A Baby's Life Saved by Tailored Gene Therapy

A major breakthrough in medicine has occurred. For the first time, doctors have used a custom-made CRISPR-based gene therapy to treat a baby's rare and deadly genetic condition. This isn't just any condition. It's a metabolic disorder that can kill up to half of the children who have it in their infancy. The baby, named KJ, was born last summer with a severe form of carbamoyl phosphate synthetase 1 (CPS1) deficiency. This disorder stops the liver from making a crucial enzyme. This enzyme breaks down ammonia, a waste product, into urea, which is then removed from the body through urine. Without this enzyme, ammonia builds up and can damage organs. KJ's parents and the medical team faced a tough challenge. Until now, the only cure for CPS1 was a liver transplant. But babies often have to wait until they're older for this procedure. During this wait, they're at risk of severe complications, including brain damage. Fortunately, researchers at a leading hospital and medical school had been working on customized gene therapies for rare genetic diseases. KJ became their first test case. The researchers developed a personalized gene-editing drug for KJ. This therapy uses a form of CRISPR to fix a specific part of the defective gene causing his condition. The goal was to repair the defect so KJ's liver could break down ammonia normally. The therapy was first tested on mice and then monkeys before being given to KJ. He received his first dose in February 2025 and two higher doses in the following months with no serious side effects. Since then, KJ has shown significant improvement. He can now eat more protein and needs lower doses of another treatment used to manage his condition. He also recovered from common childhood infections, which can be dangerous for people with CPS1. While it's too early to know if the therapy is safe in the long term, the results so far are promising. The researchers believe their approach can be adapted to treat many other rare genetic diseases. This success story highlights the potential of personalized medicine. It shows how tailored treatments can make a real difference in the lives of patients with rare conditions. However, it's important to note that this is just the beginning. More research and testing are needed to ensure the safety and effectiveness of this therapy in the long run. But for now, KJ's story offers hope for a new era of personalized medicine.