scholarly journals Twin Studies in Auto-immune Disease

1994 ◽  
Vol 43 (1-2) ◽  
pp. 71-81 ◽  
Author(s):  
R.D.G. Leslie ◽  
M. Hawa
Keyword(s):  
Environmental Factors ◽  
Lupus Erythematosus ◽  
Genetic Factors ◽  
Disease Risk ◽  
Twin Studies ◽  
Identical Twins ◽  
Test Bed ◽  
Immune Mediated ◽  
Organ Specific ◽  
Insulin Dependent

AbstractImmune-mediated diseases affect up to 5% of the population and are a major cause of morbidity and mortality. These diseases can be organ specific, such as insulin-dependent diabetes (IDDM) and non-organ specific, such as Rheumatoid Arthritis (RA). Identical and non-identical twins have been used to establish whether these diseases are determined by genetic or environmental factors. The results of these studies have been collated in a new section of the Mendel Institute in Rome.Diseases included in these studies included IDDM, RA, Systemic Lupus Erythematosus (SLE), Multiple Sclerosis (MS) and Myasthenia. Striking differences in concordance rates between identical and non-identical twins in all these studies suggest that genetic factors are important in causing these diseases. All the diseases are known to be associated with HLA genes on chromosome 6 which may account for some or all of the genetic susceptibility. However, in the majority of pairs the affected twin has an unaffected co-twin. These observations suggest that non-genetically determined factors, probably environmental factors and not somatic mutations, are critical. The study of unaffected co-twins, who are at high disease-risk, has allowed the identification of changes which precede and predict the clinical disease. The immune-mediated destruction in many of these diseases is probably caused by T-lymphocytes. Twin studies have shown the importance of genetic factors in determining T-cell responses. Identical twins should, therefore, provide the perfect test bed to assess the role of T-cells in immune-mediated diseases.

Trauma Exposure and Stress Response: Exploration of Mechanisms of Cause and Effect

2007 ◽  
Vol 10 (4) ◽  
pp. 564-572 ◽  
Author(s):  
Kerry L. Jang ◽  
Steven Taylor ◽  
Murray B. Stein ◽  
Shinji Yamagata
Keyword(s):  
Stress Response ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Traumatic Events ◽  
Environmental Influences ◽  
Twin Studies ◽  
Posttraumatic Stress Symptoms ◽  
Dizygotic Twin ◽  
Stress Symptoms ◽  
Assaultive Trauma

AbstractPeople differ markedly in their risk for developing posttraumatic stress symptoms (PTSS) after exposure to traumatic events. Twin studies suggest that the trauma-PTSS relationship is moderated by genetic and environmental influences. The present study tested for specific types of genetic and environmental interaction effects on PTSS. A sample of 222 monozygotic and 184 dizygotic twin pairs reported on lifetime frequency of assaultive and nonassaultive trauma and associated PTSS. Biometric analyses indicated that in the case of nonassaultive trauma, PTSS were directly affected by environmental factors that also influence exposure to nonassaultive trauma. For assaultive trauma both genetic and non-shared environmental influences jointly affected PTSS, and the number of traumatic events moderated the severity of PTSS. Genetic factors were found to become less important beyond some threshold (e.g., 3 or 4 types of serious trauma) suggesting that genetic factors — which may confer either risk or resilience to PTSS — modify these symptoms within a range of human experience, beyond which environmental effects supervene.

