scholarly journals On the Nature of Monozygotic Twin Concordance and Discordance for Autistic Trait Severity: A Quantitative Analysis

2019 ◽  
Vol 50 (4) ◽  
pp. 263-272 ◽  
Author(s):  
Lauren Castelbaum ◽  
Chad M. Sylvester ◽  
Yi Zhang ◽  
Qiongru Yu ◽  
John N. Constantino
Keyword(s):  
Quantitative Analysis ◽  
Twin Studies ◽  
Monozygotic Twin ◽  
Autism Spectrum ◽  
Data Sets ◽  
Autistic Trait ◽  
Heritable Variation ◽  
Diagnostic Threshold ◽  
Mz Twins ◽  
New Evidence

AbstractThe characterizing features of autism spectrum disorder (ASD) are continuously distributed in nature; however, prior twin studies have not systematically incorporated this knowledge into estimations of concordance and discordance. We conducted a quantitative analysis of twin–twin similarity for autistic trait severity in three existing data sets involving 366 pairs of uniformly-phenotyped monozygotic (MZ) twins with and without ASD. Probandwise concordance for ASD was 96%; however, MZ trait correlations differed markedly for pairs with ASD trait burden below versus above the threshold for clinical diagnosis, with R2s on the order of 0.6 versus 0.1, respectively. Categorical MZ twin discordance for ASD diagnosis is rare and more appropriately operationalized by standardized quantification of twin–twin differences. Here we provide new evidence that although ASD itself is highly heritable, variation-in-severity of symptomatology above the diagnostic threshold is substantially influenced, in contrast, by non-shared environmental factors which may identify novel targets of early ASD amelioration.

An example of spectrum imaging used for comparison of EELS quantitative analysis techniques on Al-Li

1991 ◽  
Vol 49 ◽  
pp. 726-727
Author(s):  
John A. Hunt
Keyword(s):  
Quantitative Analysis ◽  
Large Data ◽  
Difference Spectrum ◽  
Large Data Sets ◽  
Foil Thickness ◽  
Data Sets ◽  
Analysis Techniques ◽  
Spectrum Imaging ◽  
Normal Spectrum ◽  
Electron Energy Loss

Spectrum-imaging is a useful technique for comparing different processing methods on very large data sets which are identical for each method. This paper is concerned with comparing methods of electron energy-loss spectroscopy (EELS) quantitative analysis on the Al-Li system. The spectrum-image analyzed here was obtained from an Al-10at%Li foil aged to produce δ' precipitates that can span the foil thickness. Two 1024 channel EELS spectra offset in energy by 1 eV were recorded and stored at each pixel in the 80x80 spectrum-image (25 Mbytes). An energy range of 39-89eV (20 channels/eV) are represented. During processing the spectra are either subtracted to create an artifact corrected difference spectrum, or the energy offset is numerically removed and the spectra are added to create a normal spectrum. The spectrum-images are processed into 2D floating-point images using methods and software described in [1].

New Evidence on Eastern Europe's Pollution Progress

2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Matthew E Kahn
Keyword(s):  
Sulfur Dioxide ◽  
Carbon Dioxide Emissions ◽  
National Level ◽  
Data Sets ◽  
Local Public Good ◽  
Data Set ◽  
The Czech Republic ◽  
Level Data ◽  
Good Improvement ◽  
New Evidence

Abstract Under communism, Eastern Europe's cities were significantly more polluted than their Western European counterparts. An unintended consequence of communism's decline is to improve urban environmental quality. This paper uses several new data sets to measure these gains. National level data are used to document the extent of convergence across nations in sulfur dioxide and carbon dioxide emissions. Based on a panel data set from the Czech Republic, Hungary and Poland, ambient sulfur dioxide levels have fallen both because of composition and technique effects. The incidence of this local public good improvement is analyzed.

scholarly journals Examining the association between childhood autistic traits and adolescent hypomania: a longitudinal twin study

2021 ◽  
pp. 1-10
Author(s):  
Mark J. Taylor ◽  
Angelica Ronald ◽  
Joanna Martin ◽  
Sebastian Lundström ◽  
Georgina M. Hosang ◽  
...  
Keyword(s):  
Age Of Onset ◽  
Large Population ◽  
Autistic Traits ◽  
Evidence Base ◽  
Population Based ◽  
Autism Spectrum ◽  
Autistic Trait ◽  
Structured Interviews ◽  
Twin Design ◽  
Longitudinal Twin Study

