Mexico, the First Child with Three Different Parents

Was born the first child with the DNA of three different parents

The baby, born on 6 April 2016, is the first to incorporate the DNA of three parents, assembled with a new technique that allowed the baby to not inherit from his mother a serious neurodegenerative disease.

Mother’s disease

The mother is a healthy carrier of Leigh’s syndrome, a lethal disease that affects the developing nervous system, and that had already caused several deaths in the family: the death of two children born with the disease, and 4 abortions.
Leigh’s syndrome is an incurable disease that does not allow a regular development of the nervous system in early childhood. The genes that cause it are enclosed in the DNA of mitochondria which are carriers of the 37 genes that each of us inherits from our mother and that are separated from the rest of the DNA contained in the cell nucleus.

The Technique

It was John Zhang, head of the New Hope Fertility Center in New York, who went to Mexico to do the procedure, forbidden in the United States because “there are no rules”. For Zhang “saving lives is the ethical thing to do”.
To prevent the fetus from inheriting the disease, Zhang and colleagues used a variant of “in vitro fertilization with three parents”, thanks to the collaboration of a healthy egg donor. The nucleus was extracted from the donor’s ovum and replaced with that of the mother’s ovule, the resulting new egg was then fertilized with the seed of the father.

The Outcome

The system gives less guarantees and on five embryos created, only in one case has there been a regular development, which was then implanted in the mother allowing pregnancy and the birth of the child.
Only 1% of the mitochondrial DNA of the child seems to have inherited the mutations responsible for the disease: too little for it to express itself.