Custom genetic treatment saved infant’s life, study says

Scientists at Children’s Hospital of Philadelphia and Penn Medicine successfully treated a baby boy using customized CRISPR therapy, according to a medical study published Thursday. Nine-month-old KJ Muldoon was born with a rare, life-threatening metabolic disease known as severe carbamoyl phosphate synthetase 1 deficiency, they said. The disease prevents the body from properly removing nitrogen waste and leads to a buildup of ammonia in the blood, according to the National Organization for Rare Disorders. Muldoon was diagnosed shortly after birth and spent the first few months of his life in the hospital on a very restrictive diet while scientists developed his treatment.

He is the first known person in the world to be treated with this type of gene therapy, according to the National Institutes of Health, which supported the researchers.

How was the therapy made? Doctors used the gene-editing tool CRISPR to identify which one of his 20,000 genes was mutated to cause the disorder. They used that information to create a personalized therapy to fix the mutation and gave Muldoon three injections of the treatment in his liver. He has responded well to the treatment, according to the case details published in The New England Journal of Medicine. 

How is KJ now? The baby boy is growing well and has been able to go home to be with his siblings, his father Kyle Muldoon said, according to the hospital. His mother, Nicole, said the family trusted doctors not just to help KJ but also other families in their position. KJ’s disease typically requires a liver transplant, but patients must wait until they are medically stable to undergo the surgery. During that wait, patients risk significant damage from ammonia in their system.