1. {{Thematic papers: new concepts in developing brain disorders-autism}}. {Anat Rec (Hoboken)}. 2011; 294(10): spc1.
The cover shows a sagittal view of developing human brain, including cerebellum, brainstem and spinal cord. The background reveals the extensive immunohistochemically labeled serotonergic and noradrenergic cortical fibers in the rodent cortex. The individual puzzle blocks are representative data included in this issue.
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2. Al Abdulmohsen T, Kruger TH. {{The contribution of muscular and auditory pathologies to the symptomatology of autism}}. {Med Hypotheses}. 2011.
Most research concerning the pathology of autism is focused on the search for central abnormalities that account for the production of symptoms. We, however, instead of looking at muscular and auditory features as merely associated manifestations, propose that they are somatic contributors by which some of the main clinical features of autism might be explained. Evidence suggests that muscles affect emotional experience. We think certain muscular dysfunctioning can impair communication and social interaction, and create stereotypic behavior, giving rise to the diagnostic features of autism. Furthermore, because speech is synchronized with facial movements and voice is controlled mainly through auditory feedback, a distortion of auditory feedback could disrupt voice, which in turn might cause parallel abnormal facial muscle functioning.
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3. Baghdadli A, Assouline B, Sonie S, Pernon E, Darrou C, Michelon C, Picot MC, Aussilloux C, Pry R. {{Developmental Trajectories of Adaptive Behaviors from Early Childhood to Adolescence in a Cohort of 152 Children with Autism Spectrum Disorders}}. {J Autism Dev Disord}. 2011.
This study examines change in 152 children over an almost 10-year period (T1: 4.9 (+/-1.3) years; T2: 8.1 (+/-1.3) years; T3: 15(+/-1.6) years) using a group-based, semi-parametric method in order to identify distinct developmental trajectories. Important deficits remain at adolescence in the adaptive abilities of children with Autism spectrum disorders, but changes in adaptive skills show two distinct growth rates. The univariate analysis reveals that low growth trajectories for both social and communication outcome are associated with the following characteristics at age 5: low cognitive and language skills, presence of epilepsy, and severity of autism. The multivariate analysis confirms that risk factors at age 5, were low language and severity of autism for both social and communication outcomes 10 years later, and that hours of early intervention was protective factor for communication.
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4. Bellani M, Fornasari L, Chittaro L, Brambilla P. {{Virtual reality in autism: state of the art}}. {Epidemiol Psychiatr Sci}. 2011; 20(3): 235-8.
Autism spectrum disorders are characterized by core deficits with regard to three domains, i.e. social interaction, communication and repetitive or stereotypic behaviour. It is crucial to develop intervention strategies helping individuals with autism, their caregivers and educators in daily life. For this purpose, virtual reality (VR), i.e. a simulation of the real world based on computer graphics, can be useful as it allows instructors and therapists to offer a safe, repeatable and diversifiable environment during learning. This mini review examines studies that have investigated the use of VR in autism.
5. Ciuladaite Z, Kasnauskiene J, Cimbalistiene L, Preiksaitiene E, Patsalis PC, Kucinskas V. {{Mental retardation and autism associated with recurrent 16p11.2 microdeletion: incomplete penetrance and variable expressivity}}. {J Appl Genet}. 2011.
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6. Gebregziabher M, Shotwell MS, Charles JM, Nicholas JS. {{Comparison of Methods for Identifying Phenotype Subgroups Using Categorical Features Data With Application to Autism Spectrum Disorder}}. {Comput Stat Data Anal}. 2012; 56(1): 114-25.
We evaluate the performance of the Dirichlet process mixture (DPM) and the latent class model (LCM) in identifying autism phenotype subgroups based on categorical autism spectrum disorder (ASD) diagnostic features from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision. A simulation study is designed to mimic the diagnostic features in the ASD dataset in order to evaluate the LCM and DPM methods in this context. Likelihood based information criteria and DPM partitioning are used to identify the best fitting models. The Rand statistic is used to compare the performance of the methods in recovering simulated phenotype subgroups. Our results indicate excellent recovery of the simulated subgroup structure for both methods. The LCM performs slightly better than DPM when the correct number of latent subgroups is selected a priori. The DPM method utilizes a maximum a posteriori (MAP) criterion to estimate the number of classes, and yielded results in fair agreement with the LCM method. Comparison of model fit indices in identifying the best fitting LCM showed that adjusted Bayesian information criteria (ABIC) picks the correct number of classes over 90% of the time. Thus, when diagnostic features are categorical and there is some prior information regarding the number of latent classes, LCM in conjunction with ABIC is preferred.
