1. Bradshaw J, Shic F, Chawarska K. {{Brief Report: Face-Specific Recognition Deficits in Young Children with Autism Spectrum Disorders}}. {J Autism Dev Disord};2010 (Dec 14)

This study used eyetracking to investigate the ability of young children with autism spectrum disorders (ASD) to recognize social (faces) and nonsocial (simple objects and complex block patterns) stimuli using the visual paired comparison (VPC) paradigm. Typically developing (TD) children showed evidence for recognition of faces and simple objects, but not complex block patterns. Children with ASD were successful at recognizing novel objects and block patterns, but showed no evidence for face recognition. These findings suggest that young children with ASD have specific impairments in face recognition, and that they may have advantage over TD controls when processing complex nonsocial stimuli.

2. Buhler E, Bachmann C, Goyert H, Heinzel-Gutenbrunner M, Kamp-Becker I. {{Differential Diagnosis of Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder by Means of Inhibitory Control and ‘Theory of Mind’}}. {J Autism Dev Disord};2011 (Mar 4)

Autism spectrum disorders (ASD) and attention deficit hyperactivity disorders (ADHD) are both associated with deficits in executive control and with problems in social contexts. This study analyses the variables inhibitory control and theory of mind (ToM), including a developmental aspect in the case of the latter, to differentiate between the disorders. Participants with an ASD (N = 86), an ADHD (N = 84) and with both disorders (N = 52) in the age range of 5-22 years were compared. Results were differences in inhibitory control (ADHD < ASD) and in the ToM performance among younger (ASD < ADHD) but not among older children. We discuss whether common deficits in ToM differ in the developmental course.

3. Cheung AY, Horvath LM, Grafodatskaya D, Pasceri P, Weksberg R, Hotta A, Carrel L, Ellis J. {{Isolation of MECP2-null Rett Syndrome patient hiPS cells and isogenic controls through X-chromosome inactivation}}. {Hum Mol Genet};2011 (Mar 3)

Rett Syndrome (RTT) is a neurodevelopmental autism spectrum disorder that affects girls due primarily to mutations in the gene encoding Methyl-CpG Binding Protein 2 (MECP2). The majority of RTT patients carry missense and nonsense mutations leading to a hypomorphic MECP2 while null mutations leading to the complete absence of a functional protein are rare. MECP2 is an X-linked gene subject to random X-chromosome inactivation resulting in mosaic expression of mutant MECP2. The lack of human brain tissue motivates the need for alternative human cellular models to study RTT. Here we report the characterization of a MECP2 mutation in a classic female RTT patient involving rearrangements that remove exons 3 and 4 creating a functionally null mutation. To generate human neuron models of RTT, we isolated human induced Pluripotent Stem cells (hiPS) from RTT patient fibroblasts. RTT-hiPS cells retained the MECP2 mutation, are pluripotent and fully reprogrammed, and retained an inactive X-chromosome in a nonrandom pattern. Taking advantage of the latter characteristic, we obtained a pair of isogenic wild-type and mutant MECP2 expressing RTT-hiPS cell lines that retained this MECP2 expression pattern upon differentiation into neurons. Phenotypic analysis of mutant RTT-hiPS cell-derived neurons demonstrated a reduction in soma-size compared to the isogenic control RTT-hiPS cell-derived neurons from the same RTT patient. Analysis of isogenic control and mutant hiPS-derived neurons represents a promising source for understanding the pathogenesis of RTT and the role of MECP2 in human neurons.

4. Ganz JB, Earles-Vollrath TL, Heath AK, Parker RI, Rispoli MJ, Duran JB. {{A Meta-Analysis of Single Case Research Studies on Aided Augmentative and Alternative Communication Systems with Individuals with Autism Spectrum Disorders}}. {J Autism Dev Disord};2011 (Mar 5)

Many individuals with autism cannot speak or cannot speak intelligibly. A variety of aided augmentative and alternative communication (AAC) approaches have been investigated. Most of the research on these approaches has been single-case research, with small numbers of participants. The purpose of this investigation was to meta-analyze the single case research on the use of aided AAC with individuals with autism spectrum disorders (ASD). Twenty-four single-case studies were analyzed via an effect size measure, the Improvement Rate Difference (IRD). Three research questions were investigated concerning the overall impact of AAC interventions on targeted behavioral outcomes, effects of AAC interventions on individual targeted behavioral outcomes, and effects of three types of AAC interventions. Results indicated that, overall, aided AAC interventions had large effects on targeted behavioral outcomes in individuals with ASD. AAC interventions had positive effects on all of the targeted behavioral outcome; however, effects were greater for communication skills than other categories of skills. Effects of the Picture Exchange Communication System and speech-generating devices were larger than those for other picture-based systems, though picture-based systems did have small effects.

