Why Are Autism Rates Steadily Rising?
Stefania Sterling was just 21 when she had her son, Charlie. She was young and healthy, with no genetic issues apparent in either her or her husband's family, so she expected Charlie to be typical.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period."
It wasn't until she went to a Mommy and Me music class when he was one, and she saw all the other one-year-olds walking, that she realized how different her son was. He could barely crawl, didn't speak, and made no eye contact. By the time he was three, he was diagnosed as being on the lower functioning end of the autism spectrum.
She isn't sure why it happened – and researchers, too, are still trying to understand the basis of the complex condition. Studies suggest that genes can act together with influences from the environment to affect development in ways that lead to Autism Spectrum Disorder (ASD). But rates of ASD are rising dramatically, making the need to figure out why it's happening all the more urgent.
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Indeed, the CDC's latest autism report, released last week, which uses 2016 data, found that the prevalence of ASD in four-year-old children was one in 64 children, or 15.6 affected children per 1,000. That's more than the 14.1 rate they found in 2014, for the 11 states included in the study. New Jersey, as in years past, was the highest, with 25.3 per 1,000, compared to Missouri, which had just 8.8 per 1,000.
The rate for eight-year-olds had risen as well. Researchers found the ASD prevalence nationwide was 18.5 per 1,000, or one in 54, about 10 percent higher than the 16.8 rate found in 2014. New Jersey, again, was the highest, at one in 32 kids, compared to Colorado, which had the lowest rate, at one in 76 kids. For New Jersey, that's a 175 percent rise from the baseline number taken in 2000, when the state had just one in 101 kids.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period," said Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School, who was involved in collecting the data.
The study echoed the findings of a surprising 2011 study in South Korea that found 1 in every 38 students had ASD. That was the the first comprehensive study of autism prevalence using a total population sample: A team of investigators from the U.S., South Korea, and Canada looked at 55,000 children ages 7 to 12 living in a community in South Korea and found that 2.64 percent of them had some level of autism.
Searching for Answers
Scientists can't put their finger on why rates are rising. Some say it's better diagnosis. That is, it's not that more people have autism. It's that we're better at detecting it. Others attribute it to changes in the diagnostic criteria. Specifically, the May 2013 update of the Diagnostic and Statistical Manual of Mental Disorders-5 -- the standard classification of mental disorders -- removed the communication deficit from the autism definition, which made more children fall under that category. Cynical observers believe physicians and therapists are handing out the diagnosis more freely to allow access to services available only to children with autism, but that are also effective for other children.
Alycia Halladay, chief science officer for the Autism Science Foundation in New York, said she wishes there were just one answer, but there's not. While she believes the rising ASD numbers are due in part to factors like better diagnosis and a change in the definition, she does not believe that accounts for the entire rise in prevalence. As for the high numbers in New Jersey, she said the state has always had a higher prevalence of autism compared to other states. It is also one of the few states that does a good job at recording cases of autism in its educational records, meaning that children in New Jersey are more likely to be counted compared to kids in other states.
"Not every state is as good as New Jersey," she said. "That accounts for some of the difference compared to elsewhere, but we don't know if it's all of the difference in prevalence, or most of it, or what."
"What we do know is that vaccinations do not cause autism."
There is simply no defined proven reason for these increases, said Scott Badesch, outgoing president and CEO of the Autism Society of America.
"There are suggestions that it is based on better diagnosis, but there are also suggestions that the incidence of autism is in fact increasing due to reasons that have yet been determined," he said, adding, "What we do know is that vaccinations do not cause autism."
Zahorodny, the pediatrics professor, believes something is going on beyond better detection or evolving definitions.
"Changes in awareness and shifts in how children are identified or diagnosed are relevant, but they only take you so far in accounting for an increase of this magnitude," he said. "We don't know what is driving the surge in autism recorded by the ADDM Network and others."
He suggested that the increase in prevalence could be due to non-genetic environmental triggers or risk factors we do not yet know about, citing possibilities including parental age, prematurity, low birth rate, multiplicity, breech presentation, or C-section delivery. It may not be one, but rather several factors combined, he said.
"Increases in ASD prevalence have affected the whole population, so the triggers or risks must be very widely dispersed across all strata," he added.
There are studies that find new risk factors for ASD almost on a daily basis, said Idan Menashe, assistant professor in the Department of Health at Ben-Gurion University of the Negev, the fastest growing research university in Israel.
"There are plenty of studies that find new genetic variants (and new genes)," he said. In addition, various prenatal and perinatal risk factors are associated with a risk of ASD. He cited a study his university conducted last year on the relationship between C-section births and ASD, which found that exposure to general anesthesia may explain the association.
