COMT and schizophrenia: The candidate-gene approach has been used in several molecular studies on schizophrenia, which focus on genes that encode for proteins associated with schizophrenia pathophysiology, such as neurotransmitter dopamine (catechol-O-methyl transferase [COMT]), Ras association domain family member 1 (RASSF1) and glycoprotein M6A (GPM6A) genes (10).