An investigation by The Wall Street Journal has looked into Silicon Valley companies pushing the most controversial frontiers of assisted reproduction. It combines two rather different themes. Number one: the production of numerous embryos from which to choose based on a polygenic score that includes predispositions to hundreds of diseases and even a handful of desirable non-medical traits. Number two: gene-editing of embryos (also known as heritable or germline editing), which we’ve discussed many times since the case of the CRISPR babies in China and which now seems to be gaining new ground (the most talked-about company in this field is called Preventive).

Paradoxically, this new phase is beginning when we still know nothing about the follow-up to that first Chinese experiment. Therefore, I think it is useful to republish two texts.
A short piece I prepared today for the Italian public radio on the mystery surrounding Lulu and Nana, and an article on polygenic scoring that I recently wrote for the magazine of the daily newspaper Corriere della Sera.

WHAT EVER HAPPENED TO LULU AND NANA?

Somewhere in China, three very special little girls are growing up. They are the first humans born with genetically modified DNA. They’re usually referred to as the CRISPR babies. Two of them are twin girls, known by the pseudonyms Lulu and Nana. For the third child, we don’t even have a nickname. No photos of them have ever been released—neither at birth nor since. All we know is that they are now between six and seven years old, and that they are the result of a genetic experiment condemned by nearly the entire scientific and bioethical community. Its author, biophysicist He Jiankui, dreamed of becoming a scientific star but instead ended up in a Chinese prison for three years, convicted of a crime akin to medical malpractice. His aim was to create children resistant to HIV using gene editing. If that sounds like a good idea, think again: there’s no justification for using a cutting-edge, high-risk technique to prevent an infection that can already be avoided through conventional means. It’s a matter of risk versus benefit. Moreover, judging from the few data disclosed when the scandal broke in late 2018, the experiment didn’t even succeed technically. The girls may be mosaics, with some cells immune to the virus and others not. Since then, a curtain of secrecy has fallen, and nothing is known about their current health. Not even the World Health Organization obtained any data when it requested it from the Chinese government. When asked about their condition, the scientist responsible dodges the question, citing privacy concerns. The Economist tried again this February and came up empty-handed. We find ourselves in a paradoxical situation: we live in the information age, yet we have no up-to-date news about an event of huge historical significance.
(Anna Meldolesi, Radio 3 Scienza, November 13, 2025)

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WHAT KIND OF CHILD DO YOU WANT? HERE COMES POLYGENIC SELECTION

Dear prospective parents, would you like “the power to protect your children before pregnancy even begins”? We’ve been talking about designer babies and à la carte children for decades. But the summer of 2025 marked a turning point, as the idea was revived in Silicon Valley with new approaches and messaging—potentially seductive to a wider audience. The perfect child remains a mirage, yet new screening and computational techniques can help parents choose, from among possible embryos, those that seem to best combine their genetic contributions. The premise is to give up natural reproduction to produce many in vitro embryos—say, around fifteen per couple—and sequence them.

Prospective parents receive a “report card” for each potential child and, with the help of a consultant, choose the “best” one. In the case of Orchid, the scores consist of a list of yes/no answers indicating the presence of 1,200 monogenic diseases and a series of numbers reflecting predisposition to about a dozen polygenic disorders. Let’s take the seller at his word. Personally, I tend to, since among Orchid’s investors is genomics veteran George Church. But skepticism is legitimate, because both the DNA amplification protocol and the algorithms are proprietary secrets. Still, let’s suppose the approach works. If would-be parents have a family history of a particular condition and no moral objections to producing surplus embryos, it might make sense to pay the physical and financial price of assisted reproduction with intensive screening (the tests alone cost $2,500 per embryo).

However, the benefits shrink for fertile couples not at special risk—particularly because, once the embryos carrying monogenic diseases are ruled out, none will be perfect, and parents must choose among different predispositions. For instance, would you rather accept a slightly higher risk of schizophrenia to lower the risk of diabetes, or vice versa? The anxiety rises just thinking about it. And yet, the company markets its services as an option every woman should consider—just like choosing an epidural or a home birth. Since the first Orchid Baby was born in 2023, the company has partnered with about a hundred clinics. Following in its wake, more reckless companies have joined in. Nucleus, in particular, offers polygenic scores for non-medical traits such as height or IQ. The reliability of such probabilistic predictions is highly questionable, but the offer exists—and the open question is how strong demand will be. Though I’m a techno-optimist, this time I feel compelled to hit the brakes. (Anna Meldolesi, 7–Corriere della Sera, September 26, 2025)