scholarly journals Twin study of symptom dimensions in psychoses

2001 ◽  
Vol 179 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Alastair G. Cardno ◽  
Pak C. Sham ◽  
Robin M. Murray ◽  
Peter McGuffin
Keyword(s):  
Factor Analysis ◽  
Twin Study ◽  
Genetic Basis ◽  
Psychotic Disorders ◽  
Familial Aggregation ◽  
Molecular Genetic ◽  
Genetic Effect ◽  
Genetic Studies ◽  
Symptom Dimensions ◽  
Genetic Loading

BackgroundSymptomatology in psychoses can be summarised as quantitative symptom dimensions, but their genetic basis is unknown.AimsTo investigate whether genes make an important contribution to symptom dimensions.MethodA total of 224 probandwise twin pairs (106 monozygotic, 118 same-gender dizygotic) where probands had psychosis were ascertained from the Maudsley Twin Register in London. Factor analysis was performed on lifetime symptoms rated on the Operational Checklist for Psychotic Disorders (OPCRIT). Correlations of dimension scores within monozygotic and dizygotic pairs concordant for Research Diagnostic Criteria psychoses were performed. Relationships between dimension scores and genetic loading for psychoses were assessed using logistic regression.ResultsPatterns of familial aggregation consistent with a genetic effect were found for the disorganised dimension and for some measures of the negative, manic and general psychotic dimensions. Disorganised dimension scores were related significantly to genetic loading for psychoses.ConclusionsThe disorganised dimension, and possibly other symptom dimensions, may be useful phenotypes for molecular genetic studies of psychoses.

scholarly journals Factor Analysis of Negative Symptom Items in the Structured Interview for Prodromal Syndromes

2018 ◽  
Vol 45 (5) ◽  
pp. 1042-1050 ◽  
Author(s):  
Matilda Azis ◽  
Gregory P Strauss ◽  
Elaine Walker ◽  
William Revelle ◽  
Richard Zinbarg ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Functional Outcome ◽  
Negative Symptom ◽  
Negative Symptoms ◽  
Psychotic Disorders ◽  
The United States ◽  
Structured Interview ◽  
Symptom Dimensions ◽  
Increased Risk ◽  
Active Research

Abstract Background Negative symptoms occur early in the clinical high risk (CHR) state and indicate increased risk of conversion to psychotic disorder and poor functional outcome. However, while the negative symptom domain has shown to be parsimoniously explained by a 2-factor construct in schizophrenia, there has yet to be an established factor structure of negative symptoms in CHR. Methods 214 individuals meeting the Structured Interview for Psychosis-Risk Syndromes (SIPS) criteria for CHR were recruited through 3 active research programs in the United States. Exploratory Factor Analysis was conducted on the 6 negative symptom items of the SIPS, and factors were evaluated with respect to functional outcome and depression. Results Factor analysis indicated a 2-factor hierarchical model with 2 negative symptom dimensions reflecting volition (Occupational Functioning and Avolition) and emotion (Expression of Emotion, Experience of Emotion and Social Anhedonia). Linear Regression showed that the emotion factor was associated with poor social function, and the volition factor was associated with poor role function and depression. Conclusions Similar to factor solutions identified in adults diagnosed with psychotic disorders, results indicated that the SIPS negative symptom subscale is not a unidimensional construct. Rather, the SIPS negative subscale has 2 distinct factors that have different associations with clinical outcome and should be interpreted independently. Results have significant relevance for informing the valid assessment and conceptual interpretation of early clinical phenomenology in the psychosis prodrome.