A Behavioral-Genetic Study of Alexithymia and its Relationships with Trait Emotional Intelligence

2011 ◽  
Vol 14 (6) ◽  
pp. 539-543 ◽  
Author(s):  
Holly M. Baughman ◽  
Sara Schwartz ◽  
Julie Aitken Schermer ◽  
Livia Veselka ◽  
K. V. Petrides ◽  
...  
Keyword(s):  
Emotional Intelligence ◽  
Individual Differences ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Twin Studies ◽  
Trait Emotional Intelligence ◽  
Behavioral Genetic ◽  
Genetic And Environmental Factors ◽  
Trait Emotional Intelligence Questionnaire ◽  
Behavioral Genetic Study

The present study is the first to examine relationships between alexithymia and trait emotional intelligence (trait EI or trait emotional self-efficacy) at the phenotypic, genetic, and environmental levels. The study was also conducted to resolve inconsistencies in previous twin studies that have provided estimates of the extent to which genetic and environmental factors contribute to individual differences in alexithymia. Participants were 216 monozygotic and 45 dizygotic same-sex twin pairs who completed the Toronto Alexithymia Scale-20. In a pilot study, a sub-sample of 118 MZ and 27 DZ pairs also completed the Trait Emotional Intelligence Questionnaire. Results demonstrated that a combination of genetic and non-shared environmental influences contribute to individual differences in alexithymia. As expected, alexithymia and trait EI were negatively correlated at the phenotypic level. Bivariate behavioral genetic analyses showed that that all but one of these correlations was primarily attributable to correlated genetic factors and secondarily to correlated non-shared environmental factors.

Shared genetic factors may not explain the raised risk of comorbid inflammatory diseases in multiple sclerosis

2012 ◽  
Vol 18 (10) ◽  
pp. 1430-1436 ◽  
Author(s):  
H Roshanisefat ◽  
S Bahmanyar ◽  
J Hillert ◽  
T Olsson ◽  
S Montgomery
Keyword(s):  
Multiple Sclerosis ◽  
Genetic Factors ◽  
Cox Regression ◽  
Disease Risk ◽  
Inflammatory Diseases ◽  
Inflammatory Conditions ◽  
Disease Characteristics ◽  
Immune Mediated ◽  
Risk Patients ◽  
Shared Genetic

Background: Comorbid inflammatory conditions in multiple sclerosis (MS) patients suggest shared risks with MS. Objective: To estimate if the risk of immune-mediated disease in MS patients and their parents is increased. Methods: Swedish register data were analysed using Cox regression to estimate immune-mediated disease risk among 11284 fathers and 12006 mothers of MS patients, compared with 123158 fathers and 129409 mothers of index subjects without MS. Similar analyses were conducted among 20276 index subjects with MS and 203951 without. Results: Parents of patients with MS did not have a significantly altered immune-mediated disease risk. Patients with MS had a consistently raised risk for several immune-mediated diseases: ulcerative colitis, Crohn’s disease, type 1 diabetes, psoriasis, polyarthritis nodosa and pemphigoid. The risk was more pronounced for diseases diagnosed subsequent to MS onset. Conclusion: The increased occurrence of other immune-mediated diseases in MS patients may not be due to shared genetic factors and surveillance bias is likely to be the main or possibly the entire explanation. If not entirely explained by surveillance bias, a modestly raised occurrence of comorbid diseases may be due to shared environmental risks or factors related to MS disease characteristics.

Concordance for Stuttering in Monozygotic and Dizygotic Twin Pairs

1981 ◽  
Vol 24 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Pauline M. Howie
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Identical Twins ◽  
Dizygotic Twin ◽  
Same Sex ◽  
Maximum Accuracy ◽  
Estimated Risk ◽  
Genetic And Environmental Factors

The role of genetic factors in the etiology of stuttering was investigated in 30 pairs of same-sex twins, each pair containing at least one stutterer. Care was taken to ensure maximum accuracy in zygosity classification and objectivity in stuttering diagnosis. Zygosity classification was made independently of stuttering diagnosis. Pair-wise concordance for stuttering was significantly higher in identical twins (63%) than in fraternal same-sex twins (19%). The estimated risk of stuttering in the monozygotic (MZ) co-twin of a stutterer was .77, and .32 in the dizygotic (DZ) co-twin of a stutterer, The findings strongly suggest the operation of genetic factors in stuttering, However, the presence of as many as six pairs of identical twins who were discordant for stuttering underlines the importance of the interaction of genetic and environmental factors in the etiology of this disorder.

