The IOM, part of the National Academy of Sciences, organized the meeting with the help of a planning committee that included representatives from the National Institutes of Health, IOM and various advocacy groups, including two members of the Autism Speaks leadership team. Alison Singer, executive vice president of communications & awareness, and Sophia Colamarino, vice president of research, served on the committee and helped formulate the list of invitees to the panel, topics for discussion, and agenda. Autism Speaks board member Sallie Bernard and Gary Goldstein, chair of Autism Speaks' Scientific Advisory Committee, also participated in a panel discussion looking at the unique strengths the public and private sectors each bring to the table in combating autism.

What Do We Know? What Do We Need?

The clinical problem of autism was discussed during the workshop's first day. While the problem of variability of symptoms between children has always made this developmental disorder difficult to study, it may provide a unique opportunity to researchers interested in differing environmental exposures.

Genetic and environmental factors may be studied based on specific behavioral symptoms – what causes this disorder in one group may not apply to another group. Autism may be actually considered “autisms” based on the clinical spectrum of symptoms. Researchers suggest that these variable symptoms may result from a combination of different genetic predispositions plus diverse environmental influences acting at various stages of development.

Using a combination of genetic tools, targets from ongoing studies and analytical techniques, these genetic factors should be identified to determine the mechanism by which environmental factors may influence behavior. As Pat Levitt from Vanderbilt University explained “(the argument) is not nature versus nurture, it is nature and nurture together”.

Other disorders have strong gene x environment interactions, and the panel heard from researchers studying other diseases using a wide array of methods to identify environmental risk factors. These included lead exposure, schizophrenia, and asthma.

The role of gene x environment interactions have been studied through controlled environments, occupational exposures, longitudinal and naturalistic settings, and large-population based epidemiological research. Researchers who study gene x environment interactions in other disorders and diseases point to large epidemiological studies which combine careful collection of genetic and clinical data together with biomarker assessment for detection and validation of biological markers.

Tools for Studying Environmental Influences?

Studying environmental factors quickly requires techniques that can screen and identify potential exposures of interest efficiently and effectively. These tools include animal models and cell cultures. Animal models provide insight on mechanisms for neurodevelopmental disorders, and methods for testing different genes and exposures of interest.

Using these techniques, environmental risk factors, including toxicants can be studied under different conditions and genetic backgrounds. New technologies from studies of other diseases, such as infectious diseases, may be used to better identify and define the mechanism by which exposures contribute to autism .

Clues on what risk factors and what genes should be investigated further may come from epidemiology studies. These include the Centers for Disease Control-funded SEED study , the CHARGE study , and the EARLI network, which are designed to study pre- and post-natal risk factors as well as provide information about medical and birth history.

Other large studies such as the National Children's Study and international birth registries provide rich datasets to identify exposure histories, medical histories, and biobank repositories for further study.

International studies of autism in countries with different exposure levels and prenatal risk factors (including diet and medical care) provide a unique opportunity to evaluate gene x environment interactions. These projects provide a wealth of data that offers valuable information about what factors are associated with autism.

Technology, Infrastructure Needs for Future Research

The panel clearly identified the need for biomarkers of autism, and representatives from the NIH and CDC presented information on tools and studies that may help autism researchers better identify potential exposures of interest. These include improvement of exposure assessment using standard measures in blood and urine, and development of more dynamic measures.

A wide array of potential exposures suggest that researchers should “cast a wide net” when determining how, when and which chemicals to test for. In addition, researchers should identify biomarkers that are specific for autism and also sensitive enough to pick up subtle pathophysiology.

After listening to a day-and-a-half of discussions, panel participants were asked to identify and suggest future needs based on gaps in current research. These included, but were not limited to: better definition of autism spectrum disorders to identify subtypes, standardization of assessment measures and enhanced utilization of existing and new datasets, enhancement of biobanks and biorepositories, and more studies of medical co-morbidities such as immune dysfunction.

Building new resources as well as taking advantage of existing studies will provide new insights into the causes of autism (or autisms) for faster development of treatment protocols and discoveries which could lead to a cure.

Partnerships between the public and private sector and involvement of advocacy organizations were instrumental in the success of this meeting, and will be important in future scientific opportunities. A summary of the conference proceedings will be published by the IOM and be available later this year. An agenda for the meeting plus the presentations of each researcher can be found here: http://www.iom.edu/?id=42481