Scientists have raised fresh questions over the effectiveness and safety of a ‘gene-editing’ technique which leads to the creation of ‘three-parent babies’.
The technique, known as mitochondrial replacement therapy or ‘three-parent IVF’, aims to prevent babies inheriting an array of health problems which may lead to developmental delays, seizures, deafness and in some cases heart failure.
The 'three-parent' IVF technique can be carried out in two different ways. Both of these aim to create an embryo that does not carry a mitochondrial disorder, by replacing the cytoplasm containing the abnormal mitochondria from an affected mother, with cytoplasm and mitochondria from an unaffected woman.[1]
Many concerns have been raised as to the ethics of ‘three-parent babies’, including the unknown consequences of genetic material from three 'parents' being passed down the human germline, and the fact it could lead to ‘gender-abortion’.
Now, a report from The New York Stem Cell Foundation (NYSCF) has discovered ‘potential adverse’ outcomes when using the technique. Researchers for NYSCF found that in some trials, the transfer of unhealthy mitochondria could sometimes ‘carry-over’ and dominate the healthy mitochondria. The amount of carry-over mitochondria may increase over time, potentially causing one of the diseases the therapy was intended to cure, and therefore nullifying the technique’s effect.
The senior author of the study Dieter Egli has recommended the procedure shouldn’t be used until a solution is found, as it "would defeat the purpose of doing mitochondrial replacement."
Last year, the UK government legalized ‘three parent IVF’, although the country’s fertility regulator, Human Fertilisation and Embryology Authority (HEFA), is yet to green-light its use in a clinic.
HFEA has looked at the findings of the new study and will wait for further experiments on the efficiency and safety ‘three parent IVF’ before approving the technique for clinical use.
'Increasing concern' over 'widely discredited' IVF treatment
The news comes just days after the HFEA and several leading experts proclaimed their "increasing concern" over questionable and "widely discredited" fertility treatments, being offered at private clinics.
In a series of enlightening interviews published by The Independent, experts claim clinics are handing out" expensive, potentially harmful stuff like Smarties", giving "false hope", and selling expensive add-ons despite little evidence that some of them work.
Related Links:
Three-person embryos may fail to vanquish mutant mitochondria (Nature)
Genetic Drift Can Compromise Mitochondrial Replacement by Nuclear Transfer in Human Oocytes (Cell Stem Cell)
NYSCF research advances mitochondrial replacement (NYSCF)
[1] CMF File 51: Three-parent embryos for mitochondrial disorders (Christian Medical Fellowship)
3 Parent Babies: Andrea Williams discusses on BBC Radio Suffolk