R Plomin

..A callous and unemotional disposition is an indicator of early-onset antisocial behaviour...

..Such an approach can be readily applied to the assessment of disease phenotypes reducing the time, cost and amount of DNA starting material required for large-scale epigenetic analyses...

..We demonstrate that this approach can be effectively applied to the truly genomewide Affymetrix GeneChip Mapping 500 K Array...

..An efficient solution is to genotype case and control DNA pools using SNP microarrays. We demonstrate that this is practical using DNA pools of 100 individuals...

..DNA will revolutionize psychological research and treatment during the coming decades...

..g is one of the most heritable behavioural traits, and genes that contribute to the heritability of g will certainly be identified. What are the scientific and social implications of finding genes associated with g?..

..Finally, the authors discuss behavioral genomics and predict that DNA will revolutionize psychological research and treatment early in the 21st century...

..The seven papers in this special section chart where we are in the quest for quantitative trait loci (QTLs) in key areas of child psychology and psychiatry such as reading and hyperactivity. But we are not there yet...

..Third, genes that affect one learning disability are also likely to affect other learning disabilities. These quantitative genetic findings have far-reaching implications for molecular genetics and neuroscience as well as psychology...

....

..To review recent developments in the study of nonshared environment; that is, the environmental influences that make children growing up in the same family different, rather than similar...

....

..Molecular genetics, one of the most energetic and exciting areas of science, is slowly but surely coming to educational psychology...

..Instead we are using the same design to screen markers such as cSNPs and SNPs in regulatory regions that are likely to include functional polymorphisms in which the marker can be presumed to be the QTL...

..Deoxyribonucleic acid (DNA) will integrate life sciences research on intelligence; bottom-up molecular biological research will meet top-down psychological research in the brain...

....

..The present SNP strategy combined with DNA pooling and large samples represents a step towards identifying QTLs of small effect size associated with complex traits in the postgenomic era when all functional polymorphisms will be known...

..11 (P < 0.00000003) with g. This shows that future SNP sets that will incorporate many more SNPs could be useful for predicting genetic risk and for investigating functional systems of effects from genes to brain to behavior...

..This index, which has a sib correlation of 0.22, will be used as a quantitative phenotype in the molecular genetic phase of GENESiS...

..The implications of this result for theories of cognitive development are discussed...

..In this way, generalist genes may prove invaluable in integrating top-down and bottom-up approaches to the systems biology of the brain...

..Although replication is necessary, these results suggest that the genetic etiology of low g during infancy and early childhood is at least as great as the heritability of g in the unselected population...

..Because the genetic and environmental origins of V and P delays in infancy differ, they are better considered separately rather than combined into a composite measure of general cognitive delay...

....

..The results validate the use of parental report questionnaire data to determine zygosity in infancy...

..Similar estimates were found for unselected individual differences and selected extreme groups. A framework is proposed that focuses on quantifying the etiologies of disorders (QED) as measured on continuous dimensions...

..These findings have important implications for attempts to identify specific genes responsible for genetic influence on personality...

..We tested the hypothesis that, in early childhood, overweight is as heritable as weight and that weight and overweight are linked genetically...

....

..CONCLUSIONS: These first results of the application of DNA pooling in systematic analysis of allelic association are encouraging...

..These data suggest that higher SSADH activity is associated with higher intelligence across the general population. The effect is small, with each allele having an effect size translating to about 1.5 IQ points...

....

....

....

..Results were discussed in light of the potential contributions of development behavioural genetic research in understanding individual differences in the stability and change of maladjustment...

..The purpose of this paper is to recommend this technique to the behavioral genetics community and to present results of our use of this technique to obtain DNA by mail for 114 2-year-olds and 116 adults...

..A general cognitive ability (g) appears to underlie the performance of HS mice on a battery tapping diverse cognitive demands...

..Because the children from the families with obese parents were not yet overweight, differences observed in the two types of families are more likely to be causes than effects of obesity...

..We conclude that QTL effect sizes, even for highly heritable common disorders and quantitative traits such as early reading disability and ability, might be much smaller than previously considered...

..This emphasises the potential importance of X-linked genes in the developmental trajectories of behaviour and mental health and the need to stratify genetic analysis of behaviours by gender...

..Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples...

..Although the genetic and environmental factors of asthma have been investigated in adolescence and adulthood, no previous studies have focused on the early development of asthma...

..For the foreseeable future, association studies involving whole-genome scanning will combine strategies using both single-nucleotide and simple-sequence-repeat polymorphisms...

..In this article, I argue that a mouse model of g could provide a powerful analytic tool for exploring cognitive processes that are linked functionally by genes...

..Although the power of the sibling data is low, the combined findings from the two designs suggest that genetic effects on depressive symptoms in childhood may be somewhat smaller than previously estimated in twin studies...

....

....

..However, little is known about the etiology of co-morbidity for the disability extremes of reading and mathematics...

..More broadly, our experience demonstrates the potential for collaborative exploratory visualization to act as a lingua franca for large-scale interdisciplinary research...

..Molecular genetic research is beginning to identify quantitative trait loci that are associated with the genetically related emotional domains of neuroticism, anxiety and depression...

