Sleep Problems in Angelman Syndrome Start in Infancy, New Research Finds

Sleep problems in children with Angelman syndrome (AS), particularly abnormal nighttime duration and night-walking, start in early infancy, a new study shows.

The research, “Sleep phenotypes in infants and toddlers with neurogenetic syndromes,” was published in the journal Sleep Medicine.

Children with neurogenetic syndromes show high prevalence of sleep problems. In AS, typical sleep disruptions include night walking, short sleep duration, and increased sleep onset latency (time to fall asleep).

These problems are well-documented in preschool- and school-age children, having impact on child behavior and parental stress. But, despite reports of the effect of sleep problems on cognitive development, attention, and emotional regulation in healthy infants, few studies have analyzed sleep disturbances in neurogenetic syndromes during infancy and early childhood.

So, aiming to inform on the emergence of sleep problems and potential treatment strategies, the researchers compared parent-reported sleep problems in infants and toddlers with three rare neurogenetic syndromes – AS, Williams syndrome (WS), and Prader-Willi syndrome (PWS) – with those of same-aged typically developing controls.

The study included 80 infants and toddlers (18 AS, 19 WS, 19 PWS, and 24 controls), aged six to 46 months. Their mothers completed the 12-point Brief Infant Sleep Questionnaire. Analysis focused on sleep onset latency, total sleep duration, daytime and nighttime sleep duration, and sleep problem severity, as assessed by both maternal impression and National Sleep Foundation guidelines.

Evaluation of children with neurogenetic syndromes revealed that 41 percent of mothers reported problematic sleep, whereas national guidelines revealed 29 percent of children with abnormal sleep durations.

Children with AS and WS showed the most severe sleep disturbances, particularly regarding nighttime sleep duration in the early developmental stage. Conversely, infants and toddlers with PWS showed largely typical patterns, which suggests delayed onset of sleep problems in PWS.

Increased periods of night-walking also were observed in AS. However, infants and toddlers with AS did not demonstrate as much increase in sleep onset latency and night-walking problems as older children in other studies.

So, this pattern suggests that sleep problems in children with AS “likely emerge in early infancy and may be targeted proactively,” the researchers wrote. Of note, 17 percent of the AS cohort was taking sleep-related medications, indicating that interventions are already in place at young ages.

Overall, the study suggests that “sleep problems in AS are more extensive than those observed in several other neurogenetic syndromes, warranting further research to develop syndrome-specific screening and intervention protocols that may minimize the negative developmental implications for this population,” the team concluded.

Future work should aim to replicate these findings in larger groups, assess sleep problems across childhood, and evaluate the association of sleep disturbances with other problems, including family functioning.

The study’s senior author was Bridgette L. Tonnsen, PhD, from the Department of Psychological Sciences, Purdue University, in West Lafayette, Indiana.