Table 1.
Selection of DRD3 Ser9Gly Polymorphism Association Studies with TD
| Rating Scales | >1 Rating | Sample Size | Ethnicity or Nationality | Main Findings | Ref |
|---|---|---|---|---|---|
| AIMS | Yes | 100 | Caucasian | Association with TD and the Gly-allele (p=0.03) and with the Gly/Gly genotype (p=0.01) | [13] |
| AIMS | No | 112 | 85: Caucasian; 25: African American | Higher AIMS total scores associated with Gly/Gly genotype compared to Ser/Gly and Ser/Ser genotype (p=0.0005) | [12] |
| AIMS | No | 116 | Ashkenazi and non-Ashkenazi | TD associated with Ser/Gly genotypes (p=0.0008); total AIMS scores with genotypes carrying Gly alleles (p=0.02) | [63] |
| AIMS | No | 71 | European Caucasian | Tendency for an association between homozygosity for the Gly-variant and TD (p=0.20) | [64] |
| AIMS | No | 115 | Taiwan Chinese | Higher AIMS scores with Ser/Gly genotypes compared to Ser/Ser and Gly-Gly genotypes (p=0.01) | [65] |
| AIMS | ? | 113 | Korean | Gly/Gly genotype significantly associated with TD (p=0.02), but no allelic association in AIMS analysis | [66] |
| AIMS | Yes | 317 | Chinese | Non-significant; but Ser/Ser genotype associated with TD in logistic regression analysis (p=0.01) | [67] |
| AIMS | Yes | 101 | Chinese | Higher TD observed in ser-gly heterozygotes (p=0.08) | [68] |
| AIMS | No | 516 | American mix | Presence of at least one Gly-allele associated with limb TD in white women (OR 2.2, 95% CI 1.0–4.9); severe TD (n = 49) associated with Gly-alleles | [69] |
| AIMS | ? | 102 | Greek | Gly genotypes (Gly/Gly or Gly/Ser vs. Ser/ser) associated with AIMS scores (p=0.001) | [70] |
| AIMS | No | 146 | Russian | Non-significant; but Gly-variant significantly associated with TD in log-normal regression (p=0.02) | [38] |
| Meta-Analysis | |||||
| Various | ? | 780 | African-American, Ashkenazi, Caucasian, Chinese, German, Japanese | Gly-allele carrier status increased susceptibility to TD (OR = 1.33) | [35] |
| Various | ? | 695 | Ashkenazi, Caucasian, Chinese, German, Japanese, Korean | The Gly allele increased the risk relative to the Ser allele (OR=1.17) | [36] |
| AIMS (12 of 13 studies) | ? | 2026 | European, Asian, Mixed (US) | No or little effect of the DRD3 Ser9Gly polymorphism and occurrence of TD | [37] |