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This article reports the first camera-trap record of twin caracal kittens in Saudi Arabia. The caracal is a widespread wild felid in Arabia, but information on its reproduction in the region is scarce. The camera-trap photographs taken in August 2023 show a female caracal with her twin kittens in the Asir region. The caracal population in Saudi Arabia is considered rare, but recent surveys confirm their presence and breeding in the south-west of the country. The caracal is categorized as Least Concern on the IUCN Red List, but regional assessments suggest it is threatened or declining in certain areas. [Extracted from the article]

Objective: To investigate the association of folic acid (FA) supplementation with birth weight, the risk of small for gestational age (SGA) and low birth weight (LBW) in singleton and twin pregnancy.Design: A population-based cross-sectional survey.Setting: Twenty counties and ten districts in Shaanxi Province of northwestern China, 2013.Participants: 28 174 pregnant women with their infants, covering 27 818 single live births and 356 twin live births.Results: The prevalence of FA supplementation in singletons and twins was 63·9 and 66·3 %. The mean birth weight was 3267 (sd 459·1) g, 2525 (sd 534·0) g and 2494 (sd 539·5) g; the prevalence of SGA was 14·3, 51·4 and 53·4 %; the prevalence of LBW was 3·4, 42·4 and 46·6 % among singleton, twin A and twin B, respectively. Compared with non-users, women with FA supplementation were (β 17·3, 95 % CI 6·1, 28·4; β 166·3, 95 % CI 69·1, 263·5) associated with increased birth weight, lower risk of SGA (OR 0·85, 95 % CI 0·80, 0·92; OR 0·45, 95 % CI 0·30, 0·68) and LBW (OR 0·82, 95 % CI 0·71, 0·95; OR 0·50, 95 % CI 0·33, 0·75) in singletons and twins, and more prominent effects in twins. Moreover, there were significant interactions between FA supplementation and plurality on birth weight, SGA and LBW.Conclusions: The present study suggests the association of periconceptional 0·4 mg/d FA supplementation with increased birth weight and reduced risk of SGA and LBW in both singletons and twins, and this association may be more prominent in twins. [ABSTRACT FROM AUTHOR]

High protein intake in young children is associated with excess gains in weight and body fat, but the specific role of different protein sources has yet to be described. The study aimed to investigate the role of different types of protein in the post-weaning stage on weight, BMI and overweight/obesity at 60 months. Intakes of animal, dairy and plant protein and a dietary pattern characterising variation in protein types at 21 months of age were estimated using a 3-d diet diary in a cohort of 2154 twins; weight and height were recorded every 3 months from birth to 60 months. Longitudinal mixed-effect models investigated the associations between sources of protein intake or dietary pattern scores and BMI, weight and overweight/obesity from 21 months up to 60 months. Adjusting for confounders, dairy protein intake at 21 months was positively associated with greater weight (46 (95 % CI 21, 71) g and BMI up to 60 months (0·04 (95 % CI 0·004, 0·070) kg/m2) and the odds of overweight/obesity at 3 years (OR 1·12; 95 % CI 1·00, 1·24). Milk showed associations of similar magnitude. A dietary pattern low in dairy protein and high in plant protein was associated with lower weight gain up to 60 months, but not overweight/obesity. Intake of dairy products in early childhood is most strongly associated with weight gain, compared with other protein sources. A dietary pattern characterised by lower protein intake and greater protein source diversity at 2 years may confer a lower risk of excess weight gain. [ABSTRACT FROM AUTHOR]

Metabolomic and microbiome profiling are promising tools to identify biomarkers of food intake and health status. The individual's genetic makeup plays a significant role on health, metabolism, gut microbes and diet and twin studies provide unique opportunities to untangle gene–environment effects on complex phenotypes. This brief review discusses the value of twin studies in nutrition research with a particular focus on metabolomics and the gut microbiome. Although, the twin model is a powerful tool to segregate the genetic component, to date, very few studies combine the twin design and metabolomics/microbiome in nutritional sciences. Moreover, since the individual's diet has a strong influence on the microbiome composition and the gut microbiome is modifiable (60 % of microbiome diversity is due to the environment), future studies should target the microbiome via dietary interventions. [ABSTRACT FROM PUBLISHER]