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7. Good P. {{Do salt cravings in children with autistic disorders reveal low blood sodium depleting brain taurine and glutamine?}}. {Med Hypotheses}. 2011.
Because boys are four times more likely than girls to develop autism, the role of male hormones (androgens) has received considerable scrutiny. Some researchers implicate arginine vasopressin, an androgen-dependent hormone from the pituitary gland that elicits male behavior. Elevated vasopressin is also the most common cause of low blood sodium (hyponatremia) – most serious in the brains of children. Hyponatremia causes astrocytes to swell, then release the amino acids taurine and glutamine and their water to compensate. Taurine – the brain osmolyte/inhibitory neurotransmitter that suppresses vasopressin – was the amino acid most wasted or depleted in urine of autistic children. Glutamine is a critical metabolic fuel in brain neurons, astrocytes, endothelial cells, and the intestines, especially during hypoglycemia. Because glutamine is not thought to cross the blood-brain barrier significantly, the implications of low blood glutamine in these children are not recognized. Yet children with high brain glutamine from urea cycle disorders are rarely diagnosed with autistic disorders. Other common events in autistic children that release vasopressin are gastrointestinal inflammation, hypoglycemia, and stress. Signs of hyponatremia in these children are salt cravings reported online and anecdotally, deep yellow urine revealing concentration, and relief of autistic behavior by fluid/salt diets. Several interventions offer promise: (a) taurine to suppress vasopressin and replenish astrocytes; (b) glutamine as fuel for intestines and brain; (c) arginine to spare glutamine, detoxify ammonia, and increase brain blood flow; and (d) oral rehydration salts to compensate dilutional hyponatremia. This hypothesis appears eminently testable: Does your child crave salt? Is his urine deep yellow?
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8. Hiramoto T, Kang G, Suzuki G, Satoh Y, Kucherlapati R, Watanabe Y, Hiroi N. {{Tbx1: identification of a 22q11.2 gene as a risk factor for autism spectrum disorder in a mouse model}}. {Hum Mol Genet}. 2011.
Although twin studies indicate clear genetic bases of autism spectrum disorder (ASD), the precise mechanisms through which genetic variations causally result in ASD are poorly understood. Individuals with 3 Mb and nested 1.5 Mb hemizygosity of the chromosome 22q11.2 represent genetically identifiable cases of ASD. However, because more than 30 genes are deleted even in the minimal deletion cases of 22q11.2 deficiency, the individual 22q11.2 gene(s) responsible for ASD remain elusive. Here, we examined the impact of constitutive heterozygosity of Tbx1, a 22q11.2 gene, on the behavioral phenotypes of ASD and characterized the regional and cellular expression of its mRNA and protein in mice. Congenic Tbx1 heterozygous (HT) mice were impaired in social interaction, ultrasonic vocalization, memory-based behavioral alternation, working memory and thigmotaxis, compared with wild-type (WT) mice. These phenotypes were not due to non-specific alterations in olfactory function, exploratory behavior, motor movement or anxiety-related behavior. Tbx1 mRNA and protein were ubiquitously expressed throughout the brains of C57BL/6J mice, but protein expression was enriched in regions that postnatally retain the capacity of neurogenesis, and in fact, postnatally proliferating cells expressed Tbx1. In postnatally derived hippocampal culture cells of C57BL/6J mice, Tbx1 levels were higher during proliferation than during differentiation, and expressed in neural progenitor cells, immature and matured neurons and glial cells. Taken together, our data suggest that Tbx1 is a gene responsible for the phenotypes of 22q11.2 hemizygosity-associated ASD possibly through its role in diverse cell types, including postnatally and prenatally generated neurons.
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9. Leehey MA, Legg W, Tassone F, Hagerman R. {{Fibromyalgia in fragile X mental retardation 1 gene premutation carriers}}. {Rheumatology (Oxford)}. 2011.
