Table 3. The characteristics of the included studies in the meta analysis.
| Year | Area | Ethnicity | Genotypingmethod | No. ofcases | No. ofcontrols | Cases | Controls | HWE(Control) | |||||
| First Author(ref.) | AA | AG | GG | AA | AG | GG | p | ||||||
| Deng Lin | 2002 | China | Asian | DHPLC | 84 | 91 | 17(20.2) | 48(57.2) | 19(22.6) | 35(38.5) | 42(46.1) | 14(15.4) | 0.826 |
| Jun Sui | 2009 | China | Asian | PCR-RFLP | 241 | 272 | 71(29.5) | 110(45.6) | 60(24.9) | 115(42.3) | 124(45.6) | 33(12.1) | 1.000 |
| Liangchun Shih | 2012 | Taiwan | Asian | PCR-RFLP | 176 | 176 | 67(38.1) | 86(48.9) | 23(13.0) | 43(24.4) | 105(59.7) | 28(15.9) | 0.010 |
| Our study | 2014 | China | Asian | PCR-RFLP | 165 | 191 | 61(37.0) | 92(55.8) | 12(7.2) | 71(37.2) | 88(46.1) | 32(16.7) | 0.650 |
| R. Catarino | 2008 | Portugal | European | PCR-RFLP | 84 | 247 | 21(25.0) | 40(47.6) | 23(27.4) | 69(27.9) | 138(55.9) | 40(16.2) | 0.052 |
| Raquel J. Catarino | 2006 | Portugal | European | PCR-RFLP | 94 | 187 | 26(27.7) | 42(44.7) | 26(27.6) | 54(18.9) | 105(56.1) | 28(15.0) | 0.054 |