DAT1 Gene Polymorphism in Children with Attention Deficit Hyperactivity Disorder

Background: Attention deficit hyperactivity disorder (ADHD) as a commonneuro - developmental disorder is associated with inattention, excessive activity, impulsive behavior or a combination of these symptoms. Environmental and genetic factors are involved in this disorder; Dopamine Active Transporter 1 gene (DAT1) is one of these genetic factors. In this study the association between the 10 or 9 - repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3’-untranslated region (UTR) of the DAT1 gene and ADHD, is examined. Methods: A total of 124 children with ADHD and 129 healthy children, ranging from 5 to 14 years old were selected from the north - western area of Iran as the case group and the control group, respectively. DAT1 gene polymorphism was investigated using the PCR-VNTR technique. Results: Using the Hardy - Weinberg law and chi - square test for analyzing the results of the DAT1 gene, it was observed that the genotypes 9/10 and 10/10 of DAT1 gene were significantly higher among children with ADHD than that in control group (P = 0.002). Conclusions: Based on these finding, it can be concluded that a significant relationship exists between DAT1 gene repeats and ADHD in North - west Iran and this can be used as a diagnostic biomarker in the prognosis of this disorder.