3 Parents, 1 Child?!

3 parent

Imagine having a father, a biological mother, ANDDD another genetically related mother. Sounds crazy, but could soon be a possibility.

There has been much talk in the media recently about the new in vitro fertilization method. A ground breaking new method that will eliminate any mutations within mitochondrial DNA that can be passed from mother to child, but at the same time, creating a child from the DNA of 3 adults. After much reading of the many articles on the web, this is my quick summary of what 3 parent IVF involves!

Mitochondrial DNA?

Some diseases such as mitochondrial myopathies (muscle affecting conditions) can be caused by mutations within the mitochondrial DNA, separate to the DNA powerhouse that is the nucleus. It is the nucleus that contains 46 chromosomes, half from the mother and half from the father but it is in the cytoplasm of all but the red blood cell that mitochondria are found. These cells work hard to create energy for the cell to use in various processes, and is also where around 1% of the DNA found in a person is located. The DNA is in a circular form, and contains 37 genes.

And how is it done?

There are two methods that both result in the DNA of the child being passed down from 3 parents, and eliminates any chance of mitochondrial diseases being present in the child. Both methods involve the use of a donor, to get mitochondrial DNA without defects that may cause disease.  Every year, around 1 in 200 children are born with a mitochondrial disease.

The first  method involves creating an embryo with the intended parents sperm and egg, and the pronuclei of this removed and planted into a donor embryo, and is known as a pro-nuclear transfer.  [4]Mitochondrialdisease-creditAusSMC

Image from [4]

The other is  known as a maternal spindle transfer [1].  The chromosomes from an unfertilized egg containing defects within the mitochondrial DNA are taken and transplanted into an empty egg from a donor, and then fertilization is allowed to take place. Experiments using these methods have shown to be successful with eggs able to undergo fertilization in a lab [3].0,,16253959_401,00

Image from [3]

Will everyone be happy about this?

These new methods will help progress science in previously unimaginable ways.  However, regulation of these needs to be strictly observed.  The Human Fertilisation and Embryology Authority (HFEA) in 2008 made an amendment to the HFE 1990 Act, allowing, “regulations to be passed that will allow techniques, which alter the mitochondrial DNA of an egg or embryo, to be used in assisted conception to prevent the transmission of serious mitochondiral disease.” [2] This allows the research into replacement to go ahead but not treatment as of yet, but others have doubts as to whether it should be allowed at all.  Pro-life groups are against the creation and destruction of embryos, and wish for IVF and research on embryos to be abolished.

Others are asking if this is even needed when there are alternative solutions.  Egg donation and PGD (preimplantation genetic diagnosis) [5] are already in use and the consequences of their use known, whereas these new techniques are not totally known, and donor eggs are already high in demand.

I personally believe this is a great idea, enabling infertile couples to have more options into their quest for parenthood.  What do you reckon?

References/extra reading

[1] http://www.dw.de/three-way-ivf-faces-public-consultation/a-1625448

[2] http://www.nhs.uk/news/2012/09September/Pages/Consultation-launched-on-three-parent-IVF.aspx)

[3] http://www.nhs.uk/news/2012/10October/Pages/Three-parent-IVF-creates-viable-human-embryos.aspx

[4] http://www.sciencemediacentre.co.nz/infographics/

[5] Poulton and Oakeshott (2012) Nuclear transfer to prevent maternal transmission of mitochondrial DNA disease, BM,J 345:e6651

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s