Dietary fat intake is correlated with increased insulin resistance (IR). However, it is unknown whether gene–diet interaction modulates the association. This study estimated heritability of IR measures and the related genetic correlations with fat intake, and tested whether dietary fat intake modifies the genetic influence on type 2 diabetes (T2D)-related traits in Chinese child twins. We included 622 twins aged 7–15 years (n 311 pairs, 162 monozygotic (MZ), 149 dizygotic (DZ)) from south-eastern China. Dietary factors were measured using FFQ. Structural equation models were fit using Mx statistical package. The intra-class correlation coefficients for all traits related to T2D were higher for MZ twins than for DZ twins. Dietary fat and fasting serum insulin (additive genetic correlation (rA) 0·20; 95 % CI 0·08, 0·43), glucose (rA 0·12; 95 % CI 0·01, 0·40), homoeostasis model of assessment-insulin resistance (Homa-IR) (rA 0·22; 95 % CI 0·10, 0·50) and the quantitative insulin sensitivity check index (Quicki) (rA−0·22; 95 % CI −0·40, 0·04) showed strong genetic correlations. Heritabilities of dietary fat intake, fasting glucose and insulin were estimated to be 52, 70 and 70 %, respectively. More than 70 % of the phenotypic correlations between dietary fat and insulin, glucose, Homa-IR and the Quicki index appeared to be mediated by shared genetic influence. Dietary fat significantly modified additive genetic effects on these quantitative traits associated with T2D. Analysis of Chinese twins yielded high estimates of heritability of dietary fat intake and IR. Genetic factors appear to contribute to a high proportion of the variance for both insulin sensitivity and IR. Dietary fat intake modifies the genetic influence on blood levels of insulin and glucose, Homa-IR and the Quicki index. [ABSTRACT FROM PUBLISHER]

It is unknown whether influences of midlife whole diet on the long-term CHD mortality risk are independent of genetic and common environmental factors or familial predisposition. We addressed this question prospectively using data from the National Heart, Lung, and Blood Institute Twin Study. We included 910 male twins who were middle-aged and had usual diet assessed with nutritionist-administered, crosschecked dietary history interview at baseline (1969-1973). Moderation-quantified healthy diet (MQHD), a dietary pattern, was created to evaluate a whole diet. Primary outcome was time-to-CHD death. Hazard ratios (HR) were estimated using frailty survival model. Known CHD risk factors were controlled. During the follow-up of 40 years through 31 December 2009, 113 CHD deaths, 198 total cardiovascular deaths and 610 all-cause deaths occurred. In the entire cohort, the multivariable-adjusted HR for the overall association (equivalent to a general population association) was 0·76 (95% CI 0·66, 0·88) per 10-unit increment in the MQHD score for CHD, and the multivariable-adjusted HR for a twin with a MQHD score ten units higher than his co-twin brother was 0·79 (95% CI 0·64, 0·96, P=0·02) for CHD independent of familial predisposition. Similar results were found for a slightly more food-specified alternative moderation-quantified healthy diet (aMQHD). The between-pair association (reflecting familial influence) was significant for CHD for both MQHD and aMQHD. It is concluded that associations of MQHD and aMQHD with a lower long-term CHD mortality risk are both nutritionally and familially affected, supporting their use for dietary planning to prevent CHD mortality. [ABSTRACT FROM AUTHOR]

Background: Twin studies have lacked statistical power to apply advanced genetic modelling techniques to the search for cognitive endophenotypes for bipolar disorder.Aims: To quantify the shared genetic variability between bipolar disorder and cognitive measures.Method: Structural equation modelling was performed on cognitive data collected from 331 twins/siblings of varying genetic relatedness, disease status and concordance for bipolar disorder.Results: Using a parsimonious AE model, verbal episodic and spatial working memory showed statistically significant genetic correlations with bipolar disorder (rg = |0.23|-|0.27|), which lost statistical significance after covarying for affective symptoms. Using an ACE model, IQ and visual-spatial learning showed statistically significant genetic correlations with bipolar disorder (rg = |0.51|-|1.00|), which remained significant after covarying for affective symptoms.Conclusions: Verbal episodic and spatial working memory capture a modest fraction of the bipolar diathesis. IQ and visual-spatial learning may tap into genetic substrates of non-affective symptomatology in bipolar disorder. [ABSTRACT FROM AUTHOR]

