The Placenta — Fast, Loose, and in Control

The placenta exhibits unique biological behaviors, including extensive clonal genetic mosaicism and somatic mutations similar to pediatric cancers, yet without cancer driver mutations. A study by Coorens et al. analyzed 86 placentas, revealing large monoclonal expansions and region-specific genetic variations, likely due to oxidative DNA damage in early hypoxic development. The placental epigenome, resembling cancer cells in hypomethylation, may contribute to these anomalies. These findings challenge conventional prenatal diagnostics, as confined placental mosaicism (e.g., trisomy rescue) can lead to misdiagnoses. The study also explores implications for pregnancy complications like preeclampsia and intrauterine growth restriction, though no direct mutation-phenotype links were found. Further research is needed to understand the role of genetic mosaicism in placental function and lifespan.

The placenta exhibits unique biological behaviors, including extensive clonal genetic mosaicism and somatic mutations similar to pediatric cancers, yet without cancer driver mutations. A study by Coorens et al. analyzed 86 placentas, revealing large monoclonal expansions and region-specific genetic variations, likely due to oxidative DNA damage in early hypoxic development. The placental epigenome, resembling cancer cells in hypomethylation, may contribute to these anomalies. These findings challenge conventional prenatal diagnostics, as confined placental mosaicism (e.g., trisomy rescue) can lead to misdiagnoses. The study also explores implications for pregnancy complications like preeclampsia and intrauterine growth restriction, though no direct mutation-phenotype links were found. Further research is needed to understand the role of genetic mosaicism in placental function and lifespan.