Association between homozygosity at the COMT gene locus and obsessive compulsive disorder

A functional polymorphism in the coding region of the catechol O-methyltran sferase (COMT) gene has been reported in previous studies to be associated with obsessive compulsive disorder (OCD), particularly in males [Karayiorgo u et al,, 1997, 1999], Using a family-based population analysis, we attempt ed to replicate these findings in a group of 72 OCD patient/parent trios co llected from Buffalo, New York, and Toronto, Canada, Analysis of allele and genotype frequencies using the haplotype relative risk (HRR) and transmiss ion disequilibrium test (TDT) did not identify an association between a par ticular allele and OCD as had been previously reported. Furthermore, no evi dence was found to support the findings of a gender-based association for C OMT when the patients and the parents of the same gender were compared, How ever, our genotype results (n = 72) demonstrate a tendency for association between homozygosity at the COMT locus and OCD (homozygosity analysis: chi (2) = 5.66, P = 0.017; genotypic analysis: chi (2) = 5.78, P = 0.056), Alth ough these findings do not replicate the previous reports, they do provide limited support to demonstrate a trend for homozygosity at the COMT locus i n the OCD patients and, in turn, further implicate a potential role for COM T in the genetic etiology of OCD, (C) 2000 Wiley-Liss, Inc.