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Nosological and genetic aspects of Asperger syndrome.

The validity of Asperger syndrome (i.e., apart from high-functioning autism) continues to be the topic of considerable debate. Consistent with Asperger's original description of the condition there appear to be some important potential differences from autism if both conditions are strictly defined. Although the importance of genetic factors in the transmission of autism is increasingly clear it also appears that genetic factors may play an even more important role in Asperger syndrome (AS). The nosological validity of this condition and its relation to the various PDD spectrum disorder remains an important topic for future research. Well-designed and carefully controlled studies are needed in which patterns of comorbidity and associated problems in family members can be carefully assessed. Such studies will contribute to our understanding of the relationship of AS and autism and may clarify important genetic mechanisms of relevance to autism.

Developmental Disabilities↗

Immune activation of peripheral blood and mucosal CD3+ lymphocyte cytokine profiles in children with autism and gastrointestinal symptoms.

Gastrointestinal pathology, characterized by lymphoid nodular hyperplasia and entero-colitis, has been demonstrated in a cohort of children with autistic spectrum disorder (ASD). Systemic and intestinal mucosal immune dysregulation was assessed in ASD children with gastrointestinal (GI) symptoms (n = 18), and typically developing controls (n = 27), including non-inflamed controls (NIC) and inflamed GI control children with Crohn's disease (CD), by analysis of intracellular cytokines in CD3+ lymphocytes. In both peripheral blood and mucosa, CD3+ TNFalpha+ and CD3+ IFNgamma+ were increased in ASD children compared with NIC (p < 0.004) and reached levels similar to CD. In contrast, peripheral and mucosal CD3+ IL-10+ were markedly lower in ASD children with GI symptoms compared with both NIC and CD controls (p < 0.02). In addition, mucosal CD3+ IL-4+ cells were increased (p < 0.007) in ASD compared with NIC. There is a unique pattern of peripheral blood and mucosal CD3+ lymphocytes intracellular cytokines, which is consistent with significant immune dysregulation, in this ASD cohort.

Autistic Disorder↗

Screening for infants with developmental deficits and/or autism: a Swedish pilot study.

The purpose of this study was to develop an instrument (SEEK) for the early detection of developmental deficits and/or autistic spectrum disorders among children by the age of 8 months at eight child health care centers in southern Sweden. Health visitors, trained by the research team, screened 312 infants. SEEK captured 5 infants with several points. Twenty-one percent of the infants obtained at least one SEEK point. At the 18-month follow-up, 5 children still showed more obvious signs of developmental problems. The health visitors found SEEK to be very satisfactory and easy and quick to use and its items and questions to be easy to administer. The results have indicated a new systematic methodology to examine infants, which is to be further developed.

Analysis of Variance↗

Autism: a large unmet medical need and a complex research problem.

Autism has been becoming the focus of attention as its apparently increasing prevalence is better appreciated. According to some estimates, the frequency of children with autistic spectrum disorder (ASD) can be as high as 1 in 150. The diagnosis can be made as early as 2 years of age, and autistic patients often have a normal life span. Thus, in terms of the number of "patient years," ASD represents a market that is as large as that of the biggest neurological indication, Alzheimer's disease. Despite the clear unmet medical need, no effective treatment is available. This may be because the mechanism of ASD is not understood. The aim of the present paper is to review recent advances in autism research and to discuss some of the most stressing problems mainly from a preclinical research standpoint. We hope to draw attention to the need to study this devastating disease that places an enormous burden on the society in general and the relatives and caregivers of autistic patients in particular.

Animals↗

Behavioral manifestations of autism in the first year of life.

In the interest of more systematically documenting the early signs of autism, and of testing specific hypotheses regarding their underlying neurodevelopmental substrates, we have initiated a longitudinal study of high-risk infants, all of whom have an older sibling diagnosed with an autistic spectrum disorder. Our sample currently includes 150 infant siblings, including 65 who have been followed to age 24 months, who are the focus of this paper. We have also followed a comparison group of low-risk infants. Our measures include a novel observational scale (the first, to our knowledge, that is designed to assess autism-specific behavior in infants), a computerized visual orienting task, and standardized measures of temperament, cognitive and language development. Our preliminary results indicate that by 12 months of age, siblings who are later diagnosed with autism may be distinguished from other siblings and low-risk controls on the basis of: (1) several specific behavioral markers, including atypicalities in eye contact, visual tracking, disengagement of visual attention, orienting to name, imitation, social smiling, reactivity, social interest and affect, and sensory-oriented behaviors; (2) prolonged latency to disengage visual attention; (3) a characteristic pattern of early temperament, with marked passivity and decreased activity level at 6 months, followed by extreme distress reactions, a tendency to fixate on particular objects in the environment, and decreased expression of positive affect by 12 months; and (4) delayed expressive and receptive language. We discuss these findings in the context of various neural networks thought to underlie neurodevelopmental abnormalities in autism, including poor visual orienting. Over time, as we are able to prospectively study larger numbers and to examine interrelationships among both early-developing behaviors and biological indices of interest, we hope this work will advance current understanding of the neurodevelopmental origins of autism.