....

..We assessed the relative contribution of genes and environment for two aspects of appetite that have been implicated in obesity...

..Results are interpreted in light of contribution of genetic studies to debates on child and adolescent psychopathology...

..002). This suggests that, within the normal spectrum of allele length, increased repeat numbers may have a limiting influence on cognitive performance...

..Appropriate modelling of life events in linkage and association analyses should help to identify QTLs for depression and anxiety...

....

....

....

..There are now some opportunities for direct translational research but there is a much greater need for hypothesis-based bridging studies that occupy a crucial mid-phase in the pathway from science findings to health benefits...

..We conclude that, despite the considerable differences in mathematics curricula from 7 to 9 years, the same genetic effects largely operate at the two ages...

..Despite current interest in attachment disorder, there is concern about its discrimination from other disorders and an unproven assumption of an environmental aetiology...

..The TEDS dataset is proving valuable in genome-wide association research that tries to identify some of the many genes responsible for the ubiquitous heritability of behavior...

..The basis for this association is poorly understood. How early language is related to each of the triad of impairments characteristic of ASDs is also in need of clarification...

..Language acquisition is predictive of successful reading development, but the nature of this link is poorly understood...

..However, to date, it is not known whether the association between genetic variation in FTO and obesity is mediated through effects on energy intake or energy expenditure...

..The contribution of genetic factors in the persistence of and early recovery from stuttering was assessed...

..To understand the overlap between the etiology of obesity and normal variation in BMI in children...

..Similar to GWA analyses of other complex traits, it is likely that most of the heritable variation in environmental measures such as family chaos is due to many genes of very small effect size...

..We conclude that low mathematical performance is the quantitative extreme of the same genetic and environmental factors responsible for variation throughout the distribution...

..These conclusions have far-reaching implications for education and child development as well as for molecular genetics and neuroscience...

....

..The heritability difference was even more pronounced in magnitude when hyperactive symptoms were controlled. CU traits thus appear to index one valid way of sub-typing children with early-onset AB...

..This study takes an individual differences approach to determine the degree of phenotypic and aetiological overlap between autistic traits and ADHD behaviours in the general population...

..We conclude that Internet testing can be reliable and valid for collecting cognitive test data on large samples even for children as young as 10 years...

..This study investigated, in a community sample, the aetiology of ADHD-like traits and the aetiological overlap between the two dimensions that define the ADHD disorder...

..Body mass index (BMI) has been shown to be highly heritable, but most studies were carried out in cohorts born before the onset of the "obesity epidemic."..

..The purpose of the present study was to test the developmental origins of some of these associations in a large longitudinal sample of children...

..We also found evidence of genetically mediated child effects; in which genetically influenced antisocial behavior evoke parental negativity towards the child...

..Parents who encourage imitation may also tend to foster the development of language, pretence, and socially insightful behavior...

....

..To examine the etiologies of covariation of childhood sleep problems and other behavioral/emotional problems in young children...

....

....

..Third, the authors explored the influence of family environment variables. Fourth, the authors sought interactions between parental familial vulnerability and family environment...

....

..These results suggest that although some dimensions of peers are somewhat mediated by genetic factors, nonshared environmental influence is substantial...

..This finding held even when we excluded those children with language impairment whose nonverbal score indicated general cognitive delay. These results point to a general genetic factor that includes both language and nonverbal problems...

..Furthermore, measures of parental education and the child's history of ear infections failed to substantially improve the prediction...

..49, which is significantly greater than heritability for the rest of the population in early childhood. These results suggest that mild mental impairment is a good target for neuroscience research on global brain function and dysfunction...

..However, little is known about the genetics of these categories and especially about the phenotypic and genetic structure of related behaviours in pre-school children...

....

..We found weak evidence for association with COMT genotype, when the females and males were considered separately, and for MAOA genotype in males only. There was no significant interaction between COMT and MAOA...

..DNA has been obtained so far for more than 4000 pairs and is being used initially in molecular genetic studies of language problems and hyperactivity...

..72 heritability and 0.10 shared environment). The strong genetic component, which this study confirms, is not unitary but distributes differently across the phenotypic aspects of otitis media and probably across pathogenetic stage...

..2) around 64 cM (43-70 cM) near marker D1S2892 and another on chromosome 6p (LOD 2.7) around 47 cM (34-63 cM) near marker D6S1610. Further exploratory sex-specific analyses suggested that these QTLs might have sex-limited effects...

..Modeling results suggested that genetic factors mediated phenotypic stability throughout this entire period, whereas most age-to-age instability appeared to be due to nonshared environmental influences...

....

..Using longitudinal genetic analyses, the authors conclude that genetic effects account for both change and continuity in prosocial behavior and nonshared environment contributes mainly to change...

..64 and shared environment correlation of 1.00. We conclude that to a large extent, the same genetic and environmental factors underlie the development of individual differences in a wide range of linguistic skills...

....

..That is, the genetic input into brain structure and function is general not specific...

..abstract_text> ..

....

..Identifying genes associated with reading disability will eventually lead to better diagnoses, individually tailored treatments, and interventions that can prevent the development of reading disability. ..

....