Table 2. Frequencies of the 5-HTTLPR alleles and polymorphisms of the included studies&.
| Biallelic genotype approach | HWE | Triallelic genotype approach | HWE | ||||||||||||||||||||
| PTSD | Controls | P-value | PTSD | Controls | P-value | ||||||||||||||||||
| S | L | SS | SL | LL | S | L | SS | SL | LL | S' | L' | S'S' | S'L' | L'L' | S’ | L' | SvS' | S'Lv | LvL' | ||||
| Lee [18] | 2005 | 175 | 25 | 77 | 21 | 2 | 319 | 75 | 129 | 61 | 7 | 0.81 | – | – | – | – | – | – | – | – | – | – | – |
| Koenen [16] | 2009 | – | – | – | – | – | – | – | – | – | – | – | 17 | 21 | 4 | 9 | 6 | 539 | 603 | 116 | 307 | 148 | 0.06 |
| Mellman [21 | 2009 | 42 | 70 | 5 | 32 | 19 | 35 | 93 | 7 | 21 | 36 | 0.16 | 66 | 46 | 20 | 26 | 10 | 67 | 61 | 18 | 31 | 15 | 0.81 |
| Xie [20] | 2009 | – | – | – | – | – | – | – | – | – | – | – | 234 | 224 | 58 | 118 | 53 | 957 | 1089 | 234 | 489 | 300 | 0.20 |
| Grabe [19] | 2009 | 40 | 94 | 6 | 28 | 33 | 1294 | 1898 | 264 | 766 | 566 | 0.86 | 48 | 86 | 8 | 32 | 27 | 1512 | 1680 | 364 | 784 | 448 | 0.55 |
| Thakur [47] | 2009 | 23 | 25 | 8 | 7 | 9 | 22 | 12 | 7 | 8 | 2 | 0.09 | – | – | – | – | – | – | – | – | – | – | – |
| Kolassa [17] | 2010 | 112 | 550 | 15 | 82 | 234 | 29 | 125 | 1 | 27 | 49 | 0.20 | – | – | – | – | – | – | – | – | – | – | – |
| Saying [48] | 2010 | 30 | 28 | 6 | 18 | 5 | 41 | 55 | 6 | 29 | 13 | 0.045 | – | – | – | – | – | – | – | – | – | – | – |
| Koenen [50] | 2011 | 10 | 34 | 1 | 8 | 13 | 45 | 103 | 12 | 21 | 41 | 0.005 | 21 | 23 | 4 | 13 | 5 | 67 | 81 | 17 | 33 | 24 | 0.39 |
| Morey [49] | 2011 | 22 | 22 | 7 | 8 | 7 | 18 | 22 | 3 | 12 | 5 | 0.34 | 26 | 18 | 10 | 6 | 6 | 22 | 18 | 5 | 12 | 3 | 0.34 |
| Valente [46] | 2011 | 55 | 71 | 13 | 29 | 21 | 38 | 30 | 9 | 20 | 5 | 0.26 | – | – | – | – | – | – | – | – | – | – | – |
| Wang [45] | 2011 | 207 | 217 | 56 | 95 | 61 | 131 | 221 | 21 | 89 | 66 | 0.28 | 261 | 163 | 94 | 73 | 45 | 164 | 188 | 29 | 106 | 41 | 0.005 |
| Xie (AA) [51] | 2012 | 222 | 650 | 26 | 170 | 240 | 1269 | 3997 | 170 | 929 | 1534 | 0.07 | – | – | – | – | – | – | – | – | – | – | – |
| Xie (EA) [51] | 2012 | 460 | 564 | 96 | 268 | 148 | 2511 | 3187 | 566 | 1379 | 904 | 0.34 | – | – | – | – | – | – | – | – | – | – | – |
S, short allele; L, long allele; S' as S + LG; and L' as LA.
&
Dominant model (S+ vs LL or S'+vs L'L'): S+ (or S'+) genotype frequencies are calculated as the sum of SS (or S'S') and SL (or S'L') frequencies. Recessive model (SS vs L+ or S'S' vs L'+): L+ (or L'+) genotype frequencies are calculated by the sum of LL (or L'L') and SL (or SvL') genotype frequencies.