scholarly journals Epidemiology and genetics of hypodontia and microdontia: A study of twin families

2014 ◽  
Vol 85 (6) ◽  
pp. 980-985 ◽  
Author(s):  
Kwang Ho Jeong ◽  
Daeeun Kim ◽  
Yun-Mi Song ◽  
Joohon Sung ◽  
Young Ho Kim
Keyword(s):  
Environmental Factors ◽  
Monozygotic Twins ◽  
Genetic Effect ◽  
Recurrence Risk ◽  
Additive Genetic Effect ◽  
Dental Anomalies ◽  
Sibling Pairs ◽  
Recurrence Risk Ratio ◽  
Genetic And Environmental Factors ◽  
The Impact

ABSTRACT Objective:  To identify genetic and environmental factors contributing to hypodontia and microdontia by using Korean twin family data. Materials and Methods:  A total of 1267 individuals (525 men and 742 women; 180 monozygotic twins [MZ] and 43 dizygotic twins [DZ] from 282 families) underwent an oral examination as part of the Healthy Twin Study in Korea. Dental anomalies classified as hypodontia or microdontia were diagnosed using radiographs and clinical examinations. In order to estimate genetic contributions to dental anomalies, we estimated the pairwise concordance rate (PCR), recurrence risk ratio (RRR), and heritability (h2). Results:  The prevalence of hypodontia and microdontia was 3.55% and 3.00%, respectively. MZ had the highest PCR and RRR (13.0–15.3). The PCR and RRR values for both anomalies were much higher for DZ (5.0–11.9) than for siblings (1.4–2.6), despite the fact that DZ pairs and sibling pairs share 50% genetic identity. Further genetic analysis revealed both an additive genetic effect (0.38 when hypodontia and microdontia were pooled) and a strong “twin effect” (0.52 when hypodontia and microdontia were pooled). Conclusions:  This twin-based study revealed that the formation of dental anomalies is affected by both genetic and environmental factors, and that the impact of these factors varies according to the specific dental anomaly.

scholarly journals A Comparison of Personality, Life Events, Comorbidity, and Health in Monozygotic Twins Discordant for Anorexia Nervosa

2017 ◽  
Vol 20 (4) ◽  
pp. 310-318 ◽  
Author(s):  
Laura M. Thornton ◽  
Sara E. Trace ◽  
Kimberly A. Brownley ◽  
Monica Ålgars ◽  
Suzanne E. Mazzeo ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Environmental Factors ◽  
Life Events ◽  
Statistical Power ◽  
Monozygotic Twins ◽  
Health And Wellbeing ◽  
Gastrointestinal Problems ◽  
Genetic And Environmental Factors ◽  
The Impact ◽  
Mz Twins

Genetic and environmental factors contribute to the etiology of anorexia nervosa (AN). The co-twin control design is one of the most powerful methods available to evaluate environmental factors that could contribute to differences between monozygotic (MZ) twins who are discordant for AN. Using available data from a unique and rare sample of 22 Swedish female MZ pairs discordant for AN, we compared personality, life events, comorbidity, and health factors. Twins with AN had significantly higher perfectionism scores than unaffected co-twins and reported younger ages at first diet than unaffected co-twins who had dieted. Consistent with previous literature, more twins with AN reported gastrointestinal problems than unaffected co-twins. Although not significant due to low statistical power, more unaffected co-twins reported experiencing emotional neglect than twins with AN. Early dieting may be a harbinger of the development of AN or an early symptom. Higher perfectionism may represent a risk factor, sequela, or both. Sibling perception of neglect is noteworthy given the impact of an ill child with AN on family function and wellbeing. The health and wellbeing of siblings should be addressed clinically when one child in the family suffers from AN.

scholarly journals Impact of Genetic and Environmental Factors on hsCRP Concentrations and Response to Therapeutic Agents

2009 ◽  
Vol 55 (2) ◽  
pp. 256-264 ◽  
Author(s):  
Jian Shen ◽  
Jose M Ordovas
Keyword(s):  
Environmental Factors ◽  
Genetic Polymorphisms ◽  
Genetic Variants ◽  
Inflammatory Marker ◽  
Lipid Lowering ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Fenofibrate Treatment ◽  
Genetic And Environmental Factors ◽  
The Impact

