1. Alvarez-Iglesias V, Mosquera-Miguel A, Cusco I, Carracedo A, Perez-Jurado LA, Salas A. {{Reassessing the role of mitochondrial DNA mutations in autism spectrum disorder}}. {BMC Med Genet};2011 (Apr 6);12(1):50.

ABSTRACT: BACKGROUND: There is increasing evidence that impairment of mitochondrial energy metabolism plays an important role in the pathophysiology of autism spectrum disorders (ASD; OMIM number: 209850). A significant proportion of ASD cases display biochemical alterations suggestive of mitochondrial dysfunction and several studies have reported that mutations in the mitochondrial DNA (mtDNA) molecule could be involved in the disease phenotype. METHODS: We analysed a cohort of 148 patients with idiopathic ASD for a number of mutations proposed in the literature as pathogenic in ASD. We also carried out a case control association study for the most common European haplogroups (hgs) and their diagnostic single nucleotide polymorphisms (SNPs) by comparing cases with 753 healthy and ethnically matched controls. RESULTS: We did not find statistical support for an association between mtDNA mutations or polymorphisms and ASD. CONCLUSIONS: Our results are compatible with the idea that mtDNA mutations are not a relevant cause of ASD and the frequent observation of concomitant mitochondrial dysfunction and ASD could be due to nuclear factors influencing mitochondrion functions or to a more complex interplay between the nucleus and the mitochondrion/mtDNA.

2. Daniels AM, Rosenberg RE, Anderson C, Law JK, Marvin AR, Law PA. {{Verification of Parent-Report of Child Autism Spectrum Disorder Diagnosis to a Web-Based Autism Registry}}. {J Autism Dev Disord};2011 (Apr 6)

Growing interest in autism spectrum disorder (ASD) research requires increasingly large samples to uncover epidemiologic trends; such a large dataset is available in a national, web-based autism registry, the Interactive Autism Network (IAN). The objective of this study was to verify parent-report of professional ASD diagnosis to the registry’s database via a medical record review on a sample of IAN Research participants. Sixty-one percent of families agreed to participate; 98% (n = 116) of whom provided documentation verifying a professionally diagnosed ASD. Results of this study suggest that information collected from parents participating in IAN Research is valid, participants can be authenticated, and that scientists can both confidently use IAN data and recruit participants for autism research.

3. Davidovitch M, Golan D, Vardi O, Lev D, Lerman-Sagie T. {{Israeli Children With Autism Spectrum Disorder Are not Macrocephalic}}. {J Child Neurol};2011 (Apr 4)

The prevalence of macrocephaly in autism spectrum disorder is reported to be much higher than in the general population, 12% to 37%. Progressive macrocephaly is even considered a warning sign for the development of autism. We evaluated the prevalence of an abnormal head circumference in children with autism in Israel and compared it with the head circumferences of children with developmental language disorder and children with normal development. We did not find a higher prevalence of macrocephaly among Israeli children with autism spectrum disorder (4.4%). Although children with autism spectrum disorder had a significantly higher rate of a head circumference above the 75th percentile compared with children with developmental language disorder, it was not significantly different compared with normal controls. We conclude that there is no increased prevalence of macrocephaly in Israeli children with autism; this can be attributed to a different genetic background.

4. He Y, Xun G, Xia K, Hu Z, Lv L, Deng Z, Zhao J. {{No significant association between RELN polymorphism and autism in case-control and family-based association study in Chinese Han population}}. {Psychiatry Res};2011 (Apr 6)

The present study genotyped four SNPs (rs736707, rs2229864, rs362691, and rs2073559) of the Reelin gene (RELN) in 165 autistic trios, 67 sporadic autistic children and 283 healthy controls with Chinese Han pedigree. Both case-control analysis and transmission disequilibrium test (TDT) found no evidence of significant association. The results do not support previous positive findings and suggest that the four single-nucleotide polymorphisms (SNP) of RELN are unlikely to be associated with childhood autism in Chinese Han population.

