Association between a catechol-o-methyltransferase polymorphism and obsessive-compulsive disorder in the Afrikaner population

Background: It has been proposed that the catechol-o-methyl transferase gen e (COMT) may play a role in the pathogenesis of obsessive-compulsive disord er (OCD). Whereas studies in a North American population showed that the lo w activity (L) allele of a functional polymorphism in COMT was associated w ith OCD in malt: patients. this result was: not supported by studies in a J apanese population. The present association study assessed the risk for OCD conferred by this COMT polymorphism in a geographically different patient group, namely, the relatively genetically homogeneous Afrikaner population of South Africa. Methods: Fifty-four unrelated OCD patients and fifty-four sex-matched controls were recruited from the same Afrikaner community. Pati ents and controls were phenotyped (DSM-IV) and genotyped for a NlaIII polym orphism with H (high activity) or L (low activity) alleles in the COMT gene . Results: The H/L genotype was significantly more common than expected in the OCD patient group (P = 0.0017). Limitations: Replication studies with r elated individuals may be useful in discovering Factors underpinning the H/ L genotype abundance in the Afrikaner population. Conclusions: These result s emphasise the need for further studies in genetically homogeneous populat ions to help define the complex etiology of this disease. (C) 2001 Elsevier Science B.V. All rights reserved.