Homozygosity at the dopamine DRD3 receptor gene in cocaine dependence.
We examined the hypothesis that the dopamine D3 receptor gene (DRD3) is a susceptibility factor for cocaine dependence. The MscI/BalI polymorphism of the DRD3 gene was examined in 47 Caucasian subjects with cocaine dependence and 305 Caucasian controls. Based on prior studies with a range of psychiatric disorders we hypothesized there would be a decrease in the frequency of the 12 genotype in the patient sample (increased homozygosity). We observed a significant decrease in the frequency of 12 heterozygotes in subjects with cocaine dependence (29.8%) vs controls (46.9%) (P </= 0.028). This percentage was still lower in those who had chronically used cocaine for more than 10 years (25%), or more than 15 years (21.5%). The DRD3 gene accounted for 1.64% of the variance of cocaine dependence. The DRD2 gene had an independent and additive effect on cocaine dependence. These findings support a modest role of the DRD3 gene in susceptibility to cocaine dependence.
Comings
D E
DE
Department of Medical Genetics, City of Hope Medical Center, Duarte, CA, USA.
Gonzalez
N
N
Wu
S
S
Saucier
G
G
Johnson
P
P
Verde
R
R
MacMurray
J P
JP
D000328:Adult; D019970:Cocaine-Related Disorders / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006720:Homozygote; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050637:Receptors, Dopamine D3; D044465:White People / Q000235:genetics
C493593:DRD3 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3