catechol-O-methyltransferase Val158Met Polymorphism Research Articles

Facial emotion recognition in schizophrenia: An exploratory study on the role of comorbid alcohol and substance use disorders and COMT Val158Met.

To explore whether facial emotion recognition (FER), impaired in both schizophrenia and alcohol and substance use disorders (AUDs/SUDs), is additionally compromised among comorbid subjects, also considering the role of catechol-O-methyltransferase (COMT) Val158Met. We conducted a cross-sectional study, randomly recruiting 67 subjects with a DSM-IV-TR diagnosis of schizophrenia, and rigorously assessing AUDs/SUDs and COMT Val158Met polymorphism. FER was assessed using the Ekman 60 Faces Test- EK-60F. As a whole, the sample scored significantly lower than normative data on EK-60F. However, subjects with comorbid AUDs/SUDs did not perform worse on EK-60F than those without, who had a better performance on EK-60F if they carried the COMT Val/Met variant. This study is the first to date examining the impact of AUDs/SUDs and COMT variants on FER in an epidemiologically representative sample of subjects with schizophrenia. Our findings do not suggest an additional impairment from comorbid AUDs/SUDs on FER among subjects with schizophrenia, whilst COMT Val158Met, though based on a limited sample, might have a role just among those without AUDs/SUDs. Based on our results, additional research is needed also exploring differential roles of various substances.

Sex-specific effects of COMT Val158Met polymorphism on corpus callosum structure: A whole-brain diffusion-weighted imaging study.

BackgroundGenetic polymorphisms play a significant role in determining brain morphology, including white matter structure and may thus influence the development of brain functions. The main objective of this study was to examine the effect of Val158Met (rs4680) polymorphism of Catechol‐O‐Methyltransferase (COMT) gene on white matter connectivity in healthy adults.MethodsWe used a whole‐brain diffusion‐weighted imaging method with Tract‐Based Spatial Statistics (TBSS) analysis to examine white matter structural integrity in intrinsic brain networks on a sample of healthy subjects (N = 82).ResultsResults revealed a sex‐specific effect of COMT on corpus callosum (CC): in males only, Val homozygotes had significantly higher fractional anisotropy (FA) compared to Met‐carriers. Volume‐of‐interest analysis showed a genotype by sex interaction on FA in genu and rostral midbody of CC, whereby Val males demonstrated higher FA than Met females.ConclusionsThese results demonstrate the key effect of genes by sex interaction, rather than their individual contribution, on the corpus callosum anatomy.

Prevalence of COMT Val158Met polymorphism in Eastern UP population.

Catechol-O-methyltransferase (COMT) is an abundant S-adenosylmethionine (SAM-)-dependent methyltransferase that methylates catechol compounds, including catecholamines and catecholestrogens.COMT gene located at chromosome 22q11.2 contains a functional polymorphism at codon 158(Val158Met), which has been related to psychiatric diseases and different types of cancer. COMT might affect tHcy levels because as a by-product it converts SAM to S-adenosylhomocysteine (SAH), which is reversibly converted to homocysteine. The aim of the present study was to determine the frequency of COMT Val158Met polymorphism in scheduled caste (SC) population of Jaunpur district. Total 100 healthy unrelated subjects belonging to SC, between the age group of 18 to70 years were randomly selected for the present study. 3 ml blood samples were collected from each subject. The inclusion criteria of subjects for present study are that they should be domicile of Uttar Pradesh, and healthy without any individual/ family history of genetic or metabolic disorders. COMT Val158Met polymorphism analysis was done by PCR-RFLP method. The Val/Val genotype was found in 48 subjects, Val/Met in 40 subjects and Met/Met genotype in 12 subjects. Genotype frequencies of Val/Val, Val/Met and Met/Met were 0.48, 0.40 and 0.12 respectively. The allele frequency of Val allele was found to be 0.68 and Met allele frequency was 0.32.

Association between Catechol-O-Methyltransferase Val158Met (158G/A) Polymorphism and Suicide Susceptibility: A Meta-analysis.