Abstract Background There is evidence that autism spectrum disorders (ASDs) co-occur with bipolar disorder (BD) relatively frequently. Individuals with BD often report symptoms of mania and hypomania during adolescence, prior to the age of onset for BD. It is unknown whether these symptoms are associated with ASDs. We examined whether diagnoses of ASDs and autistic traits were associated with hypomania in a large, population-based Swedish twin sample. Methods Parental structured interviews assessed autistic traits, and were used to assign screening diagnoses of ASDs, when twins were aged 9 or 12 (N = 13 533 pairs). Parents then completed questionnaires assessing hypomania when the twins were aged 15 and 18 (N = 3852 pairs at age 15, and 3013 pairs at age 18). After investigating the phenotypic associations between these measures, we used the classical twin design to test whether genetic and environmental influences on autistic traits influence variation in adolescent hypomania. Results Autistic traits and ASD diagnoses in childhood were associated with elevated scores on the measures of adolescent hypomania. Twin analyses indicated that 6–9% of the variance in hypomania was explained by genetic influences that were shared with autistic traits in childhood. When repeating these analyses for specific autistic trait domains, we found a stronger association between social interaction difficulties and hypomania than for other autistic trait domains. Conclusions These results indicate a genetic link between autistic traits and hypomania in adolescence. This adds to the growing evidence base of genetic factors associated with ASDs showing links with psychiatric outcomes across childhood and into adulthood.

scholarly journals Reduced language lateralization in autism and the broader autism phenotype as assessed with robust individual-subjects analyses

2020 ◽  
Author(s):  
Olessia Jouravlev ◽  
Alexander J.E. Kell ◽  
Zachary Mineroff ◽  
A.J. Haskins ◽  
Dima Ayyash ◽  
...  
Keyword(s):  
Language Processing ◽  
Large Scale ◽  
Right Hemisphere ◽  
Autism Spectrum ◽  
Functional Markers ◽  
Large Set ◽  
Autistic Trait ◽  
Functional Responses ◽  
Individual Subject ◽  
Language Lateralization

AbstractOne of the few replicated functional brain differences between individuals with autism spectrum disorders (ASD) and neurotypical (NT) controls is reduced language lateralization. However, most prior reports relied on comparisons of group-level activation maps or functional markers that had not been validated at the individual-subject level, and/or used tasks that do not isolate language processing from other cognitive processes, complicating interpretation. Furthermore, few prior studies have examined functional responses in other functional networks, as needed to determine the selectivity of the effect. Using fMRI, we compared language lateralization between 28 ASD participants and carefully pairwise-matched controls, with the language regions defined individually with a well-validated language localizer. ASD participants showed less lateralized responses due to stronger right hemisphere activations. Further, this effect did not stem from a ubiquitous reduction in lateralization across the brain: ASD participants did not differ from controls in the lateralization of two other large-scale networks—the Theory of Mind network and the Multiple Demand network. Finally, in an exploratory study, we tested whether reduced language lateralization may also be present in NT individuals with high autistic trait load. Indeed, autistic trait load in a large set of NT participants (n=189) was associated with less lateralized language activations. These results suggest that reduced language lateralization is a robust and spatially selective neural marker of autism, present in individuals with ASD, but also in NT individuals with higher genetic liability for ASD, in line with a continuum model of underlying genetic risk.

The Unique Contribution of Twin Studies to the Elucidation of Nongenetic Factors in Personality Development and Psychopathogenesis

1970 ◽  
Vol 19 (1-2) ◽  
pp. 299-302
Author(s):  
William Pollin
Keyword(s):  
Matched Control ◽  
Personality Development ◽  
Methodological Issue ◽  
Twin Studies ◽  
Birth Size ◽  
Unique Contribution ◽  
Genetic Studies ◽  
Personality Differences ◽  
Multidisciplinary Study ◽  
Mz Twins

Our Section in Bethesda is primarily engaged in studies of schizophrenia and personality formation. I will summarize a number of our ongoing studies, and then briefly focus on a methodological issue: the possibility of twin studies moving beyond their heretofore almost constant, very useful tie to genetic studies.We have previously reported an elaborate multidisciplinary study of a series of MZ twins discordant for schizophrenia, a smaller number of appropriately matched control twin pairs, and their families, aimed at studying nongenetic factors in the pathogenesis of schizophrenia (Pollin et al, 1965, 1966). We have described three interacting groups of variables which consistently differentiated the schizophrenic and nonschizophrenic twins in the discordant pairs (Pollin and Stabenau, 1965). These included an initial set of nongenetic constitutional differences, including birth size, vigor, and physiological competence; consequent different parental perceptions of, and relationships to, each of the twins in a given pair; and subsequent biological and life history differences, based on evolving personality differences, such as in fearfulness, competence, independence, initiative and the like, differentiating the schizophrenic index and the nonschizophrenic cotwins.

scholarly journals The Association Between Somatic Health, Autism Spectrum Disorder, and Autistic Traits

