The dopamine D4 receptor gene 48-base-pair-repeat polymorphism and mood disorders: a meta-analysis.
BACKGROUND
We conducted a meta-analysis to re-evaluate the role of the dopamine D4 receptor gene 48-base-pair- repeat (DRD4) polymorphism in mood disorders.


METHODS
DRD4 allele frequencies were compared between 917 patients with unipolar (UP) or bipolar affective disorder (BP) and 1164 control subjects from 12 samples, using the Cochrane Review Manager.


RESULTS
An association was found between all mood disorder groups and DRD4.2. After correcting for multiple testing, the association between DRD4.2 and BP dropped to insignificance; however, the evidence of an association between the DRD4.2 allele and UP (p < .001) and the combined group (p < .001) remained. There was no evidence for heterogeneity or publication bias.


CONCLUSIONS
These findings suggest that the DRD4.2 allele is a risk allele for depression symptomatology. Meta-analysis may be a valuable objective tool for a quantitative summary of evidence for association studies in psychiatric genetics.
López León
Sandra
S
Genetic Epidemiology Unit, Department of Epidemiology and Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands.
Croes
Esther A
EA
Sayed-Tabatabaei
Fakhredin A
FA
Claes
Stephan
S
Van Broeckhoven
Christine
C
van Duijn
Cornelia M
CM
D000483:Alleles; D016022:Case-Control Studies; D016001:Confidence Intervals; D005787:Gene Frequency; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; D019964:Mood Disorders / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4
C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4