Association of a polymorphism of the dopamine transporter gene with externalizing behavior problems and associated temperament traits: A longitudinal study from infancy to the mid-teens
There have been reports that a variable number of tandem repeats (VNTR) polymorphism situated in the 3' untranslated region of the dopamine transporter gene is associated with attention-deficit hyperactivity disorder. On the basis of these findings, we predicted an association of this polymorphism with hyperactivity, other externalizing behavior problems, and related temperament traits in a general population sample. The association was investigated using children participating in a longitudinal study of childhood temperament and development. DNA was taken from 660 children who had been assessed for temperament from 4-8 months to 15-16 years, and for behavior problems from 3-4 to 15-16 years. No significant associations were found at any age. There are a number of methodological differences from earlier studies that might explain the lack of associations with hyperactivity. It is also possible that the earlier findings are not replicable.