Figure 2.

Forest plot of odds ratios (ORs) with 95% confidence intervals (CIs) by continent, representing the odds of transmission of the short relative to those of the long 5-HTTLPR variant, transmitted from heterozygous parents to offspring with ASD. Small dashed lines represent America, dotted lines Europe, large dashed lines Asia, and dot-dashed lines America and Europe together. Both the results of individual studies (above the horizontal axis) and the pooled results (below the horizontal axis) are shown.