Doctors in the United States used CRISPR gene editing to treat a baby named KJ, who was diagnosed shortly after birth with carbamoyl-phosphate synthetase 1 deficiency (CPS1). This rare genetic disorder causes a dangerous buildup of ammonia in the blood, which can lead to seizures, coma, and death. The condition affects about one in every million newborns, and roughly half of the babies with CPS1 die early.
At six months old, KJ began receiving a customized CRISPR-based therapy at the Children’s Hospital of Philadelphia. The treatment reduced his dependence on daily medications to control ammonia levels. Doctors are closely monitoring his progress and describe the results as very promising.
CPS1 deficiency prevents the body from processing ammonia properly, which is toxic at high levels. Standard treatment includes a strict low-protein diet and often requires a liver transplant, both of which carry significant risks. The new CRISPR therapy targets the faulty gene in KJ’s liver that causes the enzyme deficiency. By precisely editing the DNA at the mutation site, the therapy allows the body’s cells to correct the error.
This treatment represents a breakthrough in personalized medicine because it can be tailored to match an individual’s unique DNA. Although KJ’s case is still early, the success suggests that CRISPR could help many others with rare single-gene disorders.
Despite this progress, challenges remain. Delivering CRISPR therapy to organs other than the liver is complex and still under study. The cost of KJ’s treatment was over €700,000, making it expensive compared to standard care. Researchers are also evaluating long-term effects, as all risks are not yet fully understood. Many genetic diseases involve multiple mutations, which may limit CRISPR’s usefulness in more complex conditions.
Still, KJ’s case provides hope that gene editing could one day treat rare but deadly genetic disorders more safely and effectively. As research advances, scientists aim to develop more affordable and scalable therapies.
