Meta-analysis shows schizophrenia is not associated with the 40-base-pair repeat polymorphism of the dopamine transporter gene

Despite over 90% power to detect a significant odds ratio as small as 1.3, no association was observed. Considering the cumulative evidence from six case-control studies and results from additional family-based studies, it seems unlikely that the 40-base-pair VTNR polymorphism of the SLC6A3 gene influences risk for schizophrenia.