Common functional Val158Met polymorphism in the Catechol-O-methyltransferase (COMT) gene may have an impact on an individual's susceptibility to suicide, but individually published results are inconclusive. Therefore, we performed this meta-analysis to provide a more precise estimation of the association between COMT 158G/A (COMT Val158Met) polymorphism and suicide susceptibility. A cross-sectional study. This systematic review and meta-analysis is a comprehensive literature search of PubMed, Scopus, Web of Science and Google Scholar databases was conducted on case-control studies published up to Mar 2017. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. We identified 14 eligible case-control studies, including 2353 suicide attempters and 2593 controls. The pooled results indicated that COMT 158G/A (COMT Val158Met) polymorphism was not significantly associated with increased overall suicide risk. The same results were revealed based on ethnicity, Hardy-Weinberg equilibrium (HWE) status and genotyping technique. However, there was significant association between COMT Val158Met polymorphism and suicide risk among females under the homozygote (AA vs. GG: OR=1.829, 95% CI=1.158-2.889, P=0.010) and recessive (AA vs. AG +GG: OR = 1.787, 95% CI=1.195, 2.671, P=0.005) models, but not among males. COMT 158G/A (COMT Val158Met) polymorphism was associated with suicide susceptibility only in females.

Effect of catechol-O-methyltransferase Val158Met polymorphism on resting-state brain default mode network after acupuncture stimulation.

The effects of acupuncture can be characterized by clear individual differences. Several revealing studies suggest an underlying role of inherited genetic factor in interindividual variability in response to acupuncture treatment. It remains unclear, however, if the modulation of acupuncture on resting brain function is influenced by genetic factors. Catechol-o-methyltransferase (COMT) Val158Met polymorphism has been shown to regulate the resting brain network, especially in the default mode network (DMN), which is a target area that responds to acupuncture stimulation. Therefore, the present study investigated the effect of COMT Val158Met polymorphism on the modulation of acupuncture in DMN connectivity in healthy Chinese young adults. Using mixed-design ANOVA analysis, we found a significant interactive effect between acupuncture and the COMT gene. For subjects carrying the Val/Met genotype, acupuncture induced decreased DMN connectivity with the left middle frontal gyrus during the post-acupuncture stage compared with the pre-acupuncture stage, which was not observed in Val/Val homozygous subjects. These results demonstrated that during sustained periods after acupuncture stimulation, the brain network is likely under genetic control, and COMT might be a candidate gene that regulates the resting DMN response to acupuncture stimulation.

Association of Catechol-O-methyltransferase polymorphism Val158Met and mammographic density: A meta-analysis

ObjectivesThe Val158Met polymorphism in catechol-O-methyltransferase (COMT) enzyme reduces the methylation of catechol estrogens, which may affect mammographic density. High mammographic density is a known risk factor of breast cancer. Our aim was to perform meta-analysis of the effect of COMT Val158Met polymorphism on mammographic density. MethodsOriginal studies reporting data on mammographic density, stratified by the presence of COMT Val158Met polymorphism, were identified and combined using genetic models Met/Val vs. Val/Val, Met/Met vs. Val/Val, Val/Met+Met/Met vs. Val/Val (dominant model) and Met/Met vs. Val/Met+Val/Val (recessive model). Subgroup analyses by breast cancer status, menopausal status and use of hormone replacement therapy (HRT) were also performed. ResultsEight studies were included in the meta-analysis. The overall effect in percent mammographic density was −1.41 (CI −2.86 to 0.05; P=0.06) in the recessive model. Exclusion of breast cancer patients increased the effect size to −1.93 (CI −3.49 to −0.37; P=0.02). The results suggested opposite effect of COMT Val158Met for postmenopausal users of HRT versus premenopausal women or postmenopausal non-users of HRT. ConclusionsCOMT Val158Met polymorphism may be associated with mammographic density at least in healthy women. Menopausal status and HRT should be taken into account in future studies to avoid masking of the underlying effects.

