Over 200K
People Affected in the U.S.
Disease Background
Developmental and epileptic encephalopathies (DEEs) refer to a diverse group of rare epilepsies that are characterized by both seizures as well as encephalopathy, which is a term used to describe developmental impairment resulting from the underlying condition. Symptoms often begin in infancy or early childhood.
Seizures may be frequent, unpredictable, and difficult to control, and some people experience more than one type of seizure. Beyond the seizures themselves, many children face challenges with learning, communication, movement, and development, creating a significant burden for both patients and their families.
Common Symptoms
- Seizures that may be frequent or difficult to control
- More than one seizure type in some individuals
- Developmental delay, slowing, or loss of previously acquired skills
- Intellectual disability that can vary in severity
- Difficulties involving movement, muscle tone, or mobility
- Challenges with speech, language, or communication
- Sleep or behavioral challenges
FAQs
What causes DEEs?
DEEs can have many different causes, including genetic changes, structural brain abnormalities, metabolic disorders, and other neurological conditions. Advances in genetic testing have identified over 900 known genes associated with DEEs, including SCN2A, SCN1A, and STXBP1. In many cases, these genetic changes affect how neurons communicate, leading to abnormal electrical activity in the brain.
Is DEE one condition?
No. DEE is an umbrella term that includes many different epilepsy syndromes and underlying causes. The age at which symptoms begin, seizure types, developmental effects, associated medical needs and long-term course can vary considerably from one person to another.
Do DEEs only affect children?
No. Although many DEEs begin in infancy or childhood, people continue to live with these conditions throughout adolescence and adulthood. Medical, developmental, and support needs may change over time, making coordinated care across the lifespan important.
How many individuals have DEEs?
Each individual DEE is rare, and the overall number of people living with DEEs is difficult to determine. DEEs include many different syndromes and underlying causes, and differences in diagnosis, terminology and access to genetic testing can affect prevalence estimates. Collectively, they affect children and adults around the world.
Are DEEs inherited?
Some DEEs are inherited, while others result from a genetic change that occurs for the first time in an affected individual. The inheritance pattern and likelihood that a condition could occur again in a family depend on the specific genetic cause. Genetic testing and counseling can help families better understand a diagnosis and its potential implications for other family members.
How are DEEs diagnosed?
Diagnosis typically involves a combination of clinical evaluation, neurological examination, electroencephalography (EEG), brain imaging, and genetic testing. Identifying the underlying cause can help guide treatment decisions and provide important information about prognosis and potential clinical trial opportunities.
How are DEEs managed?
Care is individualized and may involve antiseizure medications, dietary therapy, medical devices or surgery, as well as physical, occupational, speech, and developmental therapies. Management often requires a multidisciplinary healthcare team and depends on the specific diagnosis and needs of the individual.
Explore More
Link to: Clinical Trials
Clinical Trials
Explore Praxis-sponsored research in DEEs, including information about ongoing and completed clinical studies.
Link to: Expanded Access Policy
Expanded Access Policy
Read Praxis’ policy regarding requests for access to investigational therapies outside of clinical trials.