The writer is a science commentator
When a couple in China emailed a prominent neuroscientist, it was out of love and desperation for their young daughter Mei (not her real name). A single, rare genetic mutation, they discovered, was slowing her development. Could gene therapy help?
Through a support group for affected families, the couple contacted Zilong Qiu, a talented researcher in Shanghai with a TEDx talk, start-up company and patented treatment for a genetic syndrome under his belt. For the sum of $860,000, Qiu agreed to treat Mei. Within a week of receiving the tailor-made therapy, in early 2025, the six-year-old was dead. A catastrophic immune reaction triggered fatal blood clotting.
A joint investigation by Science magazine and Retraction Watch, a non-profit organisation that tracks disputed research, revealed the tragedy only last month. Mei’s family, who recorded their discussions with Qiu, allege they were not told that death was a possible outcome, nor of safety issues flagged by earlier animal tests.
Other aspects of this grievous tale deserve scrutiny: a risky experimental treatment was undertaken for a non-fatal condition; oversight by external authorities, regulators and ethical review boards in China was insufficient to avert tragedy. The episode is another blow to a country vying to become a global leader in biotech. Truly advancing science means being open, honest and transparent about mistakes, as well as successes.
Genetic medicine takes several forms, all aimed at treating or curing disease by targeting faulty genes. Gene therapy involves flooding the affected organ with copies of a healthy gene to compensate for a dysfunctional one (viruses are usually used to piggyback the healthy copies in). Genome editing, also called gene editing and often using Crispr technology, makes precise edits by snipping out and sometimes replacing the rogue gene.
Last year, personalised gene therapy made headlines for “curing” an infant, known as KJ, of a potentially fatal genetic metabolic disorder (he will need life-long monitoring). The specific approach used on KJ, called base editing — which chemically changes one DNA base letter to another — had caught Qiu’s attention. Mei needed just such a letter change to correct a mutation in the CHD3 gene, which affects neuron development. Qiu told Mei’s parents that the brain-directed gene therapy would be a world first.
But three days after the injection into her spinal fluid, a jab packed with trillions of viruses to transport the base-editing instructions to the brain, Mei developed a fever. Her kidneys shut down, and she died days later. The hospital later ascribed her death to the therapy.
The Science investigation includes claims that, in pre-clinical testing, some monkeys given the therapy suffered liver and kidney damage. Several experts consulted by Science queried whether the animal data justified proceeding. In a bizarre twist, Qiu and colleagues later wrote a scientific paper for the journal Nature about the CHD3 mutation, describing the animal experiments but not disclosing the human trial or its tragic ending.
Her family have urged Nature to retract the paper. The journal’s deputy editor, Victoria Aranda, said staff were “shocked” at Mei’s death and the trial revelations: “No information that a human trial was planned or ongoing was ever shared with us, nor was any data related to human therapy shared or mentioned in any version of the submitted study.” Aranda said the journal “will take editorial action as appropriate” after an ongoing investigation had concluded, though declined to spell out possible sanctions. Neither Qiu nor his institution, Shanghai Jiao Tong University School of Medicine, responded to an FT request for comment, though the university is said to be investigating separately.
Mei was, reportedly, relatively mildly impaired by a non-fatal syndrome. Given the treatment was highly experimental, that “raises many serious ethical concern”, says Sarah Cunningham-Burley, professor of medical and family sociology at Edinburgh university and chair of the Nuffield Council on Bioethics.
He Jiankui, the Chinese scientist jailed in 2019 for creating the world’s first genome-edited babies, secretly carried out the untested procedure not to save lives but to lower the risk of HIV. The unintended consequences of his actions remain unknown.
The rationale, though, is not: parents crave better lives for their children and ambitious researchers covet world firsts. That heady partnership can push medical frontiers — but cannot erase the possibility that, as with Mei, the untried and untested can lead to the unimaginable.