Detection of maternal DNA contamination in the placenta

We use whole-genome sequencing of monozygotic (and dizygotic) twins to detect somatic mutations to infer the cellular history of the twinning event. We recruited monozygotic twins with varying degrees of fetal membranes to compare the twinning events between theses subsets. We used blood, buccal epithelial cell, placenta, and umbilical cord to trace the embryonic somatic mutations. Using the somatic mutations from various tissues we infer the approximate timing of twinning in each monozygotic twin subtypes.EGA study EGAS00001006155