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Rossignol D.A.,International Child Development Resource Center | Frye R.E.,University of Texas Health Science Center at Houston
Molecular Psychiatry | Year: 2012

A comprehensive literature search was performed to collate evidence of mitochondrial dysfunction in autism spectrum disorders (ASDs) with two primary objectives. First, features of mitochondrial dysfunction in the general population of children with ASD were identified. Second, characteristics of mitochondrial dysfunction in children with ASD and concomitant mitochondrial disease (MD) were compared with published literature of two general populations: ASD children without MD, and non-ASD children with MD. The prevalence of MD in the general population of ASD was 5.0% (95% confidence interval 3.2, 6.9%), much higher than found in the general population (∼0.01%). The prevalence of abnormal biomarker values of mitochondrial dysfunction was high in ASD, much higher than the prevalence of MD. Variances and mean values of many mitochondrial biomarkers (lactate, pyruvate, carnitine and ubiquinone) were significantly different between ASD and controls. Some markers correlated with ASD severity. Neuroimaging, in vitro and post-mortem brain studies were consistent with an elevated prevalence of mitochondrial dysfunction in ASD. Taken together, these findings suggest children with ASD have a spectrum of mitochondrial dysfunction of differing severity. Eighteen publications representing a total of 112 children with ASD and MD (ASD/MD) were identified. The prevalence of developmental regression (52%), seizures (41%), motor delay (51%), gastrointestinal abnormalities (74%), female gender (39%), and elevated lactate (78%) and pyruvate (45%) was significantly higher in ASD/MD compared with the general ASD population. The prevalence of many of these abnormalities was similar to the general population of children with MD, suggesting that ASD/MD represents a distinct subgroup of children with MD. Most ASD/MD cases (79%) were not associated with genetic abnormalities, raising the possibility of secondary mitochondrial dysfunction. Treatment studies for ASD/MD were limited, although improvements were noted in some studies with carnitine, co-enzyme Q10 and B-vitamins. Many studies suffered from limitations, including small sample sizes, referral or publication biases, and variability in protocols for selecting children for MD workup, collecting mitochondrial biomarkers and defining MD. Overall, this evidence supports the notion that mitochondrial dysfunction is associated with ASD. Additional studies are needed to further define the role of mitochondrial dysfunction in ASD. © 2012 Macmillan Publishers Limited All rights reserved. Source


Siniscalco D.,The Second University of Naples | Siniscalco D.,Center for Autism | Bradstreet J.J.,International Child Development Resource Center | Sych N.,Cell Therapy Center ll | Antonucci N.,Biomedical Center for Autism Research and Treatment
Stem Cells International | Year: 2013

Autism and autism spectrum disorders (ASDs) are complex neurodevelopmental disorders. ASDs are clinically defined by deficits in communication, social skills, and repetitive and/or restrictive interests and behaviours. With the prevalence rates for ASDs rapidly increasing, the need for effective therapies for autism is a priority for biomedical research. Currently available medications do not target the core symptoms, can have markedly adverse side-effects, and are mainly palliative for negative behaviours. The development of molecular and regenerative interventions is progressing rapidly, and medicine holds great expectations for stem cell therapies. Cells could be designed to target the observed molecular mechanisms of ASDs, that is, abnormal neurotransmitter regulation, activated microglia, mitochondrial dysfunction, blood-brain barrier disruptions, and chronic intestinal inflammation. Presently, the paracrine, secretome, and immunomodulatory effects of stem cells would appear to be the likely mechanisms of application for ASD therapeutics. This review will focus on the potential use of the various types of stem cells: embryonic, induced pluripotential, fetal, and adult stem cells as targets for ASD therapeutics. © 2013 Dario Siniscalco et al. Source


Frye R.E.,University of Arkansas for Medical Sciences | Sequeira J.M.,New York University | Quadros E.V.,New York University | James S.J.,University of Arkansas for Medical Sciences | Rossignol D.A.,International Child Development Resource Center
Molecular Psychiatry | Year: 2013

Cerebral folate deficiency (CFD) syndrome is a neurodevelopmental disorder typically caused by folate receptor autoantibodies (FRAs) that interfere with folate transport across the blood-brain barrier. Autism spectrum disorders (ASDs) and improvements in ASD symptoms with leucovorin (folinic acid) treatment have been reported in some children with CFD. In children with ASD, the prevalence of FRAs and the response to leucovorin in FRA-positive children has not been systematically investigated. In this study, serum FRA concentrations were measured in 93 children with ASD and a high prevalence (75.3%) of FRAs was found. In 16 children, the concentration of blocking FRA significantly correlated with cerebrospinal fluid 5-methyltetrahydrofolate concentrations, which were below the normative mean in every case. Children with FRAs were treated with oral leucovorin calcium (2 mg kg-1 per day; maximum 50 mg per day). Treatment response was measured and compared with a wait-list control group. Compared with controls, significantly higher improvement ratings were observed in treated children over a mean period of 4 months in verbal communication, receptive and expressive language, attention and stereotypical behavior. Approximately one-third of treated children demonstrated moderate to much improvement. The incidence of adverse effects was low. This study suggests that FRAs may be important in ASD and that FRA-positive children with ASD may benefit from leucovorin calcium treatment. Given these results, empirical treatment with leucovorin calcium may be a reasonable and non-invasive approach in FRA-positive children with ASD. Additional studies of folate receptor autoimmunity and leucovorin calcium treatment in children with ASD are warranted. © 2013 Macmillan Publishers Limited. Source


