Comparison of micro RNA levels between children with and without attention deficit and hyperactivity disorder

Objective: Attention deficit hyperactivity disorder (ADHD) is disease that has a highly genetic component although the knowledge about the mechanisms of this disease are limited. In this study we aimed to evaluate the levels of miR-132 and miR-942 which have been shown to be associated with dopamine transporter protein (DAT1) and dopamine receptor 5 (DRD5) genes respectively that play a role in ADHD development. Methods: Fifty children who had diagnosed with ADHD according to DSM-5 and 48 healthy controls were included in the study. Evaluation of serum levels of miR-132 and miR-942 was held in Gaziantep University genetics laboratory. Results: Children with ADHD were found to have significantly higher levels of miR-132 than the control group (p = 0.001) and their miR-942 levels were also found to be higher but not statistically significant (p = 0.181). Conclusion: Our study found that expression of miR-132 in ADHD group was significantly higher. There was no significant difference between the two groups in terms of miR-942 levels. It has been shown that miR-132 takes place in processes such as neuronal plasticity, dendritic development, synaptic physiology, NMDA receptor depolarization and miR-132 level dysregulation have been shown to be involved in neuropsychiatric disorders like schizophrenia, autism, Alzheimer's and Parkinson's disease. m-942 levels have been shown to be altered in some cancers and infectious processes like hepatitis C. In our study, we propose that elevated levels of miRNA in children with ADHD may be a factor in the formation of the disease and it's clinical presentation. In the light of these findings, evaluation of miR-132 and miR-942 can contribute to the knowledge about the pathogenesis of ADHD and improve our understanding of this disease. Our study is important because it is the first study evaluating miR-132 and miR-942 levels in children with ADHD.