5. Krishnaswami S, McPheeters ML, Veenstra-Vanderweele J. {{A Systematic Review of Secretin for Children With Autism Spectrum Disorders}}. {Pediatrics};2011 (Apr 4)

Context: As many as 1 in every 110 children in the United States has an autism spectrum disorder (ASD). Secretin is 1 of many medical treatments studied for treating the symptoms of ASDs, but there is currently no consensus regarding which interventions are most effective. Objective: To systematically review evidence regarding the use of secretin in children with ASDs who are aged 12 years and younger. Methods: We searched the Medline, PsycINFO, and ERIC (Education Resources Information Center) databases from 2000 to May 2010 and reference lists of included articles. Two reviewers independently assessed each study against predetermined inclusion/exclusion criteria. Two reviewers independently extracted data regarding participant and intervention characteristics, assessment techniques, and outcomes and assigned overall quality and strength-of-evidence ratings on the basis of predetermined criteria. Results: Evidence from 7 randomized controlled trials supports a lack of effectiveness of secretin for the treatment of ASD symptoms including language and communication impairment, symptom severity, and cognitive and social skill deficits. No studies have resulted in significantly greater improvements in measures of language, cognition, or autistic symptoms when compared with placebo; study authors who reported improvement over time did so equally for both the intervention and placebo groups. Conclusions: Secretin has been studied extensively in multiple randomized controlled trials, and there is clear evidence that it lacks benefit. The studies of secretin included in this review uniformly point to a lack of significant impact of secretin in the treatment of ASD symptoms. Given the high strength of evidence for a lack of effectiveness, secretin as a treatment approach for ASDs warrants no further study.

6. McPheeters ML, Warren Z, Sathe N, Bruzek JL, Krishnaswami S, Jerome RN, Veenstra-Vanderweele J. {{A Systematic Review of Medical Treatments for Children With Autism Spectrum Disorders}}. {Pediatrics};2011 (Apr 4)

Context: As many as 1 in every 110 children in the United States has an autism spectrum disorder (ASD). Many medical treatments for ASDs have been proposed and studied, but there is currently no consensus regarding which interventions are most effective. Objective: To systematically review evidence regarding medical treatments for children aged 12 years and younger with ASDs. Methods: We searched the Medline, PsycInfo, and ERIC (Education Resources Information Center) databases from 2000 to May 2010, regulatory data for approved medications, and reference lists of included articles. Two reviewers independently assessed each study against predetermined inclusion/exclusion criteria. Studies of secretin were not included in this review. Two reviewers independently extracted data regarding participant and intervention characteristics, assessment techniques, and outcomes and assigned overall quality and strength-of-evidence ratings on the basis of predetermined criteria. Results: Evidence supports the benefit of risperidone and aripiprazole for challenging and repetitive behaviors in children with ASDs. Evidence also supports significant adverse effects of these medications. Insufficient strength of evidence is present to evaluate the benefits or adverse effects for any other medical treatments for ASDs, including serotonin-reuptake inhibitors and stimulant medications. Conclusions: Although many children with ASDs are currently treated with medical interventions, strikingly little evidence exists to support benefit for most treatments. Risperidone and aripiprazole have shown benefit for challenging and repetitive behaviors, but associated adverse effects limit their use to patients with severe impairment or risk of injury.

7. Pfaff DW, Rapin I, Goldman S. {{Male predominance in autism: neuroendocrine influences on arousal and social anxiety}}. {Autism Res};2011 (Apr 4)

