Abstract
An in-depth investigation into the genetics of the placenta reveals its tumor-like nature and shows how it may help normalize genetic mutations in the fetus that would otherwise have resulted in miscarriage.
The research team, led by the University of Cambridge and the Wellcome Sanger Institute, think that as the fetus divides away from the placenta, it uses it as a place to deposit genetic defects that would otherwise cause health problems.
This study, which is published in the journal Nature, is the first to carry out whole-genome sequencing of multiple placental samples – 86 bulk placental samples and 106 microdissections from different parts of the placenta.
The placentas the researchers tested were highly mutated and often contained copy number changes in a similar fashion to cancerous tissue. Based on their findings, the researchers believe that this mosaic state is actually normal for placental tissue and not the rare exception.
“Chunks of normal tissue elsewhere in the body are composed of millions of cells that come from different cell lineages. This design probably protects the tissue from genetic errors of individual linages,” Sam Behjati, M.D., Ph.D., a group leader at the Sanger who co-led the research, told Clinical OMICs.