Data on the diets of young children in the UK are limited, despite growing evidence of the importance of early diet for long-term health. We used the largest contemporary dietary data set to describe the intake of 21-month-old children in the UK. Parents of 2336 children aged 21 months from the UK Gemini twin cohort completed 3-d diet diaries in 2008/2009. Family background information was obtained from questionnaires completed 8 months after birth. Mean total daily intakes of energy, macronutrients (g and %E) and micronutrients from food and beverages, including and excluding supplements, were derived. Comparisons with UK dietary reference values (DRV) were made using t tests and general linear regression models, respectively. Daily energy intake (kJ), protein (g) and most micronutrients exceeded DRV, except for vitamin D and Fe, where 96 or 84 % and 70 or 6 % of children did not achieve the reference nutrient intake or lower reference nutrient intake (LRNI), respectively, even with supplementation. These findings reflect similar observations in the smaller sample of children aged 18–36 months in the National Diet and Nutrition Survey. At a population level, young children in the UK are exceeding recommended daily intakes of energy and protein, potentially increasing their risk of obesity. The majority of children are not meeting the LRNI for vitamin D, largely reflecting inadequate use of the supplements recommended at this age. Parents may need more guidance on how to achieve healthy energy and nutrient intakes for young children. [ABSTRACT FROM AUTHOR]

Traditionally, it has been widely acknowledged that genes together with adult lifestyle factors determine the risk of developing some metabolic diseases such as insulin resistance, obesity and diabetes mellitus in later life. However, there is now substantial evidence that prenatal and early-postnatal nutrition play a critical role in determining susceptibility to these diseases in later life. Maternal nutrition has historically been a key determinant for offspring health, and gestation is the critical time window that can affect the growth and development of offspring. The Developmental Origins of Health and Disease (DOHaD) hypothesis proposes that exposures during early life play a critical role in determining the risk of developing metabolic diseases in adulthood. Currently, there are substantial epidemiological studies and experimental animal models that have demonstrated that nutritional disturbances during the critical periods of early-life development can significantly have an impact on the predisposition to developing some metabolic diseases in later life. The hypothesis that epigenetic mechanisms may link imbalanced early-life nutrition with altered disease risk has been widely accepted in recent years. Epigenetics can be defined as the study of heritable changes in gene expression that do not involve alterations in the DNA sequence. Epigenetic processes play a significant role in regulating tissue-specific gene expression, and hence alterations in these processes may induce long-term changes in gene function and metabolism that persist throughout the life course. The present review focuses on how nutrition in early life can alter the epigenome, produce different phenotypes and alter disease susceptibilities, especially for impaired glucose metabolism. [ABSTRACT FROM PUBLISHER]

Investigations into the genetic architecture of diet–disease relationships are particularly relevant today with the global epidemic of obesity and chronic disease. Twin studies have demonstrated that genetic makeup plays a significant role in a multitude of dietary phenotypes such as energy and macronutrient intakes, dietary patterns, and specific food group intakes. Besides estimating heritability of dietary assessment, twins provide a naturally unique, case–control experiment. Due to their shared upbringing, matched genes and sex (in the case of monozygotic (MZ) twin pairs), and age, twins provide many advantages over classic epidemiological approaches. Future genetic epidemiological studies could benefit from the twin approach particularly where defining what is ‘normal’ is problematic due to the high inter-individual variability underlying metabolism. Here, we discuss the use of twins to generate heritability estimates of food intake phenotypes. We then highlight the value of discordant MZ pairs to further nutrition research through discovery and validation of biomarkers of intake and health status in collaboration with cutting-edge omics technologies. [ABSTRACT FROM PUBLISHER]

Ageing is a complex multifactorial process, reflecting the progression of all degenerative pathways within an organism. Due to the increase of life expectancy, in recent years, there is a pressing need to identify early-life events and risk factors that determine health outcomes in later life. So far, genetic variation only explains ~20–25 % of the variability of human survival to age 80+. This clearly implies that other factors (environmental, epigenetic and lifestyle) contribute to lifespan and the rate of healthy ageing within an individual. Twin studies in the past two decades proved to be a very powerful tool to discriminate the genetic from the environmental component. The aim of this review is to describe the basic concepts of the twin study design and to report some of the latest studies in which high-throughput technologies (e.g. genome/epigenome-wide assay, next generation sequencing, MS metabolic profiling) combined with the classical twin design have been applied to the analysis of novel ‘omics’ to further understand the molecular mechanisms of human ageing. [ABSTRACT FROM PUBLISHER]

