Catechol-0-methyltransferase (COMT) catalyzes the transfer of a methyl group from S-adenosylmethionin to catecholamines, including the neurotransmitters dopamine, noradrenaline, adrenaline [1].

The human COMT gene is found at chromosome 22, band q11.2 and consists of 6 exons [2]. A single G→A base pair change in exon 4 of the COMT gene results in valine→methionin amino acid change at codon 158 of membrane bound COMT (MB-COMT) and codon 108 of soluble COMT (S-COMT). This change (Val158/108Met) is associated with 3-4-fold lower enzymatic activity of COMT [3].

Approximately 25% of Caucasians are homozygous for the high activity allele (COMT*H), another 25% are homozygous for the low activity allele (COMT*L), and the remaining half exhibit heterozygous COMT*H/*L genotypes, associated with intermediate enzyme activity [4]. There are, however, marked racial differences in the genetically determined COMT activity. The frequency of COMT*L/*L genotype is about 6% only in the East Asian populations [5].

Some recent studies reported an association between the Val158/108Met polymorphism of the COMT gene and different psychiatric disorders: schizophrenia [6, 7], bipolar affective disorder [8], depression [9], panic disorder [10, 11]. Moreother, several studies have also reported associations between the COMT gene and both out-directed [3, 12, 13, 14] and self-directed [15] aggression in schizophrenic and schizoaffective patients.

So, common genetic mechanism is likely to predispose to different mental disease and such behavior disorders as aggressive behavior.

In this study we addressed further the possible role of the COMT gene in the risk of schizophrenia and aggressive behavior in population from Russia.