2019 ◽  
Vol 50 (4) ◽  
pp. 233-246 ◽  
Author(s):  
Pei-Yin Pan ◽  
Kristiina Tammimies ◽  
Sven Bölte
Keyword(s):  
Autism Spectrum Disorder ◽  
Twin Pair ◽  
Monozygotic Twins ◽  
Twin Studies ◽  
Autistic Traits ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Social Responsiveness ◽  
Somatic Health ◽  
Validated Questionnaire

AbstractThis study used a twin cohort to investigate the association of autism spectrum disorder (ASD) and autistic traits with somatic health. A total of 344 twins (172 pairs; mean age 15.56 ± 5.62 years) enriched for ASD and other neurodevelopmental conditions were examined. Medical history and current physical problems were collected with a validated questionnaire to determine twin’s somatic health. The Social Responsiveness Scale (SRS-2) was used to measure the participant’s severity of autistic traits. Identified somatic health issues with significant within-twin pair differences were tested in relation to both ASD diagnosis and autistic traits in a co-twin control model. Twins with ASD exhibited more neurological and immunological health problems compared to those without ASD (p = 0.005 and p = 0.004, respectively). The intra-pair differences of neurological conditions and SRS-2 score were significantly correlated in monozygotic twins differing for autism traits (r = 0.40, p = 0.001), while the correlation was not found for immunological problems. In addition, a conditional model for analysis of within-twin pair effects revealed an association between neurological problems and clinical ASD diagnosis (Odds ratio per neurological problem 3.15, p = 0.02), as well as autistic traits (β = 10.44, p = 0.006), after adjusting for possible effects of co-existing attention deficit hyperactivity disorder and general intellectual abilities. Our findings suggest that neurological problems are associated with autism, and that non-shared environmental factors contribute to the overlap for both clinical ASD and autistic traits. Further population-based twin studies are warranted to validate our results and examine in detailed the shared genetic and environmental contributions of neurological problems and ASD.

Automatic Quantitative Analysis of 3D Brain Data Sets: Application to a Pediatric Population

NeuroImage ◽  
1998 ◽  
Vol 7 (4) ◽  
pp. S727 ◽  
Author(s):  
Alex P. Zijdenbos ◽  
Jay N. Giedd ◽  
Jonathan D. Blumenthal ◽  
TomአPaus ◽  
Judith L. Rapoport ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Pediatric Population ◽  
Data Sets ◽  
Brain Data

scholarly journals Twin Legacies: Victor and Vincent McKusick / Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell–Silver Syndrome; Twins’ Language Skills / Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins

2016 ◽  
Vol 19 (2) ◽  
pp. 158-162
Author(s):  
Nancy L. Segal
Keyword(s):  
Supreme Court ◽  
Language Skills ◽  
Twin Studies ◽  
Medical Genetics ◽  
Identical Twins ◽  
Identical Twin ◽  
New Mother ◽  
Biographical Account ◽  
Silver Syndrome ◽  
Mz Twins

The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the ‘Father of Medical Genetics’, while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell–Silver Syndrome (RSS) and a study of twins’ language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO.

scholarly journals Autism spectrum heterogeneity: fact or artifact?

2020 ◽  
Vol 25 (12) ◽  
pp. 3178-3185 ◽  
Author(s):  
Laurent Mottron ◽  
Danilo Bzdok
Keyword(s):  
Autistic Traits ◽  
Fold Increase ◽  
Autism Spectrum ◽  
Machine Learning Algorithms ◽  
Qualitative Properties ◽  
Diagnostic Practices ◽  
Clinical Intuition ◽  
Dsm 5 ◽  
Diagnostic Threshold ◽  
Categorical Diagnosis

AbstractThe current diagnostic practices are linked to a 20-fold increase in the reported prevalence of ASD over the last 30 years. Fragmenting the autism phenotype into dimensional “autistic traits” results in the alleged recognition of autism-like symptoms in any psychiatric or neurodevelopemental condition and in individuals decreasingly distant from the typical population, and prematurely dismisses the relevance of a diagnostic threshold. Non-specific socio-communicative and repetitive DSM 5 criteria, combined with four quantitative specifiers as well as all their possible combinations, render limitless variety of presentations consistent with the categorical diagnosis of ASD. We propose several remedies to this problem: maintain a line of research on prototypical autism; limit the heterogeneity compatible with a categorical diagnosis to situations with a phenotypic overlap and a validated etiological link with prototypical autism; reintroduce the qualitative properties of autism presentations and of current dimensional specifiers, language, intelligence, comorbidity, and severity in the criteria used to diagnose autism in replacement of quantitative “social” and “repetitive” criteria; use these qualitative features combined with the clinical intuition of experts and machine-learning algorithms to differentiate coherent subgroups in today’s autism spectrum; study these subgroups separately, and then compare them; and question the autistic nature of “autistic traits”

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