The Genetics of Gambling and Behavioral Addictions

CNS Spectrums ◽  
2006 ◽  
Vol 11 (12) ◽  
pp. 931-939 ◽  
Author(s):  
Daniela S.S. Lobo ◽  
James L. Kennedy
Keyword(s):  
Pathological Gambling ◽  
Familial Aggregation ◽  
Molecular Genetic ◽  
Genetic Research ◽  
Genetic Influences ◽  
Behavioral Addictions ◽  
Psychiatric Genetics ◽  
Negative Consequences ◽  
Future Directions ◽  
Genetic Studies

ABSTRACTBehavioral addictions are considered as the repetitive occurrence of impulsive behaviors without consideration of their potential negative consequences. These addictions represent an increasing cost to society and are an important new field of research in psychiatric genetics. There has been a growing body of evidence on the familial aggregation and genetic influences on the development of behavioral addictions and mainly on pathological gambling. The aim of this article is to critically review findings of family and molecular genetic studies on behavioral addictions, focusing on pathological gambling and commenting on other disorders where appropriate. This review provides a comprehensive approach to genetic studies on behavioral addiction and points out the necessity of expanding the genetic research in this field. Future directions for genetic studies in this field are also discussed.

scholarly journals Heritability of Personality

2017 ◽  
Vol 26 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Denis Bratko ◽  
Ana Butković ◽  
Tena Vukasović Hlupić
Keyword(s):  
Current Knowledge ◽  
Familial Aggregation ◽  
Meta Analysis ◽  
Molecular Genetic ◽  
Monozygotic Twins ◽  
Environment Interaction ◽  
Genetic Studies ◽  
Behavioral Genetic ◽  
Dizygotic Twins ◽  
Intraclass Correlations

The aim of this study is to simplify the issue of the concept of heritability, to give an introduction to the behavioral genetic theory and methods, as well as to give an overview of the current knowledge about heritability of personality and the quantitative and molecular genetic approach to estimate heritability. Following that, results on heritability of personality are summarized. In addition, we reanalyzed all available behavioral genetic studies published before 2010, which were included in Vukasović and Bratko (2015) meta-analysis, to estimate the correlations between different family members: 1) monozygotic twins reared together; 2) monozygotic twins reared apart; 3) dizygotic twins reared together; 4) dizygotic twins reared apart; 5) mother and offspring; 6) father and offspring. Estimates of the family resemblance for personality were .54 from intraclass correlations for twin pairs reared together, .45 for intraclass correlations for monozygotic twin pairs reared apart, and .26 and .28 for familial aggregation. This finding is in line with the conclusion of the previous meta-analysis, which showed that the study design is a significant moderator of personality heritability, with twin studies showing higher estimates compared to family and adoption studies. Following that, findings from molecular genetic studies on personality and from gene-environment interaction studies are summarized. Finally, recommendations for future studies are given.

scholarly journals Correlation and familial aggregation of dimensions of psychosis in affected sibling pairs from China

2008 ◽  
Vol 193 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Evangelos Vassos ◽  
Pak C. Sham ◽  
Guiqing Cai ◽  
Hong Deng ◽  
Xiehe Liu ◽  
...  
Keyword(s):  
Social Adjustment ◽  
Clinical Characteristics ◽  
Familial Aggregation ◽  
Pair Correlation ◽  
Intraclass Correlation ◽  
Kappa Statistics ◽  
Global Functioning ◽  
Genetic Studies ◽  
Symptom Dimensions ◽  
Sibling Pairs

BackgroundA number of studies with conflicting results have examined the familiality of schizophrenia syndromes in Western populations.AimsThe objective of this study was to determine, using clinical data from concordant sibling pairs, whether symptom dimensions and other clinical characteristics of schizophrenia show familial aggregation and are therefore potentially useful traits in genetic studies.MethodWe measured clinical and demographic features, and symptom dimensions of schizophrenia in 137 families from China who had two or more affected members with schizophrenia. Within-sibling pair correlation was assessed with intraclass correlation coefficient and kappa statistics.ResultsGlobal functioning, positive, disorganisation and dysphoric symptoms, premorbid schizotypal and schizoid traits, premorbid social adjustment, type and age at illness onset all showed significant evidence of familial aggregation. DSM–IV schizophrenia subtypes were also found to be familial.ConclusionsThis is the first study in a large non-European population to confirm that schizophrenia dimensions and clinical characteristics show significant familiality, implying possible heritability. This supports their use in the delineation of homogeneous subsets for future genetic studies.

