Figure 4From: A macroepigenetic approach to identify factors responsible for the autism epidemic in the United StatesMethionine synthase links oxidative stress to epigenetic regulation. Figure 4 shows how exposure to toxic substances, such as OP pesticides, HFCS, or heavy metals, inhibits methionine synthase through effects of oxidative stress. As a result, decrease of SAM to SAH ratio will lead to a decrease in DNA methylation and consequently to altered PON1 gene expression.Back to article page