title: No association between D3 dopamine receptor (DRD3) alleles and cocaine dependence.
abstract: Cocaine is thought to act in the brain primarily by blocking dopamine re-uptake. The dopamine D3 receptor (genetic locus DRD3) is localized to brain regions that have been implicated in the reinforcing effects of a number of substances of abuse, including cocaine. The DRD3 coding region contains a polymorphism identifiable as a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). This polymorphism leads to an amino acid substitution at position 9 in the extracellular N-terminus of the D3 dopamine receptor. We examined alleles of the DRD3 gene in cocaine dependence using a genetic association strategy in samples of 62 white and 62 black cocaine-dependent individuals. Comparisons were made with local (Connecticut) control subjects for both groups, and with a larger sample of literature controls (for the white subjects) and a contrast group of schizophrenic patients (for the black subjects). No association was found between cocaine dependence and DRD3 alleles in either group (Bonferroni corrected). There was a significant difference in allele frequency between whites and blacks. These results are consistent with no role for genetic variation of the D3 dopamine receptor in susceptibility to cocaine dependence.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine and West Haven VA Medical Center, West Haven, CT 06516, USA.
authors.forename: M
authors.initials: M
authors.lastname: Freimer
authors.forename: H
authors.initials: H
authors.lastname: Kranzler
authors.forename: S
authors.initials: S
authors.lastname: Satel
authors.forename: J
authors.initials: J
authors.lastname: Lacobelle
authors.forename: K
authors.initials: K
authors.lastname: Skipsey
authors.forename: D
authors.initials: D
authors.lastname: Charney
authors.forename: J
authors.initials: J
authors.lastname: Gelernter