Face-brain asymmetry in autism spectrum disorders

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Autism spectrum disorders (ASDs) present significant heterogeneity, complicating research into their causes and pathogenesis.
• Identifying reliable biomarkers and endophenotypes is crucial for advancing molecular research and understanding genetic and developmental mechanisms in ASD.

Observation:

• Dense surface modeling and pattern-matching algorithms were employed to analyze facial morphology in boys with ASD and their first-degree relatives.
• Facial asymmetry was significantly detected in boys with ASD, particularly in the supra- and periorbital regions, correlating with right-hemisphere frontal pole development.
• Unaffected mothers of children with ASD exhibited significant facial asymmetry, more pronounced than in controls, suggesting a potential genetic link or susceptibility.

Findings:

• Pattern-matching algorithms successfully discriminated between boys with ASD and controls (AUC=0.82) and between unaffected mothers of ASD children and controls (AUC=0.76).
• Significant facial asymmetry was observed in boys with ASD (P<0.01) and their unaffected mothers (P<0.03), with unaffected fathers showing no significant asymmetry.
• Unaffected male siblings of individuals with ASD displayed facial patterns more similar to ASD boys than controls, indicating potential inherited traits.

Implications:

• Facial asymmetry may serve as a valuable, non-invasive biomarker for ASD, aiding in early identification and targeted research.
• The findings suggest a potential genetic influence on both brain and facial development in ASD, possibly mediated by maternal genes.
• Further research coordinating facial and brain studies in ASD probands and their families, especially mothers, is warranted to elucidate the underlying genetic and developmental pathways.