Frye R.E.,University of Texas Health Science Center at Houston | Rossignol D.A.,International Child Development Resource Center
Pediatric Research | Year: 2011

Autism spectrum disorder (ASD) is a devastating neurodevelopmental disorder. Over the past decade, evidence has emerged that some children with ASD suffer from undiagnosed comorbid medical conditions. One of the medical disorders that has been consistently associated with ASD is mitochondrial dysfunction. Individuals with mitochondrial disorders without concomitant ASD manifest dysfunction in multiple high-energy organ systems, such as the central nervous, muscular, and gastrointestinal (GI) systems. Interestingly, these are the identical organ systems affected in a significant number of children with ASD. This finding increases the possibility that mitochondrial dysfunction may be one of the keys that explains the many diverse symptoms observed in some children with ASD. This article will review the importance of mitochondria in human health and disease, the evidence for mitochondrial dysfunction in ASD, the potential role of mitochondrial dysfunction in the comorbid medical conditions associated with ASD, and how mitochondrial dysfunction can bridge the gap for understanding how these seemingly disparate medical conditions are related. We also review the limitations of this evidence and other possible explanations for these findings. This new understanding of ASD should provide researchers a pathway for understanding the etiopathogenesis of ASD and clinicians the potential to develop medical therapies. Copyright © 2011 International Pediatric Research Foundation, Inc. Source


Rossignol D.A.,International Child Development Resource Center | Frye R.E.,University of Texas Health Science Center at Houston
Developmental Medicine and Child Neurology | Year: 2011

Aim The aim of this study was to investigate melatonin-related findings in autism spectrum disorders (ASD), including autistic disorder, Asperger syndrome, Rett syndrome, and pervasive developmental disorders, not otherwise specified. Method Comprehensive searches were conducted in the PubMed, Google Scholar, CINAHL, EMBASE, Scopus, and ERIC databases from their inception to October 2010. Two reviewers independently assessed 35 studies that met the inclusion criteria. Of these, meta-analysis was performed on five randomized double-blind, placebo-controlled studies, and the quality of these trials was assessed using the Downs and Black checklist. Results Nine studies measured melatonin or melatonin metabolites in ASD and all reported at least one abnormality, including an abnormal melatonin circadian rhythm in four studies, below average physiological levels of melatonin and/or melatonin derivates in seven studies, and a positive correlation between these levels and autistic behaviors in four studies. Five studies reported gene abnormalities that could contribute to decreased melatonin production or adversely affect melatonin receptor function in a small percentage of children with ASD. Six studies reported improved daytime behavior with melatonin use. Eighteen studies on melatonin treatment in ASD were identified; these studies reported improvements in sleep duration, sleep onset latency, and night-time awakenings. Five of these studies were randomized double-blind, placebo-controlled crossover studies; two of the studies contained blended samples of children with ASD and other developmental disorders, but only data for children with ASD were used in the meta-analysis. The meta-analysis found significant improvements with large effect sizes in sleep duration (73min compared with baseline, Hedge's g 1.97 [95% confidence interval {CI} CI 1.10-2.84], Glass's Δ 1.54 [95% CI 0.64-2.44]; 44min compared with placebo, Hedge's g 1.07 [95% CI 0.49-1.65], Glass's Δ 0.93 [95% CI 0.33-1.53]) and sleep onset latency (66min compared with baseline, Hedge's g-2.42 [95% CI -1.67 to -3.17], Glass's Δ-2.18 [95% CI -1.58 to -2.76]; 39min compared with placebo, Hedge's g-2.46 [95% CI -1.96 to -2.98], Glass's Δ-1.28 [95% CI -0.67 to -1.89]) but not in night-time awakenings. The effect size varied significantly across studies but funnel plots did not indicate publication bias. The reported side effects of melatonin were minimal to none. Some studies were affected by limitations, including small sample sizes and variability in the protocols that measured changes in sleep parameters. Interpretation Melatonin administration in ASD is associated with improved sleep parameters, better daytime behavior, and minimal side effects. Additional studies of melatonin would be helpful to confirm and expand on these findings. © The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press. Source

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