scholarly journals The Pioneering Contributions of Irving Gottesman

2017 ◽  
Vol 5 (2) ◽  
pp. 424-426
Author(s):  
Keith H. Nuechterlein
Keyword(s):  
Mental Disorders ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Twin Studies ◽  
Conceptual Base ◽  
Basic Assumptions ◽  
Research Programs ◽  
The World ◽  
Stress Models ◽  
And Behavior

Irving Gottesman was one of the leading psychopathologists and behavior geneticists of our time, greatly influencing our basic conceptualization of the transmission of schizophrenia and other major mental disorders in ways that impacted research programs around the world. Here we highlight his landmark twin studies of schizophrenia, his introduction of the concept of endophenotypes, and his role in providing the conceptual base for vulnerability/stress models of schizophrenia. His ability to influence our basic assumptions about the nature of genetic factors, environmental factors, and their interaction in the onset and course of major mental disorders was truly remarkable.

scholarly journals The microbiome in inflammatory bowel disease and its modulation as a therapeutic manoeuvre

2014 ◽  
Vol 73 (4) ◽  
pp. 452-456 ◽  
Author(s):  
A. L. Hart ◽  
P. Hendy
Keyword(s):  
Inflammatory Bowel Disease ◽  
Environmental Factors ◽  
Bowel Disease ◽  
Genetic Factors ◽  
Disease Risk ◽  
Evidence Base ◽  
Disease Phenotype ◽  
Host Genetics ◽  
Genome Wide ◽  
Inflammatory Bowel

Inflammatory bowel disease (IBD) is increasing in incidence in both the developed and the developing world. Genetic, immunological and environmental factors are known to be involved. Genome-wide studies have examined the contribution played by host genetics in the development of IBD and have estimated that genetic factors are responsible for about 25 % of the disease risk. Having an IBD-associated genotype does not always lead to development of the disease phenotype, and hence it seems likely that environmental factors are key to triggering development of the disease in genetically susceptible individuals. The gut microbiota contains more cells than its human host, and mounting evidence attests to the importance of the microbiota in the development of several diseases, including IBD, metabolic syndrome and CVD. The present paper reviews the interplay between the microbiota and the mucosal immune system in health and in IBD; and discusses the evidence base for the use of therapeutic modulation of the microbiota to prevent and treat IBD.

scholarly journals The Epidemiology and Etiology of Keratoconus

2012 ◽  
Vol 1 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Ariela Gordon-Shaag ◽  
Michel Millodot ◽  
Einat Shneor
Keyword(s):  
Environmental Factors ◽  
Genetic Predisposition ◽  
Genetic Factors ◽  
Family Studies ◽  
Twin Studies ◽  
Uv Exposure ◽  
Genetic Loci ◽  
Multiple Genes ◽  
Inferior Portion ◽  
Epidemiological Information

ABSTRACT Keratoconus is a noninflammatory disorder characterized by ectasia of the central or inferior portion of the cornea. This review presents the scant epidemiological information known to date and the factors believed to cause the development of the disease. They are the genetic factors for which evidence come from family studies, twin studies and genetic loci. There appears to be multiple genes causing a keratoconus phenotype with variable penetration. However, the genetic predisposition might not be enough; environmental factors, such as eye rubbing, atopy and UV exposure, may have a role in generating the disease. How to cite this article Gordon-Shaag A, Millodot M, Shneor E. The Epidemiology and Etiology of Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):7-15.

