چکیده : 

Background: Recent research suggests that Tourette’s syndrome (TS) may result from a defect

in the dopamine system. Several candidate gene polymorphisms have been implicated in

attention deficit hyperactivity disorder, including the dopamine transporter (DAT1) and

dopamine b-hydroxylase (DBH) genes. A high rate of comorbidity between attention deficit

hyperactivity disorder and TS indicates that they may share the same pathophysiology.

Purpose: We aimed to test the hypothesis that the dopamine gene might play a role in TS.

Methods: An association study, using an independent sample of patients from the midland

region of Taiwan, was performed to investigate whether DAT1 and DBH gene polymorphisms

can be used as markers of susceptibility to TS. A total of 160 children with TS and 83 normal

control participantswere includedin the study. Polymerase chainreactionwas usedto identify

polymorphisms in the DAT1 (40 bp VNTR) and DBH (TaqI A2) genes. Genotypes and allelic

frequencies for the DAT1 and DBH gene polymorphisms in both groups were compared.

Results: The results showed that genotypes and allelic frequencies in both groups were

not significantly different. The most common genotype for DAT1 (40 bp VNTR) was the

10,10 homozygote in both groups. The most common genotype for DBH (TaqI A2) was the

T homozygote in both groups.

Conclusion: These data suggest that the DAT1 and DBH genes may not be useful markers to

predict susceptibility to TS.