When KJ Muldoon was born in the summer of 2024, his parents were told he had a disease so rare it affects about one in every 1.3 million newborns. Her condition, a severe deficiency of an enzyme known as CPS1, prevented her small body from properly breaking down proteins, flooding her blood with toxins that could cause brain damage or death. A liver transplant could correct the problem, but KJ was too small and fragile to undergo it. With each passing day, the risk of irreversible neurological damage increased.

What happened next could become the biggest medical news of the decade. In just six months, a team from Children’s Hospital of Philadelphia and Penn Medicine designed a personalized therapy capable of correcting the single misspelled letter in KJ’s DNA using a gene editing technology known as CRISPR. To deliver the therapy into KJ’s cells, doctors used the same mRNA technology used in COVID-19 vaccines. He received his first dose at six months old. One year later, KJ is walking, talking, and functioning normally at home with his family.

We call them rare diseases, but there is nothing strange about the suffering they cause. About 25 million Americans, nearly one in 13, live with rare genetic diseases. More than half are children, many of whom will not reach the age of five. Families spend years searching for accurate diagnoses, suffering from misdiagnoses, and facing financial ruin and isolation. And although the direct medical costs of rare diseases are estimated at $400 billion a year, a figure comparable to that of cancer and Alzheimer’s disease, less than five percent of them have treatments approved by the Food and Drug Administration (FDA).

Why so few? Because the economics of drug development work against small patient populations. When a disease affects only a few hundred or thousands of people, it is difficult to organize a clinical trial and the return on investment is usually insufficient. Collectively, rare diseases represent one of the world’s largest unmet medical needs.

What makes this moment different is that the technology finally exists to do something about it. Recent advances in mRNA science and CRISPR gene editing mean that the method that helped KJ can be used with other children. The technology can be reprogrammed for different diseases by introducing a small piece of genetic code that tells the molecular machinery exactly where to make the correction. Once the system is created, it can be redirected to a new disease by modifying only that part.

KJ’s doctors did everything they could, even heroically, to save him. They assembled a multidisciplinary team, condensed years of treatment development into months, and obtained approval to give the experimental therapy to KJ a week after the application was submitted to the FDA. However, no healthcare system can depend on heroic acts for every patient. Although the technology exists, there is no established protocol for applying what was done for KJ to another child, much less for the thousands of children who could benefit from this approach.

It is important to be honest about what this technology can and cannot do today. We know how to package the mRNA into tiny fatty vesicles and deliver it to the liver, which is where KJ’s cells were failing. Reaching other organs—the brain, the heart, the lungs—remains a major scientific challenge. And for conditions caused by complex genetics, rather than a simple misspelled letter, the road ahead is longer and more difficult.

I think the biggest obstacle, however, is structural. Our regulatory and commercial infrastructure was built for blockbuster drugs that treat millions of patients with the same pill. It was never designed for diseases where each patient may need a custom fix for a unique mutation. But we already have a model for individualized, high-risk interventions that correct specific defects in specific patients. We call it surgery. Consider a surgeon performing a heart valve repair. No one asks that surgeon to perform a clinical trial before operating on the next patient with slightly different anatomy. The technique is validated, the center is accredited and each procedure is tailored to each individual. What if we started thinking about mRNA-CRISPR gene editing the same way: as molecular surgery, not as a pharmaceutical?

There are promising signs that regulators and scientists recognize the problem. The FDA recently proposed a new framework that would accelerate the approval of individualized treatments for rare diseases, allowing regulators to evaluate these therapies based on evidence of their effectiveness, rather than requiring traditional large-scale clinical trials. Scientists are also working to develop the infrastructure that could take advantage of these regulatory changes. The Children’s Hospital of Philadelphia and Penn Medicine plan to start a trial that would repurpose the type of gene editor used for KJ to treat other patients. Johns Hopkins, where I work, has partnered with scientists at the Mayo Clinic and other collaborators to help found a group that seeks to standardize manufacturing, share regulatory science, and support clinical centers to deliver personalized therapies at scale.

But none of this is guaranteed. A key question is how the FDA would enforce manufacturing standards for individualized treatments. If the standards are too demanding for each personalized treatment, the platform will not be able to scale. Even with the appropriate regulatory framework, commercial infrastructure would still be necessary for its use. No pharmaceutical company is going to build a production line for a disease that affects 12 people. Someone has to bridge the gap between timely academic advancement and reproducible clinical service, and there is currently little funding for it.

Radically new scientific advances demand a radically new approach to how we regulate, manufacture, finance and administer treatments. If in ten years children continue to die from diseases that we know how to correct, it will not be because science was not prepared, but because we lacked the imagination to build a system at its level. KJ’s story is a miracle, but it should not stop at that alone; must become a role model.