for people ages 6 months to 60 months (full criteria)
at San Francisco, California and other locations
study started
estimated completion



This is a multicenter, prospective, 2-year observational study in infants and children with developmental and epileptic encephalopathies (DEEs). The DEE currently being investigated is SCN1A-positive Dravet Syndrome.

Official Title

ENVISION: Natural History Study of Infants and Children With Developmental and Epileptic Encephalopathies


This prospective, longitudinal, natural history master protocol has been designed to define the seizure, neurodevelopmental, and behavioral characteristics of SCN1A-positive Dravet Syndrome in infants and children between 6 and 60 months. It will also explore the impact of the disease on the participant's parent/caregiver quality of life (QoL) and healthcare resource utilization (HCRU).


Dravet Syndrome, severe myoclonic epilepsy, epilepsy, severe myoclonic epilepsy of infancy, SMEI, SCN1A related seizure disorder, epileptic encephalopathy, developmental and epileptic encephalopathies, DEE, Brain Diseases, Myoclonic Epilepsies, SCN1A-positive Dravet Syndrome


You can join if…

Open to people ages 6 months to 60 months

  • Aged between 6 months and 60 months.
  • Confirmed SCN1A mutation.
  • Normal development prior to onset of first seizure as defined by the Centers for Disease -Control and Prevention (CDC 2019).
  • Onset of seizures between age 3 and 15 months, inclusive.

You CAN'T join if...

  • Copy number variant of SCN1A, including SCN1A microdeletion, if affecting other genes.
  • SCN1A mutation present on both alleles.
  • Known pathogenic or clinically suspected mutation in a seizure-associated gene besides SCN1A.
  • Confirmed mutation in a gene besides SCN1A that is known to increase the severity of the seizure phenotype.
  • Known gain-of-function genetic mutation, as defined by functional studies, including p.Thr226Met.
  • History of notable developmental deficit that was evident prior to seizure onset.
  • Known central nervous system structural abnormality as found on magnetic resonance imaging or computed tomography scan of brain.
  • Currently taking or has taken for 6 or more consecutive weeks anti-seizure medications (ASMs) at a therapeutic dose that are contraindicated in SCN1A-positive Dravet Syndrome, including sodium channel blockers.
  • Known concomitant genetic mutation or clinical comorbidity that potentially confounds typical Dravet phenotype.


  • UCSF Benioff Children's Hospital
    San Francisco California 94143 United States
  • Children's Hospital Los Angeles
    Los Angeles California 90027 United States


in progress, not accepting new patients
Start Date
Completion Date
Encoded Therapeutics
Study Type
About 58 people participating
Last Updated