A preliminary report of the dopamine receptor D4 and the dopamine transporter 1 gene polymorphism and its association with attention deficit hyperactivity disorder

Abstract

Helmut Niederhofer1, Frauke Menzel2, Karl Göbel3, Brigitte Hackenberg4,5, Rainer Richter2,6, Maria Hildegard Walter2, Christian Gross7, Markus Huber8, Roger Pycha8, Hans-Jürgen Menzel9,101Ospedale Regionale di Bolzano, Via Guncina, Bolzano, Italia; 2Institute for Psychology, University of Innsbruck, Innsbruck, Austria; 3Freiburger Allee 67, Böblingen, Germany; 4University Clinic for Psychiatry, 9Institute for Medical Biology and Human Genetics, Medical University of Innsbruck, Innsbruck, Austria; 5University Clinic for Pediatrics, Medical University Vienna, Wien, Austria; 6Department of Psychosomatic Medice and Psychotherapy, University Hospital, Eppendorf, Hamburg, Germany; 7Institut für Heilpädagogik, Klessheimer Allee 81, Salzburg, Austria; 8Krankenhaus Bruneck, Bruneck, ItaliaAbstract: Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent childhood-onset psychiatric syndromes affecting 5%–10% of school-age children worldwide. Distortions in the catecholaminergic system seem to be responsible for this condition. Within this system there are several candidate genes, the dopamine receptor D4 (DRD4) and the dopamine transporter 1 (DAT1), with common polymorphism which might be associated with ADHD. We performed a family based association study with 36 trios and 19 parent proband pairs. All diagnoses were confirmed by the “Hypescheme” diagnostic computer program. In this study we did not observe an association of ADHD with DRD4 and DAT1 polymorphism neither by the haplotype relative risk (HRR) method nor by the transmission disequilibrium test (TdT) method. The odds ratio for the DRD4 7-allele was 1.01 and 0.94 for both statistical tests, respectively, and the respective odds ratio for the DAT1 6-allele were 0.91 and 0.88.Keywords: ADHD, dopamine receptor D4, dopamine transporter, haplotype relative risk, transmission disequilibrium test