Dopaminergic system genes in childhood aggression: possible role for DRD2.
Excessive or deficient levels of extracellular dopamine have been hypothesized to contribute to a broad spectrum of mood, motor, and thought abnormalities, and dopaminergic system genes have been implicated in aggressive behaviour from animal and human studies. OBJECTIVE. We examined selected members of the dopaminergic system genes for association with child aggression.


METHODS
We analyzed polymorphisms in the dopamine transporter DAT1/SLC6A3, dopamine receptor DRD2, and DRD4 genes in our sample of pervasive childhood aggression consisting of 144 cases paired with 144 healthy controls, matched for sex and ethnicity.


RESULTS
Aggressive children were significantly more likely to have the at least one copy of the G allele for the DRD2 A-241G polymorphism (genotypic P=0.02; allelic P=0.01). The DRD2 rs1079598 CC genotype was overrepresented in aggressive children compared to controls (genotype P=0.04). The DRD2 TaqIA T allele (P=0.01) and the TT genotype (P=0.01) were also significantly overrepresented in aggressive children.


CONCLUSIONS
Our preliminary results suggest that three polymorphisms in DRD2 are associated with childhood aggression. Future studies are required to replicate the current results and to further explore the relationship between the dopamine system and aggressive behaviour in children.
Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada.
Clement C
CC
Zai
Sahar
S
Ehtesham
Esther
E
Choi
Behdin
B
Nowrouzi
Vincenzo
V
de Luca
Larisa
L
Stankovich
Kristen
K
Davidge
Natalie
N
Freeman
Nicole
N
King
James L
JL
Kennedy
Joseph H
JH
Beitchman
D000374:Aggression / Q000502:physiology*; D002170:Canada; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics*; D004298:Dopamine / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4 / Q000235:genetics*
D050483:Dopamine Plasma Membrane Transport Proteins; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4; D004298:Dopamine