Precision DNA editing creates new hopes for children with Dravet syndrome

Scientists have successfully used precision DNA editing to repair a genetic mutation linked to Dravet syndrome

Dravet syndrome is a rare and life-threatening form of childhood epilepsy. The use of precision DNA editing provides children with new hope.

The study, published in Science Translational Medicine, showed that treated mice experienced dramatically fewer seizures and significantly longer survival rates after receiving a one-time genetic correction.

Dravet syndrome is a severe neurological disorder that begins in infancy and is marked by frequent, drug-resistant seizures, developmental delays, and a high risk of sudden death.

Existing treatments mainly focus on controlling symptoms and often require lifelong management. Researchers behind the new study believe gene editing could eventually provide a way to directly correct the underlying cause of the disease.

The work was led through a collaboration involving The Jackson Laboratory (JAX), the Broad Institute, Children’s Hospital of Philadelphia, and UMass Chan Medical School.

Correcting a single DNA error

The research focused on a mutation in the SCN1A gene, R613X. This mutation disrupts the production of Nav1.1, a protein channel essential for controlling electrical activity in the brain. Without proper function, neurons become overactive, increasing the likelihood of seizures.

To repair the mutation, scientists used adenine base editing (ABE), a highly precise form of gene editing that changes a single DNA letter without cutting through both strands of DNA. This approach is considered safer than older editing techniques because it reduces the risk of unintended genetic damage.

Researchers delivered the editor directly into the brains of newborn mice using a modified viral delivery system. Some mice were treated immediately after birth, while others received treatment later, around 12 days after birth. This helps to be more accurate in the timing of diagnosis in human patients.

The treatment corrected nearly 60% of the defective DNA in targeted brain cells. Even partial correction proved highly effective, as the edited cells restored normal gene activity.

The treated mice showed major improvements. Seizures were significantly reduced, survival rates increased, and protection lasted well into young adulthood. Scientists also reported very low levels of unintended DNA changes or harmful side effects in the brain.

One of the most encouraging findings was that treatment remained effective even when delivered after symptoms would normally begin. This suggests there may be a larger treatment window for children diagnosed after birth.

Genetic medicine

This study is just a small part of efforts to advance the use of gene editing to treat rare genetic diseases. The same research teams have recently reported success using similar technologies to repair mutations linked to Zellweger spectrum disorder and alternating hemiplegia of childhood.

Researchers say the long-term goal is to create a flexible gene-editing platform that can be quickly adapted to different mutations and diseases. Instead of building entirely new treatments from scratch, scientists hope future therapies can be customised by changing only the targeting component that directs the editor to the correct location in DNA.