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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study assesses the mediating role of stage of menstrual cycle in the recognition of emotional expressions. It was hypothesised that fear recognition ability would be stronger at high-oestrogen stages of the menstrual cycle. The accuracy of recognising emotional expressions was compared across 50 women who were at different stages of their menstrual cycle. It was found that accuracy to recognise emotions was significantly affected by the interaction between stages of the menstrual cycle and the emotion being displayed. Further analysis revealed that for the emotion expression of fear alone, participants were significantly more accurate at the preovulatory surge (highest oestrogen levels) than at menstruation (oestrogen levels at lowest point). The results have implications for the processes that underlie fear processing and a possible insight into the sexual dimorphism of this ability and conditions that show variations in fear recognition (e.g., autism, Turner syndrome).
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PMID:Fear recognition across the menstrual cycle. 1570 54

Autism is a neurodevelopmental disorder characterized by impairments in social skills, language, and behavior. It is now clear that autism is not a disease, but a syndrome characterized by phenotypic and genetic complexity. The etiology of autism is still poorly understood. Available evidence from a variety of sources strongly suggests that many genetic disorders are frequently associated with autism for their similar phenotypes. Based on this fact, this review begins by highlighting several principal genetic syndromes consistently associated with autism (fragile X, tuberous sclerosis, Angelman syndrome, Pader-Willi syndrome, Rett syndrome, Down syndrome and Turner syndrome). These genetic disorders include both chromosome disorders and single gene disorders. By comparing the similar phenotype, protein marker and candidate genes, we might make some breakthrough in the mechanism of autism and other genetic disorders.
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PMID:Principal genetic syndromes and autism: from phenotypes, proteins to genes. 1641 81

We describe a new hypothesis for the development of autism, that it is driven by imbalances in brain development involving enhanced effects of paternally expressed imprinted genes, deficits of effects from maternally expressed genes, or both. This hypothesis is supported by: (1) the strong genomic-imprinting component to the genetic and developmental mechanisms of autism, Angelman syndrome, Rett syndrome and Turner syndrome; (2) the core behavioural features of autism, such as self-focused behaviour, altered social interactions and language, and enhanced spatial and mechanistic cognition and abilities, and (3) the degree to which relevant brain functions and structures are altered in autism and related disorders. The imprinted brain theory of autism has important implications for understanding the genetic, epigenetic, neurological and cognitive bases of autism, as ultimately due to imbalances in the outcomes of intragenomic conflict between effects of maternally vs. paternally expressed genes.
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PMID:Imbalanced genomic imprinting in brain development: an evolutionary basis for the aetiology of autism. 1678 May 3

One-third of women with Turner syndrome (45,X) have autism-like social and communication difficulties, despite normal verbal IQ. Deletion mapping of the X-chromosome implicated 5 Mb of Xp11.3-4 as critical for recognition of facial fear, a quantitative measure of social cognition. Variability in fear recognition accuracy in Turner syndrome suggested the existence of a quantitative trait locus (QTL) revealed by X-monosomy. We aimed to identify the gene(s) influencing fear recognition by dense mapping of the 5 Mb region. Initial regression-based association mapping of fear recognition in 93 women with Turner syndrome across the critical region was performed, using genotype data at 242 single nucleotide polymorphisms (SNPs). We identified three regions of interest, in which 52 additional SNPs were genotyped. The third region then contained four SNPs associated with fear recognition (0.0030 > P > 0.00046). We obtained an independent sample of 77 Turner syndrome females that we genotyped for 77 SNPs in the initial regions of interest. Region three showed association in the same direction, maximal at SNPs rs7055196 and rs7887763 (P = 0.022 each). Four SNPs in strong linkage disequilibrium (LD), including this pair, span 40 kb within a novel transcript, EF-hand domain containing 2 (EFHC2). In the combined Turner syndrome samples, the most strongly associated SNP (P = 0.00007) has frequency of 8.8% and an estimated effect size accounting for over 13% of the variance in fear recognition. EFHC2 shows genealogy and extended LD consistent with directional selection. This novel QTL may influence social cognition in the general population and in autism.
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PMID:Identification of EFHC2 as a quantitative trait locus for fear recognition in Turner syndrome. 1716 67

The present study was carried out to examine physiological arousal modulation (heart activity and skin conductance, across baseline and cognitive tasks, in females with fragile X or Turner syndrome and a comparison group of females with neither syndrome. Relative to the comparison group, for whom a greater increase in skin conductance was associated with poor arithmetic performance and less risk taking behavior, females with fragile X displayed a minimal increase in heart activity that was nevertheless associated with poor performance on mental arithmetic. In contrast, no arousal-cognitive performance relationship emerged for the group with Turner syndrome. Taken together, our findings suggest that distinct profiles of arousal modulation might be associated with cognitive deficits in these syndrome populations.
J Autism Dev Disord 2008 Jan
PMID:Arousal modulation in females with fragile X or Turner syndrome. 1734 Feb 2