5. Kim KC, Kim P, Go HS, Choi CS, Yang SI, Cheong JH, Shin CY, Ko KH. {{The critical period of valproate exposure to induce autistic symptoms in Sprague-Dawley rats}}. {Toxicol Lett};2011 (Mar 5);201(2):137-142.

Prenatal exposure to valproic acid (VPA) induces neural tube defects and impairment in social behaviors related to autistic spectrum disorder in newborns, which make it a useful animal model of autism. In this study, we compared the effects of different time window of prenatal valproic acid exposure for inducing the altered social behaviors relevant to autism from embryonic day 7 to embryonic day 15 in Sprague-Dawley rats to determine the critical periods for the impairment. Compared to E7, E9.5 and E15 exposure, VPA exposure at E12 showed most significant changes in behaviors over control animals with reduced sociability and social preference. E9.5 exposure to valproic acid showed strong reproductive toxicity including decrease in the number of live birth. In general, exposure at E15 showed only marginal effects on reproduction and social behaviors. Finally, VPA-exposed rats at E12 were more sensitive to electric shock than VPA-exposed rats at any other periods. These results suggested that E12 is the critical period in rats when valproate exposure has prominent effects for inducing the altered social behavior similar to human autistic behavior.

6. Lintas C, Guidi F, Manzi B, Mancini A, Curatolo P, Persico AM. {{Lack of Infection with XMRV or Other MLV-Related Viruses in Blood, Post-Mortem Brains and Paternal Gametes of Autistic Individuals}}. {PLoS One};2011;6(2):e16609.

BACKGROUND: Autistic spectrum disorder (ASD) is characterized by impaired language, communication and social skills, as well as by repetitive and stereotypic patterns of behavior. Many autistic subjects display a dysregulation of the immune system which is compatible with an unresolved viral infection with prenatal onset, potentially due to vertical viral transmission. Recently, the xenotropic murine leukemia virus-related virus (XMRV) has been implicated in chronic fatigue syndrome (CFS) and in prostate cancer by several, though not all studies. METHODOLOGY/PRINCIPAL FINDINGS: We assessed whether XMRV or other murine leukemia virus (MLV)-related viruses are involved in autistic disorder. Using nested PCR targeted to gag genomic sequences, we screened DNA samples from: (i) peripheral blood of 102 ASD patients and 97 controls, (ii) post-mortem brain samples of 20 ASD patients and 17 sex- and age-matched controls, (iii) semen samples of 11 fathers of ASD children, 25 infertile individuals and 7 fertile controls. No XMRV gag DNA sequences were detected, whereas peripheral blood samples of 3/97 (3.1%) controls were positive for MLV. CONCLUSIONS| SIGNIFICANCE: No MLV-related virus was detected in blood, brain, and semen samples of ASD patients or fathers. Hence infection with XMRV or other MLV-related viruses is unlikely to contribute to autism pathogenesis.

7. Nucaro A, Pisano T, Chillotti I, Montaldo C, Pruna D. {{Chromosome 8p23.2-pter: a critical region for mental retardation, autism and epilepsy?}}. {Clin Genet};2011 (Apr);79(4):394-395.

8. Yama B, Freeman T, Graves E, Yuan S, Karen Campbell M. {{Examination of the Properties of the Modified Checklist for Autism in Toddlers (M-CHAT) in a Population Sample}}. {J Autism Dev Disord};2011 (Mar 4)

This study examines the following properties of the Modified Checklist for Autism in Toddlers (M-CHAT) in an unselected low-risk sample: (a) the maximum age for screen administration; (b) the positive screen rate in the absence of follow-up telephone interviews and; (c) the distributional properties of positive screens. Data came from a prospective cohort study (n = 1,604). Results suggest that the M-CHAT can appropriately be administered to children aged 20-48 months. Documented explanations provided by mothers during screening, appear to effectively identify potential screen misclassifications in the absence of the follow-up telephone interviews. This further emphasizes the importance of clinician expertise in verifying positive M-CHAT screens. Results have implications for the administration of the M-CHAT in clinical and research settings.