Molecular Analysis of STin2 (intron 2) variant of SLC6A4 gene in children and adolescents with Attention Deficit Hyperactivity Disorder

Abstract

Due to the heterogeneous nature of ADHD, some studies have shown an association between genetics and the disease, while other studies have not. Since the association between SLC6A4 and ADHD gene variants in the Iranian population has not been investigated, the aim of this study was molecular analysis of STin2 (intron 2) variant of SLC6A4 gene in children and adolescents with attention deficit hyperactivity disorder. Materials and Methods: In this prospective cross-sectional study, 86 patients with ADHD and 99 healthy individuals were studied according to the study criteria. Patients after obtaining a detailed history and examination of mental status and assessing its development according to international standards (DSM-IV) by a child and adolescent psychiatrist and after consultation and explanation of the test and signing informed consent by legal parents of patients Were studied. The STin2 (intron2) fragment of the SLC6A4 gene was amplified using specific primers by conventional PCR and three types of STin2 (intron2) alleles of the SLC6A4 gene were examined using the acrylamide gel method. The role of the SLC6A4 gene has been reported as one of the genes involved in some psychiatric patients such as depression. Results: In ADHD group, the frequency of 9, 10 and 12 alleles of STin2 variants was 34.9%, 29.1% and 36%, respectively. In healthy individuals, the frequency of these alleles in STin2 variant was 39.4%, 23.2% and 36.4%, respectively. There was no difference between the two groups in the frequency of alleles. In ADHD risk assessment, OR for the above alleles was 0.824, 1.354 and 0.986, respectively.