Turner syndrome (TS) is a developmental disorder most frequently arising from the loss of a complete X chromosome (karyotype 45,XO). The disorder is characterised by physiological abnormalities (notably short stature and ovarian dysfunction), emotional anomalies (including heightened anxiety) and by a neuropsychological profile encompassing deficits in visuospatial skills, memory, attention, social cognition and emotion recognition. Moreover, TS subjects are at significantly increased risk of developing attention deficit hyperactivity disorder (ADHD) and autism. At the neuroanatomical level, TS subjects display abnormalities across a number of brain structures, including the amygdala, hippocampus and orbitofrontal cortex. The TS phenotype arises due to reduced dosage of X-linked genes, and may also be modulated by parental origin of the single X chromosome. In this review, we discuss the utility of a mouse model of TS, the 39,XO mouse, in which the parental origin of the single X chromosome can be varied. This model provides the opportunity to investigate the effects of X-linked gene dosage/parent-of-origin effects on neurobiology in the absence of gross physiological abnormalities. Initial findings indicate that several features of the TS behavioural phenotype may be accurately recapitulated in the mouse. Furthermore, as X-linked gene dosage/imprinting can influence sex-specific neurobiology, investigations in the 39,XO mouse are also likely to offer insights into why certain neuropsychiatric disorders (including ADHD and autism) affect the sexes differently.
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PMID:The 39,XO mouse as a model for the neurobiology of Turner syndrome and sex-biased neuropsychiatric disorders. 1736 75

Many of the known genetically based neurodevelopmental disorders are associated with a distinctive behavioral phenotype. As these behavioral phenotypes have been elucidated by clinical research, distinctive profiles of social traits have emerged as prominent syndromic features. This article reviews social phenotypic findings for fragile X syndrome, Down syndrome, Prader-Willi syndrome, Smith-Magenis syndrome, Turner syndrome, Williams syndrome, and velocardiofacial syndrome. An analysis of these social profiles raises several questions regarding the relationship between identified social impairments and autism and the relationship between social impairments in neurodevelopmental disorders and those found in normative child populations. The unique profile of certain of the known behavioral phenotypes also serves to distinguish several dimensions of sociability that are not readily observed in typical populations.
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PMID:Social phenotypes in neurogenetic syndromes. 1756 83

Turner syndrome (TS) is a chromosomal disorder of X-monosomy in females. A minority have impaired social responsiveness, poor discrimination of facial emotions (especially fear), and abnormal amygdala-cortical connectivity. We tested the hypothesis that abnormal gaze fixation, especially with the eye region of faces, would be associated with these features, in a similar pattern to that seen in subjects with autism. Furthermore, since these features tend to be more striking in TS women whose X chromosome is maternal in origin, we also predicted that there may be a difference within the Turner's group according to parental origin of the single X. Adults with 45,X karyotype and age and IQ matched 46,XX women were recruited and tested. Facial fear recognition was significantly worse in 45,X females than controls, but there were no group differences according to parental origin of their single X chromosome. Subsequently, we tested 45,X and 46,XX women using a remote eye-tracking device, as they viewed photographs of emotional human faces. Striking differences in scanpaths were found between the TS and controls, and within the TS group, but not according to parental origin of the X chromosome. These findings provide novel evidence for abnormal face processing in some women with TS, and indicate a potential neural mechanism underlying the difficulties in some key aspects of social cognition.
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PMID:Eye tracking and fear recognition deficits in Turner syndrome. 1863 92

I review and evaluate genetic and genomic evidence salient to the hypothesis that the development and evolution of psychotic spectrum conditions have been mediated in part by alterations of imprinted genes expressed in the brain. Evidence from the genetics and genomics of schizophrenia, bipolar disorder, major depression, Prader-Willi syndrome, Klinefelter syndrome, and other neurogenetic conditions support the hypothesis that the etiologies of psychotic spectrum conditions commonly involve genetic and epigenetic imbalances in the effects of imprinted genes, with a bias towards increased relative effects from imprinted genes with maternal expression or other genes favouring maternal interests. By contrast, autistic spectrum conditions, including Kanner autism, Asperger syndrome, Rett syndrome, Turner syndrome, Angelman syndrome, and Beckwith-Wiedemann syndrome, commonly engender increased relative effects from paternally expressed imprinted genes, or reduced effects from genes favouring maternal interests. Imprinted-gene effects on the etiologies of autistic and psychotic spectrum conditions parallel the diametric effects of imprinted genes in placental and foetal development, in that psychotic spectrum conditions tend to be associated with undergrowth and relatively-slow brain development, whereas some autistic spectrum conditions involve brain and body overgrowth, especially in foetal development and early childhood. An important role for imprinted genes in the etiologies of psychotic and autistic spectrum conditions is consistent with neurodevelopmental models of these disorders, and with predictions from the conflict theory of genomic imprinting.
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PMID:Genomic imprinting in the development and evolution of psychotic spectrum conditions. 1878 62

Recognized cases of autism spectrum disorders are on the rise. It is unclear whether this increase is attributable to secular trends in biological susceptibility, or to a change in diagnostic practices and recognition. One hint concerning etiological influences is the universally reported male excess (in the range of 4:1 to 10:1). Evidence suggests that genetic influences from the X chromosome play a crucial role in engendering this male vulnerability. In this review, we discuss three categories of genetic disease that highlight the importance of X-linked genes in the manifestation of an autistic phenotype: aneuploides (Turner syndrome and Klinefelter syndrome), trinucleotide expansions (Fragile X syndrome) and nucleotide mutations (Rett Syndrome, Neuroligins 3 & 4, and SLC6A8). The lessons from these diseases include an understanding of autistic features as a broad phenotype rather than as a single clinical entity, the role of multiple genes either alone or in concert with the manifestation of autistic features, and the role of epigenetic factors such as imprinting and X-inactivation in the expression of disease severity. Better understanding of the clinical phenotypes of social cognition and the molecular neurogenetics of X-linked gene disorders will certainly provide additional tools for understanding autism in the years to come.
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PMID:Autism-lessons from the X chromosome. 1898 5


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