Genomic Imprinting and Assisted Reproductive Technologies

Genomic imprinting, referring to an epigenetic marking resulting in monoallelic gene expression, plays a critical role in development. Recently, various imprinting diseases were reported in animals (Large Offspring syndrome (LOS)) and humans (Beckwith-Wiedemann syndrome (BWS) and Angelman syndrome (AS)) born after ART. In all cases, an imprinting defect was involved (loss of methylation at ICR2 in BWS, at SNRPN in AS and at IGF2R DMR2 in LOS). These data suggest that ART procedures may impair the establishment or the maintenance (following fertilization) of methylation marks at maternally imprinted loci. In view of these data, the aim of this study is to determine if children born following ART exhibit an increased risk of imprinting defects. If the answer is yes, the second objective is to identify the problematic step in the ART procedure and thus to suppress or modify this step.