1. Banerjee A, Miller MT, Li K, Sur M, Kaufmann WE. {{Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder}}. {Brain}. 2019.
With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.
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2. Bianco E, Rota D. {{Oral findings in Rett syndrome: An update and review of the literature}}. {Dental and medical problems}. 2018; 55(4): 441-5.
Rett syndrome is a progressive pediatric neurodevelopmental disorder, predominantly affecting females, characterized by a seemingly normal prenatal and perinatal period, followed by neurodevelopmental stagnation, and then rapid regression.The purpose of this study was to provide an update of the literature on the oral aspects of Rett syndrome and their possible treatment in patients suffering from this pathology. After an electronic and manual search in MEDLINE (PubMed) and the Cochrane Library, 12 articles were found, for a total of 142 patients affected by Rett syndrome. A high prevalence of bruxism, anterior open bite, ogival palate, sucking habits, and difficulties in maintaining oral hygiene was noted. There were also oral findings related to the pharmacological treatment, which included xerostomia, glossitis, erythema multiforme, gingival hyperplasia, dysphagia, and lingual paralysis. It is important for the dentist to know what problems related to the oral cavity can be encountered in a patient diagnosed with Rett syndrome and what preventive measures can be applied.
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3. Capkova P, Srovnal J, Capkova Z, Staffova K, Becvarova V, Trkova M, Adamova K, Santava A, Curtisova V, Hajduch M, Prochazka M. {{MLPA is a practical and complementary alternative to CMA for diagnostic testing in patients with autism spectrum disorders and identifying new candidate CNVs associated with autism}}. {PeerJ}. 2019; 6: e6183.
Background: Autism spectrum disorder (ASD) is a complex heterogeneous developmental disease with a significant genetic background that is frequently caused by rare copy number variants (CNVs). Microarray-based whole-genome approaches for CNV detection are widely accepted. However, the clinical significance of most CNV is poorly understood, so results obtained using such methods are sometimes ambiguous. We therefore evaluated a targeted approach based on multiplex ligation-dependent probe amplification (MLPA) using selected probemixes to detect clinically relevant variants for diagnostic testing of ASD patients. We compare the reliability and efficiency of this test to those of chromosomal microarray analysis (CMA) and other tests available to our laboratory. In addition, we identify new candidate genes for ASD identified in a cohort of ASD-diagnosed patients. Method: We describe the use of MLPA, CMA, and karyotyping to detect CNV in 92 ASD patients and evaluate their clinical significance. Result: Pathogenic and likely pathogenic mutations were identified by CMA in eight (8.07% of the studied cohort) and 12 (13.04%) ASD patients, respectively, and in eight (8.07%) and four (4.35%) patients, respectively, by MLPA. The detected mutations include the 22q13.3 deletion, which was attributed to ring chromosome 22 formation based on karyotyping. CMA revealed a total of 91 rare CNV in 55 patients: eight pathogenic, 15 designated variants of unknown significance (VOUS)-likely pathogenic, 10 VOUS-uncertain, and 58 VOUS-likely benign or benign. MLPA revealed 18 CNV in 18 individuals: eight pathogenic, four designated as VOUS-likely pathogenic, and six designated as VOUS-likely benign/benign. Rare CNVs were detected in 17 (58.62%) out of 29 females and 38 (60.32%) out of 63 males in the cohort. Two genes, DOCK8 and PARK2, were found to be overlapped by CNV designated pathogenic, VOUS-likely pathogenic, or VOUS-uncertain in multiple patients. Moreover, the studied ASD cohort exhibited significant (p < 0.05) enrichment of duplications encompassing DOCK8. Conclusion: Multiplex ligation-dependent probe amplification and CMA yielded concordant results for 12 patients bearing CNV designated pathogenic or VOUS-likely pathogenic. Unambiguous diagnoses were achieved for eight patients (corresponding to 8.7% of the total studied population) by both MLPA and CMA, for one (1.09%) patient by karyotyping, and for one (1.09%) patient by FRAXA testing. MLPA and CMA thus achieved identical reliability with respect to clinically relevant findings. As such, MLPA could be useful as a fast and inexpensive test in patients with syndromic autism. The detection rate of potentially pathogenic variants (VOUS-likely pathogenic) achieved by CMA was higher than that for MLPA (13.04% vs. 4.35%). However, there was no corresponding difference in the rate of unambiguous diagnoses of ASD patients. In addition, the results obtained suggest that DOCK8 may play a role in the etiology of ASD. Lien vers le texte intégral (Open Access ou abonnement)
4. Hadad BS, Schwartz S, Binur N. {{Reduced perceptual specialization in autism: Evidence from the other-race face effect}}. {Journal of experimental psychology General}. 2019.
