ASA's 37th National Conference on Autism Spectrum Disorders (July 13-15, 2006)
|Friday, July 14, 2006: 1:45 PM-3:00 PM
|#2072- Environmental Factors in Developmental Disabilities: The Emerging Science
|Gene-environment interactions and the role environmental factors might play in leading to developmental disorders are just beginning to be studied. No single environmental agent has been implicated as a unique cause of these disorders; furthermore, investigations of most environmental agents are hampered by the absence of neurodevelopmental toxicity data for most industrial chemicals in widespread use. In this session, leading researchers will highlight the emerging science on these issues and the questions that still need to be addressed.
| - Dr. Martha Herbert is an Assistant Professor of Neurology at Harvard Medical School, a Pediatric Neurologist at the Massachusetts General Hospital and at Cambridge Hospital, and a member of the Harvard-MIT-MGH Martinos Center for Biomedical Imaging. She also received the Cure Autism Now Innovator Award and directs the Cure Autism Now Foundation's Brain Development Initiative. Her research program includes studying what makes some autistic brains unusually large, how the parts of the brain are connected and coordinated with each other, and how we can measure changes in brain function that can result from treatment interventions.
- Mady Hornig, MD, MA, directs translational research in the Greene Laboratory at Columbia University’s Mailman School of Public Health. Her research focuses on understanding how infections, pollutants, and other stressors may trigger otherwise silent genetic factors to cause neuropsychiatric conditions. She developed the “three strikes” hypothesis to explain the mechanisms whereby autism and other neurodevelopmental disorders may occur, positing that the coincidence of genes, environment, and timing is responsible. In 2004, with a novel mouse model, Hornig was the first to implicate genetic susceptibility in the risk for neurodevelopmental damage after early life exposure to low doses of mercury.
- Dr. Ted Schettler is the science director of the Science and Environmental Health Network, and science advisor to Health Care Without Harm, an international campaign in support of environmentally responsible health care. He has worked extensively with community groups and non-governmental organizations throughout the United States and internationally, addressing many aspects of human health and the environment. He has served on advisory committees of the U.S. Environmental Protection Agency and the National Academy of Sciences, and he continues to work closely with Greater Boston Physicians for Social Responsibility. Dr. Schettler is co-author of Generations at Risk: Reproductive Health and the Environment, which examines reproductive and developmental health effects of exposure to a variety of environmental toxicants. He is also co-author of In Harm's Way: Toxic Threats to Child Development, which discusses the impact of environmental exposures on neurological development in children. Ted has published numerous articles in the medical literature, and is frequently quoted in the popular press.
In the United States approximately one in six children suffers from some kind of developmental or learning disability, and some of these conditions, such as autism and attention deficit disorder, appear to be on the rise. Also on the rise in children are disorders involving the immune system, such as diabetes and asthma. Although there is controversy in some cases about whether increasing statistics mean more affected children or greater awareness, in either case we are facing upwards of 12 million children with developmental disorders.
Although genetics undoubtedly plays a significant role, that role may in many cases contribute to increasing vulnerability to environmental factors rather than leading inevitably to the developmental condition. One active area of research focuses on the way that genetic vulnerability and environmental factors interact to lead to altered development. The study of gene-environment interactions, and the role environmental factors might play in leading to developmental disorders, is just beginning. No single environmental agent has been implicated as a unique cause of these disorders; furthermore, investigations of most environmental agents are hampered by the absence of neurodevelopmental toxicity data for most industrial chemicals in widespread use, even when population-wide exposures are documented to be on the rise.
Despite these data gaps, many environmental agents are known to alter brain development as well as function, and may lead to oxidative stress, inflammation, and other metabolic changes increasingly documented in autism and other developmental conditions. In addition, such chronic metabolic changes are being identified not only in the brain but also in other organs of the body, particularly the gastrointestinal and the immune systems, body tissues that are particularly vulnerable to environmental influences.
If the environment plays a role in the production of developmental disorders, identification of the mechanisms by which environmental factors may lead to these changes may also help us discover ways to treat these problems, thereby improving the level of functioning of affected individuals. The study of gene-environment interactions and of environmental influences in developmental disorders will also yield opportunities for understanding the causes and nature of developmental disorders, and which individuals may be at risk. Finally, if there are avoidable causes of or contributors to developmental disorders, identifying them will permit us to develop strategies to prevent exposures to such factors in the future. Reducing exposure to risky and dangerous environmental agents will be a service to future generations. Identifying ways of treating these disorders based on an understanding of gene-environment interactions has the potential to increase the number of treatments available to children affected now.
Learning objectives for this session will include the following:
1. Attendees will learn about evidence relating to the numbers of affected individuals and whether these numbers have changed over time.
2. Attendees will learn about the ways in which environmental factors can alter brain development and function.
3. Attendees will learn how genes may alter the vulnerability of an individual to certain environmental factors, rendering some individuals susceptible, and others relatively resistant, to the development of brain disorders after early life exposures.
4. Attendees will learn how delineating the mechanisms by which environmental factors affect development and function will promote discovery of new treatment strategies capable of improving the level of functioning amongst affected individuals.