The DRD2 A1 allele: a behavioural genetic risk factor in hepatitis C infection of persistent drug abusers

Hepatitis C is highly prevalent among intravenous drug abusers, but to date research has not widely explicated behavioural risk factors regarding acquisition of infection. The A(1) allele of the D-2 dopamine receptor (DRD2) gene is a hypothesized risk factor in the development of severe drug dependence and alcoholism. The present study compares the frequency of the A(1) allele of the DRD2 gene among 37 patients presenting to a hepatitis clinic for treatment of hepatitis C, 23 hepatitis C-negative drug-abusing patients maintained on methadone and 33 non-drug-abusing controls. The results indicated that hepatitis C-positive patients were significantly more likely to display the A(1) allele than hepatitis C-negative patients, who were in turn more likely to have the A(1) allele than controls. Furthermore, the hepatitis C subjects manifested more persistent drug-seeking behaviour than the other drug-abusing group. The implications of this finding in terms of drug-related reward are discussed. Future research should attempt to evaluate host risk factors, ill order to enable more precisely targeted attempts at harm minimization