Imprinting and assisted reproduction [Imprinting und assistierte reproduktion]

Imprinting is an epigenetic process by which certain chromosomal regions are differentially marked in the male or female germline so that after fertilisation only the paternal or maternal allele of a gene is active. The imprint involves the methylation of regulatory DNA regions. Incorrect or absent imprints lead to changes in gene expression and developmental disorders. Imprinting defects are one cause of Beckwith-Wiedemann syndrome and Angelman syndrome. Animal experiments have shown that hormone treatment and the culture of oocytes and early embryos can lead to imprinting defects. Preliminary epidemiological data on children conceived by assisted reproductive technology (ART) indicate that ART may be associated with an increased risk for Beckwith-Wiedemann syndrome and Angelman syndrome. The increased risk may be due to the treatment or linked to the fertility problems of the parents. © 2006 Springer Medizin Verlag.