Researches on Genetic and Environment Risk Factors for Autism
Now, there is a project, expanding and coordinating two complementary studies, tries to find out more. The project funded by Autism Speaks will conduct multi-site studies focusing on a study of more than 2000 infant siblings of children with autism, who are at higher genetic risk for developing the disorder. Many of these infants will be followed from close to conception through early childhood. In the case of high risk infants, detailed measures of brain development will be taken using state-of-the-art neuroimaging.
The project will collect data during critical periods of development, including genetic, neurobiological, diagnostic and environmental information on families recruited. These studies will provide new insights into the genetic and environmental risk factors that contribute to autism, as well as contributing data useful to studies searching for the earliest possible diagnosis of autism spectrum disorder (ASD).
One of the two projects is the Early Autism Risk Longitudinal Investigation (EARLI) network lead by Drexel University. EARLI will explore possible risk factors and biological indicators for ASD during the prenatal, neonatal and early postnatal periods. The project will enroll and follow up to 1200 mothers of children with autism at the start of a new pregnancy and document the development of their newborn siblings through age three. This groundbreaking study will provide a unique opportunity for studying possible autism environmental risk factors and biomarkers during different developmental windows as well as an opportunity to investigate the interplay of genetic susceptibility and environmental exposure. EARLI will begin enrolling subjects in the spring of 2009.
In the second project is the Infant Brain Imaging Study (IBIS) lead by researcher Joseph Piven, M.D. IBIS will help to identify brain differences in children who develop ASD using brain imaging techniques to monitor and analyze the brain development of 544 very young infant siblings of children with autism. Some of these infants may go on to develop ASD. Their brain images will be compared to those of other “typical” infants, to identify differences between children who develop autism and those who do not. This study involves examination and correlation of the brain and behavioral changes in very early life that may mark the onset of autistic symptoms. Little is known about the abnormal processes during early brain development in children with ASD and this research could offer new insights that lead to earlier diagnosis of ASD.
“These comprehensive studies will help us better understand the onset of ASD and hopefully capture the earliest possible indicators of autism. Both of these studies will also significantly add to our knowledge about the causes of autism by looking at the interaction between genetic susceptibility and environmental exposures. It is our hope that this collaborative effort will facilitate early screening and hopefully lead to effective prevention and treatment strategies,” noted Geraldine Dawson, Ph.D., Chief Science Officer at Autism Speaks. It “seeks to enhance the capacity of some established core research efforts by allowing DNA and additional exposure data to be collected, supporting longitudinal research over time, and facilitating collaboration among separate research institutions to maximize the scientific opportunities available and the impact of their findings.”
Environmental exposures during pregnancy and infancy are another significant aspect of the EARLI study. A number of environmental exposures, including dietary and lifestyle factors, medications and personal care product use, and suspected neurotoxicants including persistent organic pollutants will be investigated with data and samples collected in EARLI.
“The EARLI study is designed explicitly to collect accurate information on a wide range of exposures during the most important times for brain development,” said Dr. Newschaffer, a professor and department chair at the Drexel University School of Public Health. “We are optimistic that this unique study, which also incorporates genetic information from parents and children, will give us an excellent chance of untangling some of the complex causes of autism.”
The UNC-Chapel Hill brain imaging study will not only examine the brain but also behavioral changes through MRI imaging and behavioral assessments at 6, 12 and 24 months of age. Depicted at http://www.unchealthcare.org/site/newsroom/autism, one Clayton North Carolina family participates in this study hoping to find that missing piece to the autism puzzle.
UNC researchers have previously found that children with autism have larger brains, from five to 10 percent larger at two years of age than children without autism, and this enlargement or overgrowth of the brain starts around the end of a child’s first year of life. Also at the end of the first year of life, behavioral researchers led by Lonnie Zwaigenbaum, M.D., from University of Alberta in Edmonton, have identified the onset of the social symptoms associated with autism.
This is an “unprecedented study of the genetic underpinnings of early behaviors as they become evident in infants and toddlers with autism and will allow us to study the genetic basis for early changes in brain volume and neural circuitry concurrent with the emergence of autistic behavior,” explained Dr. Piven Professor of Psychiatry and Director of the Carolina Institute for Developmental Disabilities who directs IBIS at UNC-Chapel Hill. “It is our hope that this study will lead to a much deeper understanding of the pathophysiology underlying the development of autism, and will eventually lead to rational approaches to early intervention.”