Age Factors↗

Spontaneous mucosal lymphocyte cytokine profiles in children with autism and gastrointestinal symptoms: mucosal immune activation and reduced counter regulatory interleukin-10.

A lymphocytic enterocolitis has been reported in a cohort of children with autistic spectrum disorder (ASD) and gastrointestinal (GI) symptoms. This study tested the hypothesis that dysregulated intestinal mucosal immunity with enhanced pro-inflammatory cytokine production is present in these ASD children. Comparison was made with developmentally normal children with, and without, mucosal inflammation. Duodenal and colonic biopsies were obtained from 21 ASD children, and 65 developmentally normal paediatric controls, of which 38 had signs of histological inflammation. Detection of CD3+ lymphocyte staining for spontaneous intracellular TNFalpha, IL-2, IL-4, IFNgamma, and IL-10, was performed by multicolor flow cytometry. Duodenal and colonic mucosal CD3+ lymphocyte counts were elevated in ASD children compared with noninflamed controls (p<0.03). In the duodenum, the proportion of lamina propria (LP) and epithelial CD3(+)TNFalpha+ cells in ASD children was significantly greater compared with noninflamed controls (p<0.002) but not coeliac disease controls. In addition, LP and epithelial CD3(+)IL-2+ and CD3(+)IFNgamma+, and epithelial CD3(+)IL-4+ cells were more numerous in ASD children than in noninflamed controls (p<0.04). In contrast, CD3(+)IL-10+ cells were fewer in ASD children than in noninflamed controls (p<0.05). In the colon, LP CD3(+)TNFalpha+ and CD3(+)IFNgamma+ were more frequent in ASD children than in noninflamed controls (p<0.01). In contrast with Crohn's disease and non-Crohn's colitis, LP and epithelial CD3(+)IL-10+ cells were fewer in ASD children than in nondisease controls (p<0.01). There was a significantly greater proportion of CD3(+)TNFalpha+ cells in colonic mucosa in those ASD children who had no dietary exclusion compared with those on a gluten and/or casein free diet (p<0.05). There is a consistent profile of CD3+ lymphocyte cytokines in the small and large intestinal mucosa of these ASD children, involving increased pro-inflammatory and decreased regulatory activities. The data provide further evidence of a diffuse mucosal immunopathology in some ASD children and the potential for benefit of dietary and immunomodulatory therapies.

Adolescent↗

Supporting families of preschool children with autism: what parents want and what helps.

This paper describes a local education authority project to provide support to the families of preschool children with autistic spectrum disorders. As part of an evaluation study, all parents were interviewed when their children entered full-time education and left the service's caseload. The report outlines key findings regarding levels of satisfaction with the service provided and describes parental responses to the different components of the support offered. All parents rated the input of the support worker as 'very useful'. Parents particularly valued the following: support to 'make sense' of their child's development and needs; practical strategies for facilitating language and engaging in interactive play; and support to the nurseries and playgroups attended by their children. The interviews also looked at parents' experience of diagnosis and their needs in the immediate aftermath. Key implications of these findings, and of this model of service delivery, are also discussed.

Adolescent↗

Pathological demand avoidance syndrome: a necessary distinction within the pervasive developmental disorders.

A proposal is made to recognise pathological demand avoidance syndrome (PDA) as a separate entity within the pervasive developmental disorders, instead of being classed under "pervasive developmental disorder not otherwise specified" (PDDnos, DSM-IV). Discriminant functions analysis shows PDA to be significantly different on many counts from classic autism and Asperger's syndrome, both separately and together, including an equal sex ratio (150 cases). Demand avoidance using social manipulation is seen in all children, which strongly contrasts with the features of autistic spectrum disorders. A criterial structure is described, supported by statistical data from a random sample of 50 children diagnosed with PDA, together with a follow up sample of 18 young adults.

Asperger Syndrome↗

Could oxytocin administration during labor contribute to autism and related behavioral disorders?--A look at the literature.

This literature review summarizes recent potential evidence, most of which is at the molecular/mechanistic level, in support of Hollander's hypothesis that excess oxytocin (OT), possibly through OT administration at birth, could contribute to the development of autistic spectrum disorders and related syndromes by proposed down regulation of the OT receptor (OTR). In this review, recent molecular evidence for OTR internalization by excess OT is related to OT's reported effects on animal social behavior, favoring social bondage, notably in sheep, voles, rats and especially mice. Adding indications for OT's capability of crossing the maternal placenta and OT's possibility of crossing an underdeveloped or stressed infantile blood brain barrier at birth, a causal connection between OT excess and behavioral disorders such as autism can be supported from a molecular perspective. Possible strategies such as a thorough statistical analysis of numerous birth records as well as molecular studies such as radiotracing using labeled OT are proposed to test this hypothesis.

