Concurrent Schizophrenia-Like Psychosis in Monozygous Twins Suffering from CNS Disorder

1973 ◽  
Vol 122 (571) ◽  
pp. 675-677 ◽  
Author(s):  
Albert West
Keyword(s):  
Twin Study ◽  
Genetic Factor ◽  
Environmental Influences ◽  
Twin Studies ◽  
Identical Twin ◽  
Cerebral Dysfunction ◽  
The Relationship ◽  
Monozygous Twins

Twin studies and investigations into the relationship between schizophrenia-like psychosis and cerebral dysfunction are of considerable interest. Refinement in twin studies has led to less emphasis being placed upon the genetic factor, but the pitfalls surrounding twin techniques, especially with regard to monozygous pairs and the similarity of their environment, have led Penrose (1971) to the opinion that twin study ‘is especially useful, not for genetical researches but in assessing the effects of environmental influences which lead to discordance in identical twin pairs'.

scholarly journals The Value of Twins for Health and Medical Research: A Third of a Century of Progress

2020 ◽  
Vol 23 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Jeffrey M. Craig ◽  
Lucas Calais-Ferreira ◽  
Mark P. Umstad ◽  
Dedra Buchwald
Keyword(s):  
Genetic Variation ◽  
Medical Research ◽  
Twin Study ◽  
Environmental Influences ◽  
Twin Studies ◽  
Twin Research ◽  
Study Designs ◽  
Genetic Contributions

AbstractIn 1984, Hrubec and Robinette published what was arguably the first review of the role of twins in medical research. The authors acknowledged a growing distinction between two categories of twin studies: those aimed at assessing genetic contributions to disease and those aimed at assessing environmental contributions while controlling for genetic variation. They concluded with a brief section on recently founded twin registries that had begun to provide unprecedented access to twins for medical research. Here we offer an overview of the twin research that, in our estimation, best represents the field has progress since 1984. We start by summarizing what we know about twinning. We then focus on the value of twin study designs to differentiate between genetic and environmental influences on health and on emerging applications of twins in multiple areas of medical research. We finish by describing how twin registries and networks are accelerating twin research worldwide.

A Danish Twin Study of Manic-Depressive Disorders

1977 ◽  
Vol 130 (4) ◽  
pp. 330-351 ◽  
Author(s):  
A. Bertelsen ◽  
B. Harvald ◽  
M. Hauge
Keyword(s):  
Personality Disorders ◽  
Twin Study ◽  
Genetic Factor ◽  
Depressive Disorders ◽  
Total Population ◽  
Genetic Difference ◽  
Twin Studies ◽  
Dizygotic Twins ◽  
Manic Depressive ◽  
Danish Twin

SummaryThe existence of a nation-wide twin register and central psychiatric register has made possible a catamnestic investigation of an unselected and representative sample of twins with manic-depressive disorders.From a total population of 11,288 same-sexed twin pairs born 1870–1920 in Denmark 126 probands from no pairs were ascertained. Among the co-twins of 69 monozygotic probands there were found 46 with manic-depressive disorders, and a further 14 had presented other psychoses or marked affective personality disorders or had committed suicide, yielding a proband rate of strict concordance, C1 = 0·67 and of broad, partial concordance, C2 = 0·87. The corresponding direct pairwise concordance rates were 32/55 = 0·58 and 46/55 = 0·84 respectively. For the dizygotic twins the proband concordance rate of C1 was 11/54 = 0·20 and of C2 20/54 = 0·37, and the direct pairwise rates were 9/52 = 0·17 and 18/52 = 0·35 respectively. The differences between the pairwise rates for the monozygotic and dizygotic twins are significant (P < 0·001 at χ2 analysis). This finding is in accordance with previous twin studies of manic-depressive disorders and confirms the evidence of a strong genetic factor. The concordance with respect to unipolar and bipolar forms was not in contradiction to recent evidence of a genetic difference between the bipolar and unipolar form, the latter probably related to the female sex.

scholarly journals Genetic and environmental influences on the relationship between ADHD symptoms and internalizing problems: A Chinese twin study

2015 ◽  
Vol 171 (7) ◽  
pp. 931-937 ◽  
Author(s):  
Tian-Jiao Chen ◽  
Cheng-Ye Ji ◽  
Shang-Shang Wang ◽  
Paul Lichtenstein ◽  
Henrik Larsson ◽  
...  
Keyword(s):  
Internalizing Problems ◽  
Twin Study ◽  
Environmental Influences ◽  
Adhd Symptoms ◽  
The Relationship

scholarly journals The 2016 Satellite Meeting of the International Society of Twin Studies: An Overview/Tribute to Irving I. Gottesman/Research: MZ Twinning After Single Embryo Transfer; Twin Study of Mononucleosis; Cerebral Injury After Twin-To-Twin Transfusion Syndrome Surgery/Human Interest: Sixteen Twin Pairs Born in a Single Hospital; Death of an Identical Twin Playwright; Twin Themes in Advertising; Conjoined Twins Separated in Saudi Arabia; Murder of One Twin By Her Co-Twin Disproved

