COMT and schizophrenia: The genotypic distributions of the three genotypes in the COMT genes are as follows: healthy controls, Met/Met 5 (8.3%), Val/Met 25 (41.7%), Val/Val 30 (50.0%); patients with schizophrenia, Met/Met 4 (8.9%), Val/Met 21(46.7%), Val/Val 20 (44.4%).