The baby became pregnant via IVF
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Eight young children seem to be shielded from severe genetic disorders following their birth through a three-parent DNA technique. This method involved replacing defective maternal mitochondria with those from a female donor.
Approximately 1 in 5,000 individuals carry mitochondrial defects that provide energy to cells and are inherited solely from the mother. Such defects may result from genetic mutations leading to issues like blindness, seizures, and, in extreme cases, death. “Families find it incredibly challenging to cope with these diseases. They are heart-wrenching,” states Bobby McFarland from Newcastle University, UK.
In 2015, the UK first sanctioned a procedure called pronuclear transfer for women at high risk of passing on mitochondrial conditions, particularly those who cannot benefit from pre-implantation genetic testing.
This nuclear transfer technique utilizes eggs from both mothers and donors, which are fertilized with paternal sperm via IVF. After roughly 10 hours, the nuclei from both eggs are extracted, leaving behind the crucial genetic material that is separate from mitochondrial DNA.
The nucleus from the mother is subsequently inserted into the donor’s egg, yielding an embryo that primarily inherits DNA from its biological parent while acquiring mitochondria from the donor. Some mitochondrial DNA from the mother may still be unintentionally transmitted, according to Burt Smeet from Maastricht University in the Netherlands.
McFarland, who pioneered this method with her team, has applied the technique to 19 women harboring harmful mutations in over 80% of their mitochondria, typically the level that causes issues.
Seven of the women achieved pregnancy after the final embryo transfer, resulting in eight healthy births, including one pair of twins.
The researchers evaluated blood samples from the newborns, finding no harmful mitochondrial DNA mutations in five, and only trace levels in the remaining three. “The results have exceeded expectations,” says Mike Murphy from Cambridge University.
In the months or years following these nuclear transfers, all children have shown progress with developmental milestones. However, some may encounter complications that may or may not be linked to the procedure. For instance, one child developed high blood fat levels and an abnormal heartbeat, both of which were successfully addressed, while another experienced epilepsy at 7 months old, which resolved on its own.
The research team plans to monitor these children to assess the long-term consequences of the procedure.
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Source: www.newscientist.com