Background: The differential impact of depression across different periods in life on mortality remains inconclusive. We aimed to examine the association of depression that occurs at different age with all-cause mortality, and to explore the roles of dementia, as well as genetic and early-life environmental factors, in this association., Methods: From the Swedish Twin Registry, 44,919 twin individuals were followed for up to 18 years. Depression was ascertained using the National Patient Registry and categorized as early-life (<45 years), midlife (45-64 years), and late-life (≥65 years) depression according to the age of the first diagnosis. Deaths were identified through the Cause of Death Register. Generalized estimating equation, generalized structural equation, and conditional logistic regression were used for unmatched, mediation, and co-twin matched analyses, respectively., Results: In unmatched analyses, the multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of mortality were 1.71 (1.46-2.00) for depression at any age, 1.72 (1.36-2.17) for early-life, 1.51 (1.19-1.90) for midlife, and 4.10 (2.02-8.34) for late-life depression. Mortality was significantly higher in individuals with late-life depression than those with earlier-life depression ( p < 0.05). The mediation analysis showed that 59.83% of the depression-mortality association was mediated by dementia. No significant difference in ORs between the unmatched and co-twin matched analyses was observed ( p = 0.09)., Conclusions: Depression is associated with an increased risk of all-cause mortality, and dementia mediates approximately 60% of the impact of depression on mortality in late life. Genetic and early-life environmental factors may not play a significant role in the depression-mortality association.

The large hippopotamus I Hippopotamus amphibius i is categorized as Vulnerable on the IUCN Red List. According to data from the Association of Zoos and Aquariums (AZA), of the 561 recorded births among hippopotamuses in AZA institutions from 1880 to 2021, only 6 (1%) were twins. Given the precarious status of hippopotamuses in Nigeria, our observation of twins is encouraging. [Extracted from the article]

By surveying extensive epidemiological behavioural and sexual risk factors in a Korean twin cohort, risk factors for human papillomavirus (HPV) infection were investigated in South Korea. A total of 912 vaginal specimens were collected from the Healthy Twin Study, consisting of twins and their families. A range of epidemiological, behavioural, and sexual activity characteristics were evaluated using multivariate logistic regression analyses of family and twin relationships, adjusted to elucidate the risk factors for HPV infection. Of the various epidemiological characteristics, the possibility of extramarital affairs [odds ratio (OR) 2·48, 95% confidence interval (CI) 1·02–6·02] significantly increased the prevalence of HPV infection. Our multivariate regression analysis indicated that oral contraceptive use (OR 40·64, 95% CI 0·99–1670·7) and history of sexually transmitted disease (OR 2·56, 95% CI 0·93–7·10) were strongly associated with an increase in HPV infection. On the other hand, more frequent vaginal douching (OR 0·32, 95% CI 0·13–0·77) significantly decreased the prevalence of HPV infection. Our results suggested that HPV infection is associated with both biological and behavioural factors. [ABSTRACT FROM AUTHOR]

Cobalamin (Cbl) is an essential B vitamin involved in the normal functioning of the nervous system, the formation of key components of blood, DNA synthesis and methylation, and energy production. Physiological levels of Cbl vary greatly within populations, although the basis for this variability remains largely unknown. We conducted a twin study to characterise the basis of variation in plasma Cbl levels and to test whether common genetic polymorphisms in genes known to cause defects in inborn errors of Cbl metabolism and transport are also associated with mean plasma Cbl levels in the general population. The present results showed that plasma levels of Cbl were heritable, with genetic and phenotypic variance increasing with age, and levels significantly correlated with age, BMI, exercise, alcohol consumption, smoking status, social class and folate levels, which collectively accounted for up to 15% of Cbl variation. Of eight genes responsible for the defects of the Cbl metabolic pathway (cblA–G and mut), MMAA, MMACHC, MTRR and MUT harboured polymorphisms that showed evidence of association with Cbl levels. Characterisation of the heritable component of variation in Cbl levels can facilitate the early diagnosis and prognosis of Cbl insufficiency/deficiency in individuals at a higher risk of associated diseases. [ABSTRACT FROM AUTHOR]

