Dopamine genes and attention-deficit hyperactivity disorder: a review.
OBJECTIVE
To review the results of genetic studies investigating dopamine-related genes in attention-deficit hyperactivity disorder (ADHD).


METHODS
Papers (association/linkage, meta-analyses and animal model studies) were identified through searches of the PubMed database and systematically reviewed.


RESULTS
Consistent results from molecular genetic studies are pointing strongly to the possible link between 2 specific genes, the dopamine transporter (SLC3A6) and the dopamine receptor 4 (DRD4), and ADHD.


CONCLUSIONS
The implication of SLC6A3 and DRD4 genes in ADHD appears to be one of the most replicated in psychiatric genetics and strongly suggests the involvement of the brain dopamine systems in the pathogenesis of ADHD. However, more work is required to further these findings by genotype-to-phenotype correlations and identify the functional allelic variants/mutations that are responsible for these associations. The role of other dopamine genes, which may have smaller effects than SLC6A3 and DRD4, needs also to be determined.
DiMaio
Salvatore
S
Douglas Hospital Research Centre, Department of Psychiatry, McGill University, Montreal, Que.
Grizenko
Nathalie
N
Joober
Ridha
R
D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D004298:Dopamine / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins; D015870:Gene Expression; D008040:Genetic Linkage / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins; D010641:Phenotype; D017448:Receptors, Dopamine D2 / Q000235:genetics; D050638:Receptors, Dopamine D4
C493599:DRD4 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017448:Receptors, Dopamine D2; C493214:SLC6A3 protein, human; D050638:Receptors, Dopamine D4; D004298:Dopamine