The Use of Discordant MZ Twins to Generate Hypotheses regarding Non-shared Environmental Influence on Anxiety in Middle Childhood

Glutathione and cysteine are major antioxidants in blood that are associated with health and longevity. To ensure their measurement, careful attention to avoid auto-oxidation is necessary to stabilize the samples. Since no report of these compounds has been reported in children, our goal was to determine their levels of reduced and oxidized glutathione (GSH and GSSG) and cysteine (Cys and CSSC), To this end, 140 healthy children, ages 2 to 9 years from the Louisville Twin Study were studied. Blood samples were collected and analyzed for GSH, GSSG, Cys, and CSSC by our HPLC dual electrochemical method. The results showed that GSH and total GSH (GSH + GSSG) levels for monozygotic (MZ) twins were significantly higher (P < 0.001) than levels for dizygotic (DZ) twins. However, the opposite occurred for Cys and total Cys (Cys + CSSC) in that the levels were significantly higher for DZ twins than for MZ twins. (P < 0.005-0.013). In spite of this marked difference in zygosity, the withinpair correlations for twin pairs used for estimating heritability suggested that there was a major environmental influence for total GSH and total Cys. Finally. GSH levels were significantly lower for young (2–9 years) children than adults (P < 0.001).

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Cohabitation is associated with a greater resemblance in gut microbiota which can impact cardiometabolic and inflammatory risk

BMC Microbiology ◽

10.1186/s12866-019-1602-8 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 2

Author(s):

Casey T. Finnicum ◽

Jeffrey J. Beck ◽

Conor V. Dolan ◽

Christel Davis ◽

Gonneke Willemsen ◽

...

Keyword(s):

Gut Microbiota ◽

Environmental Influence ◽

Alpha Diversity ◽

P Value ◽

Genetic Profile ◽

Microbiota Composition ◽

Significant Difference ◽

Mz Twins ◽

Gut Microbiota Composition ◽

Inflammatory Burden

Abstract Background The gut microbiota composition is known to be influenced by a myriad of factors including the host genetic profile and a number of environmental influences. Here, we focus on the environmental influence of cohabitation on the gut microbiota as well as whether these environmentally influenced microorganisms are associated with cardiometabolic and inflammatory burden. We perform this by investigating the gut microbiota composition of various groups of related individuals including cohabitating monozygotic (MZ) twin pairs, non-cohabitating MZ twin pairs and spouse pairs. Results A stronger correlation between alpha diversity was found in cohabitating MZ twins (45 pairs, r = 0.64, p = 2.21 × 10− 06) than in non-cohabitating MZ twin pairs (121 pairs, r = 0.42, p = 1.35 × 10− 06). Although the correlation of alpha diversity did not attain significance between spouse pairs (42 pairs, r = 0.23, p = 0.15), the correlation was still higher than those in the 209 unrelated pairs (r = − 0.015, p = 0.832). Bray-Curtis (BC) dissimilarity metrics showed cohabitating MZ twin pairs had the most similar gut microbiota communities which were more similar than the BC values of non-cohabitating MZ twins (empirical p-value = 0.0103), cohabitating spouses (empirical p-value = 0.0194), and pairs of unrelated non-cohabitating individuals (empirical p-value< 0.00001). There was also a significant difference between the BC measures from the spouse pairs and those from the unrelated non-cohabitating individuals (empirical p-value< 0.00001). Intraclass correlation coefficients were calculated between the various groups of interest and the results indicate the presence of OTUs with an environmental influence and one OTU that appeared to demonstrate genetic influences. One of the OTUs (Otu0190) was observed to have a significant association with both the cardiometabolic and inflammatory burden scores (p’s < 0.05). Conclusions Through the comparison of the microbiota contents of MZ twins with varying cohabitation status and spousal pairs, we showed evidence of environmentally influenced OTUs, one of which had a significant association with cardiometabolic and inflammatory burden scores.

