Things to Know about "Three-Parent" Babies

Things to Know About Three-Parent Babies  Find more blogs about genetics and genealogy at UK has become the first nation to approve laws that allow for the creation of what has been called “three-parent” babies. The first baby born from this procedure could have his or her first birthday in 2016. What does this mean for genealogists (and their family trees)?

A family tree is a visual representation that shows exactly how members of the same family are related. Parents go in one line, their offspring go in the next line, and so on. Typically, spouses are connected to each other with a dashed line.

The offspring of a married couple is connected to them on a family tree by a line. This is true if the offspring are the biological children of their parents, or of the offspring had been adopted by their parents. How would a genealogist include a “three-parent” baby on a family tree?

To uncover the answer to this question, a person must first understand what, exactly, is meant by the phrase “three-parent” baby. One way to think of it is as a modified IVF (in vitro fertilization) technique. It is a process that replaces a woman’s genetically defective mitochondria with healthy mitochondria from a donor.

The process starts with an egg that contains unhealthy mitochondria. The mother’s nuclear material is removed from the egg and kept. Next, a donor (who has healthy mitochondria) donates an egg. The nuclear material is removed from that egg. The mother’s nuclear material is then put into the egg that has healthy mitochondria. Of course, sperm is still required for fertilization.

In other words, the “third-parent” isn’t technically a parent at all. The egg donor does not carry the developing baby to term – the mother does that. The egg donor is unable to pass her DNA onto the child (because her DNA has been removed). The donor can only contribute the healthy mitochondria – which comes out to less than 0.2% of the total DNA the baby receives. The father who the sperm comes from, and who fertilizes the egg, is still the father.

The only difference is that the mother and father can now have a baby that will be healthy. The baby won’t develop a disease that is associated with faulty mitochondrial DNA. The baby will, instead, receive healthy mitochondrial DNA.

The laws in the UK state that the woman who donates her healthy mitochondria will remain anonymous. She will not have rights over the child and will not be involved in the child’s upbringing. Genealogists can rest assured that the correct way to place a “three-parent” baby on a family tree is below his or her mother and father.

Image by JD Hancock on Flickr.

Related Articles at

* What is the Genographic Project?

* Spouses Share Genetic Similarity

* Diseases You Can Learn About from Genetic Testing

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