BACKGROUND Catecholamine-O-methyl-tranferase (COMT) initiates dopamine degradation. Its activity is mainly determined by a single nucleotide polymorphism in the COMT gene (Val158Met, rs4680) separating high (Val/Val, COMT(HH)), intermediate (Val/Met, COMT(HL)) and low metabolizers (Met/Met, COMT(LL)). We investigated dopaminergic denervation in the striatum in PD patients according to COMT rs46...

Evidence suggests that dopamine levels in the prefrontal cortex (PFC) modulate executive functions. A key regulator of PFC dopamine is catechol-O-methyltransferase (COMT). The activity level of the COMT enzyme are influenced by sex and the Val158Met polymorphism (rs4680) of the COMT gene, with male sex and Val alleles both being associated with higher bulk enzyme activity, and presumably lower ...

Little is known about the genetic factors modulating the progression of Huntington's disease (HD). Dopamine levels are affected in HD and modulate executive functions, the main cognitive disorder of HD. We investigated whether the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, which influences dopamine (DA) degradation, affects clinical progression in HD. We carried out...

BACKGROUND Alzheimer's disease (AD) is the leading cause of dementia worldwide and is associated with individual, familial and social burdens. Catechol-O-methyltransferase (COMT) may have a prominent role in AD pathophysiology by affecting the metabolism of catecholamine neurotransmitters and estrogen. Although the COMT rs4680 gene polymorphism has been investigated as a susceptibility factor f...

Sex steroids are of profound importance for several physiological processes including reproduction, growth, and maintenance of skeletal integrity. Serum levels of sex steroids are associated with bone mineral density (BMD) and have been shown to be predictive of fracture risk in older people. Sex steroid levels in serum, and also BMD and fracture risk, are under genetic control. Catechol-O-meth...

OBJECTIVES Dopamine neurotransmission is a critical factor for executive function, which is controlled by the prefrontal cortex in humans. Although the contribution of genetic factors to the regulation of brain dopaminergic activity is widely acknowledged, identification of a genotype-phenotype association has not yet been clearly established. In this study, we therefore evaluated the effects o...

BACKGROUND Cognitive deficits such as poor selective attention and executive functions decline have been reported in patients with schizophrenia. Many studies have emphasized the role of dopamine in regulating cognitive functions in the general population as well as in schizophrenia. However, the relationship between cognitive processes, schizophrenia and dopaminergic candidate genes is an orig...

The catechol-O-methyltransferase (COMT) gene is considered as a candidate gene in obsessive-compulsive disorder (OCD). Specifically, the COMT low-activity M158 allele has been suggested to be associated with OCD. However, there is no study reporting that COMT activity is decreased in OCD patients and that the decrease is mediated by the V158M polymorphism. Therefore, the purpose of our study wa...

There have been several reports on the association between the Val(158)Met genetic polymorphism of the catechol-O-methyltransferase (COMT) gene, as well as the serotonin transporter-linked polymorphic region (5-HTTLPR) of the serotonin transporter gene (SLC6A4), and frontolimbic region volumes, which have been suggested to underlie individual differences in emotion processing or susceptibility ...

The present study was aimed to investigate the modulatory role of plasma folate and eight putatively functional polymorphisms of one-carbon metabolism on catecholamine methyltransferase (COMT)-mediated oxidative DNA damage and breast cancer risk. Plasma folate and 8-oxo-2'-deoxyguanosine (8-oxodG) were estimated by commercially available kits, while polymorphisms were screened by PCR-RFLP and P...