Autistic Disorder↗

Motion and form coherence detection in autistic spectrum disorder: Relationship to motor control and 2:4 digit ratio.

Children with autistic spectrum disorder and controls performed tasks of coherent motion and form detection, and motor control. Additionally, the ratio of the 2nd and 4th digits of these children, which is thought to be an indicator of foetal testosterone, was measured. Children in the experimental group were impaired at tasks of motor control, and had lower 2D:4D than controls. There were no group differences in motion or form detection. However a sub-group of children with autism were selectively impaired at motion detection. There were significant relationships between motion coherence detection and motor control in both groups of children, and also between motion detection, fine motor control and 2D:4D in the group of children with autistic spectrum disorder.

Asperger Syndrome↗

The social anxiety spectrum.

Social anxiety disorder is well suited to the spectrum concept because it has trait-like qualities of early onset, chronicity, and no empirically derived threshold that demarcates normal from clinically significant trait social anxiety. Social anxiety disorder has been shown to respond to relatively specific pharmacologic and cognitive-behavioral therapies, which makes identification of other conditions that may lie on the social anxiety disorder spectrum important because of possible treatment implications. Biologic markers associated with social anxiety disorder also may be shared by similar but nonidentical traits, such as behavioral inhibition and detachment. Clarification of the trait spectrums associated with specific biologic systems offers an opportunity for improving the understanding of the origin of these conditions. Strong evidence exists that at least some forms of shyness, avoidant personality disorder, and selective mutism lie on a social anxiety disorder spectrum. For several other disorders that share a prominent focus on social comparison, significant subgroups of patients seem to have features of social anxiety disorder. These disorders include major depression (especially the atypical subtype), body dysmorphic disorder, and eating disorders. Several other disorders marked by social dysfunction or inhibition, including substance use disorders (especially alcoholism), paranoid disorder, bipolar disorder, autism, and Asperger's disorder, also may show some overlap with social anxiety disorder features (e.g., social anxiety as a cause or complication of substance abuse, social avoidance in paranoid disorder, social disinhibiton in bipolar disorder, and social communication deficits in autism and Asperger's disorder). Social anxiety disorder also is associated with other anxiety disorders in general and other phobias in particular. In respect to traits, a growing body of evidence links behavioral inhibition to the unfamiliar to a social anxiety disorder spectrum with some specificity. Biologic measures of dopamine system hypoactivity have been linked to social anxiety disorder, trait detachment, and general deficits in reward and incentive function. It remains to be clarified, however, whether this brain system function is best characterized by a social anxiety disorder spectrum or some variant that incorporates social reward deficits or social avoidance behavior. Social anxiety disorder, shyness, and behavioral inhibition all seem to have a genetic component, but more research is needed to attempt to identify a more specifically heritable temperament associated with these conditions. Finally, the emergent concept of a social anxiety spectrum needs maturation. Although the notion of a single social anxiety disorder spectrum currently has some clinical use, the authors believe that exclusive focus on the notion of a single continuum with two extremes--from social disinhibition in mania to the most severe form of social anxiety, avoidant personality disorder--is premature and limiting in respect to etiologic research. An alternative approach is to conceptualize multiple, probably overlapping spectra in this area of social psychopathology. Individual dimensions might be based on various core phenomenologic, cognitive, or biologic characteristics. A bottom-up biologic approach holds promise for identifying spectra with a common etiology that might respond to specific treatments. Taking a pluralistic view of the concept of spectrum at this stage may help accelerate our understanding of social anxiety and related disorders.

Brain↗

Autistic symptoms in children with attention deficit-hyperactivity disorder.

Children with the syndrome of disorders of attention, motor control and perception (DAMP) invariably fill diagnostic criteria for attention deficit hyperactivity disorder (ADHD) and commonly have symptoms of autistic spectrum disorders. This study estimates the rate of autistic symptoms in a sample of children with ADHD by using the parent-rated Autism Criteria Checklist. A high proportion of parents (between 65-80%) reported significant difficulties in social interaction (particularly in empathy and peer relationships), and communication (particularly in imaginative ability, nonverbal communication and maintaining conversation). The nature and relationship between ADHD and pervasive developmental disorders is considered, as well as implications for assessment, diagnosis and treatment.

Adolescent↗

Fragile X positivity in Chinese children with autistic spectrum disorder.

Chromosome analysis was performed in 105 Chinese children (96 boys, 9 girls) with autistic spectrum disorder to assess fragile X positivity. Seventy percent of these autistic children were mentally retarded. None of the children in the infantile autism group (N = 75) had fragile X positivity. Two boys in the autistic condition group (N = 30) had clinical features and chromosomal positivity for fragile X syndrome. The low (2%) prevalence rate of fragile X positivity in children with different degrees of expressivity of autistic features may be related to other factors rather than to pure autistic characteristics per se.