Emerging accounts of autism suggest that flexible and broadly tuned perceptual representations, presumably resulting from reduced specialization, may underlie atypical perception. Here, we examined the other-race effect (ORE) to study face processing specialization arising from specific experience with own-race faces. Face discrimination was tested for own- and other-race faces in typically developed individuals and in individuals with autism spectrum disorder (ASD). For each race, faces were morphed to vary discrimination difficulty, and orientation was manipulated to examine inversion effects. The ASD group displayed overall lower sensitivity and reduced inversion effects in processing faces. Importantly, the processing advantage for own-race faces was substantially smaller in this group, resulting specifically from the reduced specialization for the own-race faces. Moreover, the typical larger inversion effect for Caucasian faces was not observed in the ASD group; sensitivity to orientation was smaller and equivalent for the two face races. These more broadly tuned representations in autism may account for the overall weaker representations of faces and suggest, more broadly, that a failure in perceptual specialization may underlie atypical perception in autism. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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5. Heathers J, Gilchrist KH, Hegarty-Craver M, Grego S, Goodwin MS. {{AN ANALYSIS OF STEREOTYPICAL MOTOR MOVEMENTS AND CARDIOVASCULAR COUPLING IN INDIVIDUALS ON THE AUTISM SPECTRUM}}. {Biological psychology}. 2019.
One of the core diagnostic features of autism spectrum disorder (ASD) is engagement in stereotypical motor movements, although the etiology of this repetitive behavior is unknown. Since the 1960s, it has been hypothesized that stereotypical motor movements serve a homeostatic regulation function, and thereby a putative coupling mechanism to cardiovascular arousal. However, to date, surprisingly few reports explicitly assess cardio-somatic coupling and stereotypical motor movements. The present exploratory study investigates coupling of stereotypical body rocking and hand flapping to heart rate and heart rate variability (HRV) in a convenience sample (n = 10) of children and young adults with moderate to profound ASD. Motor movements were recorded via video and three-axis accelerometry, and simultaneous electrocardiographic signals were obtained to determine cardiovascular indices at or around the onset of naturalistically occurring stereotypy. Analysis of the heart rate revealed both repetitive body rocking and hand flapping in particular were found to associate with a strikingly similar cardiovascular pattern of acceleration and deceleration unrelated to physical demands associated with the movements themselves. Furthermore, neither type of stereotypical movement provoked directional change in heart rate variability. The implications of these results and opportunities for future research are discussed.
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6. Hessl D, Harvey D, Sansone S, Crestodina C, Chin J, Joshi R, Hagerman RJ, Berry-Kravis E. {{Effects of mavoglurant on visual attention and pupil reactivity while viewing photographs of faces in Fragile X Syndrome}}. {PLoS One}. 2019; 14(1): e0209984.
BACKGROUND: Numerous preclinical studies have supported the theory that enhanced activation of mGluR5 signaling, due to the absence or reduction of the FMR1 protein, contributes to cognitive and behavioral deficits in patients with fragile X syndrome (FXS). However multiple phase 2 controlled trials in patients with FXS have failed to demonstrate efficacy of compounds that negatively modulate mGluR5, including two phase 2b randomized controlled trials (RCT) of mavoglurant (AFQ056, Novartis Pharma AG), when the primary measures of interest were behavioral ratings. This has cast some doubt onto the translation of the mGluR5 theory from animal models to humans with the disorder. METHODS: We evaluated social gaze behavior-a key phenotypic feature of the disorder-and sympathetic nervous system influence on pupil size using a previously-validated eye tracking paradigm as a biobehavioral probe, in 57 adolescent or adult patients with FXS at baseline and following three months of blinded treatment with one of three doses of mavoglurant or placebo, within the context of the AFQ056 RCTs. RESULTS: Patients with FXS treated with mavoglurant demonstrated increased total absolute looking time and number of fixations to the eye region while viewing human faces relative to baseline, and compared to those treated with placebo. In addition, patients had greater pupil reactivity to faces relative to baseline following mavoglurant treatment compared to placebo. DISCUSSION: The study shows that negative modulation of mGluR5 activity improves eye gaze behavior and alters sympathetically-driven reactivity to faces in patients with FXS, providing preliminary evidence of this drug’s impact on behavior in humans with the disorder.
