Genetic Variation in Serotonin Transporter Modulates Tactile Hyperresponsiveness in ASD

Area of Science:

• Neuroscience
• Genetics
• Developmental Psychology

Background:

• Serotonin system dysfunction is implicated in autism spectrum disorder (ASD).
• The serotonin transporter (SERT) is a candidate gene for ASD risk.
• SERT influences sensory circuit development, particularly somatosensory processing.

Purpose of the Study:

• To investigate the association between common SERT genetic variants and sensory responsiveness in children with ASD.
• To test the hypothesis that higher SERT expression genotypes correlate with tactile hyperresponsiveness in ASD.

Main Methods:

• Caregiver-based assessments of sensory function in 47 children with ASD and 38 typically developing (TD) children.
• Genotyping for functional SERT promoter polymorphisms (5-HTTLPR and rs25531).
• Correlation analysis between sensory patterns, age, repetitive behaviors, and SERT genotypes.

Main Results:

• Children with ASD exhibited increased sensory hypo- and hyperresponsiveness compared to TD children.
• Hyporesponsive sensory patterns correlated negatively with age; hyperresponsive patterns correlated positively with repetitive behavior.
• High-expressing SERT genotypes were significantly associated with increased tactile hyperresponsiveness in the ASD group.

Conclusions:

• Genetic variations increasing SERT function may specifically affect somatosensory processing in individuals with ASD.
• SERT genetic polymorphisms represent potential biological markers for sensory symptoms in ASD.