Infectious mononucleosis is a clinical manifestation of primary Epstein–Barr virus infection. It is unknown whether genetic factors contribute to risk. To assess heritability, we compared disease concordance in monozygotic to dizygotic twin pairs from the population-based California Twin Program and assessed the risk to initially unaffected co-twins. One member of 611 and both members of 58 twin pairs reported a history of infectious mononucleosis. Pairwise concordance in monozygotic and dizygotic pairs was respectively 12·1% [standard error (s.e.)=1·9%] and 6·1% (s.e.=1·2%). The relative risk (hazard ratio) of monozygotic compared to dizygotic unaffected co-twins of cases was 1·9 [95% confidence interval (CI) 1·1–3·4, P=0·03], over the follow-up period. When the analysis was restricted to same-sex twin pairs, that estimate was 2·5 (95% CI 1·2–5·3, P=0·02). The results are compatible with a heritable contribution to the risk of infectious mononucleosis. [ABSTRACT FROM AUTHOR]

ObjectiveTo determine the association between long-term leisure-time physical activity/inactivity and eating behaviours in twin pairs discordant for physical activity for 30 years.DesignCo-twin control design with cross-sectional data collection using questionnaire on eating habits and 5 d food diary. Differences in eating behaviours between physically active and inactive co-twins were analysed with pairwise tests.SettingFinland.SubjectsSixteen same-sex twin pairs (seven monozygotic and nine dizygotic, mean age 60 years) discordant for physical activity, selected from the Finnish Twin Cohort on the basis of physical activity discordance for 30 years, blinded to their possible differences in eating behaviours.ResultsThe eating habits questionnaire revealed that physically active co-twins more frequently reported that it is easy to eat according to need, whereas overeating and/or restrictive eating was more common among the inactive co-twins (P = 0·035). Avoiding calories was more common among the active than inactive co-twins (P = 0·034). Based on food diaries the physically active co-twins had daily energy intake on average 15·5 kJ/kg higher than their inactive co-twins (P = 0·030). The active co-twins also had a higher intake of vitamin C (P = 0·004), total water (P = 0·044), legumes and nuts (P = 0·015) and sweets (P = 0·036), as well as a lower energy-adjusted intake of meat (P = 0·013).ConclusionsThe physically active persons seem to eat more but not necessarily healthier food. However, habitual physical activity may help in eating according to need and in reaching and maintaining a healthy body composition. Therefore, it is necessary to incorporate both dietary and physical activity advice into health counselling. [ABSTRACT FROM PUBLISHER]

Background: Twin data permit decomposition of comorbidity into genetically and environmentally derived correlations. No previous twin study includes all major forms of anxiety disorder.Aims: To estimate the degree to which genetic and environmental risk factors are shared rather than unique to dimensionally scored panic disorder, generalised anxiety disorder, phobias, obsessive-compulsive disorder and post-traumatic stress disorder.Method: Data obtained from 2801 young-adult Norwegian twins by means of the Composite International Diagnostic Interview were analysed with the Mx program.Results: A multivariate common factor model fitted best. The latent liability to all anxiety disorders was substantially more heritable (54%) than the individual disorders (23% to 40%). Most of the genetic effect was common to the disorders. Genes contributed just over 50% to the covariance between liabilities.Conclusions: The five anxiety disorders all share genetic and environmental risk factors. This has implications for the revision of the anxiety disorder section in DSM-V. [ABSTRACT FROM AUTHOR]

The article comments on the conclusion of political scientists John Alford, Carolyn Funk and John Hibbing after using the classical twin method that political ideologies are influenced by genetics. Human twins were often used by researchers in attempts to assess the degree of genetic influence on behavioral traits. Empirical evidence present an argument that trait relevant equal environments assumptions have been violated.

The article comments on the value of twin studies in understanding the role of genetics in complex human behavior. The best approach is to test for and control violations of the equal environments assumption (EEA) on heritability estimates rather than rejecting empirical evidence because of possible EEA violations. Twin studies establish the genetic component to political orientations.

