From the Guidelines
The COMT Val/Val genotype does not result in slower breakdown of catecholamines, but rather the opposite, as the valine allele of COMT is associated with lower concentrations of cortical dopamine due to its role in the enzymatic breakdown of catecholamines such as dopamine, epinephrine, and norepinephrine 1.
Key Points
- The COMT Val158Met polymorphism is understood to decrease the availability of dopamine and detrimentally affect neurotransmission and, consequently, aspects of cognition such as executive functioning 1.
- The Val/Val genotype of COMT has been associated with poorer scores in attention, verbal fluency, and motor speed in patients with cancer, and is therefore a possible risk factor for cognitive impairment 1.
- Catechol-O-methyltransferase (COMT) plays an important role in the metabolism of catecholamines including dopamine, epinephrine, and norepinephrine, and its polymorphisms have been implicated in the risk of chemotherapy-induced cognitive impairment 1.
Relevance to Catecholamine Breakdown
- The evidence suggests that the COMT Val/Val genotype is associated with faster breakdown of catecholamines, leading to lower concentrations of cortical dopamine and impaired neurotransmission 1.
From the Research
Catechol-O-Methyltransferase (COMT) Val/Val Genotype and Catecholamine Breakdown
- The COMT Val/Val genotype is associated with higher dopamine metabolism, resulting in reduced dopamine transmission 2.
- The Val/Val variant of the enzyme has higher enzymatic activity compared to the Met-containing variant, which confers a marked reduction in COMT catalytic activity 3.
- The COMT Val158Met polymorphism affects the breakdown of catecholamines, with the Val allele resulting in 40% greater enzymatic activity than the Met allele 4.
Effect of COMT Val/Val Genotype on Catecholamine Breakdown
- The Val/Val genotype results in higher dopamine metabolism, which could lead to faster breakdown of catecholamines 2.
- However, the relationship between COMT genotype and catecholamine breakdown is complex and may be influenced by other factors, such as methionine sulphoxide reductase activity 3.
- The COMT Val/Val genotype has been associated with differential response to certain antidepressant medications, such as mirtazapine, which may be related to its effect on catecholamine breakdown 5.
Summary of Findings
- The COMT Val/Val genotype is associated with higher enzymatic activity and faster breakdown of catecholamines 2, 3, 4.
- The relationship between COMT genotype and catecholamine breakdown is complex and may be influenced by other factors 3, 5.
- Further research is needed to fully understand the effects of the COMT Val/Val genotype on catecholamine breakdown and its implications for human health and disease 2, 3, 6, 5, 4.