Autism. It’s the nation’s second-most prevalent neurological disorder. It’s three times more common than juvenile diabetes, and it currently impacts one in 110 children in the United States. It’s more prevalent in boys than girls, and about one percent of the entire U.S. population has an autism spectrum disorder. The disease has been known by researchers and doctors for decades. Yet, there still is no known cause of the disease.
Theories have historically ranged from cold-hearted mothers to vaccines to heritability and environmental factors. The demands and impact of autism on families is staggering. Meanwhile, the societal impact of autism is in the tens-of-billions of dollars annually. Indeed, autism is one of today’s most pressing epidemics.
However, there may be light at the end of the tunnel. Public health science may offer the keys to unlocking the mysteries of autism. The approaches used by public health scientists offer new ways of examining autism spectrum disorders (ASD) and its interdisciplinary foundation is helping to spur advances that may have researchers on the cusp of translational findings to diagnose, treat and prevent the disease.
Researchers at the Drexel University School of Public Health are at the forefront of today’s research on ASDs. They are leading national studies on the possible causes of autism, as well as conducting unique explorations into the interplay of genetics and the environment. The results could yield significant breakthroughs.
Autism is a serious brain-based neurodevelopmental disorder. Autism is defined by the impairment of communication, deficits in social interaction, and restrictive and repetitive behaviors. The severity of these impairments can vary greatly. Therefore, no two children with autism are alike, and each will have their own symptoms at varying degrees.
The neurodevelopmental pathology of autism has been under study by scientists for more than 30 years,
and while still very little is known, scientists at Drexel University believe it is likely to be of prenatal origin.
Autism is heritable. In fact, parents with a child with autism are considerablly more likely, perhaps as high as fifteen times more likely, to have another child with autism than the general population. Yet, the genetic mechanism that underlies autism is extremely complex.
“We know that many different genetic changes are linked to autism etiology,” said Dr. Craig Newscaffer, a professor and autism expert at the School of Public Health. Dr. Newschaffer leads the national EARLI study at the school. “There are locations on almost every chromosome that scientists have identified being of interest,
with some potential correlation to autism.”
In fact, today’s researchers believe that different combinations of these genetic factors are involved in different causes of autism in children. Scientists also know that because of the complexity of the heritability of autism that genes also set the stage for an increased susceptibility for other factors, or environmental factors, to trigger autism.
“We do not know much about these environmental factors, and much of our efforts here at Drexel
University are on identifying these,” said Newschaffer.
Public Health Science
The Centers for Disease Control & Prevention report that one in 110 children in the U.S. have an ASD. One in 85 boys, and one in 315 girls in the U.S. are diagnosed with autism.
Alarmingly, the prevalence of autism continues to rise.
In fact, the prevalence of children with an autism special education classification in Pennsylvania has risen more than 500 percent since 2000. Today, matching national data, approximately one percent of children in Pennsylvania are diagnosed with an ASD. Scientists and economists believe that autism costs society between $35 billion and $90 billion annually in medical, direct and indirect costs.
“When you have a prevalent condition that is responsible for much burden to society, a public health response makes sense,” said Newschaffer. A public health approach to a disease or epidemic looks at the entire population, and seeks to prevent the disease where possible and promote the wellness and quality of life of those who already have the diagnosis.
The U.S. Department of Health and Human Services Interagency Autism Coordinating Committee helps to foster and set research priorities for interdisciplinary research among institutions and fields for autism. They set new cross-cutting themes for autism research this year, and five out of the 11 themes they highlighted were public health approaches to science. They included prevention, earlier detection, lifespan perspective, community engagement and the ethical, legal and societal implications of the disorder.
The public health strategies to prevent the rise or spread of diseases are threefold: primary, secondary
Primary prevention aims to reduce or eliminate the avoidable causes. However, in order for this to happen, researchers need to know the causes of a disease. In autism’s case, scientists are not yet at that point. Researchers Dr. Igor Burstyn and Dr. Brian Lee, faculty members at the Drexel University School of
Public Health, are leading research projects to better understand the avoidable causes of autism in the
Secondary prevention involves detecting and diagnosing a disease early enough to cure the person entirely, or to substantially improve his or her quality of life in the long-term. Dr. Newschaffer leads the Early Autism Risk Longitudinal Investigation (EARLI) study at the Drexel University School of Public Health. Funded by the National Institutes of Health (NIH), EARLI is one of only a handful of the federal agency’s Autism Centers of Excellence, and is one of the leading national studies designed to investigate the potential environmental risks that may interplay with genetics to cause autism. The EARLI study follows young babies at increased risk for autism very closely employing the very latest early detection approaches.
Tertiary prevention involves helping those already living with a disease to maximize their quality of life. These approaches are critically important to individuals with autism and their families – especially as researchers work to develop effective primary and secondary prevention strategies.
Today’s science on autism is focusing on the interplay of genes and the environment, and scientists are hopeful that it will bring about meaningful results. In subsequent pages of this edition of Interaction you will learn more about how professors Newschaffer, Lee and Burstyn use public health approaches to study the potential
causes of autism.
Mindful of the impact that any new findings for an illness may have on the public and society, Dr. Michael Yudell, an assistant professor and public health historian at the Drexel University School of Public Health, has lead a series of programs and research projects on the ethics and best practices of communicating research findings for autism in a way that informs people, yet does not overstate findings or unnecessarily alarm people on the potential impact of an environmental factor.
