CYP2D6 and schizophrenia: We identified three different genotypes: the SNP genotype with the AL-2 allele (CYP2D6*4) and without the functional AL-1 allele, which indicates a slow metabolizer; the CYP2D6*WT genotype, found in the majority of our pediatric patients with schizophrenia, has extensive metabolic activity, carrying the functional AL-1 allele; and last, we identified the WT/4* genotype in about 27% of the patients, which has intermediate metabolism, carrying a functional allele (WT) and a nonfunctional allele (*4).