Background: Despite current interest in attachment disorder, there is concern about its discrimination from other disorders and an unproven assumption of an environmental aetiology.Aims: To test whether behaviours suggestive of attachment disorder are distinct from other childhood behavioural and emotional problems and are solely environmentally determined.Method: In a community sample of 13,472 twins, we carried out factor analysis of questionnaire items encompassing behaviours indicative of attachment disorder, conduct problems, hyperactivity and emotional difficulties. We used behavioural genetic model-fitting analysis to explore the contribution of genes and environment.Results: Factor analysis showed clear discrimination between behaviours suggestive of attachment disorder, conduct problems, hyperactivity and emotional problems. Behavioural genetics analysis suggested a strong genetic influence to attachment disorder behaviour, with males showing higher heritability.Conclusions: Behaviours suggestive of attachment disorder can be differentiated from common childhood emotional and behavioural problems and appear to be strongly genetically influenced, particularly in boys. [ABSTRACT FROM AUTHOR]

Background: Depression rises markedly in adolescence, a time when increased and new genetic influences have been reported.Aims: To examine'new'and'stable' genetic and environmental factors on depressive symptoms in adolescence and young adulthood.Method: A questionnaire survey investigated a sample of twin and sibling pairs at three time points over an approximately 3-year period. Over 1800 twin and sibling pairs reported depressive symptoms at the three time points. Data were analysed using multivariate genetic models.Results: Depressive symptoms at all time points were moderately heritable with substantial non-shared environmental contributions. Wave 1 genetic factors accounted for continuity of symptoms at waves 2 and 3. 'New'genetic effects at wave 2 also influenced wave 3 symptoms. New non-shared environmental influences emerged at each time point.Conclusions: New genetic and environmental influences may explain age-related increases in depression across development. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189 dizygotic young adult male twin pairs. Increased knowledge about interactions between genes and environment may provide insight into why some individuals are more prone to obesity than others.Design: Information about PA, BMI, dietary habits, WC and potential confounders was collected by questionnaire in 1998 and 2002. The cohort data were analysed by mixed linear models.Results: Twins with low PA attained larger WC than twins with high PA (difference 2.5 cm; 95% confidence interval (CI) 1.3, 3.6). The twins with the lowest fibre intake were found to have attained the highest WC and to have increased most in BMI (difference between highest and lowest fibre intakes: 1.6 cm, 95% CI 0.4, 2.9 and 0.45 kg m−2, 95% CI 0.15, 0.76, respectively). Furthermore, our results suggested the presence of interactions so that twins with genetic susceptibility to obesity were more prone to have larger WC if sedentary than twins without genetic susceptibility.Conclusion: PA and a diet rich in fibre may be protective against weight gain among younger adult men. An interaction between PA, genes and attained WC is a novel finding which needs confirmation by other studies. [ABSTRACT FROM AUTHOR]

Background: Medically unexplained disabling fatigue in young people is familial and frequently associated with depressed mood.Aims: To examine the degree of sharing of genetic and environmental influences on the symptoms of depression and fatigue in this age group.Method: The parents of twins aged 8-17 years, derived from a population-based register, completed a questionnaire regarding lifetime-ever disabling fatigue in both twins. Twins aged 11 years or over completed the Mood and Feelings Questionnaire. The genetic and environmental influences on fatigue and the relationship with depression were examined using bivariate genetic analysis.Results: Parent-rated data were obtained for 1468 twin pairs (65%) and self-rated data from 930 older twin pairs (58%). Bivariate analysis of fatigue and depression suggested that genetic and environmental influences on disabling fatigue were mainly specific to fatigue.Conclusions: Unexplained disabling fatigue in childhood is substantially familial and has mainly an independent aetiology from depression. [ABSTRACT FROM AUTHOR]

Twins can be used to investigate the biological basis for observed associations between birth weight and later disease risk, as they experience in utero growth restriction compared with singletons, which can differ in magnitude within twin pairs despite partial or total genetic identity. In the present study, sixty monozygotic and seventy-one dizygotic same-sex twin pairs aged 19???50 years and eighty-nine singleton controls matched for age, gestational age, sex, maternal age and parity were recruited from an obstetric database. Associations between fasting lipid levels and birth weight were assessed by linear regression with adjustment for possible confounding factors. Twins were significantly lighter at birth but were not significantly different in adult height, weight or lipid levels from the singleton controls. There was a significant inverse association between birth weight and both total and LDL-cholesterol levels among singleton controls (???0??53mmol/l per kg (95% CI ???0??97, ???0??09), P=0??02 and ???0??39mmol/l per kg (95% CI ???0??76, ???0??02), P=0??04, respectively), but there was no significant association between birth weight and lipid levels in either unpaired or within-pair analysis of twins. The results suggest that the in utero growth restriction and early catch-up growth experienced by twins does not increase the risk of an atherogenic lipid profile in adult life. [ABSTRACT FROM PUBLISHER]

