Document Type : original article


1 Department of Cognitive Neuroscience, Faculty of Education and Psychology University of Tabriz, Tabriz, Iran.

2 Department of Animal biology, Faculty of Natural Sciences, University of Tabriz

3 Department of Animal Biology¸ Faculty of Natural Sciences¸ University of Tabriz

4 Animal biology, Natural sciences, University of Tabriz, Tabriz, Iran



Background: ADHD is the most prevalent psychiatric health issue in youth, which may also affect adults. Environmental and genetic factors both contribute significantly to the development and progression of this condition. Monoamine oxidases, which catalyze the metabolism of dopaminergic neurotransmitters, are involved in the pathogenesis of ADHD.

Objective: The purpose of this study was to determine the connection between polymorphic variations rs6323 and uVNTR in the MAO-A gene and the risk for ADHD in Iranian-Azeri children.

Methods: Clinical evaluation was used to recruit 137 ADHD patients (female 22, male 115) and 100 control persons (female 48, male 52) from the East Azerbaijan region in northern Iran. Genomic DNA was taken from their peripheral blood samples and genotyping was performed using PCR-based amplification of target sites. SPSS (Version 16) and the javastat online statistics program ( were used for statistical analysis.

Results: The rs6323TT genotype was shown to be a significant risk factor for ADHD (OR 3.619, 95 percent CI 0.878-17.213, p = 0.044). The 5R allele of uVNTR was shown to have a substantial protective impact against the development of ADHD (OR0.349, 95 percent confidence interval0.151-0.797, p = 0.006).

Conclusion: Our findings indicate that MAOA gene polymorphisms may play a role in the start and development of ADHD in Iranian-Azeri youngsters. However, more research with bigger sample sizes is necessary to corroborate these results.