1. Hamilton SM, Spencer CM, Harrison WR, Yuva-Paylor LA, Graham DF, Daza RA, Hevner RF, Overbeek PA, Paylor R. {{Multiple autism-like behaviors in a novel transgenic mouse model}}. {Behav Brain Res};2011 (Mar 17);218(1):29-41.

Autism spectrum disorder (ASD) diagnoses are behaviorally based with no defined universal biomarkers, occur at a 1:110 ratio in the population, and predominantly affect males compared to females at approximately a 4:1 ratio. One approach to investigate and identify causes of ASD is to use organisms that display abnormal behavioral responses that model ASD-related impairments. This study describes a novel transgenic mouse, MALTT, which was generated using a forward genetics approach. It was determined that the transgene integrated within a non-coding region on the X chromosome. The MALTT line exhibited a complete repertoire of ASD-like behavioral deficits in all three domains required for an ASD diagnosis: reciprocal social interaction, communication, and repetitive or inflexible behaviors. Specifically, MALTT male mice showed deficits in social interaction and interest, abnormalities in pup and juvenile ultrasonic vocalization communications, and exhibited a repetitive stereotypy. Abnormalities were also observed in the domain of sensory function, a secondary phenotype prevalently associated with ASD. Mapping and expression studies suggested that the Fam46 gene family may be linked to the observed ASD-related behaviors. The MALTT line provides a unique genetic model for examining the underlying biological mechanisms involved in ASD-related behaviors.

2. Kushak RI, Lauwers GY, Winter HS, Buie TM. {{Intestinal disaccharidase activity in patients with autism: Effect of age, gender, and intestinal inflammation}}. {Autism};2011 (Mar 17)

Intestinal disaccharidase activities were measured in 199 individuals with autism to determine the frequency of enzyme deficiency. All patients had duodenal biopsies that were evaluated morphologically and assayed for lactase, sucrase, and maltase activity. Frequency of lactase deficiency was 58% in autistic children </= 5 years old and 65% in older patients. As would be expected, patients with autism at age 5 > years demonstrated significant decline in lactase activity (24%, p = .02) in comparison with </= 5 years old autistic patients. Boys </= 5 years old with autism had 1.7 fold lower lactase activity than girls with autism (p = .02). Only 6% of autistic patients had intestinal inflammation. Lactase deficiency not associated with intestinal inflammation or injury is common in autistic children and may contribute to abdominal discomfort, pain and observed aberrant behavior. Most autistic children with lactose intolerance are not identified by clinical history.

3. Reisinger LM, Cornish KM, Fombonne E. {{Diagnostic Differentiation of Autism Spectrum Disorders and Pragmatic Language Impairment}}. {J Autism Dev Disord};2011 (Mar 17)

The present study examined diagnostic differentiation between school-aged children with autism spectrum disorders (ASD) and children with pragmatic language impairment (PLI). Standardized diagnostic instruments were used to investigate the relationship between severity of ‘autism triad’ impairments and group membership. The Autism Diagnostic Observation Schedule was administered to 19 children with PLI and 22 children with ASD. Parents completed the Social Communication Questionnaire. There was a significant difference between diagnostic groups in the level of the severity of behaviors represented by the Communication and Reciprocal Social Interaction sub-domains on both diagnostic measures. Currently displayed Repetitive and Restricted Behaviors and Interests were not found to be useful for differentiating between groups. The similarities found between groups have important implications for intervention.

4. Yu KK, Cheung C, Chua SE, McAlonan GM. {{Can Asperger syndrome be distinguished from autism? An anatomic likelihood meta-analysis of MRI studies}}. {J Psychiatry Neurosci};2011 (Mar 1);36(2):100138.

Background: The question of whether Asperger syndrome can be distinguished from autism has attracted much debate and may even incur delay in diagnosis and intervention. Accordingly, there has been a proposal for Asperger syndrome to be subsumed under autism in the forthcoming Diagnostic and Statistical Manual of Mental Disorders, fifth edition, in 2013. One approach to resolve this question has been to adopt the criterion of absence of clinically significant language or cognitive delay – essentially, the « absence of language delay. » To our knowledge, this is the first meta-analysis of magnetic resonance imaging (MRI) studies of people with autism to compare absence with presence of language delay. It capitalizes on the voxel-based morphometry (VBM) approach to systematically explore the whole brain for anatomic correlates of delay and no delay in language acquisition in people with autism spectrum disorders. Methods: We conducted a systematic search for VBM MRI studies of grey matter volume in people with autism. Studies with a majority (at least 70%) of participants with autism diagnoses and a history of language delay were assigned to the autism group (n = 164, control n = 190). Those with a majority (at least 70%) of individuals with autism diagnoses and no language delay were assigned to the Asperger syndrome group (n = 136, control n = 214). We entered study coordinates into anatomic likelihood estimation meta-analysis software with sampling size weighting to compare grey matter summary maps driven by Asperger syndrome or autism. Results: The summary autism grey matter map showed lower volumes in the cerebellum, right uncus, dorsal hippocampus and middle temporal gyrus compared with controls; grey matter volumes were greater in the bilateral caudate, prefrontal lobe and ventral temporal lobe. The summary Asperger syndrome map indicated lower grey matter volumes in the bilateral amygdala/hippocampal gyrus and prefrontal lobe, left occipital gyrus, right cerebellum, putamen and precuneus compared with controls; grey matter volumes were greater in more limited regions, including the bilateral inferior parietal lobule and the left fusiform gyrus. Both Asperger syndrome and autism studies reported volume increase in clusters in the ventral temporal lobe of the left hemisphere. Limitations: We assigned studies to autism and Asperger syndrome groups for separate analyses of the data and did not carry out a direct statistical group comparison. In addition, studies available for analysis did not capture the entire spectrum, therefore we cannot be certain that our findings apply to a wider population than that sampled. Conclusion: Whereas grey matter differences in people with Asperger syndrome compared with controls are sparser than those reported in studies of people with autism, the distribution and direction of differences in each category are distinctive.