Comissionat per Universitats i Recerca del Departament d'Innovacio, Universitats I Empresa (DIVE): 2014SGR489Web of Scienc

Teoría de la mente en trastornos del neurodesarrollo: más allá del trastorno del espectro autista

Resumen: Introducción: La teoría de la mente (ToM) es la capacidad humana de percibir, interpretar y atribuir los estados mentales de las otras personas y la alteración de esta función cognitiva es un síntoma nuclear del trastorno del espectro autista (TEA). Hay otros trastornos del neurodesarrollo como el trastorno obsesivo-compulsivo de inicio en la infancia (TOC) y el síndrome de Tourette (ST), que pueden presentarse con disfunciones cognitivas, y en los que la ToM ha sido menos estudiada, especialmente en población juvenil. El objetivo de este estudio fue comparar la ToM avanzada entre grupos de jóvenes con diagnóstico de TOC, ST o TEA y un grupo de controles sanos. Métodos: Se entrevistaron clínicamente a varones de entre 11 y 17 años con diagnóstico principal de TOC (n = 19), ST (n = 14), TEA (n = 18), y un grupo control de sujetos sanos (n = 20). Se les administró instrumentos de estimación de cociente intelectual, severidad de los síntomas psiquiátricos y las pruebas para evaluar la ToM: la tarea Historias de la vida cotidiana y el Test de la mirada. Resultados: Los jóvenes con ST presentan dificultades similares para resolver tareas de ToM avanzada al nivel de los pacientes con TEA, a diferencia de los pacientes con TOC de inicio en la infancia que presentan resultados similares a los controles sanos. Conclusiones: La ToM está alterada en otros trastornos del neurodesarrollo más allá del TEA, como en el ST. Abstract: Introduction: Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group. Methods: Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n = 19), TS (n = 14), or ASD (n = 18), and a control group (n = 20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the “Stories from everyday life” task and the “Reading the mind in the eyes” test). Results: Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls. Conclusions: ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS

Theory of mind in neurodevelopmental disorders: beyond autistic spectrum disorder

Introduction: Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group. Methods: Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n = 19), TS (n = 14), or ASD (n = 18), and a control group (n = 20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the ''Stories from everyday life'' task and the ''Reading the mind in the eyes” test). Results: Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls. Conclusions: ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS. Resumen: Introducción: La Teoría de la Mente (ToM) es la capacidad humana de percibir, interpretar y atribuir los estados mentales de las otras personas y la alteración de esta función cognitiva es un síntoma nuclear del Trastorno del Espectro Autista (TEA). Hay otros trastornos del neurodesarrollo como el Trastorno Obsesivo-Compulsivo de inicio en la infancia (TOC) y el Síndrome de Tourette (ST), que pueden presentarse con disfunciones cognitivas, y en los que la ToM ha sido menos estudiada, especialmente en población juvenil. El objetivo de este estudio fue comparar la ToM avanzada entre grupos de jóvenes con diagnóstico de TOC, ST o TEA y un grupo de controles sanos. Métodos: Se entrevistaron clínicamente a varones de entre 11 y 17 años con diagnóstico principal de TOC (n = 19), ST (n = 14), TEA (n = 18), y un grupo control de sujetos sanos (n = 20). Se les administraron instrumentos de estimación de cociente intelectual, severidad de los síntomas psiquiátricos, y las pruebas para evaluar la ToM: la tarea Historias de la Vida Cotidiana y el Test de la Mirada. Resultados: Los jóvenes con ST presentan dificultades similares para resolver tareas de ToM avanzada al nivel de los pacientes con TEA, a diferencia de los pacientes con TOC de inicio en la infancia que presentan resultados similares a los controles sanos. Conclusiones: La ToM está alterada en otros trastornos del neurodesarrollo más allá del TEA, como en el ST