In 2010 the Gene Environment Interaction Model of Autism CHARGEd to the Fore

"Uncovering environmental causes of autism

CHARGE (Childhood Autism Risks from Genetics and the Environment) was launched in 2003 as a study of 1,000 to 2,000 children with differing patterns of development. The goal is to better understand the causes and contributing factors for autism or developmental delay. Three groups of children are being enrolled in the CHARGE study: children with autism, children with developmental delay who do not have autism and children from the general population. All of them are evaluated for a broad array of exposures and susceptibilities.

Refining our understanding of environment-gene interactions

Little is known about what causes autism or developmental delay. We will learn how genes and the environment interact to change children’s behaviors and skills. By studying a large number of children, we will discover which particular genes and/or environmental exposures might result in non-typical patterns of development and special subtypes of autism or developmental delay."

2010 could be known as the year that serious autism research arising from the genetic-environmental interaction model CHARGE'd to the fore with two major genetic-environmental focused autism research studies being published and receiving widespread attention.   2010 could also come to be known as  the year that  the "it's gotta be genetic" model of autism causation began its retreat from the battlefield in our attempt to understand autism causes  and seek autism cures.  Nothing can be done to retroactively counter the  time, financial resources,  attention and energies lost promoting the ill conceived notion that all autism disorders are 100% genetically based but there are now clear signs we are moving forward in our efforts to understand what causes autism disorders and real progress is being made.

Researchers involved with the recent mitochondrial dysfunction study and the proximity to proximity to highways (and air borne pollutants) study used data from the CHARGE program.  In each case the study authors are careful to report the limitations of their studies and to indicate that their studies indicate associations but do not, as yet,  identify specific causes of autism disorders. The studies  are exploratory and provide the foundation for further research.  Such studies are long overdue and are very welcome. 

A solid foundation for serious autism research has been established.  The autism research paradigm shift whispered about over  the last 3 years is now fully emerging and we are seriously studying the interaction of genetic and environmental research.  The gene environment model of autism is strongest in  California where researchers like  Dr. Irva Hertz-Picciotto, principal investigator on the CHARGE study, Dr.  Heather E. Volk  and Dr. Cecelia Giulvi use data from the CHARGE program as the basis for their research. 

The gene environment model of autism was also featured prominently at the  US Senate Committee on Environment and Public Works, Subcommittee on Children’s Health hearing entitled, "State of Research on Potential Environmental Health Factors with Autism and Related Neurodevelopment Disorders"   in August 2010. One of those who made written submission to the hearing was Dr. Isaac N. Pessah, Director UC Davis Center for Children’s Environmental Health and Disease Prevention Professor of Toxicology and a Co-Investigator with the CHARGE study.

There are signs Canada has also  begun to embrace the gene environment model of autism causation.  The York Alliance Autism Research Group includes  Dr. Dorothy Crawford,  focusing on gene environment interaction as causes of autism disorders in her research. Even the US IACC (Interagency Autism Coordinating Committee) has acknowledged, albeit somewhat timidly, the emergence of the gene environment model in understanding autism causation:

"As with many complex disorders, causation is generally thought to involve some forms of genetic risk interacting with some forms of non-genetic environmental exposure. ... In addition, a number of other environmental factors are being explored through research because they are known or suspected to influence early development of the brain and nervous system. Recent studies suggest factors such as parental age, exposure to infections, toxins, and other biological agents may confer environmental risk. ... Progress in identifying environmental factors which increase autism risk has been made recently (Eskenazi et al., 2007; Palmer et al., 2006; Palmer, Blanchard,; Wood, 2009; Rauh et al., 2006; Roberts et al., 2007; Windham et al., 2006), although this area of research has received less scientific attention and far fewer research dollars than genetic risk factors"

I have bold highlighted the last quoted statement from the IACC because it confirms exactly what has been said about autism research funding by autism researches from Dr. Teresa Binstock to Dr. Irva Hertz-Picciotto. Funding dollars have gone overwhelmingly toward genetic based autism research at the expense of environment autism research and that imbalance must be corrected.  Hopefully, as the gene environment model continues to gain ground amongst scientists involved in autism research that imbalance will also be corrected by funding authorities from government agencies to Autism Speaks.

