Association Study Of Dopamine D4 Receptor Gene Polymorphism And Attention Deficit Hyperactivity Disorder

Objective:To investigate the distribution of frequency of (CT)n polymorphism of dopamine D5 receptor(DRD5) gene in Han nationality Guangxi province and the relationship between attention deficit hyperactivity disorder(ADHD) children and the dopamine D5 receptor gene .Methods:The diagnoses were ascertained according to DSM-â…£criteria .DNA was extracted directly from blood lymphocytes .Genotyping followed standard polymerase chain reaction (PCR) methods and .PCR products were separated and analysed on an Applied Biosystems (ABI) 3100 sequencer .The Hardy-Weinberg equilibrium was calculated using the allele frequency. Associations of polymorphisms with ADHD were examined by using family-based association study in an extension of haplotype-based haplotype relative risk(HHRR) and transmission disequilibrium test(TDT). Results:1,in our study, we found the repeat numbers of the (CT)n repeat polymorphism of DRD5 gene were 10 to 19. In control group : the common alleles were n=12 (22.06%)and n=16(22.06%); in case group:the common alleles were n=12 (27.42%). In both groups, the frequency distributions of allele were no significantly difference between males and females. 2,Genotyping frequencies of the cases and the controls were all met the Hardy-Weinberg equilibrium. 3,No significant association was found between ADHD and DRD5(CT)n polymorphism by using HHRR. 4,TDT analysis forADHD, in complete trios only, demonstrates that for DRD5*12,DRD5*14,DRD5*15 genes, there is linkage in the presence of linkage disequilibrium, with P<0.05. Conclusion:1,We find a total of 10 alleles in the Han nationality in Guangxi province, the repeat number is 10 to 19. The...