NO EVIDENCE FOR AN ASSOCIATION OF AFFECTIVE-DISORDERS WITH HIGH-ACTIVITY OR LOW-ACTIVITY ALLELE OF CATECHOL-O-METHYLTRANSFERASE GENE

Catechol-o-methyltransferase (COMT) is art enzyme that inactivates bio logically active or toxic catechols. Previous studies have yielded inc onsistent results on the relationship between erythrocyte COMT activit y and affective disorders. Recently an amino acid change (Val-108-Met) of the COMT protein was shown to determine high- and low-activity all eles of the enzyme. Using polymerase chain reaction and the restrictio n enzyme NLaIII, we genotyped 107 patients with bipolar disorder, 62 w ith unipolar depression, and 121 controls. Neither bipolar nor unipola r patients differ significantly in the genotypic or allelic frequency from the control group. Even when the bipolar and unipolar patients we re pooled into a single group, the distributions of both the genotypes and the alleles for the patient group were similar to those for the c ontrols. We conclude that genetic variation that determines high and l ow activities of COMT does not have a major effect on the vulnerabilit y to affective disorders in our sample. (C) 1997 Society of Biological Psychiatry.