Epigenetics and assisted reproductive technologies: human imprinting syndromes.

With the rise in use of assisted reproductive technologies (ARTs), there has been an increased awareness of potential genetic problems that may be initiated or propagated using these techniques. Several population studies have suggested a small but significantly increased risk of imprinting disorders like Angelman syndrome, Beckwith-Wiedemann syndrome, and possibly transient neonatal diabetes in children born through ARTs. Although the absolute risk appears to be very small, this association logically leads to the question of how ARTs affect gene imprinting. Studies investigating culture medias, timing of embryo transfer, intracytoplasmic sperm injection, and type of infertility have not yielded an association. There is evidence that the period of gamete development and the period during which imprinted genes must maintain methylation are vulnerable points at which errors may occur. Further evidence linking aberrant methylation to subfertility and superovulation make epigenetics and ARTs an area that requires additional research.