Table 4.
Dopamine D2 receptor gene (a sampling)
| Polymorphism (s) | Study findings | References | Comments |
|---|---|---|---|
| SNP rs: 1800497 | TaqA1 allele associates with sever alcoholism | Blum et al. (1990) | First study to associate with alcoholism (called reward gene) |
| ANKKI -p.Glu713Lys | DRD2 Taq1A RFLP is a single nucleotide polymorphism (SNP) that causes an amino acid substitution within the 11th ankyrin repeat of ANKK1 | Neville et al. (2004) | The ANKKI gene is a reflection of DRD2 A1 allele |
| SNP rs: 1800497 | This SNP has been found to predict future RDS behaviors as high as 74 % | Blum et al. (1996) | Using Bayesian analysis |
| SNP rs: 1800497 | Presence of the A1+ genotype (A1/A1, A1/A2) compared to the A− genotype (A2/A2), is associated with reduced density | Noble et al. (1991) | This reduction causes hypodopaminergic functioning in the dopamine reward pathway |
| SNP rs: 6277 at exon 7 | T+ allele associates with alcohol dependence | Hill et al. (2008) | Associates with drug seeking behavior and other RDS behaviors |
| SNP rs: 1800497 | 10 year follow up that carriers of the DRD2 A1 allele have a higher rate of mortality compared to carriers of the A2 allele in alcohol dependent individuals | Dahlgren et al. (2011) | Taq IA1allele and a substantially increased relapse rate |
| DRD2-haplotypes I-C-G-A2 and I-C-A-A1 | Confirmed the hypothesis that haplotypes, which are supposed to induce a low DRD2 expression, are associated with alcohol dependence | Kraschewski et al. (2009) | High frequency of haplotype was associated with Cloninger Type 2 and family history of alcoholism |
| SNP rs: 1800497 | Genotype analysis showed a significantly higher frequency for the TaqIA polymorphism among the addicts (69.9 %) compared to control subjects (42.6 %; Fisher’s exact χ(2), P < 0.05) | Teh et al. (2012) | The addicts had higher scores for novelty seeking (NS) and harm avoidance (HA) personality traits |