Whatever the cause, health practitioners are seeing the consequences in real time.
"People say rates are higher because of the changes in the diagnostic criteria," said Dr. Roseann Capanna-Hodge, a psychologist in Ridgefield, CT. "And they say it's easier for children to get identified. I say that's not the truth and that I've been doing this for 30 years, and that even 10 years ago, I did not see the level of autism that I do see today."
Sure, we're better at detecting autism, she added, but the detection improvements have largely occurred at the low- to mid- level part of the spectrum. The higher rates of autism are occurring at the more severe end, in her experience.
A Polarizing Theory
Among the more controversial risk factors scientists are exploring is the role environmental toxins may play in the development of autism. Some scientists, doctors and mental health experts suspect that toxins like heavy metals, pesticides, chemicals, or pollution may interrupt the way genes are expressed or the way endocrine systems function, manifesting in symptoms of autism. But others firmly resist such claims, at least until more evidence comes forth. To date, studies have been mixed and many have been more associative than causative.
"Today, scientists are still trying to figure out whether there are other environmental changes that can explain this rise, but studies of this question didn't provide any conclusive answer," said Menashe, who also serves as the scientific director of the National Autism Research Center at BGU.
"It's not everything that makes Charlie. He's just like any other kid."
That inconclusiveness has not dissuaded some doctors from taking the perspective that toxins do play a role. "Autism rates are rising because there is a mismatch between our genes and our environment," said Julia Getzelman, a pediatrician in San Francisco. "The majority of our evolution didn't include the kinds of toxic hits we are experiencing. The planet has changed drastically in just the last 75 years –- it has become more and more polluted with tens of thousands of unregulated chemicals being used by industry that are having effects on our most vulnerable."
She cites BPA, an industrial chemical that has been used since the 1960s to make certain plastics and resins. A large body of research, she says, has shown its impact on human health and the endocrine system. BPA binds to our own hormone receptors, so it may negatively impact the thyroid and brain. A study in 2015 was the first to identify a link between BPA and some children with autism, but the relationship was associative, not causative. Meanwhile, the Food and Drug Administration maintains that BPA is safe at the current levels occurring in food, based on its ongoing review of the available scientific evidence.
Michael Mooney, President of St. Louis-based Delta Genesis, a non-profit organization that treats children struggling with neurodevelopmental delays like autism, suspects a strong role for epigenetics, which refers to changes in how genes are expressed as a result of environmental influences, lifestyle behaviors, age, or disease states.
He believes some children are genetically predisposed to the disorder, and some unknown influence or combination of influences pushes them over the edge, triggering epigenetic changes that result in symptoms of autism.
For Stefania Sterling, it doesn't really matter how or why she had an autistic child. That's only one part of Charlie.
"It's not everything that makes Charlie," she said. "He's just like any other kid. He comes with happy moments. He comes with sad moments. Just like my other three kids."
China vs. the West: Who Will Lead the Way in Embryo Editing Research?
Junjiu Huang and his team performed a miracle. A few miracles, actually. The researchers at Sun Yat-sen University in Guangzhou, China used the precise new DNA editing tool called CRISPR-CAS9 to edit a human embryo, replacing a single base. In doing so, they edited out beta-thalassemia, a blood disorder that reduces the production of hemoglobin, which can result in pale skin, fatigue, higher risk of blood clots, and other symptoms.
The race is on, and it's one everyone is going to try to win.
Huang's group, which did not respond to an email requesting comment for this story, injected 86 embryos and observed them for 48 hours. After that period -- a time long enough for CRISPR to split the DNA, other molecules to replace the base, and the embryos to grow to eight cells -- they tested 54 of the 71 that survived. Of those, only a few had the replacement base, according to a report of the study published in Protein & Cell. The experiment stopped there as the embryos, which had been acquired from local fertility clinics, were non-viable and not implanted.
But procreation was not the point. Far from it, in fact. The point was to demonstrate that it could be done, that in some far off (or not so far off) future, doctors could use CRISPR to eliminate diseases like Tay-Sachs, Huntington's, and cystic fibrosis that are caused by genetic mutations. Going a step further, perhaps they could eventually even tailor embryos that will develop into adults with specific traits like height and IQ.
Experts agree that we are far from that point, years if not decades away from leveraging CRISPR to cure diseases and decades if not centuries from being able to build designer babies. In that frame, Huang's achievement is just a small step, a blip on the timeline of human achievement. But seen in another light, it's yet another sign that we need to start talking about DNA modification now, establishing protocols, procedures, and plans that guide the subject before we get so far down the road that momentum is impossible to stop.