Objective. FM is a disorder of altered pain regulation and is characterized by pain, fatigue, poor sleep and psychological impairments; thus, it is classified as a central sensitivity syndrome. Female carriers of a premutation in the fragile X mental retardation 1 (FMR1) gene frequently have widespread musculoskeletal pain and sometimes have been diagnosed with FM, especially if they have the motor signs of fragile X-associated tremor ataxia syndrome (FXTAS). Studies suggest that FM occurs in persons with a genetic predisposition. We describe the clinical features of female FMR1 premutation carriers with symptoms of FM.Methods. A sample of patients was selected that participated in studies at two tertiary referral academic centres on the phenotype and therapy of FXTAS.Results. This selected sample of patients, five female premutation carriers, has FM symptoms or diagnoses and other central sensitivity syndromes.Conclusion. Since FM affects 2-4% of the world’s population and about 1 in 250 females are FMR1 carriers, a study screening females with FM for the presence of the FMR1 premutation is worthwhile. A finding of increased prevalence of FMR1 carriers among females with FM would impact the standard evaluation of FM. Presently, guidelines for FMR1 genetic testing includes early menopause, congenital intellectual disability, autism spectrum disorder, tremor or ataxia, and a family history of FXTAS or fragile X syndrome. The latter is a common cause of autism and developmental delay. Such testing is important because female carriers are at risk of having a child with fragile X syndrome.
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10. Newman C, Cashin A, Waters CD. {{Response to letter to the editor: A modified hermeneutic phenomenological approach with individuals who have autism}}. {Res Nurs Health}. 2011.
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11. Pina-Camacho L, Villero S, Fraguas D, Boada L, Janssen J, Navas-Sanchez FJ, Mayoral M, Llorente C, Arango C, Parellada M. {{Autism Spectrum Disorder: Does Neuroimaging Support the DSM-5 Proposal for a Symptom Dyad? A Systematic Review of Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging Studies}}. {J Autism Dev Disord}. 2011.
A systematic review of 208 studies comprising functional magnetic resonance imaging and diffusion tensor imaging data in patients with ‘autism spectrum disorder’ (ASD) was conducted, in order to determine whether these data support the forthcoming DSM-5 proposal of a social communication and behavioral symptom dyad. Studies consistently reported abnormal function and structure of fronto-temporal and limbic networks with social and pragmatic language deficits, of temporo-parieto-occipital networks with syntactic-semantic language deficits, and of fronto-striato-cerebellar networks with repetitive behaviors and restricted interests in ASD patients. Therefore, this review partially supports the DSM-5 proposal for the ASD dyad.
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12. Robinson EB, Koenen KC, McCormick MC, Munir K, Hallett V, Happe F, Plomin R, Ronald A. {{A Multivariate Twin Study of Autistic Traits in 12-Year-Olds: Testing the Fractionable Autism Triad Hypothesis}}. {Behav Genet}. 2011.
Autistic traits-social impairment, communication impairment, and restricted and repetitive behaviors and interests-are heritable in the general population. Previous analyses have consistently reported limited genetic and environmental overlap between autistic trait domains in samples assessed in middle childhood. Here we extend this research to parent-report data for 12-year-olds. Data from 5,944 pairs in the Twins Early Development Study were analyzed to explore the domain-specific heritability and degree of shared genetic and environmental influences across different autistic traits in the general population and among individuals scoring in the top 5% of each domain. Sex differences in the etiological estimates were also tested in these analyses. Autistic traits were moderately to highly heritable (0.58-0.88) at age 12. Bivariate genetic correlations in the full sample (0.18-0.40) and the extremes (0.24-0.67), as well as even lower unique environmental correlations, all suggested considerable fractionation of genetic and environmental influences across autistic trait domains, in line with previous findings.
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13. Walsh P, Elsabbagh M, Bolton P, Singh I. {{In search of biomarkers for autism: scientific, social and ethical challenges}}. {Nat Rev Neurosci}. 2011; 12(10): 603-12.
There is widespread hope that the discovery of valid biomarkers for autism will both reveal the causes of autism and enable earlier and more targeted methods for diagnosis and intervention. However, growing enthusiasm about recent advances in this area of autism research needs to be tempered by an awareness of the major scientific challenges and the important social and ethical concerns arising from the development of biomarkers and their clinical application. Collaborative approaches involving scientists and other stakeholders must combine the search for valid, clinically useful autism biomarkers with efforts to ensure that individuals with autism and their families are treated with respect and understanding.
