Britain’s fertility regulator on Wednesday confirmed the births of the U.K.’s first babies created using an experimental technique combining DNA from three people, an effort to prevent the children from inheriting rare genetic diseases.
The Human Fertilization and Embryology Authority said fewer
than five babies have been born this way in the U.K. but did not provide
further details to protect the families’ identities. The news was first
reported by the Guardian newspaper.
In 2015, the U.K. became the first country to adopt
legislation regulating methods to help prevent women with faulty mitochondria —
the energy source in a cell — from passing defects on to their babies. The
world’s first baby born using the technique was reported in the U.S. in 2016.
The genetic defects can result in diseases such as muscular
dystrophy, epilepsy, heart problems and intellectual disabilities. About one in
200 children in Britain is born with a mitochondrial disorder. To date, 32
patients have been authorized to receive such treatment.
For a woman with faulty mitochondria, scientists take
genetic material from her egg or embryo, which is then transferred into a donor
egg or embryo that still has healthy mitochondria but had the rest of its key
DNA removed.
The fertilized embryo is then transferred into the womb of
the mother. The genetic material from the donated egg comprises less than 1% of
the child created from this technique.
“Mitochondrial donation treatment offers families with
severe inherited mitochondrial illness the possibility of a healthy child,” the
U.K. fertility regulator said in a statement Wednesday. The agency said it was
still “early days” but it hoped the scientists involved, at Newcastle
University, would soon publish details of the treatment.
Britain requires every woman undergoing the treatment to
receive approval from the Human Fertilization and Embryology Authority. The
regulator says that to be eligible, families must have no other available
options for avoiding passing on genetic disease.
Many critics oppose the artificial reproduction techniques,
arguing there are other ways for people to avoid passing on diseases to their
children, such as egg donation or screening tests, and that the experimental
methods have not yet been proven safe.
Others warn that tweaking the genetic code this way could be
a slippery slope that eventually leads to designer babies for parents who not
only want to avoid inherited diseases but to have taller, stronger, smarter or
better-looking children.
Robin Lovell-Badge, a stem cell expert at the Francis Crick
Institute, a biomedical research center in London, said it would be critical to
monitor the babies’ future development.
“It will be interesting to know how well the (mitochondrial
donation) technique worked at a practical level, whether the babies are free of
mitochondrial disease and whether there is any risk of them developing problems
later in life,” he said in a statement.
Scientists in Europe published research earlier this year
that showed in some cases, the small number of abnormal mitochondria that are
inevitably carried over from the mother’s egg to the donor’s can reproduce when
the baby is in the uterus, which could ultimately lead to a genetic disease.
Lovell-Badge said the reasons for such problems were not yet
understood and that researchers would need to develop methods to reduce the
risk.
Previous research assessing another technique to create
babies from three people, including an egg donor, found that years later the
children were doing well as teenagers, with no signs of unusual health problems
and good grades in school.
Doctors in the U.S. were the first to announce the world’s
first baby using the mitochondria donation technique, after the treatment was
conducted in Mexico. -AP