The effect of COMT Val158Met and DRD2 C957T polymorphisms on executive function and the impact of early life stress.

IntroductionPrevious research has indicated that variation in genes encoding catechol‐O‐methyltransferase (COMT) and dopamine receptor D2 (DRD2) may influence cognitive function and that this may confer vulnerability to the development of mental health disorders such as schizophrenia. However, increasing evidence suggests environmental factors such as early life stress may interact with genetic variants in affecting these cognitive outcomes. This study investigated the effect of COMT Val158Met and DRD2 C957T polymorphisms on executive function and the impact of early life stress in healthy adults.MethodsOne hundred and twenty‐two healthy adult males (mean age 35.2 years, range 21–63) were enrolled in the study. Cognitive function was assessed using Cambridge Neuropsychological Test Automated Battery and early life stress was assessed using the Childhood Traumatic Events Scale (Pennebaker & Susman, 1988).Results DRD2 C957T was significantly associated with executive function, with CC homozygotes having significantly reduced performance in spatial working memory and spatial planning. A significant genotype–trauma interaction was found in Rapid Visual Information Processing test, a measure of sustained attention, with CC carriers who had experienced early life stress exhibiting impaired performance compared to the CC carriers without early life stressful experiences. There were no significant findings for COMT Val158Met.ConclusionsThis study supports previous findings that DRD2 C957T significantly affects performance on executive function related tasks in healthy individuals and shows for the first time that some of these effects may be mediated through the impact of childhood traumatic events. Future work should aim to clarify further the effect of stress on neuronal systems that are known to be vulnerable in mental health disorders and more specifically what the impact of this might be on cognitive function.

COMT Val158Met Polymorphism and Symptom Improvement Following a Cognitively Focused Intervention for Irritable Bowel Syndrome.

Our nurse-delivered comprehensive self-management (CSM) program, a cognitive behavioral therapy intervention, is effective in reducing gastrointestinal and psychological distress symptoms in patients with irritable bowel syndrome (IBS). Findings from non-IBS studies indicate that the catechol-O-methyltransferase (COMT) Val158Met polymorphism may moderate the efficacy of cognitive behavioral therapy. It is unknown whether this COMT polymorphism is associated with symptom improvements in patients with IBS. We tested whether this COMT Val158Met polymorphism influences the efficacy of our 2-month CSM intervention. We analyzed data from two published randomized controlled trials of CSM. The combined European American sample included 149 women and 23 men with IBS (CSM, n = 111; usual care [UC], n = 61). The primary outcomes were daily reports of abdominal pain, depression, anxiety, and feeling stressed measured 3 and 6 months after randomization. Secondary outcomes were additional daily symptoms, retrospective psychological distress, IBS quality of life, and cognitive beliefs about IBS. The interaction between COMT Val158Met polymorphism and treatment group (CSM vs. UC) in a generalized estimating equation model tested the main objective. At 3 months, participants with at least one Val allele benefited more from CSM than did those with the Met/Met genotype (p = .01 for anxiety and feeling stressed, and p < .16 for abdominal pain and depression). The moderating effect of genotype was weaker at 6 months. Persons with at least one Val allele may benefit more from CSM than those homozygous for the Met allele. Future studies with larger and more racially diverse samples are needed to confirm these findings. Parent studies were registered at ClinicalTrials.gov (NCT00167635 and NCT00907790).

COMT and BDNF Gene Variants Help to Predict Alcohol Consumption in Alcohol-dependent Patients.

