Neurogenetic analysis of childhood disintegrative disorder.

The CDD group was very small because the condition is rare, so the study is exploratory and needs confirmation in larger cohorts. Participants were studied months to years after symptom onset, and the design was cross-sectional, so the study cannot show how the findings related to the regression itself. Genetic analysis did not find clearly deleterious variants, and the candidate genes were not recurrent enough to establish a genetic cause. There was no intellectual disability group without autism, so some brain or eye-tracking differences may reflect severe intellectual disability rather than childhood disintegrative disorder or autism. The fMRI and eye-tracking analyses used smaller subsets of each cohort, and obtaining high-quality data from low-functioning participants was difficult.

The study was funded by the Simons Foundation, the National Institutes of Health, the Alan B. Slifka Foundation, Rumsey Cartier, Autism Speaks, and a Hilibrand Autism Fellowship. The supplied text does not report author conflicts of interest.

Do not treat these findings as a diagnostic test or a reason to change therapy. The study was exploratory, used small groups, found no clearly deleterious genetic variants, and did not show that the eye-gaze or brain-activation patterns identify childhood disintegrative disorder in a clinic.