Background
Developmental and epileptic encephalopathies (DEEs) are a group of rare, severe epilepsies that usually begin in infancy or childhood. They are often caused by genetic changes and can affect brain development, learning and movement, as well as overall health. Although these conditions can be life-limiting, improvements in care mean that more people with DEEs are now living into adulthood. However, healthcare and research have traditionally focused on children, leaving important gaps in our understanding of how these conditions affect people as they age.
Research
The review examines the current evidence on genetic developmental and epileptic encephalopathies (DEEs) in adulthood, including diagnosis, changes in symptoms over time, associated health conditions and available treatments. Many adults may not have received comprehensive genetic testing, particularly if their condition was diagnosed before modern genetic technologies became available. Symptoms can also change with age, making childhood diagnoses more difficult to recognise in adulthood. Adults may experience additional health challenges, including movement difficulties, sleep problems and mental health conditions.
There are significant gaps in research, including a lack of long-term studies following people with DEEs throughout their lives and the frequent exclusion of adults from clinical trials. The review also explores emerging precision treatments, including gene- and RNA-based therapies designed to target the underlying genetic cause of a condition, and the need for coordinated care as people move from paediatric to adult health services.
Potential Impact
Wider access to genetic testing, alongside the reanalysis of previous test results, could help more adults receive an accurate diagnosis, inform treatment decisions and guide monitoring for other health conditions. More long-term research is needed to understand how DEEs progress into adulthood, identify changing care needs and develop treatments that improve outcomes beyond seizure control alone.
As gene- and RNA-based therapies advance, understanding their potential benefits and risks for adults will be increasingly important. Greater inclusion of adults in clinical research, alongside specialist services and multidisciplinary support, could help ensure continuity of care throughout life. Addressing these gaps could help adults with DEEs benefit from scientific advances and receive care that better supports their health, independence and quality of life.