New Treatments Are Giving Hope to Kids With Rare Genetic Diseases

Doctors and scientists around the world are making big breakthroughs in treating rare genetic diseases — illnesses caused by errors in a person's DNA that affect only a small number of people. These diseases are often very serious, and many of them have no good treatments. Now, thanks to tools like gene therapy and gene editing, some patients are seeing life-changing improvements. Researchers say early treatment is key, because some damage caused by these diseases cannot be undone.

One important group of treatments is called enzyme replacement therapy. This means doctors give patients a working version of a protein their body cannot make on its own. It has helped many people with diseases that affect the body's cells, called lysosomal storage disorders. However, this kind of therapy has limits — it cannot fix the root cause in the DNA, and it cannot reach the brain easily. That means some patients still need treatment for their whole lives.

Another set of tools uses tiny molecules called antisense oligonucleotides. These molecules can change how the body reads its own genetic instructions. A drug called nusinersen uses this method to treat spinal muscular atrophy, a disease that weakens muscles. A related drug called risdiplam does the same thing but comes as a pill that patients can swallow. Scientists even made a one-of-a-kind drug called milasen, designed for just one child with a rare brain disease.

A different type of treatment, called RNA interference, can turn off harmful genes inside the body. This approach has helped people with diseases like hereditary transthyretin amyloidosis and primary hyperoxaluria. Scientists are also testing a method called mRNA replacement therapy, where the body is given instructions to make proteins it is missing. These treatments are still being studied but show a lot of promise.

Gene therapy goes even further — it delivers a working copy of a gene right into a patient's cells. One gene therapy called voretigene neparvovec helps people with a rare form of blindness caused by a broken gene called RPE65. Another therapy, onasemnogene abeparvovec, gives babies with spinal muscular atrophy a working gene, helping them survive and reach important growth milestones. This therapy is now part of newborn screening in many places, which means babies can be treated before they even show symptoms.

Gene editing is another powerful tool that can actually change the DNA inside cells. A therapy called exagamglogene autotemcel uses a technology called CRISPR-Cas9 to edit a patient's own blood stem cells. It turns on a gene that helps the body make fetal hemoglobin, which carries oxygen in red blood cells. In clinical trials, almost all patients with sickle cell disease who received this therapy went at least 12 months without a severe pain crisis. Health agencies in the United States, the United Kingdom, and Europe all approved this therapy between late 2023 and early 2024.

Today, there are approved cell and gene therapies for many rare diseases, including inherited blindness, hemophilia, Duchenne muscular dystrophy, and sickle cell disease. In April 2026, a gene therapy called Otarmeni became the first approved treatment for genetic hearing loss. It targets a specific broken gene called OTOF and helps people who are born with severe hearing loss. However, getting approved does not always mean a drug stays available — in February 2026, the company BioMarin pulled its hemophilia gene therapy from the market for business reasons, not safety concerns.

Doctors also have to think carefully about when a treatment can truly help a patient. If a disease has already caused serious damage — like the loss of nerve cells or the buildup of scar tissue — even a well-designed therapy may not make a meaningful difference. Choosing the right treatment at the right time is extremely important. Doctors and families need to have honest conversations about what a therapy can and cannot do.

Safety is another big concern with gene and cell therapies. Some treatments using a delivery tool called adeno-associated virus, or AAV, have caused liver damage in some patients. The U.S. Food and Drug Administration issued a strong warning about one Duchenne muscular dystrophy gene therapy in November 2025 after two children died from liver failure. Other therapies have been linked to a risk of blood cancer in a small number of patients, so doctors must watch patients carefully for many years.

Scientists are working on ways to make the development of these therapies faster and safer for more people. One approach is called platform development, where the same basic delivery system is used for many different therapies. This saves time because scientists do not have to start from scratch for each new disease. The goal is to bring more life-saving treatments to more patients, as quickly and safely as possible.