1. Chang CH, Wade MG, Stoffregen TA, Hsu CY, Pan CY. {{Visual tasks and postural sway in children with and without autism spectrum disorders}}. {Res Dev Disabil} (Jul 1)
We investigated the influences of two different suprapostural visual tasks, visual searching and visual inspection, on the postural sway of children with and without autism spectrum disorder (ASD). Sixteen ASD children (age=8.75+/-1.34 years; height=130.34+/-11.03cm) were recruited from a local support group. Individuals with an intellectual disability as a co-occurring condition and those with severe behavior problems that required formal intervention were excluded. Twenty-two sex- and age-matched typically developing (TD) children (age=8.93+/-1.39 years; height=133.47+/-8.21cm) were recruited from a local public elementary school. Postural sway was recorded using a magnetic tracking system (Flock of Birds, Ascension Technologies, Inc., Burlington, VT). Results indicated that the ASD children exhibited greater sway than the TD children. Despite this difference, both TD and ASD children showed reduced sway during the search task, relative to sway during the inspection task. These findings replicate those of Stoffregen et al. (2000), Stoffregen, Giveans, et al. (2009), Stoffregen, Villard, et al. (2009) and Prado et al. (2007) and extend them to TD children as well as ASD children. Both TD and ASD children were able to functionally modulate postural sway to facilitate the performance of a task that required higher perceptual effort.
2. Gadow KD, Devincent CJ, Pisarevskaya V, Olvet DM, Xu W, Mendell N, Finch SJ, Hatchwell E. {{Parent-child DRD4 genotype as a potential biomarker for oppositional, anxiety, and repetitive behaviors in children with autism spectrum disorder}}. {Prog Neuropsychopharmacol Biol Psychiatry} (Jul 2)
The primary objective of the present study was to examine whether a combination of parent-child DRD4 genotypes results in more informative prognostic biomarkers of oppositional, separation anxiety, and repetitive behaviors in children with autism spectrum disorder (ASD). Based on prior research indicating the 7-repeat allele as a potential risk variant, participants were sorted into one of four combinations of parent-child genotypes. Owing to the possibility of parent-of-origin effects, analyses were conducted separately for mother-child (MC) and father-child (FC) dyads. Mothers completed a validated DSM-IV-referenced rating scale. Partial eta-squared (etap(2)) was used to determine the magnitude of group differences: 0.01-0.06=small, 0.06-0.14=moderate, and >0.14=large. Analyses indicated that children in MC dyads with matched genotypes had the least (7-/7-) and most (7+/7+) severe mother-rated oppositional-defiant (etap(2)=0.11) and separation anxiety (etap(2)=0.19) symptoms. Conversely, youths in FC dyads with matched genotypes had the least (7-/7-) and most (7+/7+) severe obsessive-compulsive behaviors (etap(2)=0.19) and tics (etap(2)=0.18). Youths whose parents were both noncarriers had less severe tics than peers with at least one parental carrier, and the effect size was large (etap(2)=0.16). There was little evidence that noncarrier children were rated more severely by mothers who were carriers versus noncarriers. Transmission Disequilibrium Test analyses provided preliminary evidence for undertransmission of the 2-repeat allele in youths with more severe tics (p=0.02). Parent genotype may be helpful in constructing prognostic biomarkers for behavioral disturbances in ASD; however, findings are tentative pending replication with larger, independent samples.
3. Hofstaetter JG, Roetzer KM, Krepler P, Nawrot-Wawrzyniak K, Schwarzbraun T, Klaushofer K, Roschger P. {{Altered bone matrix mineralization in a patient with Rett syndrome}}. {Bone} (Jun 18)
Rett syndrome (RTT) is a common X-linked neurodevelopmental disorder caused by mutations in the coding region of methyl-CpG-binding 2 (MECP2) gene. Patients with RTT have a low bone mineral density and increased risk of fracture. However, very little is known if bone matrix mineralization is altered in RTT. A 17-year-old girl with a classical form of RTT with a heterozygous nonsense mutation in exon 3 in the MECP2-gene was treated in our hospital. Her femoral neck BMD is 43.3% below the 3rd percentile when compared to age and sex-matched controls. She underwent surgery for correction of her scoliosis, which provided a unique opportunity to obtain bone tissue to study bone matrix mineralization (Bone Mineralization Density Distribution-BMDD) using quantitative backscattered electron imaging (qBEI) and histomorphometry. BMDD outcomes were compared to recently published normative reference data for young individuals. qBEI analysis showed a significant shift to lower matrix mineralization despite histomorphometric indices indicate a low bone turnover. There was a reduction in CaMean (-7.92%) and CaPeak (-3.97%), which describe the degree of mineralization. Furthermore the fraction of low mineralized matrix (CaLow: +261.84%) was dramatically increased, which was accompanied with an increase in the heterogeneity of mineralization (CaWidth: +86.34%). Our findings show a significantly altered bone matrix mineralization of a typical patient with RTT. This may partly explain the low bone density seen in these patients. These results also warrant further studies on the molecular role of MECP2 in bone matrix mineralization.
4. Jordan CJ. {{Evolution of autism support and understanding via the world wide web}}. {Intellect Dev Disabil} (Jun);48(3):220-227.
5. Kawasaki Y, Shinomiya M, Takayanagi M, Niwa SI. {{Paroxysmal EEG abnormalities and epilepsy in pervasive developmental disorders: Follow-up study until adolescence and beyond}}. {Brain Dev} (Jun 30)
This study examined paroxysmal abnormalities and epilepsy in EEG for individuals with pervasive developmental disorders (PDD) in two parts: first with a large number of subjects (n=1624); and second with extracted subjects followed from 5years into adolescence and beyond (n=92). Many paroxysms in PDD patients in their childhood tended to appear at various sites and the same held for paroxysms at the time of epilepsy onset. However, in adolescence and beyond, paroxysms in the frontal region prevailed as those appearing at sites other than the frontal region tended to disappear. The same held for paroxysms at the time of epilepsy onset. These paroxysms in the frontal area characteristic of PDD were named « Paroxysms at F. » It was suggested that functional abnormality in the frontal region exists in PDD through paroxysmal EEG abnormalities and epilepsy.
6. Perkins T, Stokes M, McGillivray J, Bittar R. {{Mirror neuron dysfunction in autism spectrum disorders}}. {J Clin Neurosci} (Jun 30)
Autism spectrum disorders (ASDs) are developmental conditions characterized by deficits in social interaction, verbal and nonverbal communication and obsessive/stereotyped patterns of behaviour. Although there is no reliable neurophysiological marker associated with ASDs, dysfunction of the parieto-frontal mirror neuron system has been suggested as a disturbance linked to the disorder. Mirror neurons (MNs) are visuomotor neurons which discharge both when performing and observing a goal directed action. Research suggests MNs may have a role in imitation, empathy, theory of mind and language. Although the research base is small, evidence from functional MRI, transcranial magnetic stimulation, and an electroencephalographic component called the mu rhythm suggests MNs are dysfunctional in subjects with ASD. These deficits are more pronounced when ASD subjects complete tasks with social relevance, or that are emotional in nature. Promising research has identified that interventions targeting MN related functions such as imitation can improve social functioning in ASDs. Boosting the function of MNs may improve the prognosis of ASDs, and contribute to diagnostic clarity.
7. Rossetti ZS. {{Autism & the transition to adulthood: success beyond the classroom}}. {Intellect Dev Disabil} (Jun);48(3):228-230.
