1. Bertone A, Hanck J, Kogan C, Chaudhuri A, Cornish K. {{Using Perceptual Signatures to Define and Dissociate Condition-Specific Neural Etiology: Autism and Fragile X Syndrome as Model Conditions}}. {J Autism Dev Disord} (Oct 1)
The functional link between genetic alteration and behavioral end-state is rarely straightforward and never linear. Cases where neurodevlopmental conditions defined by a distinct genetic etiology share behavioral phenotypes are exemplary, as is the case for autism and Fragile X Syndrome (FXS). In this paper and its companion paper, we propose a method for assessing the functional link between genotype and neural alteration across these target conditions by comparing their perceptual signatures. In the present paper, we discuss how such signatures can be used to (1) define and differentiate various aspects of neural functioning in autism and FXS, and subsequently, (2) to infer candidate causal (genetic) mechanisms based on such signatures (see companion paper, this issue).
2. Bharti B, Bharti S. {{Clinical-statistical gap in evaluating outcome of stool patterns in young children with autistic spectrum disorder}}. {Arch Dis Child} (Sep 30)
3. Boisvert M, Lang R, Andrianopoulos M, Boscardin ML. {{Telepractice in the assessment and treatment of individuals with autism spectrum disorders: A systematic review}}. {Dev Neurorehabil} (Oct 1)
Objective: Studies involving the use of telepractice in the delivery of services to individuals with autism spectrum disorders (ASD) were reviewed with the intent to inform practice and identify areas for future research. Methods: Systematic searches of electronic databases, reference lists and journals identified eight studies that met pre-determined inclusion criteria. These studies were analysed and summarized in terms of the: (a) characteristics of the participants, (b) technology utilized, (c) services delivered via telepractice, (d) research methodology and (e) results of the study. Results: Telepractice was used by university-based researchers, behaviour analysts, psychiatrists and psychologists to assist caretakers and educators in the delivery of services to 46 participants with ASD. The services delivered included behavioural and diagnostic assessments, educational consulting, guidance and supervision of behavioural interventions and coaching/training in the implementation of a comprehensive early intervention programme. Conclusions: Results suggests telepractice is a promising service delivery approach in the treatment of individuals with ASD that warrants additional research. Guidelines for practitioners and potential directions for future research are discussed.
4. Constantino JN, Zhang Y, Frazier T, Abbacchi AM, Law P. {{Sibling Recurrence and the Genetic Epidemiology of Autism}}. {Am J Psychiatry} (Oct 1)
Objective: Although the symptoms of autism exhibit quantitative distributions in nature, estimates of recurrence risk in families have never previously considered or incorporated quantitative characterization of the autistic phenotype among siblings. Method: The authors report the results of quantitative characterization of 2,920 children from 1,235 families participating in a national volunteer register, with at least one child clinically affected by an autism spectrum disorder and at least one full biological sibling. Results: A traditionally defined autism spectrum disorder in an additional child occurred in 10.9% of the families. An additional 20% of nonautism-affected siblings had a history of language delay, one-half of whom exhibited autistic qualities of speech. Quantitative characterization using the Social Responsiveness Scale supported previously reported aggregation of a wide range of subclinical (quantitative) autistic traits among otherwise unaffected children in multipleincidence families and a relative absence of quantitative autistic traits among siblings in single-incidence families. Girls whose standardized severity ratings fell above a first percentile severity threshold (relative to the general population distribution) were significantly less likely to have elicited community diagnoses than their male counterparts. Conclusions: These data suggest that, depending on how it is defined, sibling recurrence in autism spectrum disorder may exceed previously published estimates and varies as a function of family type. The results support differences in mechanisms of genetic transmission between simplex and multiplex autism and advance current understanding of the genetic epidemiology of autism spectrum conditions.
