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Published on: October 17, 2025
Early autism symptoms in infants with tuberous sclerosis complex
Nicole M McDonald1, Kandice J Varcin2, Rujuta Bhatt1
1UCLA Semel Institute of Neuroscience and Human Behavior, David Geffen School of Medicine, 760 Westwood Plaza, Los Angeles, CA, 90095.
Insights
Infants with tuberous sclerosis complex (TSC) and autism spectrum disorder (ASD) show early social communication deficits by 9 months. These findings highlight the need for early screening and intervention for TSC infants at risk for ASD.
Area of Science:
- Neurodevelopmental Disorders
- Genetics and Rare Diseases
Background:
- Tuberous sclerosis complex (TSC) is a genetic disorder with a high comorbidity with autism spectrum disorder (ASD).
- Approximately 50-60% of infants with TSC are diagnosed with ASD by age three.
- Previous research indicated cognitive divergence in TSC infants who develop ASD.
Purpose of the Study:
- To investigate early social communication functioning in infants with TSC.
- To compare social communication in infants with TSC who develop ASD (TSC/ASD) versus those who do not (TSC/no ASD) and low-risk infants (LR).
- To identify early indicators of ASD in infants with TSC.
Main Methods:
- Longitudinal study of infants with TSC and low-risk controls.
- Assessment of early ASD symptoms using the Autism Observation Scale for Infants (AOSI) at 9 and 12 months.
- Comparison of AOSI scores across TSC/ASD, TSC/no ASD, and LR groups, controlling for cognitive abilities.
Main Results:
- Infants in the TSC/ASD group exhibited significantly higher AOSI scores at 9 and 12 months compared to TSC/no ASD and LR groups.
- These differences in social communication deficits were not fully explained by cognitive disparities.
- Specific AOSI items, particularly those related to social referencing, predicted ASD outcome.
Conclusions:
- Early social communication deficits are evident in infants with TSC/ASD by 9 months of age.
- These deficits are distinguishable from those in infants with TSC without ASD and low-risk infants.
- Findings support early identification and targeted social communication interventions for infants with TSC.
Abstract:
Tuberous sclerosis complex (TSC) is a rare, autosomal dominant genetic syndrome that confers significantly increased risk for autism spectrum disorder (ASD), with 50-60% of infants with TSC meeting criteria for ASD by 3 years of age. In a previous study of the current longitudinal cohort, we found that infants with TSC who develop ASD (TSC/ASD) evidence decreased cognitive abilities that diverge from infants with TSC and no ASD (TSC/no ASD). We extended this work by asking whether TSC/ASD infants (n = 13) differed from TSC/no ASD infants (n = 10) and infants with low developmental risk and no ASD (LR; n = 21) in their social communication functioning during the first year of life. We measured early ASD symptoms with the Autism Observation Scale for Infants (AOSI) at 9 and 12 months of age. At both ages, infants in the TSC/ASD group had significantly higher AOSI total scores than infants in the TSC/no ASD and LR groups, which were not fully explained by differences in cognitive abilities. Several items on the AOSI at both ages were predictive of ASD outcome, particularly those representing core social communication deficits (e.g., social referencing). Our findings signal the need for further study of this population within the first year and provide strong justification for early identification and early intervention targeting social communication skills in infants with TSC. Autism Res 2017, 10: 1981-1990. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Lay Summary:
We examined early signs of autism spectrum disorder (ASD) in infants with tuberous sclerosis complex (TSC), approximately 50% of whom will meet criteria for ASD by age 3. Infants with TSC and ASD showed deficits in social communication behaviors by 9 months of age that were clearly distinguishable from behaviors in infants with TSC who do not develop ASD and low risk infants. Results support the importance of early ASD screening and intervention for infants with TSC.
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