Table 1.
Candidate genes in ADHD
| Gene | Type of study |
Variant | Chromosomal location |
Cases\trans | Controls\untrans | P value | Odds ratio (IC) | Replicated | Comments and references |
|---|---|---|---|---|---|---|---|---|---|
| DRD4 | C/C | 48 bp VNTR-7R allele | 11 | NA | NA | 1 × 10E−3 | 1.9 (1.5–2.2) | + | Meta-analyses 8 studies (Faraone et al. 1999, 2001) |
| DRD4 | FB | 48 bp VNTR-7R allele | 11 | NA | NA | 2 × 10E−5 | 1.41 (1.2–1.64) | + | Meta-analyses 13 studies (Faraone et al. 1999, 2001) |
| DRD4 | FB and C/C | 48 bp VNTR-7R allele | 11 | NA | NA | 2 × 10E−12 | 1.34 (1.23–1.45) | + | Meta-analyses 33 studies (Thapar et al. 2005) |
| DRD5 | FB and C/C | 148 bp CA(n) microsatellite marker | 4 | NA | NA | 8 × 10E−8 | 1.34 (1.21–1.50) | + | Meta-analyses 9 studies (Li et al. 2006) |
| DRD5 | FB | 148 bp CA(n) microsatellite marker | 4 | NA | NA | 8 × 10E−5 | 1.57 (1.25–1.96) | + | Meta-analyses 5 studies (Maher et al. 2002) |
| DRD5 | FB | 148 bp CA(n) microsatellite marker | 4 | NA | NA | 5 × 10E−5 | 1.24 (1.12–1.38) | + | Meta-analyses 14 studies (Lowe et al. 2004) |
| DDC | C/C | rs6592961 | 7 | 142/109/10a | 288/98/12a | 1 × 10E−5 | 2.22 (1.60–3.08)b | NA | Unique study (Ribases et al. 2009) |
| SLC6A3 (DAT1) | FB | Haplotype inside the gene | 5p13 | 168 | 99 | 3.4 × 10E−5 | 1.95 (1.05–3.63) | – | Friedel et al. (2007) and Brookes et al. (2006) |
| SLC6A4 (5-HTT) | FB | STin2.12 (A12) | 17q11.1 | 56 | 174 | 0.008 | 3.00 (1.53–5.90) | – | Unique study (Banerjee et al. 2006) |
| SLC6A4 (5-HTT) | FB | Promoter 3′UTR SNP | 17q11.1 | 65 | 49 | 0.004 | – | Unique study (Kent et al. 2002) | |
| BDNF | FB | rs6265 (Val66Met) | 11p13 | 10 | 32 | 0.0005 (paternal only) | 3.2 | – | Unique study (Kent et al. 2005) |
| TPH2 | FB | rs1843809 (G-T) | 12q15 | 52 | 22 | 0.0006 | 2.36 | – | Brookes et al. (2006), Sheehan et al. (2005) |
| ARRB2 | FB | Undisclosed | 17p13 | 103 | 66 | 0.004 | 1.56 | – | Unique study (Brookes et al. 2006) |
| PNMT | FB | Undisclosed | 17q21 | 70 | 42 | 0.008 | 1.67 | – | Unique study (Brookes et al. 2006) |
| MAOA | Alleles 3,4,5? | Xp11.23 | NA | NA | 0.0007 | – | – | Unique study (Manor et al. 2002) | |
| AR | C/C | Haplotype CAGL/GGCL | Xq11–12 | 133 | 52 | 0.0001 | – | – | Not replicated in Hispanic Caucasians (Comings et al. 1999) |
| SLC6A4 (5-HTT) | FB | 5-HTTLPR Short allele | 2,774 | 3,652 | 1 × 10E−3 | 1.13 (1.05–1.22) | + | Meta-analyses 15 studies (Thapar et al. 2005) |
Trans/Untrans Transmitted/Untransmitted, C/C = case–control study, FB = family-based study
a
Genotypes counts
b
Odds ratio for genotype