Further studies are required to better understand the association of symptomatology of schizophrenia and other psychiatric disorders with COMT gene polymorphism.
The Val158Met polymorphism of the gene encoding catechol-O-methyltransferase (COMT) is one of the most widely tested variants for association with psychiatric disorders, but replication has been inconsistent including both sex limitation and heterogeneity of the associated allele.
A variation in catechol-O-methyltransferase (COMT) gene (Val(108/158)Met) affects the physiological response of hippocampal-prefrontal circuits, predicts variation in human memory and is associated with increased risk for psychiatric disorders.
The ValMet polymorphism of the COMT gene shows a complex relation to behavior problems, influencing conduct disorder and ADHD symptoms in opposite directions in a high-risk population.
High COMT activity in women with depression is apparent mainly in patients whose first and second degree relatives revealed psychiatric disturbances, particularly affective disorders.
We then examined genetic polymorphisms in four candidate genes (DRD4, DAT, COMT and MAOA) that have been shown to contribute to the risk of developing various psychiatric disorders where attention is disrupted.
The involvement of the COMT gene in the metabolic pathway of these neurotransmitters has made it an attractive candidate gene for many psychiatric disorders.
The present study appears to be the first comprehensive meta-analysis of COMT genetic association studies to cover all psychiatric disorders for which there were available data, published in any language, and with an emphasis on investigating disorder subtypes (defined clinically or by demographic or other variables).
On the other hand, preferential transmission of COMTrs4680 A allele and A-A haplotype (P<0.05) was observed specifically in male IID probands without any behavioral problem.
Catechol O-methyltransferase (COMT) has been associated with aggression, attention deficit/hyperactivity disorder (ADHD), and other psychiatric disorders.
Catechol-O-methyltransferase (COMT): a gene contributing to sex differences in brain function, and to sexual dimorphism in the predisposition to psychiatric disorders.
These preliminary data suggest that low COMT activity may affect dopamine levels in striatum in humans and this may have implications for understanding the contribution of COMT activity to psychiatric disorders.
The identification of candidate genes for heart anomalies, mental illness, and other clinical phenotypes has been reported in the past year with a focus on TBX1 for cardiac and craniofacial phenotypes and COMT and PRODH for psychiatric disorders.
Further research with larger samples is needed to explore the interactions of the COMT gene rs4680 polymorphism and sex and psychiatric disorders on suicide attempts.
Catechol-O-methyltransferase (COMT) is one of the major mammalian enzymes involved in the metabolic degradation of catecholamines and is considered a candidate for several psychiatric disorders and symptoms, including the psychopathology associated with the 22q11 microdeletion syndrome.
Among the genes in the deleted region, catechol-O-methyltransferase (COMT) has a particular relevance for psychiatric disorders: lower COMT enzymatic activity decreases the clearance of dopamine (DA), yielding higher levels of catecholamines in the central nervous system.
A common functional polymorphism that results in a three- to four-fold difference in catechol-O-methyltransferase (COMT) enzyme activity has been related to psychiatric disorders such as ultra-ultra rapid cycling bipolar disorder, drug abuse and alcoholism (Lachman et al., 1996a; Karayiorgou et al., 1997; Vandenbergh et al., 1997; Papolos et al., 1998; Tiihonen et al., 1999).
Specifically, the Val<sup>158</sup>Met polymorphism greatly alters COMT function and cognitive performance in both psychiatric disorders and healthy controls.