0000000000125736
AUTHOR
Fernando Mulas
Meta-analysis of genome-wide association studies of attention-deficit/hyperactivity disorder
Contains fulltext : 87688.pdf (Publisher’s version ) (Closed access) OBJECTIVE: Although twin and family studies have shown attention-deficit/hyperactivity disorder (ADHD) to be highly heritable, genetic variants influencing the trait at a genome-wide significant level have yet to be identified. As prior genome-wide association studies (GWAS) have not yielded significant results, we conducted a meta-analysis of existing studies to boost statistical power. METHOD: We used data from four projects: a) the Children's Hospital of Philadelphia (CHOP); b) phase I of the International Multicenter ADHD Genetics project (IMAGE); c) phase II of IMAGE (IMAGE II); and d) the Pfizer-funded study from the…
Population differences in the International Multi-Centre ADHD Gene Project.
Contains fulltext : 71443.pdf (Publisher’s version ) (Closed access) The International Multi-Centre ADHD Gene sample consists of 674 families from eight countries (Belgium, England, Germany, Holland, Ireland, Israel, Spain, and Switzerland) ascertained from clinics for combined-type attention definity hyperactivity disorder in an offspring. 863 SNPs were successfully genotyped across 47 autosomal genes implicated in psychiatric disorders yielding a single nucleotide polymorphism (SNP) density of approximately one SNP per 2.5 kb. A global test of heterogeneity showed 269 SNPs nominally significant (expected 43). Inclusion of the Israeli population accounted for approximately 70% of these nom…
DSM-IV Combined Type ADHD Shows Familial Association With Sibling Trait Scores
Contains fulltext : 69060.pdf (Publisher’s version ) (Closed access) Attention deficit hyperactivity disorder (ADHD) is a discrete clinical syndrome characterized by the triad of inattention, hyperactivity, and impulsivity in the context of marked impairments. Molecular genetic studies have been successful in identifying genetic variants associated with ADHD, particularly with DSM-IV inattentive and combined subtypes. Quantitative trait locus (QTL) approaches to linkage and association mapping have yet to be widely used in ADHD research, although twin studies investigating individual differences suggest that genetic liability for ADHD is continuously distributed throughout the population, u…
Association between DRD2/DRD4 interaction and conduct disorder: a potential developmental pathway to alcohol dependence
1 Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil 2 King’s College London, Institute of Psychiatry, MRC Social Genetic and Developmental Psychiatry Centre, London, United Kingdom, UK 3 Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany 4 Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands 5 Psychology Department, National University of Singapore, Singapore, Singapore 6 Department of Psychiatry, Donders Institute for Brain, Cognition an…
Genome-wide association scan of quantitative traits for attention deficit hyperactivity disorder identifies novel associations and confirms candidate gene associations
Contains fulltext : 70192.pdf (Publisher’s version ) (Closed access) Attention deficit hyperactivity disorder (ADHD) is a complex condition with environmental and genetic etiologies. Up to this point, research has identified genetic associations with candidate genes from known biological pathways. In order to identify novel ADHD susceptibility genes, 600,000 SNPs were genotyped in 958 ADHD proband-parent trios. After applying data cleaning procedures we examined 429,981 autosomal SNPs in 909 family trios. We generated six quantitative phenotypes from 18 ADHD symptoms to be used in genome-wide association analyses. With the PBAT screening algorithm, we identified 2 SNPs, rs6565113 and rs5526…
Genome-wide association scan of the time to onset of attention deficit hyperactivity disorder.
