Association of ADHD, tics, and anxiety with dopamine transporter (DAT1) genotype in autism spectrum disorder.
BACKGROUND
Autism spectrum disorder (ASD) is associated with high rates of psychiatric disturbance to include attention-deficit/hyperactivity disorder (ADHD), tic disorder, and anxiety disorders. The aim of the present study was to examine the association between a variable number tandem repeat (VNTR) functional polymorphism located in the 3'-untranslated region of the dopamine transporter gene (DAT1) and the severity of these symptoms as well as the association between the DAT1 DdeI polymorphism and severity of tics.


METHODS
Parents (n = 62) and teachers (n = 57) completed a DSM-IV-referenced rating scale for 67 children with ASD.


RESULTS
According to parent ratings, children with the 10-10 repeat allele (versus a combined group of all other genotypes) exhibited less severe symptoms of hyperactivity and impulsivity as well as less severe language deficits. Teacher ratings indicated that social anxiety and tic symptoms were more severe for children with the 10-10 genotype versus all others. Exploratory analyses provided preliminary support for the notion that heterozygosity (9-10 repeat genotype) may be a risk/protective factor. There were no associations of tic severity with the DAT1 DdeI polymorphism.


CONCLUSIONS
Collectively, these results suggest that the extraordinary variability in ASD clinical phenotypes may be explained in part by the same genes that are implicated in a host of other psychiatric disorders in non-ASD populations. Nevertheless, replication with independent samples is necessary to confirm this preliminary finding.
Gadow
Kenneth D
KD
Department of Psychiatry and Behavioral Science, State University of New York at Stony Brook, Stony Brook, NY 11794-8790, USA. kenneth.gadow@stonybrook.edu
Roohi
Jasmin
J
DeVincent
Carla J
CJ
Hatchwell
Eli
E
D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D001008:Anxiety Disorders / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D001321:Autistic Disorder / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D002648:Child; D002652:Child Behavior / Q000523:psychology; D002675:Child, Preschool; D015897:Comorbidity; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D008297:Male; D009518:New York / Q000453:epidemiology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D013981:Tic Disorders / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology
D050483:Dopamine Plasma Membrane Transport Proteins; C493214:SLC6A3 protein, human