A baby is born with donor mitochondria to avoid an inherited disease

Mitochondria, the parts of a cell that make its energy, carry a little DNA of their own, passed only from mother to child; faults in it cause diseases that are often fatal in childhood. Moving the nucleus of the mother's egg into a donor's egg with healthy mitochondria gives a child that is genetically the parents' with a small part from a third person. The first such child was born in 2016, in Mexico, to avoid a rule elsewhere; Britain had already made it lawful under licence, and eight children born there were reported in 2025. It is the only change to inheritance a regulator has approved.

What would count

A child is born after a procedure that replaced the mother's faulty mitochondria with a donor's, done to prevent a named inherited disease, with the birth confirmed by the clinic or regulator; the rung in clinical use needs a regulator's licence under which such births take place outside a trial.

Who settles it: The regulator's licence record (the United Kingdom's Human Fertilisation and Embryology Authority) and the peer-reviewed birth reports

Where it stands

In clinical use. Reached on 15 March 2017, on the record of hfea.gov.uk. Could move a stage within 5 to 20 years.

The last reading

Once a week every upgrade is read against the news, against what would count above. Open a line to see what that week held. Every reading of this upgrade is on this week's reading.

• 16 October 2026 Nothing new

  Nothing in the window. Australia's mitoHOPE pilot, the first programme outside Britain, now expects its first participants in the second half of 2027, and no new British births have been reported since the eight in the New England Journal of Medicine in July 2025. On the claim still to check, the first child's birth date: the 2017 paper's abstract (PubMed 28385334) says only that the boy was 'healthy at 7 months of age' when it was written, and its full text would not load, while coverage gives both 2016-04-06 and 'May'; the claim is not settled and stays on the list.

Notes

The in-clinical-use record is the British regulator's approval of the first clinic licence, to Newcastle Fertility at Life, in March 2017; the first births under it were confirmed by the regulator in 2023 (fewer than five, in answer to a freedom-of-information request) and eight were reported in the New England Journal of Medicine in July 2025. The first-human record is the 2017 paper on the boy born in Mexico in 2016 to a mother carrying Leigh syndrome. Children born in the 1990s after a cruder transfer of egg cytoplasm also carried a donor's mitochondria, but for infertility rather than to avoid a disease, so they fall outside this entry's test. The rung in wide use needs a counted population in the hundreds or more, and the total so far is in the tens.

Still to check

Claims in this entry written from memory and not yet checked against a source. Each is cleared by checking it and either deleting the line or correcting the entry.

• The first child's birth date (2016-04-06) rests on press coverage of the case. The linked paper was read in full on 2026-10-16 and gives no birth date at all (only that the boy was seven months old when it was written), so the day still needs a source from the clinic or the authors.