Contains fulltext : 70149.pdf (Publisher’s version ) (Closed access) A time-to-onset analysis for family-based samples was performed on the genomewide association (GWAS) data for attention deficit hyperactivity disorder (ADHD) to determine if associations exist with the age at onset of ADHD. The initial dataset consisted of 958 parent-offspring trios that were genotyped on the Perlegen 600,000 SNP array. After data cleaning procedures, 429,981 autosomal SNPs and 930 parent-offspring trios were used found suitable for use and a family-based logrank analysis was performed using that age at first ADHD symptoms as the quantitative trait of interest. No SNP achieved genome-wide significance, and…
Emotional lability in children and adolescents with attention deficit/hyperactivity disorder (ADHD): clinical correlates and familial prevalence
Background: The goal of this study was to investigate the occurrence, severity and clinical correlates of emotional lability (EL) in children with attention deficit/hyperactivity disorder (ADHD), and to examine factors contributing to EL and familiality of EL in youth with ADHD. Methods: One thousand, one hundred and eighty-six children with ADHD combined type and 1827 siblings (aged 6–18 years) were assessed for symptoms of EL, ADHD, associated psychopathology and comorbid psychiatric disorders with a structured diagnostic interview (PACS) as well as parent and teacher ratings of psychopathology (SDQ; CPRS-R:L; CTRS-R:L). Analyses of variance, regression analyses, ?2-tests or loglinear mod…
A functional variant of the serotonin transporter gene (SLC6A4) moderates impulsive choice in attention-deficit/hyperactivity disorder boys and siblings
Item does not contain fulltext BACKGROUND: Impulsive drive for immediate reward (IDIR) and delay aversion are dissociable elements of the preference for immediate over delayed rewards seen in attention-deficit/hyperactivity disorder (ADHD). We hypothesized that IDIR would be associated with dopamine regulating genes and delay aversion would be associated with serotonin-regulating genes. METHODS: Impulsive drive for immediate reward and delay aversion were measured in 459 male children and adolescents (328 ADHD and 131 unaffected siblings) with a laboratory choice task. The sample was genotyped for the 5HTT (SLC6A4) promoter serotonin-transporter-linked polymorphic region polymorphism and a …
El papel de los padres en el desarrollo y aprendizaje de los niños con trastorno por déficit de atención con hiperactividad
Introduccion. Los padres de ninos con trastorno por deficit de atencion con hiperactividad (TDAH) experimentan altos niveles de estres, frecuentes enfrentamientos de pareja y limitaciones en su vida social, factores que influyen en la evolucion del trastorno y constituyen una meta terapeutica prioritaria. Objetivos. Analizar el impacto del TDAH en el ambito familiar (economia, relaciones padrehijo y entre hermanos, vida social y sentimientos y actitudes de los padres hacia su hijo) y estudiar posibles cambios en el uso de tecnicas de modificacion de conducta y en las atribuciones/expectativas de los padres, tras un programa de asesoramiento. Sujetos y metodos. Para el primer objetivo, 36 p…
Cotransmission of conduct problems with attention-deficit/hyperactivity disorder: familial evidence for a distinct disorder
Contains fulltext : 69215.pdf (Publisher’s version ) (Closed access) Common disorders of childhood and adolescence are attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD). For one to two cases in three diagnosed with ADHD the disorders may be comorbid. However, whether comorbid conduct problems (CP) represents a separate disorder or a severe form of ADHD remains controversial. We investigated familial recurrence patterns of the pure or comorbid condition in families with at least two children and one definite case of DSM-IV ADHDct (combined-type) as part of the International Multicentre ADHD Genetics Study (IMAGE). Using case diagno…
Partial replication of a DRD4 association in ADHD individuals using a statistically derived quantitative trait for ADHD in a family-based association test.
Contains fulltext : 52515.pdf (Publisher’s version ) (Closed access) BACKGROUND: Previous research found an association between single nucleotide polymorphisms (SNPs) in the promoter region of DRD4 and statistically derived phenotypes generated from attention-deficit/hyperactivity disorder (ADHD) symptoms. We sought to replicate this finding by using the same methodology in an independent sample of ADHD individuals. METHODS: Four SNPs were genotyped in and around DRD4 in 2631 individuals in 642 families. We developed a quantitative phenotype at each SNP by weighting nine inattentive and nine hyperactive-impulsive symptoms. The weights were selected to maximize the heritability at each SNP. …
The ATXN1 and TRIM31 genes are related to intelligence in an ADHD background: evidence from a large collaborative study totaling 4,963 subjects
Contains fulltext : 96400.pdf (Publisher’s version ) (Closed access) Intelligence is a highly heritable trait for which it has proven difficult to identify the actual genes. In the past decade, five whole-genome linkage scans have suggested genomic regions important to human intelligence; however, so far none of the responsible genes or variants in those regions have been identified. Apart from these regions, a handful of candidate genes have been identified, although most of these are in need of replication. The recent growth in publicly available data sets that contain both whole genome association data and a wealth of phenotypic data, serves as an excellent resource for fine mapping and …
Identifying loci for the overlap between attention-deficit/hyperactivity disorder and autism spectrum disorder using a genome-wide QTL linkage approach
Contains fulltext : 88211.pdf (Publisher’s version ) (Closed access) OBJECTIVE: The genetic basis for autism spectrum disorder (ASD) symptoms in children with attention-deficit/hyperactivity disorder (ADHD) was addressed using a genome-wide linkage approach. METHOD: Participants of the International Multi-Center ADHD Genetics study comprising 1,143 probands with ADHD and 1,453 siblings were analyzed. The total and subscale scores of the Social Communication Questionnaire (SCQ) were used as quantitative traits for multipoint regression-based linkage analyses on 5,407 autosomal single-nucleotide polymorphisms applying MERLIN-regress software, both without and with inclusion of ADHD symptom sc…
Does parental expressed emotion moderate genetic effects in ADHD? An exploration using a genome wide association scan.