We offer a neurobiologic theory based on animal work that helps account for the conspicuous male predominance in autism spectrum disorders (ASD). In young male animals, testosterone (TST) binds to androgen receptors (AR) in brainstem neurons responsible for enhancing brain arousal. As a consequence, arousal-related neurotransmitters bombard the amygdala hypersensitized by TST acting though AR. Arousal-related inputs are known to prime amygdaloid mechanisms for fear and anxiety, with resultant social avoidance. We hypothesize that similar mechanisms contribute to autism’s male predominance and to its defining impaired social skills. The theory rests on two key interacting factors: the molecular effects of TST in genetically vulnerable boys in combination with environmental stresses they experienced in utero, neonatally, or during the first years. We postulate that higher TST levels and, therefore, higher amounts of arousal-related inputs to the amygdala sensitize these genetically vulnerable male infants to very early stresses. In sharp contrast to boys, girls not only do not have high levels of TST-facilitated arousal-causing inputs to the amygdala but they also enjoy the protection afforded by estrogenic hormones, oxytocin, and the oxytocin receptor. This theory suggests that novel technologies applied to the molecular endocrinology of TST’s actions through AR will offer new avenues of enquiry into ASD. Since the high male preponderance in autism is important yet understudied, we offer our theory, which is based on detailed neurobehavioral research with animals, to stimulate basic and clinical research in animals and humans and hopefully help develop novel more effective medical treatments for autism. Autism Res 2011,4:xxx-xxx. (c) 2011 International Society for Autism Research, Wiley Periodicals, Inc.

8. Pickett J, Xiu E, Tuchman R, Dawson G, Lajonchere C. {{Mortality in Individuals With Autism, With and Without Epilepsy}}. {J Child Neurol};2011 (Apr 6)

Previous studies show higher mortality rates among individuals with autism than the general population. Comorbidity with epilepsy is an assumed, often ill-defined factor in the increased mortality rates of individuals with autism. Data from the Autism Tissue Program, a tissue donation program established to support biomedical research on autism, show that approximately one-third of its brain donors with autism also had epilepsy. Analysis of new data from the California State Department of Developmental Services is consistent with past reports showing that there is a higher than expected rate of mortality in individuals with autism and epilepsy than autism alone. Accurate, complete and accessible records on cause of death are necessary not just for brain research, but also for understanding risk factors that contribute to early death in individuals with autism spectrum disorders. Various national health care and state developmental disability agency initiatives to reduce risk of mortality are described.

9. Rutherford MD, Troubridge EK, Walsh J. {{Visual Afterimages of Emotional Faces in High Functioning Autism}}. {J Autism Dev Disord};2011 (Apr 5)

Fixating an emotional facial expression can create afterimages, such that subsequent faces are seen as having the opposite expression of that fixated. Visual afterimages have been used to map the relationships among emotion categories, and this method was used here to compare ASD and matched control participants. Participants adapted to a facial expression for 45 s then saw a neutral face for 800 ms and chose a label to describe the latter. The ASD group showed evidence of afterimages, but atypical patterns of opposition: whereas fixating negative emotions uniformly evokes a positive afterimage in the control group, fixating negative emotions was more likely to evoke a negative afterimage in the ASD group. This study was the first to provide evidence of visual aftereffects in ASD and suggests a different psychological organization among emotions in those with ASD.

10. Samson F, Mottron L, Soulieres I, Zeffiro TA. {{Enhanced visual functioning in autism: An ALE meta-analysis}}. {Hum Brain Mapp};2011 (Apr 4)

Autistics often exhibit enhanced perceptual abilities when engaged in visual search, visual discrimination, and embedded figure detection. In similar fashion, while performing a range of perceptual or cognitive tasks, autistics display stronger physiological engagement of the visual system than do non-autistics. To account for these findings, the Enhanced Perceptual Functioning Model proposes that enhanced autistic performance in basic perceptual tasks results from stronger engagement of sensory processing mechanisms, a situation that may facilitate an atypically prominent role for perceptual mechanisms in supporting cognition. Using quantitative meta-analysis of published functional imaging studies from which Activation Likelihood Estimation maps were computed, we asked whether autism is associated with enhanced task-related activity for a broad range of visual tasks. To determine whether atypical engagement of visual processing is a general or domain-specific phenomenon, we examined three different visual processing domains: faces, objects, and words. Overall, we observed more activity in autistics compared to non-autistics in temporal, occipital, and parietal regions. In contrast, autistics exhibited less activity in frontal cortex. The spatial distribution of the observed differential between-group patterns varied across processing domains. Autism may be characterized by enhanced functional resource allocation in regions associated with visual processing and expertise. Atypical adult organizational patterns may reflect underlying differences in developmental neural plasticity that can result in aspects of the autistic phenotype, including enhanced visual skills, atypical face processing, and hyperlexia. Hum Brain Mapp, 2011 (c) 2011 Wiley-Liss, Inc.

