A Fatal Reaction

A cutting-edge gene-editing trial in China went disastrously wrong. A family wants accountability.

From the July 23, 2026 issue of Science Magazine

The young girl tugged on her mother’s hand as they pressed through the doors of the hospital in Shanghai. She was 6 years old, bouncing along in a pink jacket and blue pants decorated with cartoon bears. Behind them, her father rolled a large suitcase with everything the child needed for the weeklong stay: stuffed animals, Play-Doh, an iPad loaded with episodes of Peppa Pig.

She told her parents it felt like they were going on vacation. In fact, they brought her here for an experimental gene therapy. The girl was slipping behind her peers in kindergarten. She still spoke in simple sentences and ate with training chopsticks. Underneath it all was a single mutated DNA base, a T that should have been a C.

“Your ‘book’ has a small mistake, which has caused you to have a disease that affects your growth,” read the children’s version of the informed consent form from the hospital. “Over time, it can get more serious.” Doctors hoped to repair that mistake while her brain was still building itself. It would be a clinical trial of one, funded in part by $860,000 the parents had scraped together from their own savings and from relatives.

The parents felt they were in good hands. Xinhua Hospital, which is affiliated with the Shanghai Jiao Tong University School of Medicine, was acclaimed for its pediatrics department. It was the first Chinese institution to perform open heart surgery on infants, and the first in the country to separate conjoined twins. If all went well, the hospital would make history once again. The girl would be the first person in the world to receive a gene-editing therapy directed at the brain. It would rewrite the mutated gene in her neurons, restoring the needed DNA base so she could make a vital protein.

Read the rest in the July 23, 2026 issue of Science Magazine