Autistic Disorder↗

Constructing an autistic identity: AS voices online.

Excerpts from current research with people who have autism using online discussion groups are provided. Two major themes emerged that focus on "expert" knowledge of autism and identity. In contrast to the image of people with autism being unable to speak for themselves, our research on chat rooms has demonstrated that these individuals are finding a voice in an online environment, and the Internet may be a powerful tool in enabling this voice to be heard. The challenge that experiential knowledge poses to scientific knowledge is discussed in light of diagnosis, and the positive nature of an autism spectrum (AS) identity is highlighted as a common thread in discussions.

Autistic Disorder↗

[Genetics of autism].

Autism is a severe psychiatric disorder characterised by deficits in social interaction, disturbed communication and adherence to stereotype routines and interests. Nowadays it is completely clear that this disorder has a biological basis and many observations show strong genetic determination of autism. The importance of genetic factors is supported by frequent association of this disorder with known hereditary diseases or with various chromosomal aberrations, by high concordance of the disorder in monozygotic twins, higher risk for the siblings of autistic patients and also by the frequent occurrence of milder symptoms of the autistic spectrum in more distant relatives. All these findings show that the autistic phenotype results from unfavourable combination of alleles of several genes in interplay with factors of the environment. This model of multifactorial inheritance of autism serves at present as the starting point for the search for predisposing genes in the human genome. The association is tested between autism and alleles of candidate genes selected based on known biochemical and physiological role of their protein products, or based on their location close to recurrent chromosomal rearrangements or in regions identified by whole-genome linkage analyses. Studies of most of these genes have not yielded clear-cut results yet, but the participation of some of them in the aetiology of autism is possible.

Autistic Disorder↗

Behavioral features of CHARGE syndrome (Hall-Hittner syndrome) comparison with Down syndrome, Prader-Willi syndrome, and Williams syndrome.

CHARGE syndrome, or Hall-Hitner syndrome (HHS), has been delineated as a common syndrome that includes coloboma, choanal atresia, cranial nerve dysfunction (particularly asymmetric facial palsy and neurogenic swallowing problems), characteristic ear abnormalities, deafness with hypoplasia of the cochlea and semicircular canals, genital hypoplasia, and variable heart defects, orofacial clefting, tracheo-esophageal fistula, renal anomalies, thymic/parathyroid hypoplasia, spine anomalies, short broad neck with sloping shoulders, and characteristic facial features. We conducted behavioral and personality assessments in 14 boys with HHS syndrome aged 6-21 years, and compared their characteristics with similar data from 20 age-matched boys with Down syndrome (DS), 17 boys with Prader-Willi syndrome (PWS), and 16 boys with Williams syndrome (WS). We used the Reiss Profile of Fundamental Goals and Motivation Sensitivities, the Achenbach Child Behavior Checklist (CBCL), and the Aberrant Behavior Checklist (ABC). All 14 boys with HHS were legally deaf, and 10 of the 14 were also legally blind. In comparison these other syndromes, boys with HHS had behavior that resembled autistic spectrum disorder. They were socially withdrawn, lacked interest in social contact, and manifested reduced seeking of attention from others, with hyperactivity and a need to maintain order. Though the boys with HHS showed decreased social interaction, they were not as socially impaired as in classic autism. Their language was delayed due to dual sensory impairment, cranial nerve deficits, and chronic medical problems, but their language style was not abnormal (no echolalia or jargon, no scripted phrases, and no pronoun reversal). Boys with HSS appeared frustrated, but they were not aggressive, or at risk for delinquency, manifesting few stereotypic behaviors or unusual preoccupations. They did not have a restricted repertoire of activities and interests. Their behavioral features appeared to be due to dual sensory impairment affecting hearing and vision, rather than to primary autistic spectrum disorder, but successful remediation requires similar educational interventions, which are discussed herein.

Abnormalities, Multiple↗

Magnesium profile in autism.

The aim of the present study was to determine and compare plasma and erythrocyte concentrations of magnesium in 12 autistic children (10 boys, 2 girls), 17 children with other autistic spectrum disorders (14 boys, 3 girls), 5 girls with classic Rett syndrome, and 14 normal children (7 boys, 7 girls) of the same age. No differences in intracellular Mg were found between controls and pathological subjects; however, autistic children and children with other autistic spectrum disorders had significantly lower plasma concentrations of Mg than normal subjects (p=0.013 and p=0.02, respectively). Although our study population was small, we conclude that children with autistic spectrum disorders require special dietary management. If these cases are diagnosed at an early stage, they can be helped through diet.

Adolescent↗