Re: Biomarkers of Environmental Toxicity and Susceptibility in Autism Reply

Institute of Chronic Illnesses, Inc., Silver Spring, Maryland, USA.
Journal of the neurological sciences (Impact Factor: 2.47). 10/2008; 280(1-2):101-8. DOI: 10.1016/j.jns.2008.08.021
Source: PubMed


Autism spectrum disorders (ASDs) may result from a combination of genetic/biochemical susceptibilities in the form of a reduced ability to excrete mercury and/or increased environmental exposure at key developmental times. Urinary porphyrins and transsulfuration metabolites in participants diagnosed with an ASD were examined. A prospective, blinded study was undertaken to evaluate a cohort of 28 participants with an ASD diagnosis for Childhood Autism Rating Scale (CARS) scores, urinary porphyrins, and transsulfuration metabolites. Testing was conducted using Vitamin Diagnostics, Inc. (CLIA-approved) and Laboratoire Philippe Auguste (ISO-approved). Participants with severe ASDs had significantly increased mercury intoxication-associated urinary porphyrins (pentacarboxyporphyrin, precoproporphyrin, and coproporphyrin) in comparison to participants with mild ASDs, whereas other urinary porphyrins were similar in both groups. Significantly decreased plasma levels of reduced glutathione (GSH), cysteine, and sulfate were observed among study participants relative to controls. In contrast, study participants had significantly increased plasma oxidized glutathione (GSSG) relative to controls. Mercury intoxication-associated urinary porphyrins were significantly correlated with increasing CARS scores and GSSG levels, whereas other urinary porphyrins did not show these relationships. The urinary porphyrin and CARS score correlations observed among study participants suggest that mercury intoxication is significantly associated with autistic symptoms. The transsulfuration abnormalities observed among study participants indicate that mercury intoxication was associated with increased oxidative stress and decreased detoxification capacity.

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Available from: Mark R Geier
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    • "Children eating paint chips or those with pica may develop toxic lead levels [4]. Genetically, children with autism may be less able to detoxify toxic environmental agents, and this inability may predispose them to suffer neural damage consistent with autistic behavioral traits [4]. Women with chronic metal exposure (who have accumulated high tissue levels of mercury and other metals) may pass "
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    ABSTRACT: and Aims . The etiological factors involved in the etiology of autism remain elusive and controversial, but both genetic and environmental factors have been implicated. The aim of this study was to assess the levels and possible environmental risk factors and sources of exposure to mercury, lead, and aluminum in children with autism spectrum disorder (ASD) as compared to their matched controls. Methods . One hundred ASD children were studied in comparison to 100 controls. All participants were subjected to clinical evaluation and measurement of mercury, lead, and aluminum through hair analysis which reflects past exposure. Results . The mean Levels of mercury, lead, and aluminum in hair of the autistic patients were significantly higher than controls. Mercury, lead, and aluminum levels were positively correlated with maternal fish consumptions, living nearby gasoline stations, and the usage of aluminum pans, respectively. Conclusion . Levels of mercury, lead, and aluminum in the hair of autistic children are higher than controls. Environmental exposure to these toxic heavy metals, at key times in development, may play a causal role in autism.
    Full-text · Article · Oct 2015 · Behavioural neurology
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    • "Links to oxidative stress have been identified in studies showing a decrease in the reduced form of glutathione (GSH) and the total amount of glutathione in both the brain (Chauhan et al., 2012; Rose et al., 2012a) and peripheral blood (Geier and Geier, 2006; James et al., 2006; Geier et al., 2009a, b; James et al., 2009; Al-Yafee et al., 2011) of ASD patients. However, the oxidized form of glutathione (GSSG) has been reported to be increased (James et al., 2004, 2006, 2009; Geier et al., 2009a; Adams et al., 2011; Chauhan et al., 2012; Rose et al., 2012a). Moreover, Rose et al. showed that oxidative damage has an impact on the inflammatory response in the brain of autism patients, with an increase of 3-chlorotyrosine (3-CT) and a decrease in aconitase activity (Rose et al., 2012a). "
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    ABSTRACT: Autism spectrum disorders (ASD) are a heterogeneous group of disorders which have complex behavioural phenotypes. Although ASD is a highly heritable neuropsychiatric disorder, genetic research alone has not provided a profound understanding of the underlying causes. Recent developments using biochemical tools such as transcriptomics, proteomics and cellular models, will pave the way to gain new insights into the underlying pathological pathways. This review addresses the state-of-the-art in the search for molecular biomarkers for ASD. In particular, the most important findings in the biochemical field are highlighted and the need for establishing streamlined interaction between behavioural studies, genetics and proteomics is stressed. Eventually, these approaches will lead to suitable translational ASD models and, therefore, a better disease understanding which may facilitate novel drug discovery efforts in this challenging field.
    Full-text · Article · Nov 2013 · The International Journal of Neuropsychopharmacology
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    • "Methylation capacity is also decreased in autism.[10] Moreover, the transsulfuration abnormality is associated with autism symptoms.[11] Besides, improvement of the transmethylation/transsulfuration pathways is associated with the reduction of autism symptoms.[12] "
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    ABSTRACT: There are a limited number of Food and Drug Administration (FDA)-approved medications for the treatment of autism. Meanwhile, oxidative stress and neuroinflammation are supposed to play a causative role in autism. N-acetylcysteine may provide cystine, a precursor for glutathione (GSH), which is an important antioxidant factor in the brain. We here report a child with autism, whose symptoms were markedly decreased after taking oral N-acetylcysteine 800 mg/day, in three divided doses. His social interaction was significantly increased. The score of social impairment on a visual analog scale decreased from 10 to 6 in the two-month trial. The aggressive behaviors decreased from 10 to 3. This case suggests that N-acetylcysteine may decrease some symptoms of autism.
    Full-text · Article · Oct 2012 · Journal of research in medical sciences
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