The neurobiology of alcohol dependence (AD) involves alterations in neurotransmitters and the stress response. We hypothesized that an interaction between functional variants of dopaminergic and neurotrophic genes may influence drinking in AD. The relationship between alcohol consumption and single-nucleotide polymorphisms, Val66Met in the brain-derived neurotrophic factor (BDNF), and Val158Met in the catechol-O-methyltransferase (COMT), was analyzed among 281 alcohol-dependent individuals. Individuals carrying both the COMT Met158Met genotype and the BDNF Val66Val genotype drank more than those with other variants of these genes (P = 0.039). Those who had a family history of AD also drank more than those without a family history (P = 0.048). Patients with both Met/Met genotype in the COMT Val158Met polymorphism and Val/Val genotype in the BDNF Val66Met polymorphism suffered from more health problems than those carrying other variants (P = 0.030) and had lower motivation to change drinking patterns (P = 0.031). Patients carrying both the BDNF Val66Val and COMT Met158Met variants had higher alcohol consumption. These effects may be influenced by the effects of BDNF and COMT on dopamine responses to alcohol. Motivation-enhancing strategies might benefit the group of patients identified by genotyping in this study, and also treatment aimed at reducing alcohol consumption.

COMT Val158Met polymorphism moderates the association between PTSD symptom severity and hippocampal volume.

Memory-based alterations are among the hallmark symptoms of posttraumatic stress disorder (PTSD) and may be associated with the integrity of the hippocampus. However, neuroimaging studies of hippocampal volume in individuals with PTSD have yielded inconsistent results, raising the possibility that various moderators, such as genetic factors, may influence this association. We examined whether the catechol-O-methyltransferase (COMT) Val158Met polymorphism, which has previously been shown to be associated with hippocampal volume in healthy individuals, moderates the association between PTSD and hippocampal volume. Recent war veterans underwent structural MRI on a 3 T scanner. We extracted volumes of the right and left hippocampus using FreeSurfer and adjusted them for individual differences in intracranial volume. We assessed PTSD severity using the Clinician-Administered PTSD Scale. Hierarchical linear regression was used to model the genotype (Val158Met polymorphism) × PTSD severity interaction and its association with hippocampal volume. We included 146 white, non-Hispanic recent war veterans (90% male, 53% with diagnosed PTSD) in our analyses. A significant genotype × PTSD symptom severity interaction emerged such that individuals with greater current PTSD symptom severity who were homozygous for the Val allele showed significant reductions in left hippocampal volume. The direction of proposed effects is unknown, thus precluding definitive assessment of whether differences in hippocampal volume reflect a consequence of PTSD, a pre-existing characteristic, or both. Our findings suggest that the COMT polymorphism moderates the association between PTSD and hippocampal volume. These results highlight the role that the dopaminergic system has in brain structure and suggest a possible mechanism for memory disturbance in individuals with PTSD.

Executive control in schizophrenia: a preliminary study on the moderating role of COMT Val158Met for comorbid alcohol and substance use disorders

Background: A functional polymorphism in the catechol-O-methyltransferase (COMT) gene (Val158Met) appears to influence cognition in people with alcohol/substance use disorders (AUD/SUD) and in those with psychosis.Methods: To explore the potential moderating effect of these factors, a cross-sectional study was conducted, randomly recruiting subjects with DSM-IV diagnosis of schizophrenia. AUD/SUD was rigorously assessed, as well as COMT Val158Met polymorphism. Executive control functioning was measured using the Intra-Extra Dimensional Set Shift (IED). The effect of a possible interaction between comorbid AUD/SUD and COMT Val158Met polymorphism on IED scores was explored.Results: Subjects with schizophrenia, comorbid AUD/SUD, and MetMet carriers for SNP rs4680 of the COMT gene showed worse performance on IED completed stages scores, as compared with individuals with ValVal genotype. However, among subjects without AUD/SUD, those with the MetMet variant performed better than people carrying ValVal genotype.Conclusions: This study is the first to date examining the impact of COMT on cognition in a highly representative sample of people with schizophrenia and comorbid AUD/SUD. Differential moderating effects of COMT Val/Met genotype variations may similarly influence executive functions in people with schizophrenia and comorbid AUD/SUD.

The COMT Val158Met Polymorphism Is Associated With Response to Add-on Dextromethorphan Treatment in Bipolar Disorder.