Abstract Background: Inflammation plays an instrumental role in all stages of atherosclerosis. High-sensitivity C-reactive protein (hsCRP), a systemic inflammatory marker, has been gaining recognition as an independent risk factor for cardiovascular disease (CVD). Both baseline hsCRP concentrations and drug-induced hsCRP changes are highly variable and potentially subject to genetic regulation. Content: This review summarizes the current studies examining the effect of genetic and environmental factors on baseline plasma hsCRP concentrations, with a main focus on C-reactive protein, pentraxin-related (CRP) genetic polymorphisms and various dietary components that affect hsCRP concentrations. We also address the association of CRP genetic variations with CVD risk, a relationship that may support or refute the causality of CRP in the atherosclerotic process. Moreover, we discuss the impact of CRP genetic polymorphisms on hsCRP changes in response to 3-week fenofibrate treatment in the genetic intervention of the Genetics of Lipid Lowering Drugs and Diet Network study. Summary: Genetic variants on the CRP locus and other loci and dietary and lifestyle factors are responsible for the interindividual variability of plasma hsCRP concentrations. CRP genetic variants further influence differing plasma hsCRP response after 3-week fenofibrate treatment in patients with metabolic syndrome. Future studies focusing on the influence and interaction of genetic variation on the hsCRP response to dietary and other behavior modification as well as drug treatment could have important implications for the development of more personalized preventive and therapeutic approaches to reduce CVD.

scholarly journals Genetic and environmental factors in the determination of general cognitive abilities: a twin study

2020 ◽  
Vol 15 (2) ◽  
pp. 171-176
Author(s):  
Annu ◽  
Bimla Dhanda
Keyword(s):  
Environmental Factors ◽  
Cognitive Abilities ◽  
Twin Study ◽  
Monozygotic Twins ◽  
Heritability Estimate ◽  
Intelligence Scale ◽  
Wide Range ◽  
Heritability Estimates ◽  
Genetic And Environmental Factors

The present investigation of twin study elucidated the contribution of genetic and environment to a wide range of general cognitive abilities. To conduct twin study 100 pairs of twins from two districts, namely: Bhiwani (n = 90) and Hisar (n = 110) of Haryana State, genetic and environmental influences were assessed in twin study design. The cognitive abilities of twins were measured using the Wechsler Intelligence Scale for Children (WISC-R). Home Observation for Measurement of the Environment (HOME) Inventory was taken to examine the home environment of twins. Heritability estimate was used to analyze the genes contributing to shape the cognitive abilities of twins. The result of heritability estimates revealed that the heritability estimates of general cognitive abilities namely: information (62%), similarities (57%), vocabulary (60%) and comprehension (55%) in Bhiwani district and in Hisar district, the heritability estimates were 58 per cent, 55 per cent, 56 per cent and 51 per cent for information, similarities, vocabulary and comprehension general cognitive abilities, respectively. The findings clearly elucidated that the general cognitive abilities were more influenced by genetic background than the environmental factors. The paternal involvement and physical environment were strongly associated with general cognitive abilities of twins. The monozygotic twins were more correlated in their general cognitive abilities than the dizygotic twins.

A Male Monozygotic Twinship Discordant for Homosexuality

1971 ◽  
Vol 118 (547) ◽  
pp. 675-682 ◽  
Author(s):  
K. Davison ◽  
H. Brierley ◽  
C. Smith
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Prison Population ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
The Third ◽  
Relative Contribution ◽  
Quantitative Rating ◽  
Genetic And Environmental Factors ◽  
Sexual Identification

The relative contribution of genetic and environmental factors to the development of homosexual behaviour is a controversial subject. The original suggestion that homosexuality is a purely inherited trait has been attributed to Krafft-Ebing (Kallmann, 1952). Perhaps the strongest support for this view was Kallmann's series of 40 male monozygotic twin pairs showing 100 per cent concordance for the overt practice and quantitative rating of homosexual behaviour (Kallmann, 1952). This report has been criticized, and Kallmann later conceded that the 100 per cent concordance was possibly a statistical artefact (Kallmann, 1960). Habel (1950), who obtained the index twins from a prison population, found concordant homosexuality in 3 out of 5 monozygotic pairs (60 per cent), but none of 5 dizygotic pairs. In a more recent study, Heston and Shields (1968) found concordant homosexuality in 2 out of 5 monozygotic pairs (40 per cent) and 1 out of 7 dizygotic pairs (14 per cent). Heston and Shields (1968) also report a family with a sibship of 14 which included 3 pairs of male monozygotic twins, in two of which both twins were homosexual and in the third both heterosexual; no environmental factors which differentiated the homosexual from the heterosexual sibs could be detected. These workers also refute the suggestion that the tendency for monozygotic twins to be more alike with regard to homosexuality than dizygotic twins is related not to genetic factors but to problems of sexual identification which predispose to homosexuality (Money, 1962) by pointing out that there is no evidence that monozygotic twins per se are especially prone to become homosexual.

