Dravet syndrome and other developmental epileptic encephalopathies are rare but devastating conditions that cause a host of symptoms in children, including seizures, intellectual disability, and even sudden death. 

Most cases are caused by a genetic mutation; Dravet syndrome in particular is most often caused by variants in the sodium channel gene SCN1A.

Recent research from Michigan Medicine takes aim at another variant in SCN1B, which causes an even more severe form of DEE. 

Mice without the SCN1B gene experience seizures and 100 percent mortality just three weeks after birth.

Using mouse models, the investigative team, led by Chunling Chen, M.D., and Yukun Yuan, M.D., Ph.D., in the lab of Lori Isom, Ph.D., of the Department of Pharmacology at the Medical School, tested a gene therapy to replace SCN1B to increase the expression of beta-1 protein, which is necessary for the regulation of sodium channels in the brain.

Administering the therapy to newborn mice increased their survival, reduced the severity of their seizures and restored brain neuron excitability. 

The team notes that different forms of SCN1B gene expression may result in different outcomes for the therapy.

However, the proof-of-concept is the first step toward a gene replacement therapy for SCN1B-linked developmental and epileptic encephalopathy.

Paper cited: “Neonatal but not Juvenile Gene Therapy Reduces Seizures and Prolongs Lifespan in SCN1B-Dravet Syndrome Mice,” Journal of Clinical Investigation. DOI: 10.1172/JCI182584