Autism spectrum disorder (ASD) is a complex, heritable and highly heterogeneous neurodevelopmental condition characterized by challenges in the core areas of reciprocal social communication as well as the presence of restricted and repetitive behaviors, interests and activities. To dissect the roots of phenotypic heterogeneity, Maja Bucan and her collaborator Edward S. Brodkin plan to focus on the relationship between sleep disturbances and ASD liability. Sleep problems are among the most prevalent comorbid difficulties in ASD, and there is emerging evidence for a shared etiology of ASD and sleep difficulties involving disrupted neuronal connectivity.

Leveraging their expertise and infrastructure established in their ongoing genomic studies of sleep in ASD, Bucan and Brodkin will recontact families participating in SPARK to collect actimetry data on ASD probands, their unaffected siblings (Phase 1) and parents (Phase 2). Their aims are to prioritize SPARK families for sleep studies by conducting core genomic analyses and recruiting families with both idiopathic ASD (n=100) and families of SPARK participants with deleterious variants in known ASD risk genes and synaptic genes linked to sleep disruptions (n=200). Actimetry monitoring and a combined analysis of ASD and sleep traits using the discordant sib-pair design will also be performed.

The current study would be the first to consider sleep traits in ASD by combining deep phenotyping with genetic analysis. Findings from this study are expected to improve our understanding of genetic and clinical contributors to sleep in ASD.