2016 ◽  
Vol 19 (5) ◽  
pp. 588-593
Author(s):  
Nancy L. Segal
Keyword(s):  
Saudi Arabia ◽  
Embryo Transfer ◽  
International Society ◽  
Twin Study ◽  
Twin Studies ◽  
Conjoined Twins ◽  
Single Embryo Transfer ◽  
Cerebral Injury ◽  
Identical Twin ◽  
Human Interest

The 2016 Satellite Meeting of the International Society of Twin Studies took place on June 20 in Brisbane, Australia. The host institution was the QIMR Berghofer Medical Research Institute. An overview of selected presentations and activities is provided. This synopsis is followed by a brief tribute to the recent passing of our esteemed colleague, Dr Irving I. Gottesman. Next, there are summaries of research on monozygotic twinning after single embryo transfer, a twin study of mononucleosis susceptibility, cerebral injury following twin-to-twin transfusion syndrome surgery, and a correction and clarification regarding an article by Segal (2016) on the Brazilian Twin Registry. Human interest articles cover a hospital whose 2015 newborns included 16 pairs of twins born in 1 month, the death of an identical twin playwright, twin themes in advertising, conjoined twins separated in Saudi Arabia, and the dismissed charges of the murder of one twin by her co-twin.

A preliminary population-based twin study of self-reported eating disorder

2001 ◽  
Vol 31 (2) ◽  
pp. 361-365 ◽  
Author(s):  
L. S. KORTEGAARD ◽  
K. HOERDER ◽  
J. JOERGENSEN ◽  
C. GILLBERG ◽  
K. O. KYVIK
Keyword(s):  
Eating Disorders ◽  
Anorexia Nervosa ◽  
Eating Disorder ◽  
Bulimia Nervosa ◽  
Twin Study ◽  
Twin Studies ◽  
Population Based ◽  
Dizygotic Twin ◽  
Genetic Contribution ◽  
The Relationship

Background. Twin studies have concluded that there is a substantial genetic contribution to the aetiology of eating disorders. The aim of the present study was to estimate the genetic contribution to the aetiology of self-reported eating disorders in a sample of representative twins.Method. A population cohort of 34142 young Danish twins was screened for eating disorders by a mailed questionnaire.Results. Concordance rates differed significantly across monozygotic and dizygotic twin pairs for broadly defined self-reported anorexia nervosa and bulimia nervosa. Heritability estimates of 0·48, 0·52 and 0·61 respectively were estimated for narrow and broad definitions of self-reported anorexia nervosa and for self-reported bulimia nervosa.Conclusions. There is a genetic contribution to the aetiology of self-reported eating disorders in the general population. The relationship between self-reported and clinical eating disorder remains to be examined.

Genetic and Environmental Influences on Executive Functions and Intelligence in the ABCD Study

2020 ◽  
Author(s):  
Samantha M Freis ◽  
Claire Morrison ◽  
Jeffrey M. Lessem ◽  
John K. Hewitt ◽  
Naomi P. Friedman
Keyword(s):  
Cognitive Development ◽  
Executive Functions ◽  
Genetic Correlation ◽  
Middle Childhood ◽  
Middle Age ◽  
Environmental Influences ◽  
Genetic Correlations ◽  
Twin Studies

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated and heritable; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9-10-year-olds, including 749 twin pairs) in the Adolescent Brain Cognitive Development (ABCD) Study to examine the phenotypic and genetic relations between EFs and IQ in childhood. We identified two EF factors – Common EF and Updating-Specific, which were both related to IQ (rs = .64-.81). Common EF and IQ were heritable (53-67%), and their genetic correlation (rG = .86) was not significantly different than 1. These results suggest that EFs and IQ are phenotypically but not genetically separable in middle childhood.

scholarly journals Genetic and Environmental Structure of Altruism Characterized by Recipients in Relation to Personality

Medicina ◽  
2021 ◽  
Vol 57 (6) ◽  
pp. 593
Author(s):  
Juko Ando ◽  
Tetsuya Kawamoto
Keyword(s):  
Genetic Factor ◽  
Common Factor ◽  
Dynamic Network ◽  
Self Report ◽  
Genetic Studies ◽  
Indirect Reciprocity ◽  
Environmental Structure ◽  
Additive Genetic Effects ◽  
The Relationship ◽  
Common Genetic Factor

Background and Objectives: Altruism is a form of prosocial behavior with the goal of increasing the fitness of another individual as a recipient while reducing the fitness of the actor. Although there are many studies on its heterogeneity, only a few behavioral genetic studies have been conducted to examine different recipient types: family members favored by kin selection, the dynamic network of friends and acquaintances as direct reciprocity, and strangers as indirect reciprocity. Materials and Methods: This study investigated the genetic and environmental structure of altruism with reference to recipient types measured by the self-report altruism scale distinguished by the recipient (the SRAS-DR) and examine the relationship to personality dimensions measured by the NEO-FFI with a sample of 461 adult Japanese twin pairs. Results: The present study shows that there is a single common factor of altruism: additive genetic effects explain 51% of altruism without a shared environmental contribution. The genetic contribution of this single common factor is explained by the genetic factors of neuroticism (N), extraversion (E), openness to experience (O), and conscientiousness (C), as well as a common genetic factor specific to altruism. Only altruism toward strangers is affected by shared environmental factors. Conclusions: Different types of altruistic personality are constructed by specific combinational profiles of general personality traits such as the Big Five as well as a genetic factor specific to altruism in each specific way.

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