We previously conducted a randomized, double-blind, controlled, 12-week study evaluating the effect of add-on dextromethorphan (DM), a noncompetitive N-methyl-D-aspartate receptor antagonist, on patients with bipolar disorder (BD) treated using valproate (VPA), which showed negative clinical differences. The genetic variation between each individual may be responsible for interindividual differences. The catechol-O-methyltransferase (COMT) gene has been a candidate gene for BD. In the current study, we investigated whether the COMT Val158Met polymorphism predicts treatment response to VPA + add-on DM and to VPA + placebo. Patients with BD (n = 309) undergoing regular VPA treatments were randomly assigned to groups given either add-on DM (30 mg/d) (n = 102), DM (60 mg/d) (n = 101), or placebo (n = 106) for 12 weeks. The Hamilton Depression Rating Scale and Young Mania Rating Scale were used to evaluate clinical response during weeks 0, 1, 2, 4, 8, and 12. The genotypes of the COMT Val158Met polymorphism were determined using polymerase chain reaction plus restriction fragment length polymorphism analysis. To adjust for within-subject dependence over repeated assessments, multiple linear regression with generalized estimating equation methods was used. When stratified by the COMT Val158Met genotypes, significantly greater decreases in Hamilton Depression Rating Scale scores were found in the VPA + DM (30 mg/d) group in patients with the Val/Met genotype (P = 0.008). We conclude that the COMT Val158Met polymorphism may influence responses to DM (30 mg/d) by decreasing depressive symptoms in BD patients.

Catechol-O-methyltransferase Gene Polymorphism (Val158Met) and Development of Pre-eclampsia

Catechol-O-methyltransferase (COMT) is a key enzyme in degradation pathways of estrogens and catecholamines. The present meta-analysis was done to elucidate the association of COMT Val158Met polymorphism with pre-eclampsia among pregnant women. A literature search was conducted in electronic databases including PubMed, Scopus, Elsevier, Springer and Google Scholar to find eligible studies. The pooled odds ratios (ORs) with 95% confidence intervals were calculated under dominant, recessive, co-dominant, and allelic models. This meta-analysis included 6 eligible studies consisting 2596 cases and 4223 controls. The ORs for the COMT G472A polymorphism and pre-eclampsia were indicative of positive association under several genetic models. The results indicated that COMT Val158Met polymorphism was significantly associated with the increased riskof pre-eclampsia in recessive model (AA vs. AG+GG: OR=1.522 [95% CI:1.089-2.127]; p=0.014), co-dominant model (AA vs. GG: OR=1.605 [95% CI: 1.102-2.336]; p=0.014), and allelic model (A vs. T: OR=1.200 [95% CI: 1.021-1.402]; p=0.021). In summary, COMT Val158Met polymorphism is positively associated with the increased risk of pre-eclampsia among pregnant women, especially the homozygous carriers. It could be of value to investigate its association with pre-eclampsia in combination with additional risk factors. However, very large studies with different ethnic population are required to accurately demonstrate the role of this candidate gene in development of pre-eclampsia.

Stressful life events and catechol-O-methyl-transferase (COMT) gene in bipolar disorder.

A small body of research suggests that gene-environment interactions play an important role in the development of bipolar disorder. The aim of the present study is to contribute to this work by exploring the relationship between stressful life events and the catechol-O-methyl-transferase (COMT) Val158 Met polymorphism in bipolar disorder. Four hundred eighty-two bipolar cases and 205 psychiatrically healthy controls completed the List of Threatening Experiences Questionnaire. Bipolar cases reported the events experienced 6 months before their worst depressive and manic episodes; controls reported those events experienced 6 months prior to their interview. The genotypic information for the COMT Val158 Met variant (rs4680) was extracted from GWAS analysis of the sample. The impact of stressful life events was moderated by the COMT genotype for the worst depressive episode using a Val dominant model (adjusted risk difference = 0.09, 95% confidence intervals = 0.003-0.18, P = .04). For the worst manic episodes no significant interactions between COMT and stressful life events were detected. This is the first study to explore the relationship between stressful life events and the COMT Val158 Met polymorphism focusing solely on bipolar disorder. The results of this study highlight the importance of the interplay between genetic and environmental factors for bipolar depression.

