Is Dravet syndrome an inherited disease?

Is Dravet syndrome an inherited disease?

Dravet syndrome can be inherited. It’s an autosomal dominant disorder, which means you only need to get the changed (mutated) gene — the SCN1A gene — from one parent. (Autosomal means the affected gene is on one of the 22 nonsex chromosomes from either parent.) If you’re a parent with the mutated (changed) gene, your child has a 50% chance of inheriting the defective gene.

But only between 4% and 10% of SCN1A mutations in children with Dravet syndrome are inherited from a parent. About 90% of SCN1A mutations aren’t found in the child’s parent and are new gene mutations only present in the child.

Genetics is tricky. There are over 6,000 places for mutations to occur on the SCN1A gene. This means that many children’s gene mutations haven’t been seen in other children. SCN1A mutations result in a range of associated conditions, from migraine to mild-to-moderate forms of epilepsy to the most severe form of epilepsy in Dravet syndrome.