Moon Durham-West Submitted:

Sleep challenges are present in ~70-80% of individuals with Angelman syndrome (AS). Commonly reported sleep challenges include frequent night wakings, short sleep durations, and long sleep onset latencies. Although sleep challenges are often reported, there is limited knowledge regarding sleep development in AS, particularly in the first three years.

To address these gaps, expectant developmental shifts in sleep were evaluated in infants/toddlers with AS, and sleep behaviors were compared to a case-matched typically developing (TD) group. Analyses were conducted in 30 infants/toddlers (M = 20.30 months) with AS (n = 15) and their case-matched TD peers (n = 15). Emfit (an under-the-mattress sensor) was used to assess sleep cycle duration and the presence of deep sleep. Parent-reported sleep diary data were utilized to assess circadian rhythms (percentage of sleep at night), night waking frequency, sleep duration variability, bedtime, and 24-hour sleep duration.

Infants/toddlers with AS met expectant developmental shifts in sleep. They had established circadian rhythms, such that >60% of their sleep occurred at night. They also achieved deep sleep and sleep cycles of at least 40 minutes as developmentally expected. Additionally, their 24-hour sleep durations met clinical recommendations.

In the first few years, infants/toddlers with AS slept much like their TD peers. There were no robust differences in 24-hour sleep duration or bedtime for the AS group as hypothesized. However, parents reported more night wakings in the AS group. Infants/toddlers with AS also presented with more variability than their TD peers in 24-hour and nighttime sleep duration.

These findings demonstrate that sleep in early life for infants/toddlers with AS may be more aligned with typical development than previously expected. Behavioral interventions aimed at improving night-to-night sleep consistency and reducing night wakings may be well-suited for infants/toddlers with AS.