Impact of Catechol-O-Methyltransferase Val 158Met (rs4680) Polymorphism on Breast Cancer Susceptibility in Asian Population

Background:Catechol-O-methyltransferase (COMT) is an important estrogen-metabolizing enzyme. Numerous case-control studies have evaluated the role COMT Val 158Met (rs4680;472G->A) polymorphism in the risk of breast cancer and provided inconclusive results, hence present meta-analysis was designed to get a more reliable assessment in Asian population.Methods:A total of 26 articles were identified through a search of four electronic databases-PubMed, Google Scholar, Science Direct and Springer link, up to March, 2016. Pooled odds ratios (ORs) with 95% con¬fidence intervals (CIs) were used as association measure to find out relationship between COMT Val158Metpolymorphism and the risk of breast cancer. We also assessed between study heterogeneity and publication bias. All statistical analyses were done by Open Meta-Analyst.Results:Twenty six case-control studies involving 5,971 breast cancer patients and 7,253 controls were included in the present meta-analysis. The results showed that the COMT Val158Met polymorphism was significantly associated with breast cancer risk except heterozygote model(allele contrast odds ratio (ORAvsG)= 1.13, 95%CI=1.02-1.24,p=0.01; heterozygote/co-dominant ORGAvsGG= 1.03, 95%CI=0.96-1.11,p=0.34; homozygote ORAAvsGG= 1.38, 95%CI= 1.08-1.76,p=0.009; dominant model ORAA+GAvsGG= 1.08, 95%CI=1.01-1.16,p=0.02; and recessive model ORAAvsGA+GG= 1.35, 95%CI=1.07-1.71,p=0.01). In addition, we also performed subgroup analysis based on source of controls and menopausal state of patients.Conclusions:In conclusion, the COMT Val158Met polymorphism was related to increased breast cancer susceptibility in the Asian population.

The effects on resting state EEG activity of the catechol-O-methyltransferase (COMT) Val158Met rs4680 polymorphism, and the relationship to schizotypy

