Autism is a collection of related neurobiological conditions that is being reported more often. Researchers are now exploring genetic and environmental factors that may contribute to the disorders that affect social interactions and communication. M. Daniele Fallin, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, is the principal investigator of a multistate study, called the Early Autism Risk Longitudinal Investigation, or EARLI, that is looking at siblings of those with the disorders.
The study is funded federally and by Autism Speaks, a national advocacy and science organization that will hold Walk Now for Autism Speaks outside M&T Bank Stadium on Oct. 30. The 5K walk and festival aim to raise funds and awareness. Fallin discusses the disorders and the study.
Question: How common have autism diagnoses become?
Answer: The CDC now estimates that 1 in 110 children has some type of Autism Spectrum Disorder, a term that includes autism, Asperger's and several related conditions. The prior CDC estimate, from two years earlier, was 1 in 150, but it's unclear if we're seeing a true rise in ASDs, the result of broadened criteria or better diagnosis — or a combination of those factors.
Q: What does it mean to have autism?
A: ASDs are a spectrum of neurobiological disorders that affect communication, social interactions and repetitive behaviors. But what's striking is the range of function and dysfunction. With classic autism, people might be nonverbal or display behaviors such as rocking, hand flapping or self-injury. With Asperger's, they might be extremely verbal but perhaps socially awkward. Many people with ASDs have sensory difficulties, and some have gastrointestinal problems. In short, no two people on the autism spectrum are exactly alike, but all seem to have some level of impaired communication.
Q: Why has it been so hard to figure out a cause? And why are researchers focusing on genetic and environmental risks?
A: A lot of past research has focused on either a genetic cause or an environmental cause, but we're moving beyond that one-or-the-other approach. Scientists have identified multiple genes and mutations that seem to be related to ASDs, but it's more complex than just genetics. Environmental factors — whether diet, infections or exposures — may influence how genes are expressed. ASDs are a varied set of conditions — and they may well have combinations of genetic and environmental risks. Further, when considering environmental factors that may combine with genes, both experiences of the mother during pregnancy and of the child during early life may be relevant.
Q: What will you learn from the Early Autism Risk Longitudinal Investigation that you are participating in?
A: Research shows that younger siblings of a child with ASD have a higher rate of ASDs themselves. So we are enrolling mothers who have a child with ASD, then following them at the start of a new pregnancy until that new baby turns 3. This approach allows us to gather a lot of information as it occurs during pregnancy and early life, which increases the accuracy of the data. As we gather information about maternal health, diet, behavior and environmental exposures, we're also getting biological samples, including blood and hair. All this gives us important genetic and environmental data so that many risk factors can be considered in the same study. Once the baby is born, the child will receive free developmental assessments from 6 months until age 3. The families get reports on their child's development, so if any red flags arise, parents can take that information and seek early intervention, which is key to getting the best outcome for a child. EARLI is a major undertaking, being conducted here in Maryland, in Pennsylvania and in California. We want to enroll a total of 1,200 mothers over the course of the 10-year study.
Q: Could the study help you prevent or better treat autism?
A: EARLI can't prevent ASDs for the families who participate. But the free developmental assessments can assist families in seeking early intervention if their new child is showing signs of a delay. Results from EARLI won't be available for a number of years. But in time, we hope that EARLI does uncover risk factors for autism, potentially leading to prevention or better treatment in the long term.
For more information about EARLI, go to http://www.earlistudy.org
For information about the walk, go to http://www.WalkNowForAutismSpeaks.org/baltimore