Baseline characteristics and feasibility of clinical outcome measures in <scp>CDKL5</scp> deficiency disorder: The <scp>CANDID</scp> observational study

The scales in the CANDID study capture disease-related deficits and phenotype variability in CDD. Floor effects in subdomains aligned with disease severity. The GMFM-88 lacks granularity, and its operational limitations make it unsuitable for CDD trials. Baseline analyses demonstrate the feasibility and potential value of most selected scales, supporting their use in optimizing trial design and endpoint selection for future CDD clinical trials.