Event Abstract Back to Event The effects on resting state EEG activity of the catechol-O-methyltransferase (COMT) Val158Met rs4680 polymorphism, and the relationship to schizotypy Madilyn Coles1*, Genevieve Z. Steiner1, 2, Francesca Fernandez3, 4, 5, Diana Karamacoska2, Emma Barkus2, 3, Samantha Broyd2, 3, Nadia Solowij2, 3, Christine Chiu6, Joanne Lind6 and Robert J. Barry2 1 Western Sydney University, NICM, Australia 2 Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, Australia 3 Illawarra Health and Medical Research Institute and Faculty of Science, Medicine and Health, University of Wollongong, Australia 4 Schizophrenia Research Institute, Australia 5 School of Science, Australian Catholic University, Australia 6 Macquarie University, Faculty of Medicine & Health Sciences, Australia Aims: Schizophrenia, at the clinical end of the schizotypy spectrum, is characterised by abnormal electroencephalogram (EEG) profiles and dopamine dysregulation. The gene encoding the dopamine degrading enzyme catechol-O-methyltransferase (COMT) is thought to be a schizophrenia spectrum disorder susceptibility gene, with the Val variant (cf. Met) identified as the primary risk allele. To date, few studies have investigated the link between schizotypy, EEG activity, and the COMT Val158Met polymorphism; this is the aim of this present study. Methods: Ninety-one healthy participants (Mean age = 21.4, SD = 5.0 years) had 4 minutes eyes-open resting state EEG activity recorded, were genotyped for the COMT rs4680 polymorphism (Val/Val, Val/Met, and Met/Met), and completed the Schizotypal Personality Questionnaire (SPQ; a 74-item true or false self-report); different facets of schizotypy were assessed. Results: Participant genotypes was represented as 22 % Val/Val, 44 % Val/Met, and 34 % Met/Met. Suspiciousness SPQ sub-scale scores were significantly lower for Val/Met genotype individuals compared to homozygous Val/Val and Met/Met genotypes. Val/Val genotype individuals showed reduced parietal delta, fronto-midline theta, parieto-midline alpha-2, fronto-midline beta-1 amplitudes, and reduced midline beta-2 (cf. Met/Met genotype individuals). Stepwise multiple regression showed that higher levels of delta, and lower levels of theta and beta-2 predicted 11.4 % unique variance in total SPQ scores. Conclusions: Findings indicate the importance of COMT in determining EEG oscillatory activity and trait suspiciousness, and suggest that neurophysiological function may serve as an intermediate between trait schizotypy and COMT-related differences in dopaminergic transmission. Results from theta and beta activity in this study contradict some patterns observed in schizophrenia, thus future studies should seek to replicate these COMT and EEG related findings in clinical groups. Keywords: Electroencephalograph (EEG), COMT, schizotypy, Schizophrenia, Dopamine Conference: ASP2017: 27th Annual Meeting for the Australasian Society for Psychophysiology, Parramatta, Australia, 29 Nov - 1 Dec, 2017. Presentation Type: Oral Presentation Topic: Abstract (Student Award) Citation: Coles M, Steiner GZ, Fernandez F, Karamacoska D, Barkus E, Broyd S, Solowij N, Chiu C, Lind J and Barry RJ (2019). The effects on resting state EEG activity of the catechol-O-methyltransferase (COMT) Val158Met rs4680 polymorphism, and the relationship to schizotypy. Conference Abstract: ASP2017: 27th Annual Meeting for the Australasian Society for Psychophysiology. doi: 10.3389/conf.fnhum.2017.224.00002 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Oct 2017; Published Online: 25 Jan 2019. * Correspondence: Miss. Madilyn Coles, Western Sydney University, NICM, Penrith, NSW, 2751, Australia, 18353479@student.westernsydney.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Madilyn Coles Genevieve Z Steiner Francesca Fernandez Diana Karamacoska Emma Barkus Samantha Broyd Nadia Solowij Christine Chiu Joanne Lind Robert J Barry Google Madilyn Coles Genevieve Z Steiner Francesca Fernandez Diana Karamacoska Emma Barkus Samantha Broyd Nadia Solowij Christine Chiu Joanne Lind Robert J Barry Google Scholar Madilyn Coles Genevieve Z Steiner Francesca Fernandez Diana Karamacoska Emma Barkus Samantha Broyd Nadia Solowij Christine Chiu Joanne Lind Robert J Barry PubMed Madilyn Coles Genevieve Z Steiner Francesca Fernandez Diana Karamacoska Emma Barkus Samantha Broyd Nadia Solowij Christine Chiu Joanne Lind Robert J Barry Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Association between COMT genotype and the control of memory guided saccades: Individual differences in healthy adults reveal a detrimental role of dopamine

The neural circuits involved in oculomotor control are well described; however, neuromodulation of eye movements is still hardly understood. Memory guided saccades have been extensively studied and in particular neurophysiological evidence from monkey studies points to a crucial functional role of prefrontal dopamine activity. We exploited individual differences in dopamine regulation due to the well established COMT (catechol-O-methyltransferase) Val158Met polymorphism to explore the link between prefrontal dopamine activity and memory guided saccades in healthy subjects. The COMT genotype is thought to modulate dopamine metabolism in prefrontal cortex producing differences in dopamine availability. We investigated memory guided saccades in 111 healthy subjects and determined individual genotypes. Accuracy and precision were reduced in subjects with putatively higher prefrontal dopamine levels. In contrast, we found no modulation of saccade parameters by genotype in a visually guided control task. Our results suggest that increased dopamine activity can have a detrimental effect on saccades that rely on spatial memory representations. Although these findings await replication in larger and more diverse sample sizes, they provide persuasive support that specific oculomotor parameters are sensitive to dopaminergic variation in healthy subjects and add to a better understanding of how dopamine modulates saccadic control.