"The Chinese generally don't have the religious objections to embryo research that have held back research in the West."
It's essential to do so now because the idea of DNA modification -- a realization that humanity can control its evolution -- is compelling and attractive. Imagine a world where doctors and scientists could get rid of disease before it begins or ensure a baby would arrive with an Einstein-level IQ. That's intriguing, and also terrifying. What are the rules? How do we know when to stop? What guides the process? And how can we prevent mistakes or unwanted mutations? To borrow from another famous quotation, with great power comes great responsibility.
These aren't questions for Huang and the Chinese scientific community alone. A team from Oregon recently edited viable human embryos, eliminating a mutation that can lead to heart failure while preventing any unintended consequences. Just as importantly, every embryo they edited produced the intended genetic changes, a vital step since a partial success rate, known as mosaicism, could have devastating consequences to a future child.
In London at the Francis Crick Institute, researcher Kathy Niakan used CRISPR-CAS9 to "turn off" a gene that produces the protein OCT4. Without the protein, the fertilized egg could not produce a blastocyst, which is a key structure in early mammalian development that gives rise to an embryo and placenta. The recent study wasn't designed to go further, but the use of CRISPR was important. "One way to find out what a gene does in the developing embryo is to see what happens when it isn't working," said Dr. Niakan, who was the first scientist in the world to be granted regulatory approval to edit the genes of a human embryo for research. "Now that we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes. If we knew the key genes that embryos need to develop successfully, we could improve IVF treatments and understand some causes of pregnancy failure. It may take many years to achieve such an understanding. Our study is just the first step."
The point is, CRISPR is here and it's not going anywhere. Scientists will continue to use it to learn about how humans develop. Yet different rules regarding CRISPR and embryo research in countries around the world will impact who gets there first. "I've heard the U.S.-China gene editing research parallel paths as Sputnik 2.0," said Kevin Doxzen, Science Communications Specialist at the University of California, Berkeley's Innovative Genomics Institute. The race is on, and it's one everyone is going to try to win.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest. "The Chinese generally don't have the religious (predominantly Christian) or moral objections to embryo research that have held back research in the West," said Dr. Julian Savulescu, the Uehiro Professor of Practical Ethics and Director of the Oxford Martin Programme on Collective Responsibility for Infectious Disease at the University of Oxford. "This kind of research should be done, with the right sort of ethical oversight. The concern over China leading the way is that institutional oversight mechanisms are probably not as developed as in the West but so far, there is no evidence of breaches in standards of research ethics around the published research."
Or, put another way by bioethicist Dr. Arthur Caplan, founding director of NYU Langone Health's Division of Medical Ethics: "The Chinese, because they don't care and don't have moral reservations about embryo work, are doing what they want." This lack of aversion to working with embryos manifests itself in a couple of ways. The absence of moral qualms is one. Funding is another. Huang's study, and others like it, receive funding from the government. His, for example, was supported by two grants from the National Basic Research Program and three from the National Natural Science Foundation of China.
The U.S., on the other hand, bans any federal funding for research using human embryos. A law passed in 1996 states that federal dollars can't be used for: "research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses." This restriction can shift incentives as many private institutions or commercial enterprises may have financial motivations or other goals beyond furthering basic research for the sake of general knowledge.
Embryo gene modification recently performed in the U.K. would merit 15 years in prison in Australia.
The embryo research ban is even more strict elsewhere. The Oviedo Convention, enacted in 1997, effectively prohibits germline engineering in members of the European Union. "In Italy, you can't destroy an embryo for any reason," said Alessandro Bertero, a postdoctoral fellow at the University of Washington's Department of Pathology who used to study in Italy. "It's illegal, and you'll go to jail." Later, Bertero was one of the researchers who worked with Dr. Niakan in London, an investigation that was allowed by the UK's Human Fertilisation and Embryology Authority. (In Australia, Niakan and her colleagues would face 15 years in jail due to the 2002 Prohibition of Human Cloning Act, which prohibits altering the genomes of embryonic cells.)
Despite the moral and legal reservations in the Western world, every person I spoke with for this story believed that better, more advanced studies and learning is happening in the U.S. and Europe. "The best studies in my opinion are from the labs in California and Oregon," Bertero said. "The quality of the work [in the Chinese study] – not being critical, but to be scientifically critical -- was just quick and dirty. It was, 'Let's just show that we have done it and get it out.' That doesn't mean that the quality of the work was good."
