Three-parent baby coming soon

Scientists currently working on problem of creating baby with DNA from three people. Why would anyone want to do this?

MEDICINE

Three-parent baby coming soon

Scientists are currently working on the problem of creating a baby with the DNA from three people.

Why would anyone want to do this?

Women with genetic disorders risk passing these genes on to their children.

You might have thought that some Dr, Frankenstein-like parents were creating a designer baby, such as take this woman's brains and that woman's body and then our daughter can win the Miss Universe pageant and be a nuclear physicist too, but luckily no one is up to this sort of thing, at least yet.

CURE FOR GENETIC DISORDERS

The idea behind the in-vitro fertilization (IVF) procedure is to use the DNA from a second donor woman to replace the defective DNA of the woman with a genetic disorder (genetic disease).

The healthy DNA of the donor would combine with the DNA of the parents.

MITOCHONDRIA & THEIR DNA

The specific genetic disorder studied was mitochondrial DNA disease.

Mitochondria are organelles (tiny structures) inside almost all cells in the body (but not blood cells) that convert food into energy used by the body.

Mitochondria have their own DNA which might seem strange. Biologists believe that mitochondria were once separate bacteria cells that evolved to live inside larger cells providing the function of converting food into energy, so that is why mitochondria have separate DNA (see here).

In humans, mitochondrial DNA is inherited only from the mother.

If mitochrondria have genetic faults, cells will not have enough energy to perform key functions.

A wide range of harmful medical conditions can result from genetic faults in mitochondrial DNA including organ failure, deafness, epilepsy, heart problems, muscle weakness, walking problems and early death.

To take the UK as an example, about 1 in 200 children have a genetic fault in their mitochondrial DNA but only 1 in 6500 children is believed to develop serious mitochondrial disease (see here).

THE PROCEDURE

As the BBC describes the medical procedure:
 
"The process, known as "early pronuclear transfer" involves removing the parents' key genetic material from an embryo within hours of fertilisation, leaving behind the woman's faulty mitochondria. The parental DNA, which contains all the key genes responsible for character and appearance, is then transferred into a donor woman's embryo, which has its nucleus removed but contains healthy mitochondria " (source here)

The technique was not always completely successful but faulty mitochondrial DNA transferred was always less than 2%.

The new procedure might not completely prevent transmission of genetic disorders, but the risk of faulty DNA being passed onto children is reduced significantly.

This means that faulty DNA would also not be passed down to later generations.

STUDY FINDS PROCEDURE TO BE SAFE

A study published in the scientific journal Nature has found the technique to be safe, that it will result in normal pregnancies.

The study used more than 500 eggs from 64 women, finding a significant reduction in defective mitochondria passed onto children and that the procedure had no negative effects on embryo development.

http://www.bbc.com/news/health-36481452
http://www.dailymail.co.uk/sciencetech/article-3631770/Britain-s-three-parent-baby-born-ONE-YEAR-Scientists-say-controversial-IVF-technique-ready-use.html

https://www.theguardian.com/science/2016/jun/08/doctors-edge-closer-to-creating-babies-with-dna-from-three-people

https://en.wikipedia.org/wiki/Mitochondrion

https://en.wikipedia.org/wiki/Mitochondrial_DNA

https://en.wikipedia.org/wiki/Mitochondrial_disease
https://en.wikipedia.org/wiki/Mitochondrial_donation

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