Comprehensive embryo analysis of advanced maternal age-related aneuploidies and mosaicism by short comparative genomic hybridization
ABSTRACT The short comparative genomic hybridization (short-CGH) method was used to perform a comprehensive cytogenetic study of isolated blastomeres from advanced maternal age embryos, discarded after fluorescent in situ hybridization (FISH) preimplantation genetic screening (PGS), detecting aneuploidies (38.5% of which corresponded to chromosomes not screened by 9-chromosome FISH), structural aberrations (31.8%), and mosaicism (77.3%). The short-CGH method was subsequently applied in one PGS, achieving a twin pregnancy.
- SourceAvailable from: Joris Vermeesch
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- "Finally, centric fission has been characterized as an important driver of karyotype evolution [Perry et al., 2004] and i(p) and i(q) formation is an important mechanism in UPID etiology [Kotzot, 2001, 2008]. We, as well as other groups, demonstrate that the cleavage stage embryo is prone to (peri-)centric instability or centric fission resulting in i(p) or i(q) chromosome formation in human cleavage stage embryogenesis [Wells and Delhanty, 2000; Vanneste et al., 2009; Rius et al., 2010]. "
ABSTRACT: Early human in vitro fertilized embryos frequently accumulate whole chromosome aneuploidies and segmental imbalances. This embryonic chromosomal instability does not necessarily undermine normal human development, but it may lead to loss of conception, genetic disease, and genetic variation development. In this review we provide an overview of how this instability of chromosomes arises and evolves during early human embryogenesis.Seminars in Reproductive Medicine 08/2012; 30(4):302-8. DOI:10.1055/s-0032-1313909 · 3.00 Impact Factor
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- "It was with the development of metaphase comparative genomic hybridization (CGH) using DOP-amplified single cell DNA that the extent of whole-chromosome imbalances could be probed genome-wide. For the first time also segmental chromosome imbalances were reported in approximately 7–32% of the embryos (Voullaire et al., 2000, 2002; Wells and Delhanty, 2000; Wilton, 2005; Daphnis et al., 2008; Rius et al., 2011). Mosaicism for whole-chromosome aneuploidies was detected in up to 75% of human cleavage stage embryos (Wells and Delhanty, 2000; Voullaire et al., 2002). "
ABSTRACT: Microarray analysis enables the genome-wide detection of copy number variations and the investigation of chromosomal instability. Whereas array techniques have been well established for the analysis of unamplified DNA derived from many cells, it has been more challenging to enable the accurate analysis of single cell genomes. In this review, we provide an overview of single cell DNA amplification techniques, the different array approaches, and discuss their potential applications to study human embryos.Frontiers in Genetics 03/2012; 3:44. DOI:10.3389/fgene.2012.00044
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ABSTRACT: Infusion processing using gas cluster ion beam (GCIB) technology provides several new capabilities in the areas of ultra shallow junction formation and localized or blanket SiGe formation resulting in strained-Si. This room temperature process requires only solid phase epitaxy (SPE) anneals (<700degC) for diffusionless activation and high quality SiGe or Ge formation. Initial tests indicate all standard annealing methods are compatible with the process. For the formation of ultra shallow junctions, there are four enabling aspects to this new technology: 1) no channeling is observed, so a pre-amorphizing implant (PAI) is not required for Xj<10 nm; 2) a box-like profile of the dopant can be engineered; 3) no end of range (EOR) damage is observed when Ge is included in the cluster. This creates a self-amorphizing infusion doping step that potentially advances the use of the various diffusionless activation methods since there is no issue with junction leakage; 4) by increasing the amount of Ge incorporated in the cluster and as a result into the Si surface, the boron solid solubility (Bss) can be increased, thereby lowering the Rs and Rext for the source drain extension structures. When higher infusion doses of GeH<sub>4</sub> and/or SiH<sub>4</sub> containing clusters are used, dose controlled deposition (DCD) occurs. The DCD infusion process appears to be insensitive to surface impurities such as native oxide due to the highly localized transient thermal spike (TTS). This produces a 100% amorphous layer with no post deposition interfacial layer enabling complete single crystal epitaxial regrowth of the Ge or SiGe at temperatures down to 550degC. Since this is a room temperature process, the localized infusion and deposition are compatible with photoresist patterningAdvanced Thermal Processing of Semiconductors, 2004. RTP 2004. 12th IEEE International Conference on; 02/2004