"If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
How long that remains the case, however, is an open question. A significant number of groups in China are working on germline editing in human embryos. The concern is that the Chinese will emerge as a leader sooner rather than later because they can do research with embryos more easily than their Western counterparts.
For Caplan, the NYU professor, the embryo ban in the U.S. isn't based on science; it's rooted in something else. "It's 96 percent political," he said, laughing. "It has basically ground to a halt because no one wants to see repercussions take place if federal funding is involved. The NIH isn't involved. And they won't be."
What, in his mind, would get Americans to start realizing the benefits that embryo research would provide? "The perception that other countries were moving quickly to get the advantages of CRISPR and other gene modification techniques, finding more industrial and more medical purposes," he said. "If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
Doing so would involve difficult conversations about the role of embryos in research. But these are philosophical questions that need to be approached at some point. From a U.S. perspective, doing so sooner while the American scientists still hold the technological and informational edge, is vital. Ignoring the issue doesn't make it go away.
Experts think a few changes should be made. The ban on federal funding should be lifted. Scientists and regulators should push for things like allowing federal funds to be used for the creation of new embryos for research purposes and the use of spare IVF embryos for research when the embryo would not be implanted into a woman. (Privately funded scientists can proceed in states that encourage embryonic stem cell research, like New York, New Jersey, and California, but not in restrictive ones like Louisiana and South Dakota, which prohibit creating or destroying embryos for research.) Policymakers could ban reproductive gene editing for now but look at it again after a certain period. A highly anticipated report issued earlier this year from an international guidance committee left the door open to eventual clinical trials with edited embryos. As of now, however, Congress will not allow the Food and Drug Administration to consider such trials. This is the future and it's the scientific community's responsibility to develop the ethical framework now.
"The US and Europe have the technological history and capacity to lead this research and should do so, ethically. We ought to be revising our laws and ethical guidelines to facilitate this kind of research," Professor Savulescu said. "But the challenge is to think constructively and ethically about this new technology, and to be leaders, not followers."
Is It Possible to Predict Your Face, Voice, and Skin Color from Your DNA?
Renowned genetics pioneer Dr. J Craig Venter is no stranger to controversy.
Back in 2000, he famously raced the public Human Genome Project to decode all three billion letters of the human genome for the first time. A decade later, he ignited a new debate when his team created a bacterial cell with a synthesized genome.
Most recently, he's jumped back into the fray with a study in the September issue of the Proceedings of the National Academy of Sciences about the predictive potential of genomic data to identify individual traits such as voice, facial structure and skin color.
The new study raises significant questions about the privacy of genetic data.
His study applied whole-genome sequencing and statistical modeling to predict traits in 1,061 people of diverse ancestry. His approach aimed to reconstruct a person's physical characteristics based on DNA, and 74 percent of the time, his algorithm could correctly identify the individual in a random lineup of 10 people from his company's database.
While critics have been quick to cast doubt on the plausibility of his claims, the ability to discern people's observable traits, or phenotypes, from their genomes may grow more precise as technology improves, raising significant questions about the privacy and usage of genetic information in the long term.
J. Craig Venter showing slides from his recent study on facial prediction at the Summit Conference in Los Angeles on Nov. 3, 2017.
(Courtesy of Kira Peikoff)
Critics: Study Was Incomplete, Problematic
Before even redressing these potential legal and ethical considerations, some scientists simply said the study's main result was invalid. They pointed out that the methodology worked much better in distinguishing between people of different ethnicities than those of the same ethnicity. One of the most outspoken critics, Yaniv Erlich, a geneticist at Columbia University, said, "The method doesn't work. The results were like, 'If you have a lineup of ten people, you can predict eight."
Erlich, who reviewed Venter's paper for Science, where it was rejected, said that he came up with the same results—correctly predicting eight of ten people—by just looking at demographic factors such as age, gender and ethnicity. He added that Venter's recent rebuttal to his criticism was that 'Once we have thousands of phenotypes, it might work better.' But that, Erlich argued, would be "a major breach of privacy. Nobody has thousands of phenotypes for people."
Other critics suggested that the study's results discourage the sharing of genetic data, which is becoming increasingly important for medical research. They go one step further and imply that people's possible hesitation to share their genetic information in public databases may actually play into Venter's hands.
Venter's own company, Human Longevity Inc., aims to build the world's most comprehensive private database on human genotypes and phenotypes. The vastness of this information stands to improve the accuracy of whole genome and microbiome sequencing for individuals—analyses that come at a hefty price tag. Today, Human Longevity Inc. will sequence your genome and perform a battery of other health-related tests at an entry cost of $4900, going up to $25,000. Venter initially agreed to comment for this article, but then could not be reached.