It is time to CHARGE ahead with the gene environment interaction model of understanding and researching autism disorders. 

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Genetic Autism Research Has Struck Out

Genetic autism research has struck out. After decades of standing at the  plate and swinging away with public and private autism research funding genetic autism research has provided little information about the nature of autism disorders, what causes them or possible treatments or cures. It is time to change batters and bring in significant funding for environmentally focused autism research. Hopefully public health authorities, Autism Speaks and others involved with distributing autism research funding will decide to give environmentally focused autism research it's long overdue turn at the plate.  

Dr. Isaac N. Pessah, Director, UC Davis Center for Children’s Environmental Health and Disease Prevention and Professor of Toxicology reviewed and summarized the overdue need for more environmental autism research in his testimony before the US Senate Committee and Public Works:

Re: State of Research on Potential Environmental Health Factors With Autism and Related Neurodevelopment Disorders

"... Although autism risk has strong heritability, no single locus alone appears to be sufficient to account for the full clinical phenotype. Results from many genomewide autism screens indicate that potential susceptibility genes are spread across the entire genome. Recently several very rare genetic mutations, single nucleotide polymorphisms (SNPs), de novo copy number variations, and epigenetic factors that influence DNA methylation were shown to contribute complexity in the transmission of autism risk. Yet genetics alone cannot account for the majority of autism cases currently being diagnosed. There is lack of full concordance between monozygotic twins, with some estimate ranging as low as 60%, and the prevalence of ASD among siblings has been reported as high as 14%. Interactions among multiple genes are likely to contribute to various types of autism, and heritable epigenetic factors and/or non-heritable environmental exposures are likely to significantly contribute to susceptibility and variable expression of autism and autism-related traits. It is therefore likely that constellations of epigenetic and environmental factors are contributing to the increasing prevalence of ASD, a rise that cannot be fully accounted for by changes in diagnostic criteria.


There is a critical need to identify environmental factors, including exposure to xenobiotic chemicals and changes in diet that contribute to autism risk and severity. The vast majority of public and private resources has, and continues, to support work on identifying genetic impairments associated with autism risk. From these studies we have learned that genetics alone cannot predict the majority of autism cases, the patterns of impairments, severity, nor can they predict success for current treatment modalities. Moreover, we have learned that many of the molecular and cellular systems that are associated with autism are the very same ones that are the target of environmental chemicals currently of concern to human health because of their widespread use. Further research is needed on modifiable factors that contribute to causing or protecting against autism. It is accepted that autism is 'multi-factorial,' meaning that there are multiple factors that combine to impair brain development. Increased efforts to identify environmental factors that contribute risk to developing autism spectrum are therefore essential to improve our understanding of the constellations of genes that confer differential sensitivity to distinct environmental exposures during gestational and neonatal development. Such approaches will likely prove useful in defining subgroups of children that differ in susceptibility to specific types of environmental exposures that promote autism risk, severity, and responsiveness to clinical and behavioral interventions.


We know that autism prevalence continues to increase dramatically clearly implicating environmental factors in autism risk. We must identify which environmental exposures and combination of exposures are contributing to increased overall risk in the population and identify the most susceptible groups. Only by bringing together the concerted effort of multidisciplinary teams of scientists can we identify which of the >80,000 commercially important chemicals currently in production promote developmental neurotoxicity consistent with the immunological and neurological impairments identified in individuals with idiopathic autism. It is clear that their is a critical need to identify which chemicals in the environment that influence the same biological pathways known to be affected in autism. Limiting exposure to these chemicals is the only way to mitigate or prevent autism in susceptible individuals."

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