Attention deficit hyperactivity disorder (ADHD) is a multi-factorial disorder that has defined by hyperactivity, impulsivity and attention deficits. Various neurotransmitters such as dopamine can play a role in its pathophysiology. The aim of this study was to examine the association of two common single nucleotide polymorphisms in DRD2 gene, Taq I A (T/C) and Taq I B (G/A), with ADHA risk among Iranian-Azeri population.
Materials and Methods
A study of case–control association was performed with 89 samples with attention deficit hyperactivity disorder and 96 healthy subjects. Peripheral blood samples were used for Genomic DNA extraction by salting-out method. SNP genotyping was carried out by PCR-RFLP technique. The collected data were analyzed through javastant online statistics software, using Chi-square, with a significance level of 0.05.
There was not a significant difference in the allele and genotype frequencies between ADHD and Taq1B polymorphism in cases and controls (P>0.05). In the Taq IA of DRD2 gene, TT homozygous dominants and CC homozygous recessives were more frequent in case group than in control group but significant difference was not observed (P>0.05). Also, T/C heterozygotes were more frequent among the control group than the case group, and difference was significant (P<0.05).
Our data supports lack of association between Taq1A and Taq1B gene polymorphisms and ADHD.