We developed several novel tools to genome wide screen for CNVs and SNPs in single cells. When applied to cleavage stage embryos from young fertile couples we discovered, unexpectedly, an extremely high incidence of chromosomal instability, a hallmark of tumorigenesis (Vanneste et al., Nature Medicine, 2009; Vanneste et al., Hum.Reprod., 2011). Not only mosaicisms for whole chromosome aneuploid...
