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No association for D2 and D4 dopamine receptor polymorphisms and methamphetamine abuse in Chinese males

The D2 and D4 dopamine receptors (DRD2 and DRD4) play major roles in the central effects of psychostimulants and in the reward system. Previous studies, although not all, have demonstrated associations between the DRD2 Taq I and the DRD4 exon III variable number tandem repeat (VNTR) polymorphisms and substance dependence. For this study, we have investigated the associations between these two polymorphisms and methamphetamine (MAP) dependence, as manifested in a Chinese-male sample population. No significant difference was demonstrated for genotype or allele frequency when comparing MAP-dependent and control cases for the DRD2 Taq I and the DRD4 gene exon III VNTR polymorphisms, suggesting that these two polymorphisms do not play major roles in MAP dependence for our sample of Chinese males.