Catechol O-Methyltransferase Polymorphism and Eye Tracking in Schizophrenia: A Preliminary Report

OBJECTIVE: This study examined associations between functional polymorphism (Val^108/158 Met) in the catechol O-methyltransferase (COMT) gene and eye tracking measures in schizophrenia. METHOD: Predictive pursuit and closed-loop gains of 62 patients with schizophrenia and 53 healthy comparison subjects with Val-Val, Val-Met, and Met-Met genotypes were compared. RESULTS: There was a significant diagnosis-by-genotype interaction: patients with the Met-Met genotype showed poor predictive pursuit. The Met-Met genotype in healthy subjects was associated with significantly higher predictive pursuit gain values than the Val-Val genotype in healthy subjects. The COMT genotype explained about 10% of the variance in each group’s predictive pursuit performance. DISCUSSION: These preliminary data suggest that the COMT gene is associated with predictive eye tracking performance in healthy subjects. Predictive pursuit abnormality in schizophrenia is not attributable to the Val allele. These findings suggest a complex interaction with other etiological factors (e.g., another gene), and/or with prefrontal cortical dopaminergic activity.