Association study of dopamine transporter gene (DAT1) variable tandem repeat sequence (VNTR) with obsessive-compulsive disorder in Chinese Han Population.

OBJECTIVE Multiple evidence suggests an involvement of the dopamine neurotransmitter system in Obsessive-compulsive disorder (OCD). Therefore, we explore the association of 3'UTR region of 40 bp variable tandem repeat (VNTR) polymorphism in Dopamine Transporter Gene (DAT1) in Chinese Han population. METHODS A total of 305 OCD patients and 435 healthy individuals were recruited for the study. OCD was diagnosed with the Forth Edition (DSM-IV) diagnostic criteria. After polymerase chain reaction of VNTR was used to evaluate the 40 bp VNTR polymorphism in DAT1, a case-control association analysis was performed by the χ(2) test. RESULTS The results showed that no association was found between OCD patients and controls for the genotype distribution (X(2) =0.743, P=0.690, df=2) as well as allelic (X(2)=0.172, P=0.678, OR=0.928, 95% Cl=0.885-1.224) distribution. CONCLUSIONS Our data suggest that the 40 bp VNTR polymorphism in DAT1 may not be associated with susceptibility to OCD in the Chinese Han population studied. However, this result needed to be replicated from different populations.