Case-control and within-family tests for an association between conduct disorder and DAT1.

Background: Conduct disorder (CD) is characterized by a persistent pattern of violating age-appropriate norms and the rights of others, and is one of the most frequently diagnosed disorders among children. CD is moderately heritable, but we know of no reliable associations with specific genes. Evidence suggests that a variable number tandem repeat polymorphism of the dopamine transporter (DAT1) gene may be associated with externalizing behavior in children.