Association of promoter variants of human dopamine transporter gene with schizophrenia in Han Chinese

ObjectiveAlthough dopamine was implicated in the etiology of schizophrenia, the human dopamine transporter gene (DAT1; SLC6A3) has not consistently been associated with schizophrenia. The purpose of this study was to examine whether six polymorphisms within the DAT1 gene are associated with schizophrenia.MethodsSix polymorphisms of the DAT1 gene (3 SNPs [rs6413429, rs2652511, and rs2975226] in the promoter region, one SNP [rs6347] in exon 9, and one SNP [rs27072]/one variable number tandem repeat [VNTR] in exon 15) were analyzed in 352 Chinese patients with schizophrenia and in 311 healthy controls. Pretreatment psychopathology was assessed using the Positive and Negative Syndrome Scale in a subset of 160 hospitalized schizophrenia patients who were drug-free or drug-naïve.ResultsA statistically significant difference in two polymorphisms (rs2652511 and rs2975226) and a promoter region haplotype (rs2652511, rs2975226, and rs6413429) was found between patients and healthy controls. No association with schizophrenia was found for other polymorphisms and another haplotype (3′ region). Symptoms severity (PANSS global, positive, negative and general symptoms scores) was similar regardless of DAT1 polymorphism.ConclusionThe promoter region of the DAT1 gene may play a role in increasing susceptibility to schizophrenia, but does not affect the severity of psychotic symptoms in Han Chinese.