11. Schumann G, Coin LJ, Lourdusamy A, Charoen P, Berger KH, Stacey D, Desrivieres S, Aliev FA, Khan AA, Amin N, Aulchenko YS, Bakalkin G, Bakker SJ, Balkau B, Beulens JW, Bilbao A, de Boer RA, Beury D, Bots ML, Breetvelt EJ, Cauchi S, Cavalcanti-Proenca C, Chambers JC, Clarke TK, Dahmen N, de Geus EJ, Dick D, Ducci F, Easton A, Edenberg HJ, Esk T, Fernandez-Medarde A, Foroud T, Freimer NB, Girault JA, Grobbee DE, Guarrera S, Gudbjartsson DF, Hartikainen AL, Heath AC, Hesselbrock V, Hofman A, Hottenga JJ, Isohanni MK, Kaprio J, Khaw KT, Kuehnel B, Laitinen J, Lobbens S, Luan J, Mangino M, Maroteaux M, Matullo G, McCarthy MI, Mueller C, Navis G, Numans ME, Nunez A, Nyholt DR, Onland-Moret CN, Oostra BA, O’Reilly PF, Palkovits M, Penninx BW, Polidoro S, Pouta A, Prokopenko I, Ricceri F, Santos E, Smit JH, Soranzo N, Song K, Sovio U, Stumvoll M, Surakk I, Thorgeirsson TE, Thorsteinsdottir U, Troakes C, Tyrfingsson T, Tonjes A, Uiterwaal CS, Uitterlinden AG, van der Harst P, van der Schouw YT, Staehlin O, Vogelzangs N, Vollenweider P, Waeber G, Wareham NJ, Waterworth DM, Whitfield JB, Wichmann EH, Willemsen G, Witteman JC, Yuan X, Zhai G, Zhao JH, Zhang W, Martin NG, Metspalu A, Doering A, Scott J, Spector TD, Loos RJ, Boomsma DI, Mooser V, Peltonen L, Stefansson K, van Duijn CM, Vineis P, Sommer WH, Kooner JS, Spanagel R, Heberlein UA, Jarvelin MR, Elliott P. {{Genome-wide association and genetic functional studies identify autism susceptibility candidate 2 gene (AUTS2) in the regulation of alcohol consumption}}. {Proc Natl Acad Sci U S A};2011 (Apr 6)

Alcohol consumption is a moderately heritable trait, but the genetic basis in humans is largely unknown, despite its clinical and societal importance. We report a genome-wide association study meta-analysis of approximately 2.5 million directly genotyped or imputed SNPs with alcohol consumption (gram per day per kilogram body weight) among 12 population-based samples of European ancestry, comprising 26,316 individuals, with replication genotyping in an additional 21,185 individuals. SNP rs6943555 in autism susceptibility candidate 2 gene (AUTS2) was associated with alcohol consumption at genome-wide significance (P = 4 x 10(-8) to P = 4 x 10(-9)). We found a genotype-specific expression of AUTS2 in 96 human prefrontal cortex samples (P = 0.026) and significant (P < 0.017) differences in expression of AUTS2 in whole-brain extracts of mice selected for differences in voluntary alcohol consumption. Down-regulation of an AUTS2 homolog caused reduced alcohol sensitivity in Drosophila (P < 0.001). Our finding of a regulator of alcohol consumption adds knowledge to our understanding of genetic mechanisms influencing alcohol drinking behavior.