Venturing Into the Unknown
A cornerstone of public health research is epidemiology, which is the study of health or disease patterns in the population. Epidemiologists look for risk factors that contribute to the onset or increase of a disease. This can be genetic predisposition, environmental risk factors or both. Drexel’s Dr. Burstyn is an expert in the study of
exposure biology, which is the study of the impact on the body from things in the external environment, such as air pollution, chemicals, diet, radiation, stress and infections.
However, there are so many potential environmental factors that it is difficult for researchers to single out
one particular factor’s impact on the body and its relation to the outcome of a disease. In addition, some may have no impact at all. Therefore, Dr. Burstyn uses an approach that looks at which foreign chemicals enter our bodies, at what levels and which ones correlate with the onset of an illness.
“Instead of looking at one chemical at a time, we are identifying and measuring a foreign chemical in the blood stream, and correlating it with a particular disease or illness,” said Burtsyn.
It’s not a new approach. In fact, doctors have been using this procedure for many years to study things like high cholesterol. However, technology is changing the game.
"What is new here is the idea that technology now allows us to look at all chemicals combined in our bodies,” said Dr. Burstyn. “This is the approach that we can take to study the potential causes of autism.”
“Once we know which signatures in blood reflect autism, obesity and other diseases, that’s when we can then go back and look at all of the environmental exposures that may put those chemicals into the blood stream,” said Dr. Burtsyn.
Drexel’s Dr. Lee, an environmental epidemiologist, said that one of the challenges to this approach in studying any disease is that you need to not only match the right chemical, or chemicals, but you also need to study it at the right time. For instance, the chemical might impact the mother, or might only impact the child in-utero, but not after birth. It is therefore critical for researchers to identify appropriate “exposure windows.”
Among his many research projects along these lines for cancer and other diseases, Dr. Burstyn studied
the risk of hypoxia at birth and autism. He was able to show an increased risk of autism with hypoxia
only in boys. Dr. Burstyn is also leading a study in Canada looking at various chemicals that are known to
cause neurological defects and their potential correlation with autism.
According to Dr. Lee, another important epidemiological approach to studying autism is to be sure that researchers measure not only the exposures, but also all ASD.
“I’m proud to say Drexel’s research on autism tackles this, and other epidemiological issues head on, and is
leading the way in discovering the interplay of genetics and environment in autism,” said Dr. Lee.
Drexel’s research on autism also extends overseas. For instance, Dr. Lee investigating the impact of tobacco smoking on austim risk in Sweden. In addition, scientists at Drexel are also assessing the effects of common medications for depression, asthma and epilepsy on pregnant women and potential correlations with autism in Denmark.
In addition to the research being lead by Dr. Burstyn and Dr. Lee, the EARLI study being led by scientists
at Drexel is one of the nation’s foremost studies on autism. Led by Dr. Newschaffer, it is following up to
1,200 mothers who already have a child with autism and are pregnant with another child. As noted earlier, scientists know that there is an increased risk of a child having autism if an older sibling was diagnosed with the disorder. Researchers at Drexel follow the mothers through pregnancy, take biological samples, as well as observe eating habits, and products used around the house, and take environmental samples from around the home. They will follow the mom through delivery and then follow the child through age three taking similar
biological and environmental samples. The hope is to find a correlation between genetic predisposition
and a potential myriad of environmental risk factors over a long period of time.
The Drexel University School of Public Health is not just focused on the etiological studies of autism, but
it is also exploring new methods of early intervention to help improve the quality of life for those already diagnosed with autism.
“The current tools used by medical and public health professionals to confirm a diagnosis of autism are very
valid and reliable, but are often infeasible for community-based healthcare settings because it often takes parents nearly three hours to complete and it needs to be administered by someone who is trained and certified in the assessment,” said Dr. Newschaffer. “Scientists at Drexel,” continued Dr. Newschaffer, “are helping to create more streamlined approaches to confirming the diagnosis of autism that may have implications not only for research but for better diagnosis of the disorder in communities.”
In collaboration with the National Children’s Study, Drexel researchers are looking at three new ways to
confirm the diagnosis. Each takes about 20 minutes to complete and include shorter direct observation
tools, shorter parental interviews and video-guided parental self-reporting.
“Earlier diagnosis is important because today’s early intervention strategies are showing significant promise in helping to improve the child’s quality of life,” said Dr. Newschaffer.
Leading the Way
“In the past several years we have seen tremendous progress in autism research, and we are living in
very exciting times for autism science,” said Dr.
Andy Shih, the vice president for scientific affairs at Autism Speaks. Dr. Shih believes that some discussions we are having today, we would have thought of as science fiction five years ago. The reason for that is the tremendous growth in the understanding of environmental risk factors, as well as the increased knowledge base of genes and the biology associated with autism.
“I think the public health science for autism is so exciting to me because it points the way to improved care, better outcomes and, perhaps most important, the opportunity and possibility of prevention,” said Dr. Shih. “We applaud Dr. Craig Newschaffer and his colleagues at Drexel University for leading the way and for the vision and science taking place at the University.”
“The only way to make a new important discovery in autism research is to venture into the unknown,”
said Dr. Burstyn.