Abdominal Manifestations of Systemic Lupus Erythematosus: Spectrum of Imaging Findings

2009 ◽  
Vol 60 (3) ◽  
pp. 121-132 ◽  
Author(s):  
John M. Kirby ◽  
Kartik S. Jhaveri ◽  
Zeev V. Maizlin ◽  
Mehran Midia ◽  
Ehsan Haider ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Abdominal Cavity ◽  
Renal Involvement ◽  
Imaging Findings ◽  
Systemic Lupus ◽  
Peritoneal Surface ◽  
Immune Mediated ◽  
Organ Specific ◽  
Specific Antigens

Systemic lupus erythematosus is an immune-mediated syndrome in which the immune response is to non–organ-specific antigens, and virtually every organ in the abdominal cavity may become involved. Only renal involvement forms part of the diagnostic criteria, however, a combination of typically nonspecific findings, including peritoneal surface, enteric, renal, renal tract, pancreatic, adrenal, hepatobiliary, and splenic manifestations, should be looked for in patients with known lupus or other connective tissue disease who are undergoing abdominal imaging and may suggest the diagnosis in patients presenting with an acute abdomen. Our work presents the spectrum of imaging findings of abdominal manifestations of systemic lupus erythematosus.

scholarly journals Co-aggregation and heritability of organ-specific autoimmunity: a population-based twin study

2020 ◽  
Vol 182 (5) ◽  
pp. 473-480 ◽  
Author(s):  
Jakob Skov ◽  
Daniel Eriksson ◽  
Ralf Kuja-Halkola ◽  
Jonas Höijer ◽  
Soffia Gudbjörnsdottir ◽  
...  
Keyword(s):  
Autoimmune Diseases ◽  
Atrophic Gastritis ◽  
Genetic Factors ◽  
Monozygotic Twins ◽  
Twin Studies ◽  
Addison’S Disease ◽  
Addison's Disease ◽  
Graves Disease ◽  
Dizygotic Twins ◽  
Organ Specific

Objective Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases. Design Prospective twin cohort study. Methods We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto’s thyroiditis, atrophic gastritis, celiac disease, Graves’ disease, type 1 diabetes, vitiligo and Addison’s disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation of data. Results Co-aggregation was more pronounced in monozygotic twins (median HR: 3.2, range: 2.2–9.2) than in dizygotic twins (median HR: 2.4, range: 1.1–10.0). Heritability was moderate for atrophic gastritis (0.38, 95% CI: 0.23–0.53) but high for all other diseases, ranging from 0.60 (95% CI: 0.49–0.71) for Graves’ disease to 0.97 (95% CI: 0.91–1.00) for Addison’s disease. Conclusions Overall, co-aggregation was more pronounced in monozygotic than in dizygotic twins, suggesting that disease overlap is largely attributable to genetic factors. Co-aggregation was common, and twins faced up to a ten-fold risk of developing diseases not present in their co-twin. Our results validate and refine previous heritability estimates based on smaller twin cohorts.

Cannabis use in the last year in a US national sample of twin and sibling pairs

2002 ◽  
Vol 32 (3) ◽  
pp. 551-554 ◽  
Author(s):  
K. S. KENDLER ◽  
M. C. NEALE ◽  
L. M. THORNTON ◽  
S. H. AGGEN ◽  
S. E. GILMAN ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Family Environment ◽  
Genetic Factors ◽  
Twin Studies ◽  
National Sample ◽  
Population Based ◽  
Cannabis Use ◽  
Self Report ◽  
Sibling Pairs ◽  
Sibling Resemblance

Background. Three prior population-based twin studies, none of which was nationally representative, suggested that both genetic and familial–environmental factors contribute to family resemblance for lifetime cannabis use. We seek to replicate these results in a US national probability sample of twin and sibling pairs examining only last year cannabis use.Methods. Cannabis use in the last year was assessed by self-report questionnaire. Biometrical twin analyses were performed.Results. Twin and sibling resemblance for last-year cannabis use was substantial, and much higher in monozygotic pairs than in dizygotic and sibling pairs, where levels of resemblance were similar. Modeling suggested that sibling resemblance was due to genetic factors – with a heritability of at least 60% – and probably family environmental factors. No evidence was found that cannabis use was influenced by a special twin environment.Conclusions. Consistent with prior studies, use of cannabis is substantially influenced by genetic factors but family–environment is also possibly of importance.

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