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 andadhd in north - west iran and this can be used as a diagnostic biomarker in the prognosis of this disorder.