[Scientist using a microscope. Photo Credit: Pexels]

In May 2025, the New England Journal of Medicine published a groundbreaking report that the CRISPR gene editing had been  used to treat a seven-month-old baby with a life-threatening genetic liver disease.

The outcome was a  remarkable  success.  

The treatment, designed specifically for him, not only saved his life but could also potentially transform the way rare diseases are treated in the future, with the help of gene editing technology.

The child, referred to as KJ, was born with a genetic disorder that impaired his liver’s ability to break down ammonia;  this condition, known as  severe carbamoyl phosphate synthetase 1 deficiency, stems from a rare form of genetic mutation.

Without proper treatment, ammonia builds up to dangerous levels in the blood and can lead to serious health complications and even death.

To avoid serious medical complications, KJ has been dependent on a strict diet to prevent ammonia buildup and medication to manage the condition.

However, these measures weren’t enough, and the condition became harder to manage.

In a race against time to  save KJ, doctors and scientists sought a cure.

Experts from Penn Medicine and the Children’s Hospital of Philadelphia (CHOP) came together for this project, and they used CRISPR.   

CRISPR is a new, innovative tool that can be used to edit genes.

It’s often likened  to molecular scissors that can cut and remove specific parts of our DNA.

The scientists who developed the technology were awarded the Nobel Prize in 2020 for their discovery, as it could be used to cure genetic diseases.

However, this was not just any type of CRISPR treatment.

It was uniquely personalized and tailored specifically made just for KJ.

This marked the first time anything like this had been done for a single patient.

The team also employed a specific type of CRISPR called base editing, which allows the DNA code to be switched out only partly instead of cutting the strand entirely.

This makes the editing occur more precisely and safely instead of impacting a long strand of information.

Typically, developing a new therapy can take years, if not  decades.

It has to be tested extensively in the labs on cells with numerous experiments and replicated many times.

In KJ’s case , however , this timeline had to be drastically  accelerated as KJ’s health was rapidly deteriorating by the day.

Incredibly, the treatment was effective, and KJ’s ammonia levels are manageable even with less medication and more protein intake. 

KJ is reaching developmental milestones and has been given a second chance at life.

This advancement not only changed KJ’s life, but could also change the way we treat rare genetic diseases.

While the medical community  is optimistic, it’s important to note that this was just one patient.

They’ll continue to carefully monitor KJ’s health to make sure he is doing well.

The success of this case gives many people hope, especially those with rare genetic disorders.

Until now, most medicines have been developed for large groups of patients.

But KJ’s story demonstrates that it’s now possible to create a genetic cure for just one person.

With the rapid advancement of science and technology in the healthcare field, many researchers believe that this could be a new era in medicine where people receive personalized treatment for genetic conditions.