New IVF treatment approved to prevent certain genetic defects
The UK is now the first country to pass legislation allowing the creation of embryos using the DNA of three people. Members of parliament overwhelmingly voted in favour of this advanced IVF technique. The process involves a mitochondrial DNA transfer, with the aim to stop the transfer of genetic diseases such as muscular dystrophy.
In this ground-breaking scientific procedure, embryos will be formed from the genetic material of three people: two women and one man. Faulty mitochondrial DNA within the egg will be replaced with healthy mitochondrial DNA to prevent diseases caused during maternal genetic transfer.
It’s expected that the first baby born using this variation of IVF may be born as early as 2016.
Why alter mitochondria DNA?
There are approximately 100 mitochondria in every human cell. Responsible for energy production, mitochondria also hold important genetic material. Mitochondrial DNA is inherited solely from the mother’s ovum. With 80% of mitochondrial DNA holding the code for functional proteins, the majority of mutations have significant implications for processes within the body.
Mitochondrial diseases are numerous and can range from asymptomatic to fatal. Faulty mitochondrial DNA can affect many organs within the body and manifest as lose of movement control, muscle wastage, epilepsy, liver failure, cardiovascular problems, and diabetes; among other conditions. There is mounting evidence that defective mitochondrial DNA may contribute to more diseases than previously realised.
Through a series of genetic testing, it’s possible to detect mitochondrial DNA mutations. Women that carry defective genes have a high risk of passing on these mutations to their offspring. However, this new IVF treatment may help to prevent many genetic diseases being inherited.
How does the three-parent embryo IVF treatment work?
Pioneered at Newcastle University, the mitochondrial DNA transfer can be preformed two ways.
In one approach, the mother’s egg is fertilised with the father’s sperm creating an embryo with the nuclear DNA of both parents. This nuclear DNA is then extracted and inserted into a donor egg that has the original nuclear DNA stripped.
The other technique involves extracting the nuclear DNA from the egg of the mother and inserting it into a female donor egg which has been stripped of nuclear DNA. This egg is then fertilised with sperm from the father.
Both techniques create an embryo containing healthy mitochondrial DNA from the female donor and the nuclear DNA of the father and mother. This allows for a baby to be born without inherited mitochondrial disease.
How genetically different is the baby from the mother and father?
Mitochondrial DNA does not contribute to the personality or genetic appearance of a person.
It contributes to less than 0.054% of total DNA.
Therefore, a child born as a result of a three-parent embryo is very much the genetic product of its mother and father, with the donor mitochondria only contributing a minor percentage of total DNA.
Now with legal approval, the time-line for the first baby to be born using a three-parent embryo is expected to be as follows:
- March to August – Licensing rules will be developed and published by the UK fertility regulator for assessing applications to carry out three-person IVF treatments
- Early Summer – The team at Newcastle University will publish the final safety experiments required by the regulator
- End of October – Regulations are expected to come into force.
- End of November – Clinics may apply for a licence through the regulator
- By the end of 2015 – The first attempted baby born with a three-parent embryo could take place
The future of genetic manipulation and designer babies
There is always a lot of controversy surrounding genetic manipulation and the concept of \’designer babies\’.
Proponents argue that this new IVF technique is ‘life saving’ and ‘good news for progressive medicine’. The prevention of mitochondrial diseases will improve lives and enable couples to have babies that would otherwise be disadvantaged.
However, critics argue that approving this new IVF technique raises serious ethical and safety concerns. It may also pave the way for further genetic modification, according to groups such as Human Genetics Alert.
Whether a critic or proponent of three-parent embryos, the fact remains that this is a big advancement in assisted reproduction technologies. No doubt the first baby born to this technique will make history and be monitored with much interest in the coming years.
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Dr. Kooner is Deputy Director of The Advanced Fertility Center of Chicago and has been a Specialist in Fertility Treatment since 1999.
As well as the areas that the clinic specialises in general, he is particularly interested in managing oocyte donation, female same-sex couples, single women having sperm donation and those considering egg freezing.
Dr. Kooner regularly speaks at fertility meetings. He has published in national journals and constantly contributes to the fertility research and publications from Advanced Fertility Center of Chicago.