This baby was the world's first ever healed with a personalized gene editing treatment www.nytimes.com/2025/05/15/h... BEFORE "KJ’s disease is caused by an inability to rid the body of ammonia, a byproduct of protein metabolism. Ammonia builds up in the blood and crosses into the brain. His doctors put him on a diet that severely restricted protein — just enough for him to grow. He also had a medicine that helped remove the ammonia in his blood. But he still was at high risk for brain injury or death. Any illness could make his ammonia levels soar and cause irreversible damage to his brain." AFTER "It is too soon to know if he can stop taking the medication completely, but the dosage is greatly reduced. And he is well enough for the team to start planning to discharge him home from the hospital. He is meeting milestones and his weight is now in the 40th percentile for his age, but it is not yet known if he’ll be spared a liver transplant."