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...

Higher brain dopamine content depending on lower activity of Catechol-O-Methyltransferase (COMT) in subjects with high hypnotizability scores (highs) has been considered responsible for their attentional characteristics. However, the results of the previous genetic studies on association between hypnotizability and the COMT single nucleotide polymorphism (SNP) rs4680 (Val(158)Met) were inconsis...

Cognitive performance in healthy individuals is associated with gender differences in specific tests; a female advantage has been demonstrated in language tests, whereas a male advantage has been demonstrated in spatial relation examinations. The prefrontal cortex (PFC) mediates important cognitive domains and is influenced by dopamine (DA) activity. The single nucleotide polymorphism (SNP) rs4...

Objective The current study aimed to explore the association of single nucleotide polymorphisms (SNPs) within catechol-O-methyltransferase (COMT) and dopamine receptors with schizophrenia and genetic association with risperidone treatment response. Methods A total of 690 schizophrenic patients (case group) were selected and 430 healthy people were included as the controls. All patients receiv...

The Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene may be related to individual differences in cognition, likely via modulation of prefrontal dopamine catabolism. However, the available studies have yielded mixed results, possibly in part because they do not consistently account for other genes that affect cognition. We hypothesized that COMT Met allele homozygosity, whi...

Human catechol-O-methyltransferase (COMT, EC 2.1.1.6) catalyzes the transfer of the methyl group to a variety of endogenous and exogenous catechol substrates using S-adenosyl-L-methionine as the methyl donor. This enzymatic O-methylation plays an important role in the inactivation of biologically-active and toxic catechols. A number of studies in recent years have sought to characterize the pol...

Bipolar II disorder (BP-II), characterized by recurrent dysregulation of mood, is a serious and chronic psychiatric illness. However, BP-II is commonly under-recognized, even in psychiatric settings. Because dopaminergic disturbance is thought to be involved in the development of bipolar disorder (BPD), it seems essential to investigate dopamine-related genes like the catechol-O-methyltransfera...

Preeclampsia is a leading cause of perinatal morbidity and mortality. This disorder is thought to be multifactorial in origin, with multiple genes, environmental and social factors, contributing to disease. One proposed mechanism is placental hypoxia-driven imbalances in angiogenic and anti-angiogenic factors, causing endothelial cell dysfunction. Catechol-O-methyltransferase (Comt)-deficient p...

BACKGROUND/AIM One of the risk factors for increasing psychotic disorders is the use of cannabis. It has been shown that the inactivation of dopamine and other catecholamines causes a common polymorphism generating substantial variations in COMT enzyme activity. We aimed to understand the role of cannabis in the etiology of schizophrenia with and without pre-morbid usage. PATIENTS AND METHODS...

A functional catechol-o-methyltransferase (COMT Val158/108Met) polymorphism, a valine (Val) to methionine (Met) substitution, has been associated with cognitive processing in the normal brain, older age, mild cognitive impairment and in various dementias. COMT is involved in the breakdown of dopamine and other catecholamines, especially in the frontal cortex; hence the carriers of Met allele, w...