Table 1. Characteristics of the studies included in the meta-analysis.
| Sample size | Gender (M/F) | Age, mean±SD, years | ||||||
| Study | ethnicity | Cases | Controls | Cases | Controls | Cases | Controls | HWE |
| Baratz 2010a | Caucasian | 130 | 260 | 30/100 | 60/200 | 77±9 | 77±9 | YES |
| Baratz 2010b | Caucasian | 150 | 150 | 46/104 | 46/104 | 74±8 | 74±8 | YES |
| Thalamuthu 2011 | Chinese | 57 | 121 | 12/45 | 51/70 | 67 | 65.1 | YES |
| Riazuddin 2011 | Caucasian | 170 | 180 | 62/108 | 82/98 | 66.25±12.97 | 71.99±7.52 | YES |
| Li 2011 | Caucasian | 450 | 340 | NA | NA | NA | NA | YES |
| Igo 2012 | Caucasian | 531 | 204 | 154/377 | 50/154 | 67±12 | 67±10 | NA |
| Kuot 2012 | Caucasian | 103 | 275 | 35/68 | 137/138 | 68.6±15.5 | 76.0±8.4 | YES |
| Wang 2013 | Chinese | 34 | 491 | NA | 219/272 | NA | 71.7±8.2 | YES |
| Stamler 2013 | Caucasian | 82 | 163 | NA | NA | NA | NA | YES |
NA: not available. SD: standard deviation. HWE: Hardy-Weinberg equilibrium. Baratz 2010a and Baratz 2010b are from the same study but of different cohorts.