Detecting the Causes of Autism
Autism is back in the news after the recent retraction of research published by Dr. Andrew Wakefield in The Lancet medical journal in the United Kingdom. Evidence showed parts of Wakefield's paper on the increased risk of autism due to childhood vaccinations had been falsified, and the data was horribly flawed.
Parents who don't have a child with autism may have overlooked this announcement. Parents of a child with autism witnessed the disgrace and discredit of the biggest proponent linking autism to vaccines. It may leave parents wondering, if vaccines aren't a culprit, what is?
Researchers at the Department of Psychiatry at the UNC School of Medicine are attempting to find some answers to that question. Assistant Professor Heather Cody Hazlett, Ph.D., and her collaborator Joseph Piven, M.D., are hopeful their new study will shed light on some of the potential environmental and genetic factors of autism.
Hazlett and Piven are recruiting local families to learn more about how the brains of kids with autism develop compared to their typical peers. Their study is sponsored by the National Institutes of Health and Autism Speaks.
In addition to Medical Resonance Imaging scans, Cody and Hazlett are gathering blood samples for genetic screening and additional information from observing the children. Parents complete lengthy questionnaires about potential environmental factors. Though some of the children in the study do not have any siblings with a diagnosis of autism, the majority of the infants have at least one older sibling with a diagnosis of autism.
"We know in autism they have brain 'over-growth' [with] 3- and 4-year-olds, but we want to know when it's happening," Hazlett says. This is why the researchers are looking at MRI scans of infants whose siblings have an autism diagnosis.
Unfortunately, a certain percentage of these babies will eventually be diagnosed with autism, but there is no way of knowing which ones. By observing MRI scans and behavioral interactions, the researchers may be able to let the parents know that some changes are occurring and determine when brain over-growth starts.
For information about the study, watch the UNC video "Funding Will Help to Find Possible Genetic Link to Autism" and visit www.ibis-network.org.
Study participant hopes to help others
Zandra Henderson of Clayton is a mother of three with one more on the way who agreed to have her family participate in the study. Her oldest child, an 8-year-old boy, was diagnosed with autism. They engaged in many interventions to help him integrate with his typically developing peers.
"Our son is higher-functioning, so most people that meet him don't know that there is anything wrong," Henderson says. "We did a lot of speech therapy and it really helped him. Once he was able to talk, some of the screaming and the kicking started to diminish."
When the Hendersons heard about the research study, they enrolled their oldest son's baby brother.
Henderson says she knew early on that something was different with her oldest son. She persisted in finding interventions to help him, and believes that if parents could know something is wrong even sooner than she did, it would benefit them.
"We honestly hope that if they can find something, a link of some sort, that this could help someone in the future," she says.
Looking for traits
Jaclyn Anthony, a social-clinical research associate at the Carolina Institute for Developmental Disabilities, recruits many of the families that participate in the program. Anthony says what is interesting about this research is that it includes a large number of high-risk siblings from 6 to 24 months of age and looks for behavioral, familial and neuro-biological clues. Researchers hope to gain a better understanding of the traits possessed by infants who will later develop autism.
Through MRI scans, blood samples, and environmental and observational data, the research team will attempt to piece together some links to why certain children get an autism diagnosis.
Finding out when changes occur
"We don't really know the genetic and environmental interplay. The genetics behind autism are so complex. Though you end up with the same result [on the autism spectrum], how you got there may be different" Hazlett says.
Hazlett believes there are vulnerabilities and predispositions that may make one child more likely to manifest symptoms on the autism spectrum, but that no one knows with any certainty what the true contributing factors may be. The fact that many genes are involved contributes to this puzzle. Hazelett also says that because there are potentially so many genes involved, what makes one child more vulnerable may not impact another child at all. However, as the technology becomes less expensive and new markers are identified, scientists are finding that they have better ideas of how to look for genes that could be contributors.
The brain scan images collected in the study may help scientists understand more about when these changes take place. They allow the researchers to observe how brain development progresses in the siblings of children with autism because many kids with an autism diagnosis have very different brain scans from their typical peers. The ultimate goal is to interrupt the onset of autism for kids at risk.
"We are looking at these infants because we don't know when these changes occur. Suppose what we see is that brain changes happen before behavioral changes," Hazlett says. The hope is "to capture a period where if you act beforehand, you could change that trajectory." And that's exactly the sort of information that parents of children with autism need.
Robin Whitsell is a mother of four who lives in Chapel Hill.