Causes of Dravet Syndrome
More than 85% of patients with Dravet Syndrome have a mutation (or change) in a gene called SCN1a. The SCN1a gene contains instructions (the genetic code) for the creation of a protein that controls how sodium ions move into the cells in our bodies.
A change in this gene may lead to faulty functioning of this protein, called a sodium ion channel, in the brain. The movement of sodium ions in and out of cells help control electrical messages in the brain so a faulty ion channel can cause seizures. Not all mutations to this gene cause Dravet Syndrome. Other SCN1a mutations are associated with other less severe forms of epilepsy, such as Genetic Epilepsy with Febrile Seizures + (sometimes described as GEFS+).
Above all, the one thing that families need to understand is that it is not their fault. Gene mutations happen in everyone. It is simply random when they occur, for example in an important gene like SCN1a.
In Dravet Syndrome, the gene mutation nearly always arises spontaneously and is not passed down (inherited) from parents. It is rare for mutations of the SCN1a gene to be passed from parent to child. However, some people with Dravet Syndrome may have some history of febrile seizures or epilepsy in their extended family.
Much remains to be understood about the causes of Dravet Syndrome and research is ongoing. In children with Dravet Syndrome who do not have SCN1a mutations, other genetic mutations are being explored.