Sleep disturbances in Algelman syndrome: a questionnaire study

Only few studies are available on sleep disorders in Angelman syndrome (AS), a neurodevelopmental disorder with several behaviordisturbances. The aim of this study was to determine the prevalence of sleep disorders in a relatively large group of AS subjects, compared tothat of age-matched controls. Fourty-nine consecutive parents of patients with AS (26 males and 23 females aged 2.3–26.2 years) wereinterviewed and filled out a comprehensive sleep questionnaire. Based on their genetic etiology, four groups were defined: deletion ofchromosome 15q11–13 (25 subjects); methylation imprinting mutation (six subjects), UBE3A mutations (seven subjects) and paternaluniparental disomy (five subjects). In the remaining cases genetic testings were negative. A significantly high frequency of disorders ofinitiating and maintaining sleep, prolonged sleep latency, prolonged wakefulness after sleep onset, high number of night awakenings andreduced total sleep time were found in our AS patients, as compared to age-matched controls. We also found other types of sleep disorders,never reported before, such as enuresis, bruxism, sleep terrors, somnambulism, nocturnal hyperkinesia, and snoring. No differences werefound between the four genetic aetiology groups. Moreover, we did not find important improvement of sleep disturbances from pre-pubertalto post-pubertal ages. Our data confirm the significant presence of sleep/wake rhythms fragmentation, peculiar of AS, and also demonstratethe presence of several other types of sleep disturbances in this syndrome.