Lulu and Nana, the pseudonyms given to the world’s first gene-edited babies, were born in October 2018 in China. A third baby, sometimes called Amy, was born from a separate pregnancy shortly after. All three children are now alive and reportedly being monitored by Chinese government health authorities, but almost no specific details about their health or development have been made public. What we do know is that the gene editing they received was flawed from the start, and the scientist behind the experiment went to prison.
What He Jiankui Was Trying to Do
He Jiankui, a biophysicist then working in Shenzhen, China, used the gene-editing tool CRISPR to modify embryos from couples where the father was HIV-positive. His target was a gene called CCR5, which produces a protein that HIV uses to enter human cells. About 10% of people with European ancestry naturally carry a mutation in this gene (a 32-base-pair deletion known as CCR5-delta-32) that disrupts the protein and makes them highly resistant to HIV infection. He aimed to recreate something similar in the embryos, theoretically protecting the children from HIV for life.
Eight couples enrolled in the experiment. Five did not conceive, one withdrew, and two became pregnant. The first pregnancy produced non-identical twin girls, Lulu and Nana, delivered by emergency cesarean section. The second pregnancy, confirmed to be at a very early stage when He announced his work in November 2018, later resulted in the birth of a third child.
The Edits Didn’t Work as Planned
Analysis of He’s own data revealed serious problems. Neither Lulu nor Nana received the specific 32-base-pair deletion that naturally protects against HIV. Instead, each embryo ended up with different, novel mutations of various lengths in the CCR5 gene. These new mutations had never been studied and have not been shown to prevent HIV infection.
Lulu’s results were particularly concerning: one copy of her CCR5 gene remained completely unedited (the normal version), while the other had a small 15-base-pair deletion. This means she likely still produces functional CCR5 protein from her unedited gene copy and would have little or no HIV resistance. Nana’s results looked more complete on paper, with both copies of the gene showing mutations, but the mutations were still not the well-characterized delta-32 variant.
Beyond the wrong mutations, the editing introduced two additional problems. The first was mosaicism, meaning not every cell in the embryos was edited the same way. Some cells carried the edits while others didn’t, creating a genetic patchwork throughout the body. The second problem was the risk of off-target effects, where CRISPR cut DNA in unintended locations. He tested for off-target edits using a single stem cell line derived from the embryos, but scientists pointed out this was inadequate. CRISPR-induced breaks in DNA can cause large chromosomal deletions, rearrangements, and other unpredictable changes that a limited screen would miss.
Potential Long-Term Health Risks
Even if the edits had worked exactly as intended, disabling CCR5 may carry health consequences that weren’t fully appreciated in 2018. A 2024 study published in Alzheimer’s & Dementia found that people carrying the natural CCR5-delta-32 deletion had decreased neuronal resilience to oxidative stress and a higher risk of vascular dementia, particularly when combined with other genetic risk factors. The CCR5 protein appears to play a protective role in brain blood vessel health, meaning its absence could create vulnerabilities that don’t become apparent until later in life.
For Lulu and Nana, the situation is even more uncertain than it would be for natural carriers of the delta-32 mutation. Their novel, unstudied mutations could behave differently from the natural variant in ways no one can predict. The mosaicism adds another layer of complexity, since different tissues in their bodies may carry different versions of the edit or no edit at all.
He Jiankui’s Punishment and Return
The Chinese government moved quickly after the experiment became public. A Guangdong provincial investigation confirmed that He had forged ethics approval documents and deceived subjects during recruitment. Because HIV carriers are not permitted to use assisted reproduction services in China, He had arranged for others to take blood tests in place of the HIV-positive fathers.
In December 2019, He and two collaborators were convicted of illegal medical practices. He received a three-year prison sentence and a fine of three million yuan (roughly $430,000). He was released around 2022 and, as of late 2024, is back working on human embryo genome editing in his own independent lab in Beijing. His return to the field has drawn criticism from bioethicists who argue that the relatively light sentence failed to match the severity of what he did.
Where the Children Are Now
The Chinese government has released almost no information about Lulu, Nana, or the third child since the initial investigation. State media reported that their health was being monitored, but no updates on developmental milestones, medical assessments, or follow-up genetic testing have been made public. The children would be around six years old as of 2025.
This silence is partly intentional. Releasing identifying details could expose the children to unwanted attention and stigma. But the lack of transparency also means the global scientific community has no way to assess whether the edits are causing harm. The children carry genetic changes that will be passed to their own children if they reproduce, making this not just a personal health question but a permanent alteration to the human gene pool.
How the Experiment Changed Global Policy
The immediate fallout reshaped how the world governs gene editing. In December 2018, just weeks after He’s announcement, the World Health Organization established a global expert advisory committee on human genome editing. The committee produced recommendations covering nine areas, including the creation of international registries to track gene-editing research, protocols to prevent researchers from traveling to countries with weaker oversight, and frameworks for identifying illegal or unethical experiments before they produce results.
China itself tightened its regulations, making unauthorized gene editing of human embryos a criminal offense with clearer penalties. Many countries already had laws or guidelines prohibiting heritable human genome editing, but He’s experiment exposed how easily a determined researcher could bypass institutional safeguards. The case became the defining cautionary example in bioethics, not because CRISPR technology is inherently dangerous, but because it was used recklessly, on children who could not consent, to address a problem (HIV transmission from father to child) that already had safe and effective solutions.