The DRD2 A(1) 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 acqu isition of infection. The A(1) allele of the D-2 dopamine receptor (DRD2) g ene is a hypothesized risk factor in the development of severe drug depende nce and alcoholism. The present study compares the frequency of the A(1) al lele of the DRD2 gene among 37 patients presenting to a hepatitis clinic fo r treatment of hepatitis C, 23 hepatitis C-negative drug-abusing patients m aintained on methadone and 33 non-drug-abusing controls. The results indica ted that hepatitis C-positive patients were significantly more likely to di splay 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 hepatit is C subjects manifested more persistent drug-seeking behaviour than the ot her drug-abusing group. The implications of this finding in terms of drug-r elated reward are discussed. Future research should attempt to evaluate hos t risk factors, ill order to enable more precisely targeted attempts at har m minimization.