The impacts of Val158Met in Catechol-O-methyltransferase (COMT) gene on moral permissibility and empathic concern

Dopamine levels in the brain influence emotional experiences and empathic responses to others' misfortune. Inspired by roles of Catechol-O-methyltransferase (COMT) in dopamine degradation and the link between moral judgment and empathic responses, this study investigated to what extent the Val158Met polymorphism of COMT gene contributes to individual differences in moral permissibility and empathic dispositions. One thousand two hundred and seventy-two Chinese Han college students, who were differentiated with the COMT Val158Met (rs4680) polymorphism, rated permissibility of harm in moral dilemmas and scored their empathic dispositions with Interpersonal Reactivity Index. The results showed a significant association between COMT Val158Met and the moral permissibility of committing harm. Individuals with the Val/Val genotype, which is associated with lower levels of dopamine, endorsed impersonal harm as more impermissible than those with the Val/Met and Met/Met genotypes. Results also showed that individuals with the Val/Val genotype showed higher empathic concern for others' misfortune. The findings provide the first evidence for the link between COMT gene and the moral permissibility, highlighting the roles of dopamine in social cognition.

COMT Val158Met polymorphism is associated with post-traumatic stress disorder and functional outcome following mild traumatic brain injury

Mild traumatic brain injury (mTBI) results in variable clinical trajectories and outcomes. The source of variability remains unclear, but may involve genetic variations, such as single nucleotide polymorphisms (SNPs). A SNP in catechol-o-methyltransferase (COMT) is suggested to influence development of post-traumatic stress disorder (PTSD), but its role in TBI remains unclear. Here, we utilize the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study to investigate whether the COMT Val158Met polymorphism is associated with PTSD and global functional outcome as measured by the PTSD Checklist – Civilian Version and Glasgow Outcome Scale Extended (GOSE), respectively. Results in 93 predominately Caucasian subjects with mTBI show that the COMT Met158 allele is associated with lower incidence of PTSD (univariate odds ratio (OR) of 0.25, 95% CI [0.09–0.69]) and higher GOSE scores (univariate OR 2.87, 95% CI [1.20–6.86]) 6-months following injury. The COMT Val158Met genotype and PTSD association persists after controlling for race (multivariable OR of 0.29, 95% CI [0.10–0.83]) and pre-existing psychiatric disorders/substance abuse (multivariable OR of 0.32, 95% CI [0.11–0.97]). PTSD emerged as a strong predictor of poorer outcome on GOSE (multivariable OR 0.09, 95% CI [0.03–0.26]), which persists after controlling for age, GCS, and race. When accounting for PTSD in multivariable analysis, the association of COMT genotype and GOSE did not remain significant (multivariable OR 1.73, 95% CI [0.69–4.35]). Whether COMT genotype indirectly influences global functional outcome through PTSD remains to be determined and larger studies in more diverse populations are needed to confirm these findings.

Prefrontal Volume Mediates Effect of COMT Polymorphism on Interference Resolution Capacity in Healthy Male Adults.

There exist gender differences in the modulation of catechol-O-methyltransferase (COMT) Val158Met polymorphism on cognitive performance; however, the underlying gene-anatomy-cognition pathways remain unknown. Here we hypothesize that prefrontal volume may mediate the modulation of COMT Val158Met polymorphism on interference resolution capacity in a gender-dependent manner. In 261 healthy young human subjects (143 males and 118 females), a 2-way analysis of variance showed a COMT × gender interaction (P=0.023) on interference resolution capacity. Val/Val subjects performed worse in Stroop interference test than Met/Met subjects only in males (P=0.028). Voxel-wise analysis in the whole brain also exhibited a COMT × gender interaction on gray matter volume (GMV) in the left lateral frontal pole (FP). Val/Val male individuals exhibited significantly decreased GMV in the left lateral FP than Val/Met (P=0.003) and Met/Met (P=0.006) male carriers. Mediation analysis revealed that the GMV of the left lateral FP mediated the association between COMT polymorphism and interference resolution in males. These findings provide a gene-anatomy-cognition pathway to describe how COMT Val158Met polymorphism affects interference resolution capacity via modulating the prefrontal GMV in healthy male subjects.