Iris Manor, M.D.

Objective: The primary purpose of this study was to confirm the association of a specific haplotype of the dopamine trans-porter gene and attention deficit hyperactivity disorder (ADHD), which could be one source of the heterogeneity seen across published studies. Method: The authors previously reported the association of ADHD with a subgroup of chromosomes containing specific al-leles of two variable-number tandem repeat polymorphisms within the 3 ′ untranslated region and intron 8 of the dopa-mine transporter gene. They now report on this association in a sample of ADHD combined-type probands. Results: The original observations were confirmed, with an overall odds ratio of 1.4 across samples. Conclusions: These data challenge results of meta-analyses suggesting that dopamine transporter variation does not hav