title: NOS1 and SNAP25 polymorphisms are associated with Attention-Deficit/Hyperactivity Disorder symptoms in adults but not in children.
abstract: Several investigations documented that Attention-Deficit/Hyperactivity Disorder (ADHD) is better conceptualized as a dimensional disorder. At the same time, the disorder seems to have different neurobiological underpinnings and phenotypic presentation in children compared to adults. Neurodevelopmental genes could explain, at least partly these differences. The aim of the present study was to examine possible associations between polymorphisms in SNAP25, MAP1B and NOS1 genes and ADHD symptoms in Brazilian samples of children/adolescents and adults with ADHD. The youth sample consisted of 301 patients whereas the adult sample comprises 485 individuals with ADHD. Diagnoses of ADHD and comorbidities were based on the Diagnostic and Statistical Manual of Mental Disorders-4th edition criteria. The Swanson, Nolan and Pelham Scale-Version IV (SNAP-IV) was applied by psychiatrists blinded to genotype. The total SNAP-IV scores were compared between genotypes. Impulsivity SNAP-IV scores were also compared according to NOS1 genotypes. Adult patients homozygous for the C allele at SNAP25 rs8636 showed significantly higher total SNAP-IV scores (F = 11.215; adjusted P-value = 0.004). Impulsivity SNAP-IV scores were also significantly different according to NOS1 rs478597 polymorphisms in adults with ADHD (F = 6.282; adjusted P-value = 0.026). These associations were not observed in children and adolescents with ADHD. These results suggest that SNAP25 and NOS1 genotypes influence ADHD symptoms only in adults with ADHD. Our study corroborates previous evidences for differences in the genetic contribution to adult ADHD compared with childhood ADHD.
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Angélica
authors.initials: A
authors.lastname: Salatino-Oliveira
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Glaucia C
authors.initials: GC
authors.lastname: Akutagava-Martins
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Estela M
authors.initials: EM
authors.lastname: Bruxel
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Julia P
authors.initials: JP
authors.lastname: Genro
authors.affiliation: Department of Psychiatry, Universidade de São Paulo, Brazil; Institute for Developmental Psychiatry for Children and Adolescents, Brazil.
authors.forename: Guilherme V
authors.initials: GV
authors.lastname: Polanczyk
authors.affiliation: Division of Child and Adolescent Psychiatry, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Cristian
authors.initials: C
authors.lastname: Zeni
authors.affiliation: Division of Child and Adolescent Psychiatry, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Christian
authors.initials: C
authors.lastname: Kieling
authors.affiliation: Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Karam
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Diego L
authors.initials: DL
authors.lastname: Rovaris
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Verônica
authors.initials: V
authors.lastname: Contini
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Renata B
authors.initials: RB
authors.lastname: Cupertino
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Nina R
authors.initials: NR
authors.lastname: Mota
authors.affiliation: Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Eugenio H
authors.initials: EH
authors.lastname: Grevet
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil; Adult ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: Claiton H
authors.initials: CH
authors.lastname: Bau
authors.affiliation: Institute for Developmental Psychiatry for Children and Adolescents, Brazil; Division of Child and Adolescent Psychiatry, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Brazil.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Rohde
authors.affiliation: Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil. Electronic address: mara.hutz@ufrgs.br.
authors.forename: Mara H
authors.initials: MH
authors.lastname: Hutz
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D002648:Child; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D052248:Nitric Oxide Synthase Type I / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D018709:Statistics, Nonparametric; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics*; D055815:Young Adult
chemical_list: C494208:SNAP25 protein, human; D050825:Synaptosomal-Associated Protein 25; D052248:Nitric Oxide Synthase Type I
keywords: ADHD symptoms; Impulsivity; Neurodevelopmental genes