Fig. 3

Epigenetic disorders associated with gene–environmental interaction. Until recently, congenital diseases and cancers have been considered to be the only diseases to be caused by epigenetic failures. Several lines of evidence have suggested that neurodevelopmental diseases and mental diseases are also associated with epigenetic failures. Intracytoplasmic sperm injection, a modern reproductive technique of in vitro fertilization, is thought to be associated with imprinted diseases [33]. The epigenetic effect in the fetal period is described in Fig. 2. Thus, the gene–environment interaction potentially contributes to all epigenetic diseases