Contains fulltext : 70497.pdf (Publisher’s version ) (Closed access) Studies of gene x environment (G x E) interaction in ADHD have previously focused on known risk genes for ADHD and environmentally mediated biological risk. Here we use G x E analysis in the context of a genome-wide association scan to identify novel genes whose effects on ADHD symptoms and comorbid conduct disorder are moderated by high maternal expressed emotion (EE). SNPs (600,000) were genotyped in 958 ADHD proband-parent trios. After applying data cleaning procedures we examined 429,981 autosomal SNPs in 909 family trios. ADHD symptom severity and comorbid conduct disorder was measured using the Parental Account of Ch…
Genome-wide association study of motor coordination problems in ADHD identifies genes for brain and muscle function.
Item does not contain fulltext OBJECTIVES: Motor coordination problems are frequent in children with attention deficit/hyperactivity disorder (ADHD). We performed a genome-wide association study to identify genes contributing to motor coordination problems, hypothesizing that the presence of such problems in children with ADHD may identify a sample of reduced genetic heterogeneity. METHODS: Children with ADHD from the International Multicentre ADHD Genetic (IMAGE) study were evaluated with the Parental Account of Children's Symptoms. Genetic association testing was performed in PLINK on 890 probands with genome-wide genotyping data. Bioinformatics enrichment-analysis was performed on highly…
Parent of origin effects in attention/deficit hyperactivity disorder (ADHD): analysis of data from the international multicenter ADHD genetics (IMAGE) program.
Contains fulltext : 71540.pdf (Publisher’s version ) (Closed access) There are conflicting reports suggesting that the parental origin of transmitted risk alleles may play a role in the etiology of attention deficit/hyperactivity disorder (ADHD). A recent report by Hawi and colleagues observed a generalized paternal over-transmission of alleles associated with ADHD. This was not replicated in more recent studies. Using data from a large multicenter study we examined the overall and gene-specific parent of origin effect in 554 independent SNPs across 47 genes. Transmission disequilibrium and explicit parent of origin test were performed using PLINK. Overall parent of origin effect was tested…
Meta-analysis of genome-wide linkage scans of attention deficit hyperactivity disorder
Contains fulltext : 69243.pdf (Publisher’s version ) (Closed access) Genetic contribution to the development of attention deficit hyperactivity disorder (ADHD) is well established. Seven independent genome-wide linkage scans have been performed to map loci that increase the risk for ADHD. Although significant linkage signals were identified in some of the studies, there has been limited replications between the various independent datasets. The current study gathered the results from all seven of the ADHD linkage scans and performed a Genome Scan Meta Analysis (GSMA) to identify the genomic region with most consistent linkage evidence across the studies. Genome-wide significant linkage (P(S…
Separation of Cognitive Impairments in Attention-Deficit/Hyperactivity Disorder Into 2 Familial Factors
Contains fulltext : 89304.pdf (Publisher’s version ) (Open Access) CONTEXT: Attention-deficit/hyperactivity disorder (ADHD) is associated with widespread cognitive impairments, but it is not known whether the apparent multiple impairments share etiological roots or separate etiological pathways exist. A better understanding of the etiological pathways is important for the development of targeted interventions and for identification of suitable intermediate phenotypes for molecular genetic investigations. OBJECTIVES: To determine, by using a multivariate familial factor analysis approach, whether 1 or more familial factors underlie the slow and variable reaction times, impaired response inhi…
Aetiology for the covariation between combined type ADHD and reading difficulties in a family study: the role of IQ
Background: Twin studies using both clinical and population-based samples suggest that the frequent co-occurrence of attention deficit hyperactivity disorder (ADHD) and reading ability/disability (RD) is largely driven by shared genetic influences. While both disorders are associated with lower IQ, recent twin data suggest that the shared genetic variability between reading difficulties and ADHD inattention symptoms is largely independent from genetic influences contributing to general cognitive ability. The current study aimed to extend the previous findings that were based on rating scale measures in a population sample by examining the generalisability of the findings to a clinical popul…
A high-density SNP linkage scan with 142 combined subtype ADHD sib pairs identifies linkage regions on chromosomes 9 and 16
