Mexican clinic plans 20 three-parent babies in 2017: Controversial technique could help create 'disease-free' children

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The first baby to be born using a controversial three-parent IVF technique could soon be joined by a number of other lab-created infants conceived through the same method.

Earlier this year, a healthy boy was born after being conceived using DNA from three people in an effort to avoid a debilitating genetic disease.

But the fertility clinic in Mexico which carried out the procedure says it plans to conceive a further 20 babies using the technique in the first half of 2017.

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The fertility clinic in Mexico which carried helped a couple to conceive the world's first 'three-parent baby' says it plans to conceive a further 20 babies using the technique in the first half of 2017 (stock image used)

At the heart of the technique is the replacement of faulty mitochondria – the energy producing units found in cells and passed on by the mother – with those of a healthy female donor.

But concerns have been raised around its use as mitochondria contain a small amount of DNA, meaning the child inherits DNA from the mother, father and the donor.

While the initial child, born in April, has shown the technique works, it remains unclear if the procedure is safe and effective in the long term, or if children born using mitochondrial transfer will remain disease free as they grow.

According to reports seen by New Scientist, clinical test results about to be published show the first child is now a healthy eight-month-old, with no sign of the inherited disease carried by his parents.

Analysis of the boy’s tissues reveals that ‘most’ of his mitochondria have been inherited from the donor.

However, despite the replacement, trace amounts of mutant mitochondria have been seen in his cells, with levels as high as 9 per cent seen in some cells, with an average of 3–4 per cent.

But clinicians who carried out the analysis believe the defective mitochondria will remain at acceptable levels.

Medical director of the New Hope Fertility Center Mexico, Alejandro Chavez-Badiola, has said that the clinic is working with a number of other couples looking to avoid related health conditions.

Dr John Zhang, head of the New York City embryonic team, holds the world's first 'three-person' baby after the boy was born in Mexico in April. Dr Zhang carried out the procedure at the Mexican clinic

He also hit back at claims that the Mexican clinic was chosen because of the country's lack of regulation.

He told New Scientist: 'It is wrong to say there are no rules in Mexico', citing an ethics committee approval and regulatory oversight for the initial procedure. 

'I am meeting with the government next week,' he added.

The UK became the first country in the world to table legislation on the technique.

The regulatory body behind the decision, the Human Fertility and Embryology Authority, is due to decide on whether or not the approach should be approved for use in the UK this week. 

In October, reports emerged in the journal Nature that a child conceived using the technique may have been born in China. 

According to reporter Sara Reardon, Nature learned of a scientific paper ‘in review at an unnamed journal’ which claims a child was conceived using the technique in China.

Further use of the three-parent approach was also reported by New Scientist, with two women in Ukraine receiving treatment to overcome recurrent fertility problems.

While the controversial approach has so far only been used to treat inherited disease, the Ukrainian women – who are due to give birth in early 2017 – mark the first use of the approach to treat infertility.

Chinese researchers have caused some controversy with their apparent gung-ho approach to embryonic research, with scientists using gene-editing techniques to edit human embryos earlier this year - something frowned upon by the scientific community at large.

How is the procedure done? (1) Take eggs from mother with damaged mitochondria (2) Take eggs from donor with healthy mitochondria (3) Remove and save nucleus from mother's egg (4) Remove and discard donor's nucleus (5) Place mother's nucleus in donor's egg (6) Fertilised egg with father's sperm

Three-parent IVF has so far been used to treat conditions affecting mitochondria, the energy-producing units inside cells which contain small amounts of DNA.

It involves combining the fertilised egg with healthy mitochondria of a donor, typically by switching the genetic material in the donor egg with that of the mother, before fertilisation.

But the controversy lies in the additional DNA from the donor, which is then copied to every cell in the baby’s body and can be passed on to their children as well.

The three-parent child which recently hit the headlines, born earlier this year to a Jordanian couple and as part of a procedure carried out by researchers from a New York fertility clinic, is reported to be healthy with no sign of the genetic condition carried by his parents.

As the technique is not approved by the US authorities, the parents were taken to a clinic in Mexico, where regulations are less strict.

Speaking ahead of a conference in Utah this week, the surgeon who carried out the technique, Dr John Zhang, told reporters: ‘This new technology, the first time in human history, a healthy live person that is created by two eggs recombined it together with one sperm.’

Three-parent IVF has been approved in the UK – including the approach used by Dr Zhang and team – for the treatment of mitochondrial disease, although no children have yet been born using the technique.

For the two pregnant women in Ukraine, the team used a slightly different approach, called pro-nuclear transfer.

It involved fertilising both the mother’s egg and a donor egg with the father’s sperm. 

After fertilisation, the genetic material in the donor-derived embryo is replaced with that of the parents.

Using this approach enabled the team to overcome 'embryo arrest', where implanted IVF embryos die at the earliest stages of cell division.

Further use of the three-parent approach has also been reported this year, with two women in Ukraine receiving treatment to overcome recurrent fertility problems which caused embryos to terminate in the early stages of cell division (illustrated)