Association study between dopamine D3 receptor gene polymorphism and cocaine dependents
GP Messas ; IV Meira-Lima ; D Jardim ;E Ikenaga ;MD Turchi ;
OF Franco ; A Castelo; RR Laranjeira ; H Vallada
This work was supported by FAPESP (Fundação para o Amparo à Pesquisa do Estado de São Paulo ) grantnumber 9904678-2
Previous investigations have shown that dopamine receptor sub-type 3 (DRD3) may be involved in the vulnerability to cocaine dependence. The present study investigates the Gly-9-Ser polymorphism of the DRD3 gene in 718 cocaine dependents and 782 healthy controls. No allelic or genotypic differences were found between the groups, when analyzing the whole sample. However, when subdividing the sample according to a maximum risk group of cocaine dependents (n=414), i.e. history of early onset of cocaine use and imprisonment records, an association with homozygosis was found (p<0.001). We concluded that the homozygosity of Gly-9-Ser polymorphism in the DRD3 gene may increase the vulnerability to develop cocaine dependence.