This review first outlines how epigenetic dysregulation contributes to psychosomatic disorders through altered expression of genes such as GRM2, TRPA1, SLC6A4, NR3C1, leptin, BDNF, NAT15, HDAC4, PRKCA, RTN1, PRKG1, and HDAC7. The gene discussed is TRPA1; the disease is somatoform disorder.