Discovery by Tel Aviv University researchers could revolutionize treatment for children suffering from a rare and potentially fatal form of epilepsy.
By Pesach Benson, TPS
An Israeli breakthrough in the field of genetic therapy stands to revolutionize the treatment of Dravet syndrome, a severe and fatal form of epilepsy affecting children.
This rare syndrome is caused by a genetic mutation that is not inherited from parents. Its random occurrence during fetal development makes it difficult to predict or diagnose early on. Seizures typically begin around the age of one. As the child grows, seizures can last as long as 10 minutes. Dravet Syndrome also causes developmental delays and cognitive impairment.
An estimated 15-20% of children diagnosed with Dravets Syndrome die before reaching adulthood. There is no cure, and current treatment focuses on simply reducing seizures.
However, a team of Tel Aviv University researchers led by Dr. Moran Rubinstein working in collaboration with other institutions, developed an innovative gene therapy. Their findings were recently published in the peer-reviewed Journal of Clinical Investigation.
As part of the study, a virus carrying a normal SCN1A gene was injected into the brains of mice with Dravet Syndrome. The treatment was found to be effective in a variety of critical aspects such as improvement in epilepsy, protection from early death, and significant improvement of cognitive abilities.
Notably, the treatment was found to be effective after the onset of severe epilepsy in Dravet.
In the next stage, the researchers injected the carrier virus directly into the brains of the mice with Dravet Syndrome in order for the virus to infect the malfunctioning nerve cells.
The researchers explained that direct injection into the brain was necessary because the size and properties of the virus do not allow it to pass through the blood-brain barrier. This barrier of blood vessels and tissue helps keep harmful substances from entering the brain.
Thirty one mice were treated at three weeks of age, after the onset of spontaneous convulsions — equivalent to one to two years of age in children. Thirteen mice were treated at five weeks of age — equivalent to approximately six to eight years of age in children.
The injection was performed in several areas of the brain, and in addition an empty virus was injected into the brains of forty eight mice for control.
The researchers found that the gene treatment’s highest efficiency was at three weeks of age. In these mice, the seizures stopped completely within just sixty hours of injection, life expectancy increased significantly, and the cognitive impairment was fully repaired. Even in mice treated at five weeks of age, a significant improvement was observed, with decreased epileptic activity.
For the mice in the control group mice that received an empty virus, no improvement was observed and about half died an early death.
To test the treatment’s safety, it was also applied to healthy mice, and researchers found no harmful results.
“We hope that the technique we developed in the laboratory will also reach the clinic in the future and help children with this serious disease,” Rubinstein said.
“In addition, since there is a similarity between Dravet and other rare developmental epilepsies, in terms of the patient’s symptoms and brain changes, we hope that this treatment can also help other types of genetic epilepsies, and we think that the tools we developed in this research will pave the way for the development of similar treatments for other rare diseases,” she added.