In a medical first, a child has been born using the genetic material of three different people. While the technique is controversial, the process has allowed for the child’s parents to avoid passing on a rare genetic mutation.
As reported New Scientist, a US team operating in Mexico has successfully performed the technique on a Jordanian couple, resulting in the successful birth of baby boy, now five months old. The success of the process should result in significant progress in the field of embryonic research.
The technique removes the mother’s mitochondria and replaces it with the donor’s, resulting in the baby carrying the genetic material of three people
What prompted the parents to undertake the procedure was the discovery that the mother carries the genes for Leigh syndrome, a fatal condition that affects the nervous system. While the mother is healthy, her first two children passed away due to the condition. The DNA carrying the genes for Leigh syndrome are located in the mitochondria of cells, but not the nucleus, where the majority of genetic material is stored.
In order to prevent the condition from being passed on, John Zhang from the New Hope Fertility Centre in New York City removed the nucleus from one of the mother’s eggs and inserted it into a donor egg that had its nucleus removed. The resulting egg was then fertilised using the father’s sperm. This technique removes the mother’s mitochondria and replaces it with the donor’s, resulting in the baby carrying the genetic material of three people.
The technique was performed in Mexico because it is not approved for use in the US. It differs slightly from a similar method approved for use in the UK that involves fertilising both the mother’s egg and the donor’s egg, but discarding the donor’s fertilised nucleus and replacing it with the mother’s. This was not appropriate for the couple in question, as they opposed the destruction of two embryos.
The method remains controversial, as attempts to create an embryo from three people in the 90s resulted in some babies developing genetic conditions. Early have shown that this child is healthy, though scientists will have to wait for more births before the technique can be confirmed safe.