SCN2A-Developmental and Epileptic Encephalopathies: Challenges to trial-readiness for non-seizure outcomes.

The VABS, as standardly administered, has shortcomings for addressing growth or regression in individuals with SCN2A-DEEs. Some subdomain raw scores reflected substantial floor effects. Raw scores increased so slowly over time that standardized scores declined. Alternative measures sensitive to incremental meaningful change are required if outcomes such as adaptive behavior are to be primary outcomes in short-term clinical trials.