Babies born with rare and dangerous genetic diseases are growing and thriving after obtaining experimental gene editing treatment.

The researchers described the case in a new study, saying he was one of the first customized therapy to successfully treat, which attempted to address tiny but serious mistakes in killing half of the affected babies in its genetic code. While it may take some time to provide similar personalized treatments to others, doctors hope that the technology can one day help millions of things left behind, even if genetic medicine has advanced because their condition is very rare.

"This is the first step in using gene editing therapy to treat a variety of rare genetic diseases," said Dr. Kiran Musunuru, a gene editing expert at the University of Pennsylvania.

Baby, KJ Muldoon, Clifton Heights, Pennsylvania, is one of 350 million people worldwide, suffering from rare diseases, most of which are hereditary. Shortly after birth, he was diagnosed with severe CPS1 deficiency, which some experts estimate will affect one of about a million babies. These babies lack the enzyme that helps remove ammonia from the body, so it can accumulate in the blood and become toxic. Liver transplants are an option for some people.

Parents, Kyle and Nicole Muldoon, both knew KJ's odds and they were worried they might lose him.

"We're like weighing all the options and asking all the questions about liver transplants, which is invasive, or something that has never been done before," Nicole said.

Her husband added: “We prayed, talked to people, gathered information and finally decided that this was the way we were going.”

Within six months, the Philadelphia Children’s Hospital and Pennsylvania Medicine team and their partners created a therapy designed to correct the wrong genes of KJ. They used CRISPR, a gene editing tool that won its inventor Nobel Prize in 2020. Rather than cleaving DNA strands like the first CRISPR method, a technique of flipping the mutated DNA "letter" (also known as the basis) into the correct type. It is called "basic editing" and it reduces the risk of unexpected genetic changes.

Senthil Bhoopalan, a gene therapy researcher for Senthil Bhoopalan who was not involved in the study, said the team created the treatment so quickly, which was “very exciting”. “This really sets the pace and benchmark for this approach.”

In February, KJ obtained his first IV infusion through gene editing therapy, which was performed through small fat droplets (called lipid nanoparticles) absorbed by hepatocytes.

Research author Rebecca Ahrens-Nicklas Dr.

After follow-up doses in March and April, KJ was able to eat more normally and recover well from diseases such as colds that can fatigue the body and exacerbate the symptoms of CPS1. 9½-month-old people also need to reduce medication.

"Whenever we see the smallest milestone he encounters (like a small wave or rolling over) it is a big moment for us," his mother said.

Still, researchers warned that it has been months. They need to see him for years.

“We are still in the early stages of understanding what this drug might do for KJ,” Ahrens-Nicklas said. “But every day, he showed us signs of growing and thriving.”

The researchers hope that what they learned from KJ will help other rare patients.

Gene therapy development can be very expensive, often targeting more common diseases for simple financial reasons: more patients may mean more sales, which can help pay for development costs and generate more profits. For example, the first CRISPR therapy approved by the U.S. Food and Drug Administration to treat sickle cell disease, a painful blood disease that affects millions of people around the world.

Musunuru said his team’s work — funded by the National Institutes of Health — shows that creating custom treatments doesn’t have to be expensive. He said the cost of more than $800,000 in average liver transplants and related care is "not far away."

“As we get better at making these therapies and shorter the time frame, economies of scale will start and I hope the costs will fall,” Musunuru said.

Scientists also don’t have to rework all their initial work every time they create a custom therapy, so the study “sets the stage for treating other rare situations.”

Carlos Moraes, a professor of neurology at the University of Miami, was not involved in the study, saying such research opens the door to more advances.

“Once someone makes such a breakthrough, other teams don’t take the time to apply the course and keep moving forward,” he said. “There are obstacles, but I expect them to cross over the next five to ten years.” Then the entire field will serve as a barrier because we are ready. ”