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7. Long M, Ghisari M, Kjeldsen L, Wielsoe M, Norgaard-Pedersen B, Mortensen EL, Abdallah MW, Bonefeld-Jorgensen EC. {{Autism spectrum disorders, endocrine disrupting compounds, and heavy metals in amniotic fluid: a case-control study}}. {Mol Autism}. 2019; 10: 1.
Background: Evidence has indicated that some non-inherited factors such as exposure to environmental pollutants are associated with neurodevelopment disorders like autism spectrum disorder (ASD). Studies report that endocrine disrupting compounds (EDCs), including polychlorinated biphenyls, organochlorine pesticides, perfluoroalkyl substances (PFAS), and some metals, have adverse effects on the fetal neurodevelopment. The aim of this study was to measure the amniotic fluid (AF) levels of EDCs and metals as well as the receptor transactivities induced by AF and investigate the possible link between prenatal exposure to EDCs and heavy metals and ASD risk. Methods: In this case-control study, we included AF samples of 75 ASD cases and 135 frequency-matched controls and measured the levels of the endogenous sex hormones, PFAS, and elements including heavy metals. The combined effect of endogenous hormones and EDCs on the receptor of estrogen (ER), androgen (AR), aryl hydrocarbon (AhR), and thyroid hormone-like activity were also determined and expressed as receptor ligand equivalents. We assessed the associations of AF levels of chemicals, sex hormones, and receptor activities with ASD risk using unconditional logistical regression analyses. To control for multiple comparisons, the false discovery rate (FDR) was used and q values less than 0.25 were designated as statistical significance. Results: PFAS and metals were detectable in AF samples. The ASD cases had significantly lower AF levels of PFAS than controls, and the adjusted odds ratio (OR) was 0.410 (95% CI 0.174, 0.967; p = 0.042; FDR q value = 0.437) for perfluorooctane sulfonate (PFOS). The principal component, including PFAS congeners, copper, iron, and estrogenic activity, was significantly inversely associated with ASD risk (adjusted OR = 0.100; 95% CI 0.016, 0.630; p = 0.014; FDR q value = 0.098).Testosterone level in AF weakly associated with ASD risk (adjusted OR = 1.002; 95% CI 1.000, 1.004; p = 0.05). However, after multiple comparison correction, the association was not significant (FDR q value = 0.437). No significant associations between AF-induced receptor transactivities and ASD risk were observed. The adjusted OR was 2.176 (95%CI 0.115, 41.153) for the ratio of the combined androgenic activity to combined estrogenic activity. Conclusions: The presence of PFAS and heavy metals in AF indicates that they can cross the placenta. The inverse association between levels of PFAS congeners in AF and ASD risk might relate to the weak estrogenic activities and anti-androgenic activities of PFAS.The observed tendency of positive association between the ratio of combined androgenic effect to the combined estrogenic effect and ASD risk needs further studies to explore whether EDCs together with endogenous hormones play a role in the development of ASD.
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8. Patra S, Nebhinani N, Viswanathan A, Kirubakaran R. {{Atomoxetine for attention deficit hyperactivity disorder in children and adolescents with autism: A systematic review and meta-analysis}}. {Autism Res}. 2019.
Atomoxetine is prescribed to children with autism spectrum disorder having symptoms of attention deficit hyperactivity disorder. We sought to examine the efficacy and safety of atomoxetine in this population. After screening for inclusion criteria, we identified three randomized placebo controlled trials involving 241 children. We assessed internal validity using standard Cochrane Risk of bias tool for randomized controlled trials (RCTs). We used Revman 5.3 for meta-analysis and GRADE approach to create summary of findings with grading of the quality of evidence. Atomoxetine had a benefit on improving parent-rated hyperactivity (standardized mean difference [SMD] = -0.73, 95% Confidence Interval, CI = -1.15 to -0.34) and parent-rated inattention (SMD = -0.53, 95% CI = -0.93 to -0.12) but the magnitude of effects is uncertain. However, atomoxetine was also associated with increased risk of non-serious adverse effects like nausea and vomiting, decreased sleep, and decreased appetite. Atomoxetine may be effective in improving hyperactivity and inattention in children with autism spectrum disorder and attention deficit hyperactivity disorder. However, we are uncertain about the true effect of this intervention and need more RCTs trials designed to evaluate this. Autism Research 2019. (c) 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Atomoxetine is prescribed for Attention Deficit Hyperactivity Disorder (ADHD). About a third of children and adolescents with autism also suffer from ADHD. We carried out an analysis of data reported from a specific kind of medication trials which had examined the effectiveness and side effects of atomoxetine in this patient population. We could find only three such trials and analyzed the reported data. Our analysis revealed that atomoxetine is effective in improving symptoms of ADHD like hyperactivity and inattention and also causes side effects like nausea, vomiting, decreased sleep, and decreased appetite. However, the existing data are insufficient to provide a conclusive statement with certainty and more trials are needed for this.