5. Horovitz M, Matson JL. {{Communication deficits in babies and infants with autism and pervasive developmental disorder–not otherwise specified (PDD-NOS)}}. {Dev Neurorehabil} (Oct 1)
Objective: To investigate if, and in what ways, communication impairments are present in toddlers (17–37 months) diagnosed with autism and Pervasive Developmental Disorder–Not Otherwise Specified (PDD-NOS). Methods: Study 1—The scores of 20 toddlers with autism or PDD-NOS (i.e. ASD group) were compared to those of 20 typically-developing infants on the Communication sub-scale of the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT)–Part 1. Study 2—These same scores were compared between 660 toddlers who fell into three groups: autism, PDD-NOS and non-ASD-related developmentally delayed. Results: Infants with an ASD exhibited greater communication impairments than did typically-developing infants overall and on all items. Additionally, significant differences were found in overall communication impairments and the majority of individual items between all three groups in Study 2. Conclusions: Significant communication impairments are present in toddlers diagnosed with autism and PDD-NOS before 37 months.
6. Jemel B, Mimeault D, Saint-Amour D, Hosein A, Mottron L. {{VEP contrast sensitivity responses reveal reduced functional segregation of mid and high filters of visual channels in Autism}}. {J Vis};10(6):13.
Despite the vast amount of behavioral data showing a pronounced tendency in individuals with autism spectrum disorder (ASD) to process fine visual details, much less is known about the neurophysiological characteristics of spatial vision in ASD. Here, we address this issue by assessing the contrast sensitivity response properties of the early visual-evoked potentials (VEPs) to sine-wave gratings of low, medium and high spatial frequencies in adults with ASD and in an age- and IQ-matched control group. Our results show that while VEP contrast responses to low and high spatial frequency gratings did not differ between ASD and controls, early VEPs to mid spatial frequency gratings exhibited similar response characteristics as those to high spatial frequency gratings in ASD. Our findings show evidence for an altered functional segregation of early visual channels, especially those responsible for processing mid- and high-frequency spatial scales.
7. Kaluzna-Czaplinska J, Michalska M, Rynkowski J. {{Determination of tryptophan in urine of autistic and healthy children by gas chromatography/mass spectrometry}}. {Med Sci Monit} (Oct 1);16(10):CR488-492.
Background: Tryptophan is an amino acid, which is responsible for the production of serotonin in the body. Lower levels of tryptophan may play a role in pediatric disorders. In this work the urinary level of tryptophan in autistic and healthy children was compared.<br /> Material/Methods: The samples of urine were taken from 33 autistic children (10 on a restricted diet of gluten and casein free and 23 no diet) and 21 healthy children. The level of tryptophan was determined by gas chromatography/mass spectrometry (GC/MS). In this method tryptophan was derivatized and extracted simultaneously. The method was validated.<br /> Results: Significantly lower relative urinary levels of tryptophan were obtained for both autistic children with a restricted diet 1.98+/-1.17 microg/mL (mean +/-SD) and autistic children without a diet 7.44+/-1.33 microg/mL (mean +/-SD) compared to healthy children 14.24+/-2.01 microg/mL (mean +/-SD). The method has a limit of quantification (LOQ) of 0.15 microg/mL and a lower limit of detection (LOD) of 0.04 microg/mL for tryptophan in urine.<br /> Conclusions: This method is precise and sensitive for the detection of low concentrations of tryptophan and can be applicable to monitoring its level in human urine. Children with autism have a higher deficiency of tryptophan than the control group of healthy children. Lower levels of tryptophan may lead to the worsening of autistic symptoms such as mild depression and increased irritability.<br />
8. Lewis MJ, Dictenberg JB. {{Genes, brain, and behavior: development gone awry in autism?: a report on the 23rd Annual International Symposium of the Center for the Study of Gene Structure and Function}}. {Ann N Y Acad Sci} (Sep);1205 Suppl 1:E21-36.
Autism and its highly variable symptomology were the themes of the 23rd Annual International Symposium of the Center for the Study of Gene Structure and Function at Hunter College in New York City, held 15 January 2010. The meeting explored the extensive research on autism from several perspectives-integrating research on genetics, neuroscience, and behavior-from researchers presenting new and innovative approaches to understanding the autism spectrum. Early diagnosis, intervention, and genetics were major themes because they are seen as essential areas in which progress is needed before the rise in numbers of cases of autism throughout the world, which some describe as approaching an epidemic, can be stemmed. Several genetic, neurobiological, and behavioral markers of autism have been identified that may ultimately provide the basis for early identification, and that presently define the key areas requiring intensive intervention.
