Subcortical Brain and Behavior Phenotypes Differentiate Infants With Autism Versus Language Delay

Area of Science:

• Neuroscience
• Developmental Psychology
• Pediatrics

Background:

• Younger siblings of children with autism spectrum disorder (ASD) have an elevated risk for ASD and developmental issues.
• It remains unclear whether infants with developmental concerns but without ASD share similar or different behavioral and brain characteristics compared to infants with ASD.
• The neurobiology underlying language difficulties in ASD, which are often heterogeneous and present atypical receptive-expressive profiles, is not well understood.

Purpose of the Study:

• To investigate early brain structures and their association with later language skills in high-risk infants.
• To compare brain and behavioral phenotypes between infants later diagnosed with ASD, infants with early language delay, and typically developing infants.

Main Methods:

• Utilized behavioral assessments and structural magnetic resonance imaging (MRI) in high-risk infant cohorts.
• Compared infants diagnosed with ASD (n=86), infants with early language delay (n=41), and control infants (n=398).

Main Results:

• Diminished language skills were observed at 12 months in both infants with ASD and those with early language delay.
• Atypical receptive-expressive language profiles were uniquely identified in infants with ASD at 24 months.
• Brain-behavior associations between subcortical volumes and language skills differed between infants with ASD and those with language delay.

Conclusions:

• Infants with ASD and those with language delay exhibit distinct brain mechanisms influencing language development.
• These differences suggest unique genetic and environmental risk factors contribute to ASD and language delay in infants.