In a groundbreaking achievement, doctors have successfully used personalized CRISPR gene editing to treat a baby boy, KJ Muldoon, with a rare and life-threatening genetic disorder. This bespoke therapy, tailored to correct KJ's unique mutation, marks a significant milestone in the field of genetic medicine.
Born in August 2024, KJ was diagnosed with severe carbamoyl phosphate synthetase 1 (CPS1) deficiency, a condition preventing his body from processing protein and leading to toxic ammonia buildup. Without intervention, this could cause severe brain damage or death. A liver transplant was the conventional treatment, but time was of the essence.
An international team developed a CRISPR-based therapy using base editing to target and correct the specific DNA sequence causing KJ's illness. The FDA fast-tracked the evaluation, and KJ received his first dose in February 2025. Follow-up doses were administered in March and April 2025. As of April 2025, after three doses, KJ is showing remarkable progress, tolerating more protein in his diet and requiring less medication.
This personalized approach offers hope for treating other ultra-rare genetic conditions. While the expense and complexity remain challenges, this success paves the way for future on-demand gene-editing therapies. Researchers emphasize the importance of continued monitoring to fully evaluate the long-term benefits.