scholarly journals Combat exposure severity as a moderator of genetic and environmental liability to post-traumatic stress disorder

2013 ◽  
Vol 44 (7) ◽  
pp. 1499-1509 ◽  
Author(s):  
E. J. Wolf ◽  
K. S. Mitchell ◽  
K. C. Koenen ◽  
M. W. Miller
Keyword(s):  
Environmental Factors ◽  
Post Traumatic Stress Disorder ◽  
Traumatic Stress ◽  
Stress Disorder ◽  
Combat Exposure ◽  
Shared Environment ◽  
Post Traumatic Stress ◽  
Post Traumatic ◽  
Genetic And Environmental Factors ◽  
The Impact

BackgroundTwin studies of veterans and adults suggest that approximately 30–46% of the variance in post-traumatic stress disorder (PTSD) is attributable to genetic factors. The remaining variance is attributable to the non-shared environment, which, by definition, includes combat exposure. This study used a gene by measured environment twin design to determine whether the effects of genetic and environmental factors that contribute to the etiology of PTSD are dependent on the level of combat exposure.MethodThe sample was drawn from the Vietnam Era Twin Registry (VETR) and included 620 male–male twin pairs who served in the US Military in South East Asia during the Vietnam War era. Analyses were based on data from a clinical diagnostic interview of lifetime PTSD symptoms and a self-report measure of combat exposure.ResultsBiometric modeling revealed that the effects of genetic and non-shared environment factors on PTSD varied as a function of level of combat exposure such that the association between these factors and PTSD was stronger at higher levels of combat exposure.ConclusionsCombat exposure may act as a catalyst that augments the impact of hereditary and environmental contributions to PTSD. Individuals with the greatest exposure to combat trauma were at increased risk for PTSD as a function of both genetic and environmental factors. Additional work is needed to determine the biological and environmental mechanisms driving these associations.

scholarly journals Atopic dermatitis in children: up to date insight on development and trends in therapy

2020 ◽  
Vol 23 (4) ◽  
pp. 265-270
Author(s):  
Ivan I. Balabolkin
Keyword(s):  
Atopic Dermatitis ◽  
Environmental Factors ◽  
Allergen Immunotherapy ◽  
Calcineurin Inhibitors ◽  
Barrier Dysfunction ◽  
Innate And Adaptive Immunity ◽  
Pathogenetic Therapy ◽  
Ige Mediated ◽  
Genetic And Environmental Factors ◽  
The Impact

The development of atopic dermatitis (AD) in children is determined by the impact of genetic and environmental factors, epidermal barrier dysfunction, and changes in the system of innate and adaptive immunity. 76.3% of patients have IgE-mediated atopic dermatitis. The article elucidates questions of the pathogenesis and treatment of atopic dermatitis using topical corticosteroids, calcineurin inhibitors, emollients, antihistamines, allergen immunotherapy, omalizumab, probiotics. Conducting individualized pathogenetic therapy in ATD allows you to achieve control throughout the disease.

Genetic and Environmental Factors in Monozygotic Twins with Crohn’s Disease and Their First-Degree Relatives: A Case Report

Digestion ◽  
2005 ◽  
Vol 71 (4) ◽  
pp. 262-265 ◽  
Author(s):  
Ida Vind ◽  
Cathrine Jespersgaard ◽  
Lotte Hougs ◽  
Lene Riis ◽  
Lotte Dinesen ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Case Report ◽  
Crohn's Disease ◽  
Environmental Factors ◽  
Monozygotic Twins ◽  
First Degree Relatives ◽  
Genetic And Environmental Factors
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