Biphasic sleep is a feature of sleep disturbance in SYNGAP1-RD

Sleep problems are common in children with SYNGAP1-Related Disorder (SYNGAP1-RD). The use of devices that objectively estimate sleep are complicated by co-occurring sensory disorders in this population. We examined the feasibility and validity of wrist actigraphy to examine sleep and rest-activity rhythms (RAR).

Data from five children with SYNGAP1-RD and 42 typically developing children were analyzed. All children were asked to wear the Actiwatch-2 for 14 continuous days and caregivers were asked to complete a sleep diary and the Children Sleep Health Questionnaire (CSHQ). Parametric (alpha, beta, acrophase, amplitude, up/down mesor, mesor), nonparametric (intradaily variability, interdaily stability, M10/L5 and relative amplitude), and sleep metrics-total sleep time (TST), wake after sleep onset (WASO), fragmentation index (restlessness throughout the rest period), the time of sleep bout onset, the number, and duration of sleep bouts, and the number and duration of wake bouts-were analyzed.

In children with SYNGAP1-RD, sleep bouts were distributed across the day and night and were consistent with a higher alpha. Fewer sleep bouts occurred in the early morning aligning with parent report of early morning arousal. Although there was no difference in average TST, children with SYNGAP1-RD, had fewer sleep and wake bouts that were longer in duration. Additionally, they had greater WASO and higher fragmentation index, the latter was a strong predictor of subjects with SYNGAP1-RD.

Actigraphy provides an objective measure of sleep that aligns with RAR, is consistent with parent report, and provides an ethological approach to monitoring sleep in children with SYNGAP1-RD.