As part of the International Multi-centre ADHD Gene (IMAGE) project we have completed an affected sibling pair study of 142 narrowly defined DSM-IV combined type ADHD proband-sibling pairs. We found suggestive linkage on chromosomes 9 and 16 with non-parametric multipoint peak LOD scores of 2.13 and 3.1 respectively. There have been several previous ADHD linkage scans. The UCLA study (Fisher et al. 2002; Ogdie et al. 2004; Ogdie et al. 2003), the Dutch study (Bakker et al. 2003), the German study (Hebebrand et al. 2006) and the MGH Study (Faraone et al., submitted) applied the affected sib pair (ASP) strategy; the Columbian study used extended pedigrees ascertained from a population isolate…
Genome-wide association scan of attention deficit hyperactivity disorder
Contains fulltext : 70191.pdf (Publisher’s version ) (Closed access) Results of behavioral genetic and molecular genetic studies have converged to suggest that genes substantially contribute to the development of attention deficit/hyperactivity disorder (ADHD), a common disorder with an onset in childhood. Yet, despite numerous linkage and candidate gene studies, strongly consistent and replicable association has eluded detection. To search for ADHD susceptibility genes, we genotyped approximately 600,000 SNPs in 958 ADHD affected family trios. After cleaning the data, we analyzed 438,784 SNPs in 2,803 individuals comprising 909 complete trios using ADHD diagnosis as phenotype. We present t…
Neuropsychological correlates of emotional lability in children with ADHD
Background: Emotional lability (EL) is commonly seen in patients with attention-deficit/hyperactivity disorder (ADHD). The reasons for this association remain currently unknown. To address this question, we examined the relationship between ADHD and EL symptoms, and performance on a range of neuropsychological tasks to clarify whether EL symptoms are predicted by particular cognitive and/or motivational dysfunctions and whether these associations are mediated by the presence of ADHD symptoms. Methods: A large multi-site sample of 424 carefully diagnosed ADHD cases and 564 unaffected siblings and controls aged 618 years performed a broad neuropsychological test battery, including a Go/No-Go …
Linkage to chromosome 1p36 for attention-deficit/hyperactivity disorder traits in school and home settings.
Contains fulltext : 69485.pdf (Publisher’s version ) (Closed access) BACKGROUND: Limited success has been achieved through previous attention-deficit/hyperactivity disorder (ADHD) linkage scans, which were all designed to map genes underlying the dichotomous phenotype. The International Multi-centre ADHD Genetics (IMAGE) project performed a whole genome linkage scan specifically designed to map ADHD quantitative trait loci (QTL). METHODS: A set of 1094 single selected Caucasian ADHD nuclear families was genotyped on a highly accurate and informative single nucleotide polymorphism (SNP) panel. Two quantitative traits measuring the children's symptoms in home and school settings were collecte…
Conduct disorder and ADHD: evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics study.
Contains fulltext : 71374.pdf (Publisher’s version ) (Closed access) Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with t…
Genetic heterogeneity in ADHD: DAT1 gene only affects probands without CD
Contains fulltext : 70183.pdf (Publisher’s version ) (Closed access) Previous studies have found heterogeneous association between DAT1-3'-UTR-VNTR and attention deficit hyperactivity disorder (ADHD). Various proportions of conduct disorder (CD) comorbidity in their ADHD samples may partially explain the observational discrepancies. Evidence for this comes from family and twin studies which found ADHD probands with CD (ADHD + CD) are genetically different from those without CD (ADHD - CD). Genotypes of 20 DAT1 markers were analyzed in 576 trios, consisting of 141 ADHD + CD and 435 ADHD - CD. In addition to the classical TDT test, a specific genetic heterogeneity test was performed to identi…
The relationship between ADHD and key cognitive phenotypes is not mediated by shared familial effects with IQ
BackgroundTwin and sibling studies have identified specific cognitive phenotypes that may mediate the association between genes and the clinical symptoms of attention deficit hyperactivity disorder (ADHD). ADHD is also associated with lower IQ scores. We aimed to investigate whether the familial association between measures of cognitive performance and the clinical diagnosis of ADHD is mediated through shared familial influences with IQ.MethodMultivariate familial models were run on data from 1265 individuals aged 6–18 years, comprising 920 participants from ADHD sibling pairs and 345 control participants. Cognitive assessments included a four-choice reaction time (RT) task, a go/no-go task…