Designer mitochondria: introducing the baby with three parents

A cutting-edge IVF technique which is being pioneered in the UK is set to change the way we think of conventional genetic inheritance. With the aim of combating life-threatening mitochondrial conditions in newborns, scientists are hoping to use the DNA from three donors instead of two in future IVF treatment.

Mitochondria are present in most of our cells and are responsible for generating the majority of our chemical energy. They have their own DNA (mDNA) and inherited mutations in mDNA can lead to a variety of mitochondrial disorders which affect their function, leading to heart failure, muscle weakness and death. What’s interesting is that, in humans and most other organisms, mDNA is inherited solely from the mother. As mDNA exists outside the cell’s nucleus, it is possible to separate the nucleus from the defected mDNA.

Scientists have come up with techniques that make it possible to place the mother’s nucleus into either a vacant donor egg or embryo containing healthy mitochondria. Let it bake for nine months and voilà! – a baby with genetic material from three people, clear of any mitochondrial diseases. However, since mDNA is the smallest chromosome we have and only codes for 37 genes, only a tiny percentage of the baby’s genetic make-up is from the donor.

The whole shbang. Image: HFEA

Step 1: One egg from the mother and one egg from the donor are both fertilised with the father’s sperm to create two embryos. Step 2: The nuclei are removed from both, but the donor’s is destroyed. Step 3: The donor embryo has the parent’s nucleus inserted into it before being implanted in the mother’s womb.

Regulations for this technique are on course to be drafted this year and it may well be available to couples in as little as two. Already this research is causing quite a stir as to what it might lead to in the future – designer babies, anyone? – but those carrying diseased mitochondrial genes could be getting the opportunity to have their own children who would otherwise be unable to do so.

The Human Fertilisation and Embryology Authority (HFEA) in the UK has said that there is no evidence that this advancement is unsafe and conducted their own public consultation, but are we paving the way for absurd eugenics?

Over to you:

  • Do you think this research is being rightly put into action for those families who need it most?
  • What do you think of designing a baby anyway?

Cover image courtesy of sabianmaggy

About Jack Harris

After graduating in Chemistry from The University of Edinburgh, Jack worked in Hong Kong for a year before moving to Australia. He is currently involved in teaching at The University of Adelaide. Follow him @harrisjack4

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