9. Sbacchi S, Acquadro F, Calo I, Cali F, Romano V. {{Functional annotation of genes overlapping copy number variants in autistic patients: focus on axon pathfinding}}. {Curr Genomics} (Apr);11(2):136-145.
We have used Gene Ontology (GO) and pathway analyses to uncover the common functions associated to the genes overlapping Copy Number Variants (CNVs) in autistic patients. Our source of data were four published studies [1-4]. We first applied a two-step enrichment strategy for autism-specific genes. We fished out from the four mentioned studies a list of 2928 genes overall overlapping 328 CNVs in patients and we first selected a sub-group of 2044 genes after excluding those ones that are also involved in CNVs reported in the Database of Genomic Variants (enrichment step 1). We then selected from the step 1-enriched list a sub-group of 514 genes each of which was found to be deleted or duplicated in at least two patients (enrichment step 2). The number of statistically significant processes and pathways identified by the Database for Annotation, Visualization and Integrated Discovery and Ingenuity Pathways Analysis softwares with the step 2-enriched list was significantly higher compared to the step 1-enriched list. In addition, statistically significant GO terms, biofunctions and pathways related to nervous system development and function were exclusively identified by the step 2-enriched list of genes. Interestingly, 21 genes were associated to axon growth and pathfinding. The latter genes and other ones associated to nervous system in this study represent a new set of autism candidate genes deserving further investigation. In summary, our results suggest that the autism’s « connectivity genes » in some patients affect very early phases of neurodevelopment, i.e., earlier than synaptogenesis.
10. Silverman JL, Yang M, Turner SM, Katz AM, Bell DB, Koenig JI, Crawley JN. {{Low Stress Reactivity and Neuroendocrine Factors in the BTBR T+tf/J Mouse Model of Autism}}. {Neuroscience} (Sep 30)
Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. BTBR T+tf/J (BTBR) is an inbred mouse strain that displays robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of autism, including low social interactions, reduced vocalizations in social settings, and high levels of repetitive self-grooming. Autism-relevant phenotypes in BTBR offer translational tools to discover neurochemical mechanisms underlying unusual mouse behaviors relevant to symptoms of autism. Because repetitive self-grooming in mice may be a displacement behavior elevated by stressors, we investigated neuroendocrine markers of stress and behavioral reactivity to stressors in BTBR mice, as compared to C57BL/6J, a standard inbred strain with high sociability. Radioimmunoassays replicated previous findings that circulating corticosterone is higher in the BTBR than in B6. Higher basal glucocorticoid receptor mRNA and higher oxytocin peptide levels were detected in the brains of BTBR as compared to B6. No significant differences were detected in corticotrophin releasing factor (CRF) peptide or CRF mRNA. In response to behavioral stressors, BTBR and B6 were generally similar on behavioral tasks including stress-induced hyperthermia, elevated plus-maze, light <–> dark exploration, tail flick, acoustic startle and prepulse inhibition. BTBR displayed less reactivity than B6 to a noxious thermal stimulus in the hot plate, and less immobility than B6 in both the forced swim and tail suspension depression-related tasks. BTBR, therefore, exhibited less depression-like scores than B6 on two standard tests sensitive to antidepressants, did not differ from B6 on two well-validated anxiety-like behaviors, and did not exhibit unusual stress reactivity to sensory stimuli. Our findings support the interpretation that autism-relevant social deficits, vocalizations, and repetitive behaviors are not the result of abnormal stress reactivity in the BTBR mouse model of autism.
11. Toma C, Hervas A, Balmana N, Vilella E, Aguilera F, Cusco I, Del Campo M, Caballero R, De Diego-Otero Y, Ribases M, Cormand B, Bayes M. {{Association study of six candidate genes asymmetrically expressed in the two cerebral hemispheres suggests the involvement of BAIAP2 in autism}}. {J Psychiatr Res} (Sep 30)