Background: The epidemiology of chronic fatiguing illnesses in young people is poorly understood.Aims: To estimate the lifetime prevalence of different definitions of chronic fatigue in 8- to 17-year-olds.Method: Participants came from two population-based twin series. Parents completed self-report questionnaires that inquired whether either child had ever experienced more than a few days of disabling fatigue. Telephone interviews were undertaken for individuals who had experienced such an episode.Results: Questionnaires were returned by 1468 families (65% response rate) and telephone interviews were undertaken regarding 99 of the 129 subjects (77%) who had experienced fatigue. The lifetime prevalence estimates ranged from 2.34% (95% CI 1.75-2.94) for disabling fatigue lasting 3 months to 1.29% (95% CI 0.87-1.71) for a disorder resembling adult operationally defined chronic fatigue syndrome.Conclusions: From the age of 11 years, young people have similar rates and types of chronic fatiguing illnesses to adults. [ABSTRACT FROM AUTHOR]

Background: In previous functional magnetic resonance imaging (fMRI) studies, participants with schizophrenia showed decreased language lateralisation, resulting from increased activation of the right hemisphere compared with controls.Aim: To determine whether decreased lateralisation and increased right cerebral language activation constitute genetic predispositions for schizophrenia.Method: Language activation was measured using fMRI in 12 right-handed monozygotic twin pairs discordant for schizophrenia and 12 healthy right-handed monozygotic twin pairs who were twin pairs who were matched for gender, age and education.Results: Language lateralisation was decreased in discordant twin pairs compared with the healthy twin pairs. The groups did not differ in activation of the language-related areas of the left hemisphere, but language-related activation in the right hemisphere was activation in the significantly higher in the discordant twin pairs than in the healthy pairs. Within the discordant twin pairs, language lateralisation was not significantly different between patients with schizophrenia and their co-twins.Conclusions: Decreased language lateralisation may constitute a genetic predisposition for schizophrenia. [ABSTRACT FROM AUTHOR]

Background: Antisocial behaviour in adult life has its roots in childhood.Aims: To explore the independent and joint effects of childhood characteristics on the persistence of antisocial behaviour into adult life.Method: A clinical sample of twins who were systematically ascertained in childhood was followed up 10-25 years later. A total of 225 twins were interviewed regarding childhood and adult psychiatric disorder, psychosocial functioning, and psychosocial and cognitive risk factors.Results: In univariate analyses, childhood hyperactivity and conduct disorder showed equally strong prediction of antisocial personality disorder (ASPD) and criminality in early and mid-adult life. Lower IQ and reading problems were most prominent in their relationships with childhood and adolescent antisocial behaviour. In multivariate modelling childhood conduct disorder and hyperactivity predicted adult ASPD even when intervening risk factors were accounted for. The number of hyperactive and conduct symptoms also predicted adult outcome.Conclusions: Childhood disruptive behaviour has powerful long-term effects on adult antisocial outcomes, which continue into middle adulthood. The importance of number of symptoms, the presence of disruptive disorder, and intermediate experiences highlight three areas where interventions might be targeted. [ABSTRACT FROM AUTHOR]

Background: Twin studies have found that childhood attention-deficit hyperactivity disorder (ADHD) has a strong genetic component. Estimates of heritability, the extent of non-additive genetic effects and of 'sibling contrast' effects vary between different studies.Aims: To use multiple informants to assess the extent to which observer effects influence such estimates in an epidemiological sample of twins.Method: Questionnaire packs were sent to the families and teachers of twins aged 5-16 years in the Bro Taf region of South Wales. The twins were ascertained from community paediatric registers.Results: Both parent- and teacher- rated data showed a high degree of heritability for ADHD measured as a symptom dimension, but the correlation between the two types of rater was modest. Bivariate analyses suggested that parent and teacher ratings reflect the effects of different genes. Self-report data from twins aged 11-16 years showed no evidence of genetic effects.Conclusions: Although ADHD is shown to be highly heritable by both parent- and teacher-rated data, the underlying genotypes may be substantially different. This has implications for study designs aiming to find genes that contribute to the disorder. [ABSTRACT FROM AUTHOR]

Focuses on the effectiveness of twins in examining the strength of heredity and environment. Extent of the similarities and differences between twins; Details of the history of twins espoused by scientist Francis Galton; Distinction between identical anf fraternal twin.

