Table 1. Characteristics of studies included in the meta-analysis.
| Author | Year | country | Ethnicity | Genotyping methods | No. (Cases/controls) | Genotypes Case (%) | Genotypes Contol (%) | ||||
| TT | TC | CC | TT | TC | CC | ||||||
| XU | 2010 | China | Asian | PCR-RFLP | 502/549 | 204 (40.64) | 236(47.01) | 62(12.35) | 266(48.45) | 229(41.71) | 54(9.84) |
| SON | 2013 | South Korea | Asian | PCR-RFLP | 157/201 | 69(43.9) | 75(47.8) | 13(8.3) | 110(54.7) | 74(36.8) | 17(8.5) |
| HAN | 2013 | China | Asian | Fluorescent-probe real-time quantitative PCR | 1013/999 | 451(44.52) | 444(43.83) | 118(11.65) | 456(45.65) | 424(42.44) | 119(11.91) |