Alcohol and Alcoholism Vol. 36, No. 3, pp. 262-265, 2001
© 2001 Medical Council on Alcoholism
The A1 allele of the D2 dopamine receptor gene is associated with high dopamine transporter density in detoxified alcoholics
Department of Psychiatry, University of Oulu, FIN-90220 Oulu,
1 Department of Nuclear Medicine, University of Oulu, FIN-90220 Oulu, Department of Clinical Physiology and Nuclear Medicine, University of Helsinki, FIN-00029 HUS Helsinki,
2 Department of Pharmacology, University of Turku, FIN-20520 Turku,
3 Department of Forensic Psychiatry, Department of Neurophysiology, University of Kuopio, FIN-70210 Kuopio and
4 Department of Psychiatry, University of Turku, Turku PET Centre, FIN-20520 Turku, Finland
Received 21 September 2000; first review notified 28 November 2000; accepted 27 December 2000
The A1 allele of TaqI A restriction fragment length polymorphism (RFLP) in the D2 receptor (DRD2) gene locus has been suggested to be associated with low D2 receptor density in man. Striatal dopamine transporter (DAT) densities were studied with [123I]2-ß-carbometoxy-3ß(4-iodophenyl)tropane and single-photon emission tomography in 29 detoxified alcoholics, who were also genotyped for the two alleles of TaqI A RFLP at the DRD2 receptor gene locus. Alcoholics with the A1/A2 genotypes (n = 10) had statistically significantly higher DAT densities than subjects with the A2/A2 genotypes [n = 19; 8.0 ± 1.2 (mean ± SD) vs 6.9 ± 1.1, P = 0.035]. We suggest that the TaqI A RFLP is in linkage disequilibrium with a gene variant modifying DAT density in alcoholics.