Genetic imprinting is a mechanism in which gene expression depends upon parental origin. Mutations can alter normal imprinting, thus causing genetic abnormalities. Beckwith-Widermann syndrome (BWS) , Transient Neonatal Diabetes (TND), and Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are all acquired because of either a maternal or paternal deletion on a chromosome or from inheritance of both chromosomes of a pair from one parent.
"It has been known for some time that BWS, for example, was associated with ART", said Dr. Sutcliffe, "and we set out to look at the association of all four disorders and assisted conception." Dr. Sutcliffe and his team contacted patients throughout the UK who were in support groups for the disorders and obtained family histories and details of whether or not they had had ART, and if so, which kind. Out of 82 replies from families who had had a child with BWS, 10 had used ART in order to conceive (12%). Families with children with TND, AS, and PWS were also contacted and asked the same questions.
"We found that BWS was the only disorder where there was a significant risk for children conceived by ART", said Dr. Sutcliffe. "However, we found that all affected children apart from those with BWS had a mixture of genomic mutations, whereas those with BWS had a suggested mechanism maternal loss of methylation". Methylation is a mechanism used to inactivate parts of a chromosome to prevent problems.
Contact: Mary Rice
European Society for Human Reproduction and Embryology