Characterizing Developmental and Behavioral Profiles in Developmental Synaptopathies to Inform Clinical Trial Endpoints.

Valluripalli Soorya et al. (2025) looked at kids with three rare gene syndromes: Phelan-McDermid, TSC, and PTEN.

They wanted to see if regular autism and IQ tests could track change in future drug trials.

The team ran standard tools like the ADOS and IQ scales on children with severe or variable intellectual disability.

Most kids with Phelan-McDermid scored too low for the tests to give valid numbers.

Many children with TSC or PTEN also had scattered skills that did not fit the test floors.

The authors warn that trial teams must build new, easier measures or risk false "no effect" results.

Diz et al. (2011) showed IQ scores stay stable across translated tests in preschoolers with general developmental delay. Latha’s work does not overturn this; it simply shows the same tests collapse when disability is profound.

May et al. (2019) found PEAK pre-assessments line up with IQ in an autism clinic. Latha extends the caution: even promising tools need extra-low floors for PMS-type severe ID.

Taylor et al. (2017) picked the CSHQ as a Down-syndrome-ready sleep endpoint. Latha echoes the method: choose or build scales that match the syndrome’s skill range, not the typical range.

If you consult on clinical trials, flag any protocol that lists ADOS or standard IQ as the main endpoint for kids with severe ID. Ask sponsors to add caregiver-report or sensory-based scales with lower baselines. Even in everyday practice, write reports that note “score may underestimate true ability” when the child hits the test floor. This protects both the child and the science from false “no progress” labels.