Brief Report: Characteristics of preschool children with ASD vary by ascertainment

Area of Science:

• Neurodevelopmental disorders
• Pediatric psychology
• Genetics and heritability

Background:

• Prospective infant sibling studies offer insights into autism spectrum disorder (ASD) development.
• Understanding ASD in high-risk populations is crucial for early identification and intervention.
• Community-identified ASD cases may differ from those in clinical or high-risk cohorts.

Purpose of the Study:

• To compare the clinical characteristics of children with autism spectrum disorder (ASD) identified through prospective, high-risk infant sibling studies versus community-based clinical referrals.
• To investigate potential differences in ASD presentation between these two ascertainment methods.

Main Methods:

• Comparison of clinical features in two groups of children diagnosed with ASD (n=86 per group).
• Data drawn from two Canadian longitudinal research cohorts.
• Ascertainment via prospective infant sibling studies versus clinical referral.

Main Results:

• Children with ASD identified through the prospective infant sibling cohort exhibited less severe symptoms.
• The prospective cohort included a higher proportion of girls compared to the clinically referred group.
• Significant differences in symptom severity and sex distribution were observed between the two groups.

Conclusions:

• Autism spectrum disorder (ASD) presentation varies based on ascertainment method (high-risk vs. clinical referral).
• Findings suggest that high-risk infant sibling studies may capture a milder form of ASD, with a different sex ratio.
• Implications for interpreting results from different types of ASD research cohorts are significant.