Prevalence of sleep problems in Smith-Lemli-Opitz syndrome

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive genetic disorder, characterized by multiple congenital anomalies, and intellectual disability. It is caused by a genetically inherited deficiency of the enzyme 7-dehydrocholesterol-delta-7-reductase, which results in increased serum levels of 7-dehydrocholesterol (7-DHC), and decreased levels of cholesterol. This study assesses the prevalence of sleep problems in patients with SLOS. The study group comprised 18 subjects with SLOS, ages 2-31 years (median 10.7 ± 8.5 years). Parents completed several questionnaires (Intake Demographic Form; Pediatric Sleep Questionnaire; Pediatric Daytime Sleepiness Scale). The SLOS subjects had symptoms of sleep-disordered breathing (50% snoring; 66.7% mouth breathing), problems with sleep onset [difficulty falling asleep (61.1%) sleep onset time >30 min (62%)], sleep maintenance [wake up screaming (61.1%), waking up more than twice (44.4%), having trouble falling back to sleep (66.7%), waking up early in the morning (61.1%), and restless sleep (50%)]. The subjects with SLOS needed parents in the room to fall asleep (50%), watch TV or listen to music to fall asleep (44.4%), and described bed sharing (33.3%), indicating sleep-anxiety and sleep-associations. Symptoms of excessive-daytime-sleepiness were frequently reported [un-refreshed in the morning (38.9%), daytime sleepiness (44.4%), and daytime naps (55.6%)]. Parents frequently observed difficulty of organizing tasks (66.7%), and easy distractibility (88.9%). Sleep problems such as sleep-disordered breathing, sleep-related anxiety and sleep associations, disturbed sleep patterns at night, and excessive daytime sleepiness are frequent in children with SLOS.