summary odds ratios (OR) ranging from 0.52 to 2.34 (Table 1), typical results for studies on other highly heritable phenotypes with "common variants, common disease" design [3-6]. We further assessed the variants using criteria established by the HuGENet Road Map [24] that was recently proposed for assessing cumulative evidence from genetic association studies. Using these stringent criteria, six variants displayed moderate epidemiological credibility (Grade B, Table 1). A full list of the curated information is available online at http://karg.cbi.pku.edu.cn/karg2/. For each study, we extracted meta-data including over thirty demographic and experimental variables where available (Additional file 1).
