Last year, a six-year-old girl died after undergoing an experimental gene-editing therapy. Now, the neuroscientist in charge of the research, Zilong Qiu, is facing questions following his decision to not publicly disclose the death.

Science Magazine, in collaboration with Retraction Watch, was the first to report the incident last week. On Monday, the AFP reported that the Shanghai Jiao Tong University School of Medicine in China, where Qiu works, is formally opening up an investigation into the matter. The girl’s family reportedly paid over $800,000 to help fund the trial, which was intended to test out a treatment for her rare genetic condition.

âThe School of Medicine has always attached great importance to scientific research integrity and research norms, and firmly opposes conducting medical scientific research in violation of scientific research ethics,â the university said in a statement to the AFP.

An experimental hope and failure

The girl, identified under the pseudonym Mei, was born with Snijders Blok-Campeau syndrome; she was diagnosed in 2013. This condition is caused by mutations in the gene CHD3. Symptoms can vary in severity but include intellectual disability, a larger-than-usual head, and an increased risk of seizures and heart problems. Mei reportedly had a relatively mild version, though she was starting to fall behind her peers in school and there was the possibility that she would never be able to live independently.

According to the Science report, the family heard about Qiu and his research after joining a private WeChat group (a messaging app popular in China) for parents of children with autism and other developmental disorders. Qiu and his team have been working to develop gene-editing therapies for genetic conditions, and Mei’s father reached out to him asking if she might be a suitable candidate for such a treatment. Qiu reportedly replied back within minutes and told the family that he could help.

The team aimed to correct the single mutation responsible for Mei’s condition, using two different viruses to deliver the treatment, a type of CRISPR-based gene therapy known as base editing. The therapy would attempt to edit cells directly in Mei’s brain, something that’s never been done before in humans. To ensure the therapy would edit enough cells, Qiu and his team injected hundreds of trillions of viruses into Mei’s spinal fluid.

Mei died just a week after the procedure was performed in late March 2025. Her death is believed to have been caused by a severe immune reaction to the therapy, according to the Science/Retraction Watch report. And though the hospital where the procedure took place was fined a meager amount ($3,600) by the local health department for failing to properly oversee the trial, Qiu seemingly faced no repercussions.

He and his team even moved ahead with the publication of a study in Nature detailing the therapy, even after the family asked him to withdraw it and he supposedly agreed to do so. The study itself, published this February, contains no mention of the human trial. Qiu also seems to have removed gene sequences from Mei and her family included in an earlier draft of the paper reviewed by Science/Retraction Watch, as well as a sentence acknowledging their financial support of the research. The only apparent allusion to her death is a sentence stating that “bridging the gap between preclinical research and clinical translation remains a significant challenge.”

Consequences?

Mei’s death comes in the wake of the He Jiankui scandal in China over a half decade ago. Jiankui illegally edited the genomes of several human embryos that were successfully implanted in women to make the resulting children resistant to HIV. Jiankui was sentenced to a three-year prison term, and the country established stricter regulations on conducting human research in response.

Several outside researchers and bioethicists interviewed by Science/Retraction Watch say that Qiu and his team downplayed the risks of their treatment to Mei’s family and ignored potential safety worries. These experts have also called for Nature to review the study further, citing several concerns about the quality of the animal data presented as justification for pushing forward with Mei’s therapy as well as the failure to disclose the family’s funding of the research.

âThis shouldnât have gone to trial,â Steven Gray, a researcher at the University of Texas Southwestern Medical Center who also uses viruses for gene therapy, told the outlets.

Nature reportedly told Science/Retraction Watch that it was not aware of the issues surrounding the study prior to publication. Gizmodo reached out to Nature for comment on whether it plans to review the paper but did not receive a response by the time of publication.

Meanwhile, Shanghai Jiao Tong University stated that it âattaches great importance to the matter and has set up a special working group to conduct a comprehensive investigation into the incident.â