- Three-person baby technique lets parents with genetic mutations edit the mother’s egg so they can have a healthy baby
- Now two infertile women in Ukraine have used the technique to conceive
- The technique is only legal in the United Kingdom, first birth was in April
- The first baby’s parents are Jordanian, his mother had a genetic mutation
- For the first baby created with this technique, a US team carried out the egg-editing in Mexico where there are no rules against the procedure
- ‘It is a milestone,’ surgeon Dr John Zhang told Daily Mail Online last month
- He said in the future this technique could be ‘unlimited’ – from helping older women give birth, to editing a child’s appearance or skills
Two infertile women will give birth in Ukraine after using a revolutionary technique that combines the genes of three parents, a report reveals.
The technique was designed to prevent families passing on genetic mutations, not to aid fertility.
However, the New Scientist reported on Monday that two women have used the procedure to bypass fertility issues.
Both patients are married women who been undergoing IVF when they went into ’embryo arrest’ – meaning the cells suddenly and inexplicably stopped growing half-way through the process.
One mother-to-be is 20 weeks pregnant with a son, the other 26 weeks pregnant with a daughter, the report said.
The revelation comes just two weeks after the first baby created with this technique was born.
It is not clear where the Ukrainian medics stand legally, since the United Kingdom is the only country in the world to legalize the technique – and only to bypass hereditary diseases.
The team led by Valery Zukin, director of the Clinic of Reproductive Medicine in Kiev, will elaborate on the procedures at a conference in New York this week.
According to the New Scientist, Dr Zukin performed the procedures after concluding that it was the bulk of the cells that had caused the embryo arrest – but the vital DNA could still be salvaged.
For example, it may be that certain enzymes in the mother’s cell were blocking the growth process.
To get around that, Dr Zukin told the New Scientist, they used a technique called ‘pro-nuclear transfer’.
As with standard IVF, they fertilize the mother’s egg with sperm from her husband.
They then also fertilze a donor’s egg with sperm from the husband.
Then they extract the ‘pro-nucleus’ from the mother’s egg – that is the core of the cell that contains the mother’s and father’s chromosomes that forms after fertilization.
Next they extract the pro-nucleus from the donor’s egg.
The donor’s pronucleus is discarded, and replaced with the parents’ pronucleus.
It means the baby has all of their DNA from their parents, but the egg it is housed in is likely to be stronger, healthier, and more resilient.
The first baby ever created with this technique – a boy, now five months old – was born in Mexico after a New York team treated his Jordanian parents.
Like all humans, the boy carries DNA from both his parents. But he also has a tiny piece of genetic code from a donor.
It means he has avoided inheriting a genetic condition from his Jordanian mother, known only as IS, that could kill him.
At the time, embryologists said they believe this birth should fast-forward progress around the world, offering hope to millions who face the prospect of delivering terminally ill children.
And the two upcoming Ukrainian births will no doubt spur on that momentum.
‘This is a milestone technique,’ Dr John Zhang, who led the medical team from New York City’s New Hope Fertility Center to deliver the first baby, told Daily Mail Online last month.
‘It proves for the first time that genetic information from three people can avoid disease,’ he said.
‘We now know reconstitution of human eggs can produce a healthy baby.
‘No other technique has been established.’
Dr Zhang is not naming the baby or the parents.
However, he revealed some details about the family’s devastating journey to reach this world-first.
The parents have already lost two children to the same condition – Leigh’s syndrome – their first at the age of six; their second at eight months.
Leigh’s syndrome is a severe neurological disorder which attacks the nervous system.
It gradually inhibits a child’s mental and physical abilities from the moment they are born.
Sufferers typically die by the age of three due to lung failure.
Tests revealed that, in this case, the boy’s mother carries genes for the disease in her mitochondria.
Mothers pass down a melting pot of DNA. The majority is ‘nuclear DNA’ passed down in each cell’s nucleus.
But 37 maternal genes are passed to the child in each cell’s mitochondria – the cell’s ‘battery’. Father’s never (or at least barely ever) pass down mitochondria.
Mitochondria carry just 37 genes. In this case, one in four of the mother’s mitochondria have the mutation that causes Leigh’s syndrome.
Devastated by the loss of their two children, the couple flew to America to meet with Dr Zhang at New Hope, a facility which focuses on training in new innovations.
With strict regulations in the United States, the team went to Mexico.
The boy was born through a technique called spindle nuclear transfer.
Dr Zhang removed the nucleus from one of his mother’s eggs. It was then inserted in a donor egg that had its nucleus removed.
This egg was then fertilized with sperm from the baby’s father.
Five eggs were created with this technique, only one of which survived. The findings will be showcased at the American Society for Reproductive Medicine’s Scientific Congress in Salt Lake City next month.
The technique was carried out in Mexico because it would not be approved in the US by regulators.
Echoing both the fears and excitement of the entire medical community, Dr Zhang pointed out: ‘This is just the start.’
For now, embryologists are focusing on the technique as a way to avoid hereditary diseases that prevent many adults with genetic mutations from having children.