1. Clifford SM, Hudry K, Elsabbagh M, Charman T, Johnson MH. {{Temperament in the First 2 Years of Life in Infants at High-Risk for Autism Spectrum Disorders}}. {J Autism Dev Disord}. 2012.
The current study investigated early temperament in 54 infants at familial high-risk of ASD and 50 controls. Parental report of temperament was assessed around 7, 14 and 24 months of age and diagnostic assessment was conducted at 3 years. The high-risk group showed reduced Surgency at 7 and 14 months and reduced Effortful Control at 14 and 24 months, compared to controls. High-risk infants later diagnosed with ASD were distinguished from controls by a temperament profile marked by increased Perceptual Sensitivity from the first year of life, and increased Negative Affect and reduced Cuddliness in the second year of life. Temperament may be an important construct for understanding the early infant development of ASD.
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2. Duku E, Vaillancourt T, Szatmari P, Georgiades S, Zwaigenbaum L, Smith IM, Bryson S, Fombonne E, Mirenda P, Roberts W, Volden J, Waddell C, Thompson A, Bennett T. {{Investigating the Measurement Properties of the Social Responsiveness Scale in Preschool Children with Autism Spectrum Disorders}}. {J Autism Dev Disord}. 2012.
The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement models which were tested using categorical confirmatory factor analysis did not fit well and were not unidimensional. Rasch analyses showed that a 30-item subset met criteria of unidimensionality and invariance across item, person, and over time; and this subset exhibited convergent validity with other child outcomes. This subset was shown to have enhanced psychometric properties and could be used in measuring social responsiveness among preschool age children with Autism Spectrum Disorders.
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3. Han S, Tai C, Westenbroek RE, Yu FH, Cheah CS, Potter GB, Rubenstein JL, Scheuer T, de la Iglesia HO, Catterall WA. {{Autistic-like behaviour in Scn1a(+/-) mice and rescue by enhanced GABA-mediated neurotransmission}}. {Nature}. 2012.
Haploinsufficiency of the SCN1A gene encoding voltage-gated sodium channel Na(V)1.1 causes Dravet’s syndrome, a childhood neuropsychiatric disorder including recurrent intractable seizures, cognitive deficit and autism-spectrum behaviours. The neural mechanisms responsible for cognitive deficit and autism-spectrum behaviours in Dravet’s syndrome are poorly understood. Here we report that mice with Scn1a haploinsufficiency exhibit hyperactivity, stereotyped behaviours, social interaction deficits and impaired context-dependent spatial memory. Olfactory sensitivity is retained, but novel food odours and social odours are aversive to Scn1a(+/-) mice. GABAergic neurotransmission is specifically impaired by this mutation, and selective deletion of Na(V)1.1 channels in forebrain interneurons is sufficient to cause these behavioural and cognitive impairments. Remarkably, treatment with low-dose clonazepam, a positive allosteric modulator of GABA(A) receptors, completely rescued the abnormal social behaviours and deficits in fear memory in the mouse model of Dravet’s syndrome, demonstrating that they are caused by impaired GABAergic neurotransmission and not by neuronal damage from recurrent seizures. These results demonstrate a critical role for Na(V)1.1 channels in neuropsychiatric functions and provide a potential therapeutic strategy for cognitive deficit and autism-spectrum behaviours in Dravet’s syndrome.
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4. Henninger NA, Taylor JL. {{Outcomes in adults with autism spectrum disorders: a historical perspective}}. {Autism}. 2012.
In this review, we examine the ways in which researchers have defined successful adult outcomes for individuals with autism spectrum disorders (ASDs) from the first systematic follow-up reports to the present day. The earliest outcome studies used vague and unreliable outcome criteria, and institutionalization was a common marker of poor outcomes. In the past decade, researchers have begun to standardize the measurement of adult outcomes with specific criteria based on friendships, employment, and living arrangements. Although nearly all of these studies have agreed that the majority of adults with ASD have poor outcomes, evolving concepts of what it means to be an adult could have an impact on outcomes measured. For example, some researchers have suggested that taking into account the person-environment fit could reveal a more optimistic picture of outcomes for these adults. Suggestions for future research are discussed.
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5. Legisa J, Messinger DS, Kermol E, Marlier L. {{Emotional Responses to Odors in Children with High-Functioning Autism: Autonomic Arousal, Facial Behavior and Self-Report}}. {J Autism Dev Disord}. 2012.