Genetics of the metabolic syndrome

2007 ◽  
Vol 32 (1) ◽  
pp. 89-114 ◽  
Author(s):  
Margarita Terán-García ◽  
Claude Bouchard
Keyword(s):  
Metabolic Syndrome ◽  
Genetic Basis ◽  
Familial Aggregation ◽  
Genetic Studies ◽  
True Nature ◽  
The Metabolic Syndrome ◽  
Genome Wide ◽  
The Individual ◽  
Ectopic Fat Deposition ◽  
Key Questions

The concept of a metabolic syndrome (MetS), a cluster of pre-clinical metabolic alterations commonly associated with obesity, is the object of much debate. Genetic studies have the potential to contribute to some of the key questions, including the true nature of the cluster of pre-clinical features and whether it is associated with human genetic variation. This review summarizes the evidence for the presence of familial aggregation for the individual components of MetS and their heritability levels. It also provides an overview of the studies that have dealt with candidate genes for MetS. Potential leads from genome-wide linkage scans are also discussed. The assumption is made that obesity, ectopic fat deposition and abnormal adipose tissue metabolism are responsible for alterations in lipid metabolism, which in turn generates the commonly observed pre-clinical shifts in glucose tolerance, lipids and lipoprotein profile, blood pressure, inflammatory markers, endothelial function, and a prothrombotic state. Progress in the understanding of the genetic basis of MetS should occur as soon as a consensus is reached on the true nature of MetS, its components and diagnostic criteria.

scholarly journals Clinical and genetic validity of quantitative bipolarity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Heather A. Bruce ◽  
Peter Kochunov ◽  
Braxton Mitchell ◽  
Kevin A. Strauss ◽  
Seth A. Ament ◽  
...  
Keyword(s):  
Psychiatric Diagnosis ◽  
Depressive Disorders ◽  
Psychotic Disorders ◽  
Familial Aggregation ◽  
Psychiatric Diagnoses ◽  
Genetic Studies ◽  
Heritable Trait ◽  
Components Method ◽  
Genetic Contributions ◽  
Subclinical Symptoms

Abstract Research has yet to provide a comprehensive understanding of the genetic basis of bipolar disorder (BP). In genetic studies, defining the phenotype by diagnosis may miss risk-allele carriers without BP. The authors aimed to test whether quantitatively detected subclinical symptoms of bipolarity identifies a heritable trait that infers risk for BP. The Quantitative Bipolarity Scale (QBS) was administered to 310 Old Order Amish or Mennonite individuals from multigenerational pedigrees; 110 individuals had psychiatric diagnoses (20 BP, 61 major depressive disorders (MDD), 3 psychotic disorders, 26 other psychiatric disorders). Familial aggregation of QBS was calculated using the variance components method to derive heritability and shared household effects. The QBS score was significantly higher in BP subjects (31.5 ± 3.6) compared to MDD (16.7 ± 2.0), other psychiatric diagnoses (7.0 ± 1.9), and no psychiatric diagnosis (6.0 ± 0.65) (all p < 0.001). QBS in the whole sample was significantly heritable (h2 = 0.46 ± 0.15, p < 0.001) while the variance attributed to the shared household effect was not significant (p = 0.073). When subjects with psychiatric illness were removed, the QBS heritability was similar (h2 = 0.59 ± 0.18, p < 0.001). These findings suggest that quantitative bipolarity as measured by QBS can separate BP from other psychiatric illnesses yet is significantly heritable with and without BP included in the pedigrees suggesting that the quantitative bipolarity describes a continuous heritable trait that is not driven by a discrete psychiatric diagnosis. Bipolarity trait assessment may be used to supplement the diagnosis of BP in future genetic studies and could be especially useful for capturing subclinical genetic contributions to a BP phenotype.

scholarly journals Canadian Collaborative Project on Genetic Susceptibility to MS, Phase 2: Rationale and Method