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Perceived Family Cohesion Moderates Environmental Influences on Prosocial Behavior in Nigerian Adolescent Twins

Twin Research and Human Genetics ◽

10.1017/thg.2017.15 ◽

2017 ◽

Vol 20 (3) ◽

pp. 226-235 ◽

Cited By ~ 8

Author(s):

Yoon-Mi Hur ◽

Jeanette Taylor ◽

Hoe-Uk Jeong ◽

Min-Seo Park ◽

Brett C. Haberstick

Keyword(s):

Public Schools ◽

Prosocial Behavior ◽

Family Environment ◽

Family Cohesion ◽

Environmental Influence ◽

Environmental Influences ◽

Twin Studies ◽

Environment Interaction ◽

Shared Environmental Influence ◽

Sex Limitation

Research shows that perceived family cohesion is positively related to prosocial behavior in adolescents. In this study, we investigated heritability of prosocial behavior (PB) and perceived family cohesion (FC) among Nigerian twins attending public schools in Lagos State, Nigeria (mean age = 14.7 years, SD = 1.7 years), and explored the issue of whether children's perception of cohesive family environment moderated genetic and environmental influences on (PB). The PB scale of the Strengths and Difficulties Questionnaire and the FC scale of the Family Adaptability and Cohesion Evaluation Scale III were completed by 2,376 twins (241 monozygotic (MZ) male, 354 MZ female, 440 dizygotic (DZ) male, 553 DZ female, and 788 opposite-sex DZ twins). A general sex-limitation and the bivariate genotype by environment interaction (G×E) models were applied to the data. The general sex-limitation model showed no significant sex differences, indicating that additive genetic and non-shared environmental influences were, 38% (95% CI = 31, 46) and 62% (95% CI = 54, 69) for PB and 33% (95% CI = 24, 40) and 67% (95% CI = 60, 76) for FC in both sexes. These estimates were similar to those found in Western and Asian twin studies to date. The correlation between PB and FC was 0.36. The best-fitting bivariate G×E model indicated that FC significantly moderated non-shared environmental influence unique to PB (E×E interaction). Specifically, non-shared environmental contributions to PB were highest when FC was lowest, and decreased as the levels of FC increased. However, genetic variances in PB were stable across all levels of FC. These findings suggest that FC reduces individual differences in PB by changing non-shared environmental experiences rather than genetic factors in PB.

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On Naevi and Melanomas: Two Sides of the Same Coin?

Frontiers in Medicine ◽

10.3389/fmed.2021.635316 ◽

2021 ◽

Vol 8 ◽

Author(s):

Katie J. Lee ◽

Monika Janda ◽

Mitchell S. Stark ◽

Richard A. Sturm ◽

H. Peter Soyer

Keyword(s):

Environmental Influence ◽

Treatment Strategies ◽

Clinical Genetics ◽

Risk Variants ◽

Shared Environmental Influence ◽

Genetic Overlap ◽

Total Body ◽

Prevention Counseling ◽

Two Sides ◽

Deep Phenotyping

Benign naevi are closely linked to melanoma, as risk factors, simulators, or sites of melanoma formation. There is a heavy genetic overlap between the two lesions, a shared environmental influence of ultraviolet radiation, and many similar cellular features, yet naevi remain locally situated while melanomas spread from their primary site and may progress systemically to distal organs. Untangling the overlapping contributors and predictors of naevi and melanoma is an ongoing area of research and should eventually lead to more personalized prevention and treatment strategies, through the development of melanoma risk stratification tools and early detection of evolving melanomas. This will be achieved through a range of complementary strategies: risk-adjusted primary prevention counseling; the use of lesion imaging technologies such as sequential 3D total body photography and consumer-performed lesion imaging; artificial intelligence deep phenotyping and clinical assistance; a better understanding of genetic drivers of malignancy, risk variants, clinical genetics, and polygenic effects; and the interplay between genetics, phenotype and the environment.

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Social Integration and Sleep Disturbance: A Gene-Environment Interaction Study

Collabra ◽

10.1525/collabra.29 ◽

2016 ◽

Vol 2 (1) ◽

Author(s):

David A. Sbarra

Keyword(s):

