Polymorphisms TaqI A of the DRD2, BalI of the DRD3, exon III repeat of the DRD4, and 3' UTR VNTR of the DAT: association with childhood ADHD in male African-Caribbean cocaine dependents?
The conflicting results reported by genetic studies with the variants of the genes coding for the dopaminergic system in cocaine addicts could be partially explained by the difficulties to constitute homogenous sample of patients. Childhood attention-deficit/hyperactivity disorder (ADHD), and/or impulsivity are frequently associated with cocaine addiction and could participate in the heterogeneity of the samples in cocaine addicts. Accordingly, it is hypothesized that cocaine addiction would be associated with the variants of the genes coding for the dopamine system in an homogenized sample of cocaine addicts, especially in individuals with childhood ADHD comorbidity, or with a high impulsivity score. The potential association of the variants TaqI A of the DRD2, BalI of the DRD3, exon III repeat of the DRD4, and 3' UTR VNTR of the DAT was examined in African-Caribbean males, smoked-cocaine dependents. All the subjects were assessed with the Diagnostic Interview of Genetic Studies, the Barratt's impulsivity scale, and the Wender Utah rating scale for childhood ADHD. A positive association was found with the DRD2 and DRD4 polymorphisms in the subgroups of patients with childhood ADHD, or with a high impulsivity score, which represented, respectively, 53.3 and 73.0% of the patients. Conversely, no positive association was found for any of the polymorphisms studied when the group of patients was examined as a whole. Therefore, our results suggest that the clinical dimensions of childhood ADHD and of impulsivity could be taken into account to homogenize the samples of patients in cocaine association studies.
Ballon
Nicolas
N
Department of Psychiatry, University Hospital of Fort de France, Fort de France, Martinique, French West Indies. ballon@informatique2000.fr
Leroy
Sophie
S
Roy
Christianne
C
Bourdel
Marie-Chantal
MC
Olie
Jean-Pierre
JP
Charles-Nicolas
Aimé
A
Krebs
Marie-Odile
MO
Poirier
Marie-France
MF
D020413:3' Untranslated Regions / Q000235:genetics; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000235:genetics*; D044383:Black People; D017691:Caribbean Region / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D019970:Cocaine-Related Disorders / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011954:Receptors, Dopamine / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics; D050637:Receptors, Dopamine D3 / Q000235:genetics; D050638:Receptors, Dopamine D4 / Q000235:genetics
D020413:3' Untranslated Regions; C493593:DRD3 protein, human; C493599:DRD4 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases; C060616:TGGCCA-specific type II deoxyribonucleases