Fig. 6

Begg’s funnel plot for publication bias test. a A-allele vs. G-allele model; c AG vs. GG model; e AA + AG vs. GG model. Each point represents a separate study for the indicated association. Log [OR], natural logarithm of OR. Horizontal line, mean effect size. Egger’s publication bias plot. b A-allele vs. G-allele model; d AG vs. GG model; f AA + AG vs. GG model