title: Somatic genomic variations in early human prenatal development.
abstract: Only 25 to 30% of conceptions result in a live birth. There is mounting evidence that the cause for this low fecundity is an extremely high incidence of chromosomal rearrangements occurring in the cleavage stage embryo. In this review, we gather all recent evidence for an extraordinary degree of mosaicisms in early embryogenesis. The presence of the rearrangements seen in the cleavage stage embryos can explain the origins of the placental mosaicisms seen during chorion villi sampling as well as the chromosomal anomalies seen in early miscarriages. Whereas these rearrangements often lead to implantation failure and early miscarriages, natural selection of the fittest cells in the embryo is the likely mechanism leading to healthy fetuses.
authors.affiliation: Center for Human Genetics, Leuven, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Robberecht
authors.forename: Evelyne
authors.initials: E
authors.lastname: Vanneste
authors.forename: Anne
authors.initials: A
authors.lastname: Pexsters
authors.forename: Thomas
authors.initials: T
authors.lastname: D'Hooghe
authors.forename: Thierry
authors.initials: T
authors.lastname: Voet
authors.forename: Joris R
authors.initials: JR
authors.lastname: Vermeesch