COMT and GAD1 gene polymorphisms are associated with impaired antisaccade task performance in schizophrenic patients

Area of Science:

• Neurogenetics
• Cognitive Neuroscience
• Psychiatric Genetics

Background:

• Executive functions rely on prefrontal cortex systems.
• Dopamine and GABA neurotransmission are key in prefrontal cortex function.
• Genetic variations in COMT and GAD1 genes are implicated in these pathways.

Purpose of the Study:

• Investigate the impact of COMT (rs4680) and GAD1 (rs3749034) gene polymorphisms on antisaccade performance.
• Examine these genetic influences in both healthy subjects and individuals with schizophrenia.
• Determine if genetic factors enhance diagnostic models for schizophrenia based on antisaccade measures.

Main Methods:

• Genotyping of 141 male subjects for COMT Val158/Met (rs4680) and GAD1 rs3749034 (C/T) polymorphisms.
• Assessed antisaccade (AS) performance, including error rates and latency.
• Analyzed genetic effects on AS measures in healthy controls and schizophrenic patients.
• Employed binary logistic regression to evaluate diagnostic model validity.

Main Results:

• Schizophrenic patients showed higher AS error rates, longer latencies, and increased latency variability compared to controls.
• A trend towards reduced COMT Val/Met heterozygotes and increased GAD1 rs3749034 C allele frequency was observed in patients.
• COMT genotype influenced latency variability in patients (Val homozygotes > Met carriers).
• GAD1 rs3749034 affected error rates (T carriers > C homozygotes) and latency (C homozygotes > T carriers) in patients.
• Including genotype significantly improved the diagnostic model's validity.

Conclusions:

• Specific genetic variations in COMT and GAD1 are associated with prefrontal cortex dysfunction in schizophrenia.
• These genetic polymorphisms significantly impact executive functions, specifically antisaccade performance, in patients.
• Genetic profiling can enhance the diagnostic accuracy of schizophrenia based on cognitive measures.