Social Integration ◽

Sleep Disturbance ◽

Environmental Influence ◽

Causal Effect ◽

Environmental Influences ◽

The United States ◽

Environment Interaction ◽

Increased Risk ◽

Shared Environmental Influence ◽

Low Levels

Objective: Low levels of perceived social integration, or loneliness, are associated with increased risk for a range of poor health outcomes. Sleep disturbance plays a central role in the evolutionary theory of loneliness, which provides a mechanistic account of how low levels of social integration may negatively impact health. No studies, however, have examined whether the association between social integration and sleep disturbance is consistent with a causal effect after accounting for genes that are common to both variables. Method: Using twin data (N = 905 twin pairs) from the nationally-representative Midlife in the United States (MIDUS) survey, I evaluated a series of bivariate twin models exploring whether the phenotypic association between low social integration and sleep disturbance can be explained by shared genetics. In addition, the current study specified a series of quantitative models for studying gene x environment (G X E) interactions to determine whether the genetic and environmental influences on sleep disturbance differ as a function of social integration. Results: The phenotypic association between social integration and sleep disturbance was fully accounted for by genes that are common between the two variables, suggesting that within-twin pair differences in social integration do not exert a causal influence on sleep disturbance. Social integration, however, moderated the non-shared environmental influence on sleep disturbances, with the greatest environmental influences observed at the lowest levels of social integration. Conclusions: The results of this study suggest that an essential feature of the evolutionary model of loneliness may need refinement or elaboration. The moderation findings are discussed in terms of the fit with a stress-buffering model of social support in which environmental influences on sleep disturbance are strongest when social resources are low.

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Genetic and environmental influence on the human functional connectome

10.1101/277996 ◽

2018 ◽

Cited By ~ 1

Author(s):

Andrew E. Reineberg ◽

Alexander S. Hatoum ◽

John K. Hewitt ◽

Marie T. Banich ◽

Naomi P. Friedman

Keyword(s):

Cognitive Abilities ◽

Environmental Influence ◽

Brain Connectivity ◽

Brain Regions ◽

Genetic Influence ◽

Functional Connections ◽

Functional Connectome ◽

Intermediate Phenotypes ◽

Human Connectome Project ◽

Shared Environmental Influence

AbstractDetailed mapping of genetic and environmental influences on the functional connectome is a crucial step toward developing intermediate phenotypes between genes and clinical diagnoses or cognitive abilities. We analyze resting-state data from two, adult twin samples - 390 twins from the Colorado Longitudinal Twin Sample and 422 twins from the Human Connectome Project - to examine genetic and environmental influence on all pairwise functional connections between 264 brain regions (~35,000 functional connections). Non-shared environmental influence was high, genetic influence was moderate, and shared environmental influence was weak-to-moderate across the connectome. The brain’s genetic organization is diverse and not as one would expect based solely on structure evident in non-genetically informative data or lower-resolution data. As follow-up, we make novel classifications of functional connections and examine highly-localized connections with particularly strong genetic influence. This high-resolution genetic taxonomy of brain connectivity will be useful in understanding genetic influences on brain disorders.

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Genetische Studien an Zwillingen. A. Morphologischer Teil

Acta geneticae medicae et gemellologiae ◽

10.1017/s1120962300019843 ◽

1957 ◽

Vol 6 (3) ◽

pp. 283-366 ◽

Cited By ~ 3

Author(s):

Shungo Osato ◽

Isamu Awano

Keyword(s):

Blood Cells ◽

Environmental Variability ◽

Environmental Influence ◽

Blood Platelets ◽

Age Groups ◽

Morphological Characteristics ◽

Anthropometric Measurements ◽

Body Volume ◽

High Similarity ◽

Mz Twins

SUMMARYWe have studied, in this work, environmental variability in twins, including the influence of age on the morphological and functional, physical and psychical characteristics.I. Morphological Characteristics1. For anthropometric measurements, most of the measurements of the cranium and of body lenght reveal a relatively high similarity between MZ twins, i. e. a high hereditary conditioning and low environmental influence. Most measurements of body volume and weight indicate instead a wider percentile intra-pair difference in MZ twins, indicating higher environmental susceptibility. Among constitutional indexes, Pignet-Vervaecksche's index appears to undergo the highest hereditary conditioning.2. The heart, the first section of the aorta, the lungs, thorax and stomach were examined radioscopically. Their shapes appeared largely conditioned by heredity. Their measurements (obtained by telefilms) are, in part, conditioned by heredity.3. The vessels of the retina and the capillaries of the skin are also conditioned by heredity.4. Finger and palm ridges clearly show similarity in MZ twins. Examining MZ twins belonging to different age groups we have found that similarity of finger ridges was higher in MZs between 6 and 8 years of age than in later age groups.5. As for blood cells, their size is largely conditioned by heredity, but also highly susceptible to environmental influences. The Hemogram and the Elmonogram of the leucocytes are, to a certain degree, conditioned by heredity. No clear appraisal could be made of the influence of heredity on the blood platelets count and on the reticulocytes.II. Functional Characteristics6. Body function as a whole.

