the association of drd2 gene taqi polymorphism with attention deficit hyperactivity disorder a population sample of iranian azeri-children

background 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. results 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). conclusion our data supports lack of association between taq1a and taq1b gene polymorphisms and adhd.