Gene-edited babies are the future – but these CRISPR start-ups aren’t

I hate to break this to you, but every child is a genetic experiment – and nature doesn’t care if things go wrong. Our genomes are awful messes created by conflicting evolutionary forces, and every one of us is a new throw of the genetic dice, with a hundred or so brand–new random mutations thrown into the mix. 

For this reason, I have no doubt that if civilisation survives the various looming crises – including but not limited to climate change – gene-editing embryos will one day become routine. Eventually, natural conception could even come to be regarded as irresponsible. 

We’ve an awfully long way to go before we get to that point – although you would be forgiven for thinking otherwise, if you’ve been listening to tech-bro hype this year. In 2025, we learned of no fewer than three start-ups that are aiming to create gene-edited babies.

So, are CRISPR babies just around the corner – or could start-ups like these actually be counterproductive? 

Preventing genetic disease 

Two of the start-ups – Manhattan Genomics and Preventive – have said their aim is to prevent serious inherited diseases rather than enhance people. A worthy aim. But the good news is that such conditions can already be prevented by various screening methods, such as genetic testing of IVF embryos before implantation. There are very few cases where screening will not work. 

So why would you found a company to develop a technically and legally tricky product – gene-edited embryos – when there’s already an existing product – IVF screening – without these issues? 

When I put this question to the two companies, Preventive didn’t reply, but a spokesperson for Manhattan Genomics said that couples undergoing IVF often don’t have enough embryos to select from. If embryos that carry disease can be edited rather than discarded, this increases the chances of a child being born. The company estimates that gene editing “could correct approximately 10 Huntington’s disease-affected embryos and 35 sickle cell disease-affected embryos each year just for couples currently using IVF”.  

This would equate to a tiny number of children – only around a third of implanted IVF embryos result in a live birth and this is likely to be lower after editing. What’s more, there are also serious issues with doing this. Firstly, while CRISPR methods have advanced hugely, there’s still a risk of dangerous mutations occurring as a side effect. 

Secondly, the editing process often doesn’t start or can continue after an embryo begins dividing. That means there will be different changes in different cells within a single embryo – a phenomenon called mosaicism seen in CRISPR children illegally created in China and announced in 2018. 

What this means is that you cannot tell for sure whether a disease-causing mutation has been successfully corrected in an edited embryo, and without any dangerous mutations. That’s a showstopper. 

Doing it the right way 

There are potential solutions. For instance, some gene-edited animals are created by altering stem cells and then cloning cells once you’re sure they have the desired changes. However, as I described in my previous column, cloned animals have lots of health issues and unexpected physical differences. This is why much more basic research is needed, and why rigorous scrutiny will be hugely important, if this approach is ever tried in humans. 

We now have two excellent examples of how the gene editing of embryos could be responsibly introduced, in the form of the rollout of mitochondrial donation in the UK and Australia. Mitochondria are energy-producing structures in cells that have their own tiny genome. Mutated mitochondria can cause serious diseases if passed on to children, but this can be avoided by replacing them with healthy donor mitochondria. 

A form of the mitochondrial technique was offered by private fertility clinics in the US in the 1990s, resulting in the birth of what I would describe as the first genetically modified humans. Those early efforts resulted in the technique being banned in the US. 

Mitochondrial donation used to be illegal in the UK, but after campaigning by patient groups, and widespread consultation and discussion, the law was changed and there is now case-by-case approval on a trial basis. Australia is doing much the same. 

What’s the real goal? 

This is how new reproductive techniques should be introduced: openly, legally and as part of independently overseen trials. Instead, at least two of the start-ups are reportedly considering doing experiments in countries where there are fewer laws governing the use of gene editing in embryos. 

This wouldn’t advance the science, as we wouldn’t be able to trust claims made by private companies operating outside regulatory oversight. On the contrary, it could lead to a backlash, with more countries introducing or tightening laws against gene editing.  

If billionaires – Preventive’s investors include Sam Altman of OpenAI and Brian Armstrong of Coinbase, for instance – really care about preventing serious inherited diseases, they would achieve far more by putting the money into non-profit research organisations. 

Or, rather than helping other couples have healthy kids, is the ultimate aim to have enhanced children of one’s own? That is the explicit goal of the third start-up, Bootstrap Bio.  

So, could we use gene editing to enhance our kids if we wanted? I’ll give you the answer in my column next month.