No abstract

Sleep disruption is common in individuals with autism spectrum disorder (ASD). Genes whose products regulate endogenous melatonin modify sleep patterns and have been implicated in ASD. Genetic factors likely contribute to comorbid expression of sleep disorders in ASD. We studied a clinically unique ASD subgroup, consisting solely of children with comorbid expression of sleep onset delay. We evaluated variation in two melatonin pathway genes, acetylserotonin O-methyltransferase (ASMT) and cytochrome P450 1A2 (CYP1A2). We observed higher frequencies than currently reported (p < 0.04) for variants evidenced to decrease ASMT expression and related to decreased CYP1A2 enzyme activity (p ≤ 0.0007). We detected a relationship between genotypes in ASMT and CYP1A2 (r2 = 0.63). Our results indicate that expression of sleep onset delay relates to melatonin pathway genes.

Children with autism often suffer from sleep disturbances, and compared to age-matched controls, have decreased melatonin levels, as indicated by urine levels of the primary melatonin metabolite, 6-sulfatoxymelatonin (6-SM). We therefore investigated the relationship between 6-SM levels and sleep architecture in children with autism spectrum disorders (ASD). Twenty-three children, aged 4–10 years, completed two nights of polysomnography and one overnight urine collection for measurement of urinary 6-SM excretion rate. Parents completed the Children’s Sleep Habits Questionnaire. We found that higher urinary 6-SM excretion rates were associated with increased N3 sleep, decreased N2 sleep, and decreased daytime sleepiness. The results warrant further examination to examine the effects of supplemental melatonin on sleep architecture and daytime sleepiness.

Down syndrome (DS) is the most common genetic cause of intellectual disability and results from an extra chromosome 21 (Trisomy 21). Sleep issues and/or obstructive sleep apnea (OSA) are assumed to be part of the DS phenotype with a high prevalence but are often under recognized. This cross-sectional study of children with DS examines the caregiver reported sleep behaviors of 108 children with DS, ranging in age from 1.50 to 13.40 years (mean = 5.18 years) utilizing a standardized assessment tool, the Children's Sleep Habit Questionnaire (CSHQ). The CSHQ revealed 76% of children with DS had sleep problems, which began at a young age, and continue to persist and may recur with increasing age. Furthermore, children with DS who undergone adenoid and tonsillectomy for OSA continued to have sleep problems suggesting that ongoing monitoring of sleep issues is needed in this population. Implications of sleep problems and recommended anticipatory guidance and intervention are discussed.