Association studies of dopamine D_4 receptor gene and dopamine transporter gene polymorphisms in Han Chinese patients with attention deficit hyperactivity disorder
Objective: To investigate association of the 48 bp variable number of tandem repeat (VNTR) polymorphism in the D 4 receptor gene ( DRD4 ) exon 3 and 40 bp VNTR polymorphism in the dopamine transporter gene ( DAT1 ) 3′ untranslated region with attention deficit hyperactivity disorder (ADHD) in Han Chinese children. Methods: The study samples were comprised of 340 ADHD children, 226 unrelated controls and 202 integrated ADHD trios (included proband and biological parents). The polymorphisms consiste...