Background: Attention-deficit/hyperactivity disorder (ADHD) is a frequent chronic
neuropsychiatric disorder in which different factors including environmental, genetic, and epigenetic
factors play an important role in its pathogenesis. One of the effective epigenetic factors is
recognized as MicroRNAs (miRNAs). On the other hand, it has been indicated that the single nucleotide
polymorphism (SNPs) present within 3'UTR (3' untranslated region) of mRNAs can influence
the regulation of miRNA-mediated gene and susceptibility to a diversity of human diseases.
Methods: The purpose of this study was to analyze the SNPs within the 3'UTR of miRNA target
genes associated with ADHD. 3'UTR genetic variants were identified in all genes associated with
ADHD using DisGeNET, dbGaP, Ovid, DAVID, Web of knowledge, and SNPs databases.
miRNA's target prediction databases were applied in order to predict the miRNA binding sites.
124 SNPs with MAF>0.05 were identified located in the binding site of the miRNA of 35 genes
amongst 51 genes associated with ADHD.
Results: Bioinformatics analysis predicted 81 MRE (miRNA recognition elements)-creating
SNPs, 101 MRE-breaking SNPs, 61 MRE-enhancing SNPs, and finally predicted 41 MREdecreasing
SNPs in the 3'UTR of ADHD-implicated genes. These candidate SNPs within these
genes miRNA binding sites can alter the miRNAs binding, and consequently, lead to mRNA gene
Conclusion: Therefore, these miRNA and MRE-SNPs may play important roles in ADHD, and
because of that, they would be valuable for further investigation in the field of functional verification.