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Genetic and Environmental Influence on the Human Functional Connectome

Cerebral Cortex ◽

10.1093/cercor/bhz225 ◽

2019 ◽

Vol 30 (4) ◽

pp. 2099-2113

Author(s):

Andrew E Reineberg ◽

Alexander S Hatoum ◽

John K Hewitt ◽

Marie T Banich ◽

Naomi P Friedman

Keyword(s):

Resting State ◽

Environmental Influence ◽

Brain Regions ◽

Genetic Influence ◽

Genetic Influences ◽

Imaging Data ◽

Functional Connections ◽

Functional Connectome ◽

Intermediate Phenotypes ◽

Shared Environmental Influence

Abstract Detailed mapping of genetic and environmental influences on the functional connectome is a crucial step toward developing intermediate phenotypes between genes and clinical diagnoses or cognitive abilities. We analyzed resting-state functional magnetic resonance imaging data from two adult twin samples (Nos = 446 and 371) to quantify genetic and environmental influence on all pairwise functional connections between 264 brain regions (~35 000 functional connections). Nonshared environmental influence was high across the whole connectome. Approximately 14–22% of connections had nominally significant genetic influence in each sample, 4.6% were significant in both samples, and 1–2% had heritability estimates greater than 30%. Evidence of shared environmental influence was weak. Genetic influences on connections were distinct from genetic influences on a global summary measure of the connectome, network-based estimates of connectivity, and movement during the resting-state scan, as revealed by a novel connectome-wide bivariate genetic modeling procedure. The brain’s genetic organization is diverse and not as one would expect based solely on structure evident in nongenetically informative data or lower resolution data. As follow-up, we make novel classifications of functional connections and examine highly localized connections with particularly strong genetic influence. This high-resolution genetic taxonomy of brain connectivity will be useful in understanding genetic influences on brain disorders.

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Risk Factors Influencing Smoking Behavior: A Turkish Twin Study

Twin Research and Human Genetics ◽

10.1017/thg.2014.43 ◽

2014 ◽

Vol 17 (6) ◽

pp. 563-573 ◽

Cited By ~ 5

Author(s):

Sevgi Yurt Öncel ◽

Danielle M. Dick ◽

Hermine H. Maes ◽

Fazil Alıev

Keyword(s):

Environmental Factors ◽

Nicotine Dependence ◽

Twin Study ◽

Genetic Factors ◽

Structural Equation Models ◽

Environmental Influence ◽

Smoking Behavior ◽

Smoking Initiation ◽

Smoking History ◽

Shared Environmental Influence

Aim: In this study, we introduce the first twin study in Turkey, focusing on smoking behavior, and laying the foundation to register all twins born in Turkey for research purposes. Using Turkish twins will contribute to our understanding of health problems in the context of cultural differences. Materials and methods: We assessed 309 twin pairs (339 males and 279 females) aged between 15 and 45 years living in the Kırıkkale and Ankara regions of Turkey, and administered a health and lifestyle interview that included questions about smoking status and smoking history. We analyzed the data using descriptive statistics, t-tests, chi-square tests, and bivariate and multivariate clustered logistic regression. In addition, we fit bivariate Structural Equation Models (SEM) to determine contributions of latent genetic and environmental factors to smoking outcomes in this sample. Results: One hundred seventy-eight participants (28.8%) were identified as smokers, smoking every day for a month or longer, of whom 79.2% were males and 20.8% were females. Mean values for number of cigarettes per day and the Fagerstrom Test of Nicotine Dependence (FTND; Fagerstrom, 1978) score were higher in males than in females, and age of onset was earlier in males. There was a significant positive correlation between the FTND score and number of cigarettes smoked per day, and a significant negative correlation between both variables and age at onset of smoking. Our study showed that gender, presence of a smoking twin in the family, age, alcohol use, marital status, daily sports activities, and feeling moody all played a significant role in smoking behavior among twins. The twin analysis suggested that 79.5% of the liability to FTND was influenced by genetic factors and 20.5% by unique environment, while familial resemblance for smoking initiation was best explained by common environmental factors. Conclusions: Marked differences in the prevalence of smoking behavior in men versus women were observed for the Turkish population. Genetic analyses showed that common environmental factors primarily contributed to smoking initiation, while genetic factors explained a greater proportion of variance in liability to nicotine dependence. Our study shows higher heritability estimate of the FTND scores and higher shared environmental influence on smoking initiation for both males and females than reported in previous studies.

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