Karyomapping (cell nucleus mapping) is the genetic analysis of a cell coming from an embryo created using IVF.
The resulting genetic map may determine whether the embryo has chromosomes involving a defective gene (combinations carrying involving a higher risk for diabetes, heart disease, cancer or Alzheimer’s disease, mutations causing serious diseases such as cystic fibrosis, muscular dystrophy, and Huntington’s disease), abnormalities which often lead to foetal death so that doctors will implant embryos most likely to survive.
To this date, PGD allows 2% out of 15,000 known genetic diseases to be diagnosed. The new karyomapping technique may detect all known genetic diseases in embryos except those occurring suddenly through a random mutation; this is possible within only a few weeks by removing a single cell.
The procedure at a glance
To create the gene family tree, a painless procedure is followed requiring genetic material samples from both parents –saliva samples are enough- and a first-degree relative if this person suffers from a particular disease.
Scientists will then create a “gene family tree” classifying 23 chromosome sets of all parties and thoroughly investigate them to detect any anomalies. This way, they are able not only to detect anomalies, but also verify from whom it was inherited.
IVF is performed and embryos are created. Once these embryos have eight cells, one cell is removed for genetic analysis.
Gene tree data are compared against the embryo’s DNA to verify its chromosomal structure and which chromosomes have been inherited from which grandfather or grandmother. Thus, chances of it being a carrier or experiencing certain hereditary diseases are limited.
Since many embryos are likely not to have a fully developed genetic code at the time of this test, the test may also be repeated during pregnancy to confirm data, as well as further investigate to find other possible anomalies or sudden mutations.
Success rates
Karyomapping –as is this test called- will significantly increase the chances for a healthy pregnancy, particularly in challenging cases, since the experts will be able to select the strongest embryos while reducing the wait for couples facing infertility issues.