"The bigger issue is how do we understand and use genetic information and avoid harming people."
Opens Up Pandora's Box of Ethical Issues
Whether Venter's study is valid may not be as important as the Pandora's box of potential ethical and legal issues that it raises for future consideration. "I think this story is one along a continuum of stories we've had on the issue of identifiability based on genomic information in the past decade," said Amy McGuire, a biomedical ethics professor at Baylor College of Medicine. "It does raise really interesting and important questions about privacy, and socially, how we respond to these types of scientific advancements. A lot of our focus from a policy and ethics perspective is to protect privacy."
McGuire, who is also the Director of the Center for Medical Ethics and Health Policy at Baylor, added that while protecting privacy is very important, "the bigger issue is how do we understand and use genetic information and avoid harming people." While we've taken "baby steps," she said, towards enacting laws in the U.S. that fight genetic determinism—such as the Genetic Information and Nondiscrimination Act, which prohibits discrimination based on genetic information in health insurance and employment—some areas remain unprotected, such as for life insurance and disability.
J. Craig Venter showing slides from his recent study on facial prediction at the Summit Conference in Los Angeles on Nov. 3, 2017.
(Courtesy of Kira Peikoff)
Physical reconstructions like those in Venter's study could also be inappropriately used by law enforcement, said Leslie Francis, a law and philosophy professor at the University of Utah, who has written about the ethical and legal issues related to sharing genomic data.
"If [Venter's] findings, or findings like them, hold up, the implications would be significant," Francis said. Law enforcement is increasingly using DNA identification from genetic material left at crime scenes to weed out innocent and guilty suspects, she explained. This adds another potentially complicating layer.
"There is a shift here, from using DNA sequencing techniques to match other DNA samples—as when semen obtained from a rape victim is then matched (or not) with a cheek swab from a suspect—to using DNA sequencing results to predict observable characteristics," Francis said. She added that while the former necessitates having an actual DNA sample for a match, the latter can use DNA to pre-emptively (and perhaps inaccurately) narrow down suspects.
"My worry is that if this [the study's methodology] turns out to be sort-of accurate, people will think it is better than what it is," said Francis. "If law enforcement comes to rely on it, there will be a host of false positives and false negatives. And we'll face new questions, [such as] 'Which is worse? Picking an innocent as guilty, or failing to identify someone who is guilty?'"
Risking Privacy Involves a Tradeoff
When people voluntarily risk their own privacy, that involves a tradeoff, McGuire said. A 2014 study that she conducted among people who were very sick, or whose children were very sick, found that more than half were willing to share their health information, despite concerns about privacy, because they saw a big benefit in advancing research on their conditions.
"We've focused a lot of our policy attention on restricting access, but we don't have a system of accountability when there's a breach."
"To make leaps and bounds in medicine and genomics, we need to create a database of millions of people signing on to share their genetic and health information in order to improve research and clinical care," McGuire said. "They are going to risk their privacy, and we have a social obligation to protect them."
That also means "punishing bad actors," she continued. "We've focused a lot of our policy attention on restricting access, but we don't have a system of accountability when there's a breach."
Even though most people using genetic information have good intentions, the consequences if not are troubling. "All you need is one bad actor who decimates the trust in the system, and it has catastrophic consequences," she warned. That hasn't happened on a massive scale yet, and even if it did, some experts argue that obtaining the data is not the real risk; what is more concerning is hacking individuals' genetic information to be used against them, such as to prove someone is unfit for a particular job because of a genetic condition like Alzheimer's, or that a parent is unfit for custody because of a genetic disposition to mental illness.
Venter, in fact, told an audience at the recent Summit conference in Los Angeles that his new study's approach could not only predict someone's physical appearance from their DNA, but also some of their psychological traits, such as the propensity for an addictive personality. In the future, he said, it will be possible to predict even more about mental health from the genome.
What is most at risk on a massive scale, however, is not so much genetic information as demographic identifiers included in medical records, such as birth dates and social security numbers, said Francis, the law and philosophy professor. "The much more interesting and lucrative security breaches typically involve not people interested in genetic information per se, but people interested in the information in health records that you can't change."
Hospitals have been hacked for this kind of information, including an incident at the Veterans Administration in 2006, in which the laptop and external hard drive of an agency employee that contained unencrypted information on 26.5 million patients were stolen from the employee's house.
So, what can people do to protect themselves? "Don't share anything you wouldn't want the world to see," Francis said. "And don't click 'I agree' without actually reading privacy policies or terms and conditions. They may surprise you."