Developmental pathways to autism in tuberous sclerosis complex: Evidence from a longitudinal cohort.

The association between autism spectrum disorder (hereafter referred to as autism) and tuberous sclerosis complex (TSC) is well established, yet the developmental pathways linking genetic mutation, cortical pathology, and epilepsy with autism remain unclear. The Tuberous Sclerosis 2000 Study recruited children newly diagnosed with TSC (N = 125). Data on mutation status, cortical tuber burden (magnetic resonance imaging/computed tomography), seizure history, and cognitive ability were collected. Approximately 10 years later, follow-up assessments of autism, cognitive ability, and epilepsy were completed (n = 86). Almost 40% of participants met diagnostic criteria for autism, with an additional 42% showing elevated autistic traits. Structural equation modeling identified two indirect pathways linking TSC1/TSC2 mutation with the autism factor score: one via higher cortical tuber burden and infantile spasms and one via spasms alone. Concurrent seizure severity and lower intelligence quotient scores were also associated with higher autism factor scores. These findings provide preliminary longitudinal evidence supporting developmental associations between genetic vulnerability, cortical pathology, and early severe epilepsy with later autism. This highlights the importance of further investigation of early epileptic activity and associated neurodevelopmental outcomes in TSC and may inform understanding of epilepsy-related pathways associated with autism.