University of Tübingen: Brain researchers are investigating the disease mechanism of an early childhood form of epilepsy
Dravet syndrome is one of the most common severe early childhood forms of epilepsy – and fortunately very rare with one in 15,000 people in Germany. The disease is genetic and in most cases is due to a change or loss in a gene on chromosome 2. This leads to disturbed signal transmission in the brain and, as a result, to epileptic seizures and other accompanying symptoms. A research team at the Hertie Institute for Clinical Brain Research and the University of Tübingen is now investigating a previously unexplored mechanism of the disease.
It is important for the team to emphasize that people with rare diseases are not forgotten by researchers, but that new treatment methods are also being developed for them. On the occasion of Rare Disease Day on February 28, they would like to draw attention to the fact that those affected or their treating physicians turn to specialized centers to benefit from the latest medical advances.
“In the case of Dravet syndrome, the children develop completely normally after birth until they suffer their first epileptic seizure at the age of 3 to 9 months,” explains Dr. Ulrike Hedrich-Klimosch, biologist and one of the three study leaders. “This often occurs in connection with fever. Later, the attacks can also be triggered by fatigue, emotional outbursts or infections and are often difficult or impossible to treat with medication.”
After the onset of the disease, the development slows down in most cases. There is a speech delay, but also gait disorders or behavioral problems. The majority of children later suffer from an intellectual disability.
In around 80 percent of cases, the disease is based on a random change in the SCN1A gene. As a result, a sodium channel in the brain is no longer permeable. The Tübingen research team now wants to further decode exactly how this loss of function can lead to epileptic seizures. “The sodium channel is not only found on inhibitory nerve cells, but also on special glial cells in the brain, the so-called oligodendrocytes. These wrap around nerve cell fibers and thus support them in the transmission of information,” explains Hedrich-Klimosch. “For the first time, we want to research the effects of the genetic defect on these cells. Does the disturbed sodium channel in them lead to an altered interaction with nerve cells?”
Hedrich-Klimosch is investigating this question using cell cultures and mice with an SCN1A gene defect. The neurobiologist is leading the study together with Dr. Ivana Nikić-Spiegel from the Center for Integrative Neuroscience (CIN) and Dr. Friederike Pfeiffer from the Physiological Institute, Department of Neurophysiology at the University of Tübingen. Together, the researchers have now received funding for their project from Gruppo Famiglie Dravet Associazione ONLUS in partnership with other European Dravet foundations, which have come together from parents of affected children.
“Our study is of course basic research that does not directly lead to new therapies. Nevertheless, these studies should also be made public as widely as possible so that patients can see that research is not standing still and that there are always advances that could help them in the long term.”