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9. Rhine MA, Parrott JM, Schultz MN, Kazdoba TM, Crawley JN. {{Hypothesis-driven investigations of diverse pharmacological targets in two mouse models of autism}}. {Autism Res}. 2019.
Autism spectrum disorder is a neurodevelopmental syndrome diagnosed primarily by persistent deficits in social interactions and communication, unusual sensory reactivity, motor stereotypies, repetitive behaviors, and restricted interests. No FDA-approved medical treatments exist for the diagnostic symptoms of autism. Here we interrogate multiple pharmacological targets in two distinct mouse models that incorporate well-replicated autism-relevant behavioral phenotypes. Compounds that modify inhibitory or excitatory neurotransmission were selected to address hypotheses based on previously published biological abnormalities in each model. Shank3B is a genetic model of a mutation found in autism and Phelan-McDermid syndrome, in which deficits in excitatory neurotransmission and synaptic plasticity have been reported. BTBR is an inbred strain model of forms of idiopathic autism in which reduced inhibitory neurotransmission and excessive mTOR signaling have been reported. The GABA-A receptor agonist gaboxadol significantly reduced repetitive self-grooming in three independent cohorts of BTBR. The TrkB receptor agonist 7,8-DHF improved spatial learning in Shank3B mice, and reversed aspects of social deficits in BTBR. CX546, a positive allosteric modulator of the glutamatergic AMPA receptor, and d-cycloserine, a partial agonist of the glycine site on the glutamatergic NMDA receptor, did not rescue aberrant behaviors in Shank3B mice. The mTOR inhibitor rapamycin did not ameliorate social deficits or repetitive behavior in BTBR mice. Comparison of positive and negative pharmacological outcomes, on multiple phenotypes, evaluated for replicability across independent cohorts, enhances the translational value of mouse models of autism for therapeutic discovery. GABA agonists present opportunities for personalized interventions to treat components of autism spectrum disorder. Autism Res 2019. (c) 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Many of the risk genes for autism impair synapses, the connections between nerve cells in the brain. A drug that reverses the synaptic effects of a mutation could offer a precision therapy. Combining pharmacological and behavioral therapies could reduce symptoms and improve the quality of life for people with autism. Here we report reductions in repetitive behavior by a GABA-A receptor agonist, gaboxadol, and improvements in social and cognitive behaviors by a TrkB receptor agonist, in mouse models of autism.
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10. Tonacci A, Bagnato G, Pandolfo G, Billeci L, Sansone F, Conte R, Gangemi S. {{MicroRNA Cross-Involvement in Autism Spectrum Disorders and Atopic Dermatitis: A Literature Review}}. {J Clin Med}. 2019; 8(1).
Autism Spectrum Disorder (ASD) is a category of neurodevelopmental disturbances seriously affecting social skills, to which the scientific community has paid great attention in last decades. To date, their pathogenesis is still unknown, but several studies highlighted the relevance of gene-environment interactions in the onset of ASD. In addition, an immune involvement was seen in a wide number of ASD subjects, leading several researchers to hypothesize a possible common pathogenesis between ASD and immune disturbances, including Atopic Dermatitis (AD). In general, among potential contributing factors, microRNAs (miRNAs), small molecules capable of controlling gene expression and targeting mRNA transcripts, might represent one of the major circulating link, possibly unraveling the connections between neurodevelopmental and immune conditions. Under such premises, we conducted a systematic literature review, under the PRISMA guidelines, trying to define the panel of common miRNAs involved in both ASD and AD. The review retrieved articles published between January 1, 2005, and December 13, 2018, in PubMed, ScienceDirect, PsycARTICLES, and Google Scholar. We found a handful of works dealing with miRNAs in ASD and AD, with the most overlapping dysregulated miRNAs being miR-146 and miR-155. Two possible compounds are abnormally regulated in both ASD and AD subjects, possibly cross-contributing to the interactions between the two disorders, setting the basis to investigate more precisely the possible link between ASD and AD from another, not just clinical, perspective.