Introduction: If death is only an "accident of life", according to the word of Bichat, then it can be brutal, unexpected and traumatic Objectives: We will show here the particular relationship between these particular children and their grandparents which will lead us to understand to a certain extent the trauma of this unexpected death. Methods: Exploitation and analysis of the patient file. Results:M73 years and F 63-years are the grandparents of J and his twin 5 years. J was suffering from recurrent tonsillitis, and his doctor decided to operate on him. The day of the operation, Maccompanied J. A few minutes after the doctor announce the death of J after the anesthesia. It was a shock said M. F was inconsolable and their daughter was stronger. Mand F are received in psychiatric onemonth after the death of J. They have since the death a reviviscence syndrome with flashback of the child playing and dragging in the house. F also presents an anxio-depressive syndrome. Conclusions: M-F took care of their little sons with kindness. The intensity of investment of this relationship with these twins testifies to the shock received by M and his wife to the unexpected and brutal announcement of the death of J on the operating table. F and Msuffer from post traumatic stress disorder. This text, showing the special relationship between these grandparents and their twin little sons, also raises the problem of traumatic death. [ABSTRACT FROM AUTHOR]

Introduction: Schizophrenia is a complex psychiatric disorder-its pathogenesis remains unclear, symptomatology as well as treatment outcomes vary among patients. Objectives: To report different treatment outcomes with different treatment approaches between two female monozygotic twins suffering from schizophrenia. Methods: Patients were clinically observed after diagnosis for five years, approximately twice per year. Their functionality level was evaluated based on daily activities. Results: Both twins were diagnosed with paranoid schizophrenia during university (twin A at the age of 23, one year earlier than Twin B). Although twin A experienced a less severe premorbid disorder manifestation than her sister, she was hospitalized and treated with haloperidol, discontinued her education and minimized her social contacts, whereas twin B was treated in an outpatient setting with aripiprazole per os, was stabilized in 3 months' time, continued her studies and had a stable relationship. Twin A had a relapse 13 months after the diagnosis, experienced a second 3-month hospitalization and was discharged with amisulprid 600mg/day, refusing long-acting injectable treatment. After her sister's relapse, twin B decided to start long-acting aripiprazole to reduce the risk of another episode and protect her own functionality. Twin A had 3 more episodes in the following 3 years and is currently on clozapine, 75% disabled and without social contacts. Twin B has successfully graduated university, is married with a 5-month child and is still under long-acting injectable aripiprazole. Conclusions: Different treatment approaches may lead to different treatment outcomes in early onset schizophrenia, evenwhen patients share the same genome and environment. [ABSTRACT FROM AUTHOR]

Previous research has suggested that prenatal testosterone exposure masculinises disordered eating by comparing opposite- and same-gender twins. The objective of the current study is to replicate this finding using a sample of 439 identical and 213 fraternal females, 461 identical and 344 fraternal males, and 361 males and 371 females from opposite-gender twin pairs. Disordered eating was compared across twin types using the Eating Disorder Inventory-2. Inconsistent with previous findings, a main effect of co-twin gender was not found. Our results raise questions about the validity of prior evidence of the impact of prenatal testosterone exposure on patterns of disordered eating. [ABSTRACT FROM AUTHOR]

The article focuses on the issue regarding the development of mental health research in Sri Lanka. Psychiatry around the world provides a useful example of the mutual benefits of international collaboration in psychiatric re- search. It has been describe that collaborative research approach necessary to build research capacity in the country. The setting up of the Sri Lankan twin registry was used as an example. It highlights the need for parallel development of bioethical guidelines designed to protect the ml interest from commercial exploitation. It also permits the sufficient flexibility to support the development of new ideas.