Variations in Genes Related to Sleep Patterns in Children with Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is accompanied by comorbid sleep problems in 40-80% of cases. Previous reports have shown relationships between circadian rhythm genes and sleep problems in ASD. This study aimed to (1) examine relationships between sleep problems and characteristics of children with ASD—age, sex, ASD severity, IQ, and medical conditions, and (2) explore genetic associations between 25 melatonin synthesis and suprachiasmatic nucleus (SCN) genes and sleep patterns in children with ASD. Methods: This secondary analysis used genotypic and phenotypic data on children aged 4-18-years from the Simons Simplex Collection. An exploratory factor analysis and psychometric evaluation was performed on the Simons Simplex Collection Sleep Interview (SSCSI), consisting of Nighttime problems, Daytime problems, and Sleep duration problems subscales. Expression quantitative trait loci (eQTL) and single nucleotide polymorphisms (SNPs) were identified primarily from gene expression data for 25 melatonin/SCN genes. Student’s t-tests, Chi-square, and Kruskal-Wallis or Mann-Whitney U tests were performed to detect differences between age groups, sexes, and sleep problem groups. Associations between sleep problems and child characteristics were assessed using logistic regression. Relationships between sleep problems and gene variants were tested with logistic regression and transmission disequilibrium tests. Results: Approximately 41% of children were categorized as having sleep problems. In the full sample, and in age subgroups, GID and age were the variables most frequently associated with composite sleep problems, Nighttime problems, Daytime problems, and Sleep duration problems, followed by NVIQ and male sex. Seizures were associated with composite sleep problems and Nighttime problems. ASD severity was not associated with sleep problems in this sample. No significant associations were found between sleep problems and any gene variants after correction for multiple testing. Conclusions: This study advances our understanding of sleep in ASD by showing that GID, NVIQ, age, sex, and seizures increased the odds of sleep problems; but that the gene expression-related variants in the melatonin synthesis and SCN pathways do not have a notable impact on sleep problems in children with ASD. These results reinforce that healthcare professionals should screen for sleep problems in children with ASD and suggest future lines of inquiry.