A nine-and-a-half-month-old infant named KJ Muldoon has become the first person in history to receive a personalized CRISPR-based gene-editing treatment, offering new hope for patients with rare genetic disorders, doctors at the Children’s Hospital of Philadelphia announced on Thursday.
KJ was diagnosed shortly after birth with CPS1 deficiency, a rare and life-threatening condition caused by a mutation affecting liver enzyme function. Facing the stark options of a liver transplant or experimental therapy, his parents chose a groundbreaking approach: a one-of-a-kind infusion designed specifically to correct his genetic mutation using CRISPR-Cas9 technology.
Described as “molecular scissors,” the CRISPR technique precisely edits faulty DNA. In KJ’s case, it was used to repair the gene responsible for his condition. The treatment has already shown positive results—he can now tolerate more protein in his diet and requires less medication than before.
Doctors emphasized that while the long-term effects will need continued monitoring, this marks a major milestone in personalized medicine. “We hope he is the first of many to benefit from a methodology that can be scaled to fit an individual patient’s needs,” said pediatric geneticist Dr. Rebecca Ahrens-Nicklas.
The findings were published in the New England Journal of Medicine, signaling a potentially transformative future for treating rare genetic diseases.
