Early motor abilities in infants at heightened versus low risk for ASD: A Baby Siblings Research Consortium (BSRC)...

Area of Science:

• Developmental Psychology
• Neurodevelopmental Disorders
• Pediatric Medicine

Background:

• Infants at heightened risk (HR) for autism spectrum disorder (ASD), identified as younger siblings of children with ASD, exhibit early motor differences.
• These motor differences may be more pronounced in HR infants who are later diagnosed with ASD.

Purpose of the Study:

• To examine gross motor (GM) and fine motor (FM) performance in HR infants at 6 months using the Mullen Scales of Early Learning (MSEL).
• To compare motor skills between HR infants (with varying outcomes) and low-risk (LR) infants.
• To determine if 6-month motor abilities predict ASD symptom severity at 36 months.

Main Methods:

• Administered MSEL GM and FM subscales to a large, diverse sample of HR and LR infants at 6 months.
• Analyzed performance across groups: HR with ASD, HR with elevated ADOS without ASD, HR with low ADOS without ASD, and LR infants.
• Correlated 6-month motor scores with 36-month ASD symptom severity (ADOS scores).

Main Results:

• Fine motor (FM) performance distinguished all HR groups from LR infants.
• HR infants with elevated ADOS (without ASD) showed the weakest FM and GM performance compared to LR and other HR groups.
• 6-month FM scores significantly predicted 36-month ADOS severity in the HR group, while GM scores did not.

Conclusions:

• Early fine motor deficits in HR infants are observable at 6 months and are associated with later ASD symptom severity.
• While specific motor signs for later ASD diagnosis were not identified, motor vulnerabilities impact broader developmental trajectories.
• Fine motor skills may serve as an important early indicator in developmental risk assessments.