1998 ◽  
Vol 25 (3) ◽  
pp. 216-221 ◽  
Author(s):  
A.D. Sadovnick ◽  
N.J. Risch ◽  
G.C. Ebers ◽  
Keyword(s):  
Genetic Susceptibility ◽  
Familial Aggregation ◽  
Phase 1 ◽  
Molecular Genetic ◽  
Genetic Research ◽  
Population Based ◽  
Phase 2 ◽  
Genetic Studies ◽  
Collaborative Project ◽  
Index Cases

ABSTRACT:Background:Results from the Canadian Collaborative Project on Genetic Susceptibility to Multiple Sclerosis (MS)-Phase 1 (CCPGSMS-Phase 1) together with other family data published since 1982 have led to the following conclusions about the etiology of MS: (i) genetic and non-genetic (environmental) factors are involved in the etiology of MS on a population basis; (ii) the familial aggregation of MS is genetic; (iii) maternal factors do not influence the risk for siblings to develop MS; and (iv) MS appears to be oligogenic. The present paper describes the rationale and methodology for the CCPGSMS-Phase 2.Methods:The CCPGSMS-Phase 2 is a nation-wide collaborative effort involving all the 15 Canadian MS clinics. A series of structured questionnaires is administered to MS index cases, spouse controls and mothers of index cases and spouse controls (if available) by trained interviewers. Blood samples are taken for molecular genetic studies. This national effort is coordinated by the MS Clinics in Vancouver and London.Results:The CCPGSMS-Phase 2 is in progress so specific results are not available. The study is designed to (i) increase the database for genetic epidemiological/molecular genetic research and (ii) gather population-based data to further our understanding of the non-genetic factors in the etiology of MS.Conclusions:It is anticipated that the results from this study will impact on the eventual prevention, cure and treatment of MS.

scholarly journals Molecular genetic basis of flower colour variegation in Linaria

2007 ◽  
Vol 89 (3) ◽  
pp. 129-134 ◽  
Author(s):  
LISETE GALEGO ◽  
JORGE ALMEIDA
Keyword(s):  
Molecular Basis ◽  
Genetic Basis ◽  
Anthocyanin Biosynthesis ◽  
Molecular Genetic ◽  
Flower Colour ◽  
Close Relative ◽  
Model Species ◽  
Gene Encoding ◽  
Genetic Studies ◽  
Molecular Genetic Basis

SummaryTo identify transposons that may be of use for mutagenesis we investigated the genetic molecular basis of a case of flower colour variegation in Linaria, a close relative of the model species Antirrhinum majus. We show that this variegation is attributable to an unstable mutant allele of the gene encoding dihydroflavonol-4-reductase, one of the enzymes required for anthocyanin biosynthesis. This allele carries an insertion of a transposon belonging to the CACTA family (Tl1, Transposon Linaria 1) which blocks its expression thus conferring an ivory flower colour phenotype. Tl1 is occasionally excised in dividing epidermal cells to produce clonal patches of red tissue on the ivory background, and in cells giving rise to gametes to generate reversion alleles conferring a fully coloured phenotype. This finding may open the way for targeted transposon-mutagenesis in Linaria, and hence for using this genus in comparative genetic studies.

scholarly journals Genetics of obsessive–compulsive disorder

2020 ◽  
pp. 995-1002
Author(s):  
Gerald Nestadt ◽  
Jack Samuels
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Genetic Basis ◽  
Rare Variants ◽  
Association Studies ◽  
Molecular Genetic ◽  
Twin Studies ◽  
Obsessive Compulsive ◽  
Genetic Studies ◽  
Compulsive Disorder ◽  
Candidate Gene Association

There is strong evidence that obsessive–compulsive disorder (OCD) has a genetic basis. This chapter focuses on recent findings on the genetics of OCD from genetic epidemiological (family and twin) studies, as well as from molecular genetic studies (linkage studies, candidate gene association studies, and genome-wide association studies), of common and rare variants associated with OCD. The chapter discusses the challenges and prospects in elucidating the specific genetic basis of OCD, including the genetic complexity and phenotypic definition. Genetic studies in humans and animals offer great promise in elucidating the pathophysiology of OCD and in developing more rational treatment approaches.

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