Although emotional functioning is impaired in children with autism, it is unclear if this impairment is due to difficulties with facial expression, autonomic responsiveness, or the verbal description of emotional states. To shed light on this issue, we examined responses to pleasant and unpleasant odors in eight children (8-14 years) with high-functioning autism and 8 age-matched typically developing controls. Despite subtle differences in the facial actions of the children with autism, children in both groups had similar facial and autonomic emotional responses to the odors. However, children with autism were less likely than controls to report an emotional reaction to the odors that matched their facial expression, suggesting difficulties in the self report of emotional states.
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6. Lu C, Lin L, Tan H, Wu H, Sherman SL, Gao F, Jin P, Chen D. {{Fragile X Premutation RNA is Sufficient to Cause Primary Ovarian Insufficiency in Mice}}. {Hum Mol Genet}. 2012.
Spontaneous 46,XX primary ovarian insufficiency (POI), also known as « premature menopause » or « premature ovarian failure » (POF), refers to ovarian dysfunction that results in a range of abnormalities, from infertility to early menopause as the end stage. The most common known genetic cause of POI is the expansion of a CGG repeat to 55 to 199 copies (premutation) in the 5′ untranslated region in the X-linked fragile X mental retardation 1 (FMR1) gene. POI associated with the FMR1 premutation is referred to as fragile X-associated POI (FXPOI). Here we characterize a mouse model carrying the human FMR1 premutation allele and show that FMR1 premutation RNA can cause a reduction in the number of growing follicles in ovaries and is sufficient to impair female fertility. Alterations of selective serum hormone levels, including FSH, LH, and 17ss-estradiol, are seen in this mouse model, which mimics findings in humans. In addition, we also find that LH-induced ovulation-related gene expression is specifically altered. Finally, we show that the FMR1 premutation allele can lead to reduced phosphorylation of Akt and mTOR proteins. These results together suggest that FMR1 premutation RNA could cause the POI associated with FMR1 premutation carriers, and the Akt/mTOR pathway may serve as a therapeutic target for FXPOI.
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7. Nissenkorn A, Ben-Zeev B. {{Unilateral Rhythmic Hand Tapping in Rett Syndrome: Is This Stereotypy?}}. {J Child Neurol}. 2012.
Rett syndrome is a severe neurodevelopmental disorder, with hand stereotypies as a hallmark of the disease. Epilepsy is a frequent comorbidity and is accompanied by centrotemporal spikes on electroencephalogram, but stereotypic movements should not have epileptiform correlates. During routine video-electroencephalographic investigation in 5 Rett syndrome patients, we identified a peculiar type of unilateral, highly rhythmic hand tapping accompanied by contralateral synchronous centrotemporal spikes on electroencephalography. This phenomenon is not consistent with either reflex seizures or hand stereotypies and does not respond to antiepileptic drugs. The electroencephalographic activity probably represents evoked potentials, either somatosensory or motor, whereas the rhythmic activity raises the possibility of a subcortical pacemaker for a stereotypy variant. The phenomenon could be caused by abnormal circuitry among the hyperexcitable somatosensory cortex, motor cortex, and subcortical areas in Rett syndrome. Clinicians should be aware of the nonepileptic nature of this motor behavior and should not attempt to treat it.
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8. So P, Greaves-Lord K, Van der Ende J, Verhulst FC, Rescorla L, de Nijs PF. {{Using the Child Behavior Checklist and the Teacher’s Report Form for identification of children with autism spectrum disorders}}. {Autism}. 2012.
This study evaluated the ability of the Child Behavior Checklist and the Teacher’s Report Form to identify children with autism spectrum disorders (ASD), using a sample of children with ASD (n = 458), referred children without ASD (n = 1109) and children from the general population (n = 999). A ten items ASD scale was constructed using half of the sample and the ability of this scale to discriminate between children with ASD and the other children was tested for the CBCL and the TRF separately and together in the other half of the sample. Using a cut-off score of 8 the combined CBCL/TRF ASD scale demonstrated high predictive values (NPV 95%, PPV 73%) in identifying children with ASD and children in the general population sample. This might be an acceptable percentage of false positives in general screening, considering the chance that these children might have other behavioural, emotional, and developmental problems which also need psychiatric evaluation. In the referred population, using a cut-off of 13, PPV was 49% and NPV was 85%. The high NPV indicates that in a referred population the scale is especially good at identifying children who do not need evaluation with a more ASD-specific instrument.