12. Via E, Radua J, Cardoner N, Happe F, Mataix-Cols D. {{Meta-analysis of Gray Matter Abnormalities in Autism Spectrum Disorder: Should Asperger Disorder Be Subsumed Under a Broader Umbrella of Autistic Spectrum Disorder?}}. {Arch Gen Psychiatry};2011 (Apr);68(4):409-418.

CONTEXT: Studies investigating abnormalities of regional gray matter volume in autism spectrum disorder (ASD) have yielded contradictory results. It is unclear whether the current subtyping of ASD into autistic disorder and Asperger disorder is neurobiologically valid. OBJECTIVES: To conduct a quantitative meta-analysis of voxel-based morphometry studies exploring gray matter volume abnormalities in ASD, to examine potential neurobiological differences among ASD subtypes, and to create an online database to facilitate replication and further analyses by other researchers. DATA SOURCES: We retrieved studies from PubMed, ScienceDirect, Scopus, and Web of Knowledge databases between June 3, 1999, the date of the first voxel-based morphometry study in ASD, and October 31, 2010. Studies were also retrieved from reference lists and review articles. We contacted authors soliciting additional data. STUDY SELECTION: Twenty-four data sets met inclusion criteria, comprising 496 participants with ASD and 471 healthy control individuals. DATA EXTRACTION: Peak coordinates of clusters of regional gray matter differences between participants with ASD and controls, as well as demographic, clinical, and methodologic variables, were extracted from each study or obtained from the authors. DATA SYNTHESIS: No differences in overall gray matter volume were found between participants with ASD and healthy controls. Participants with ASD were found to have robust decreases of gray matter volume in the bilateral amygdala-hippocampus complex and the bilateral precuneus. A small increase of gray matter volume in the middle-inferior frontal gyrus was also found. No significant differences in overall or regional gray matter volumes were found between autistic disorder and Asperger disorder. Decreases of gray matter volume in the right precuneus were statistically higher in adults than in adolescents with ASD. CONCLUSIONS: These results confirm the crucial involvement of structures linked to social cognition in ASD. The absence of significant differences between ASD subtypes may have important nosologic implications for the DSM-5. The publically available database will be a useful resource for future research.

13. Warren Z, McPheeters ML, Sathe N, Foss-Feig JH, Glasser A, Veenstra-Vanderweele J. {{A Systematic Review of Early Intensive Intervention for Autism Spectrum Disorders}}. {Pediatrics};2011 (Apr 4)

Context: Early intensive behavioral and developmental interventions for young children with autism spectrum disorders (ASDs) may enhance developmental outcomes. Objective: To systematically review evidence regarding such interventions for children aged 12 and younger with ASDs. Methods: We searched Medline, PsycINFO, and ERIC (Education Resources Information Center) from 2000 to May 2010. Two reviewers independently assessed studies against predetermined inclusion/exclusion criteria. Two reviewers independently extracted data regarding participant and intervention characteristics, assessment techniques, and outcomes and assigned overall quality and strength-of-evidence ratings using predetermined criteria. Results: Thirty-four unique studies met inclusion criteria. Seventeen studies were case series; 2 were randomized controlled trials. We rated 1 study as good quality, 10 as fair quality, and 23 as poor quality. The strength of the evidence overall ranged from insufficient to low. Studies of University of California Los Angeles/Lovaas-based interventions and variants reported clinically significant gains in language and cognitive skills in some children, as did 1 randomized controlled trial of an early intensive developmental intervention approach (the Early Start Denver Model). Specific parent-training approaches yielded gains in short-term language function and some challenging behaviors. Data suggest that subgroups of children displayed more prominent gains across studies, but participant characteristics associated with greater gains are not well understood. Conclusions: Studies of Lovaas-based approaches and early intensive behavioral intervention variants and the Early Start Denver Model resulted in some improvements in cognitive performance, language skills, and adaptive behavior skills in some young children with ASDs, although the literature is limited by methodologic concerns.