Why Are Autism Rates Steadily Rising?
Stefania Sterling with her son Charlie, who was diagnosed at age 3 with autism.
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."
Just Say No to Editing Human Embryos for Reproduction
Insemination of female egg under microscope
BIG QUESTION OF THE MONTH: Should we use CRISPR, the new technique that enables precise DNA editing, to change the genes of human embryos to eradicate disease – or even to enhance desirable traits? LeapsMag invited three leading experts to weigh in.
Over the last few decades, the international community has issued several bioethical guidelines and legally binding documents, ranging from UN Declarations to regional charters to national legislation, about editing the human germline--the DNA that is passed down to future generations. There was a broad consensus that modifications should be prohibited. But now that CRISPR-cas9 and related methods of gene editing are taking the world by storm, that stance is softening--and so far, no thorough public discussion has emerged.
There is broad agreement in the scientific and ethics community that germline gene editing must not be clinically applied unless safety concerns are resolved. Predicting that safety issues will indeed be minimized, the National Academy of Sciences issued a report this past February that sets up several procedural norms. These may serve as guidelines for future implementation of human embryo editing, among them that there are no "reasonable alternatives," a condition that is left deliberately vague.
I regard the conditional embrace of germline gene editing as a grave mistake: It is a dramatic break with the previous idea of a ban, departing also from the moratorium that the UNESCO International Bioethics Committee had recommended in 2015. But in a startling move, the Academy already set the next post, recommending "that genome editing for purposes other than treatment or prevention of disease and disability should not proceed at this time" (my emphasis). It recommended public discussions, but without spelling out its own role in facilitating them.
"The international community should explicitly ban embryo gene editing as a method of human reproduction."
To proceed ethically, I argue that the international community, through the United Nations and in line with the ban on human reproductive cloning, should explicitly ban embryo gene editing as a method of human reproduction. Together with guidelines adjusted for non-reproductive and non-human applications, a prohibition would ensure two important results: First, that non-reproductive human embryo research could be pursued in a responsible way in those countries that allow for it, and second, that individual scientists, public research institutes, and private companies would know the moral limit of possible research.
Basic human embryo research is required, scientists argue, to better understand genetic diseases and early human development. I do not question this, and I am convinced that existing guidelines can be adjusted to meet the moral requirements in this area. Millions of people may benefit from different non-reproductive pathways of gene editing. Germline gene editing, in contrast, does not offer any resolutions to global or local health problems – and that alone raises many concerns about the current state of scientific research.
I support a ban because germline gene editing for reproductive purposes concerns more than safety. The genetic modification of a human being is irreversible and unpredictable in its epigenetic, personal, and social effects. It concerns the rights of children; it exposes persons with disabilities to social stigmatization; it contradicts the global justice agenda with respect to healthcare; and it infringes upon the rights to freedom and well-being of future persons.
"Reproductive germline gene editing directly violates the rights of individual future person."
Apart from questions of justice, reproductive germline gene editing may well increase the stigmatization of persons with disabilities. I want to emphasize here, however, that it directly violates the rights of individual future persons, namely a future child's right to genetic integrity, to freedom, and potentially to well-being, all guaranteed in different UN Declarations of Human Rights. For all these reasons, it is an unacceptable path forward.
The way the discussion has been framed so far is very different from my perspective that situates germline gene editing in the broader framework of human rights and responsibilities. In short, many others never questioned the goal but instead focused on the unintentional side-effects of an otherwise beneficial technique for human reproduction. Some scientists see germline gene editing as an alternative to embryo selection via Preimplantation Genetic Diagnosis (PGD), a procedure in which multiple embryos are tested to find out which ones carry disease-causing mutations. Others see it as the first step to human enhancement.
Some physicians argue that in the field of assisted reproduction, not every couple is comfortable with embryo selection via PGD, because potentially, unchosen embryos are discarded. Germline gene editing offers them an alternative. It is rarely mentioned, however, that germline gene editing would most likely still require PGD as a control of the procedure (though without the purpose of selection), and that prenatal genetic diagnosis would also be highly recommended. In other words, germline gene editing would not replace existing protocols but rather change their purpose, and it would also not necessarily reduce the number of embryos needed for assisted reproduction.
In some (rare) cases, PGD is not an option, because in the couples' condition, all embryos will be affected. One current option to avoid transmitting genetic traits is to use a donor sperm or egg, though the resulting child would not be genetically related to one parent. If these parents had an obligation, as some proponents argue, to secure the health of their offspring (an argument that I do not follow), then procreation with sperm or egg donation would even be morally required, as this is the safest procedure to erase a given genetic trait.
There are no therapeutic scenarios that exclusively require reproductive gene editing even if one accepts the right to reproductive autonomy. The fact is that couples who rightly wish to secure and protect the health of their future children can be offered medical alternatives in all cases. However, this requires considering sperm or egg donation as the safest and most reasonable option – the condition the NAS Report has set.
Scientists in favor of germline gene editing argue against this: the desire for genetic kinship, they say, is a legitimate expression of a couple's reproductive freedom, and germline gene editing offers them an alternative to have a healthy child. In the future, proponents say, these (very few) couples who wish for genetically related offspring will be faced with the dilemma of either accepting the transmission of a genetic health risk to their children or weighing the benefits and risks of gene editing.
But here is a blind spot in the whole discussion.
Many scientists and some bioethicists think that reproductive freedom includes the right to a genetically related child. But even if we were to presuppose such a right, it is not absolute in the context of assisted reproduction. Although sperm or egg donation may be undesirable for some couples, the moral question of responsibility does not disappear with their reproductive rights. At a minimum, the future child's rights must be considered, and these rights go further than their health rights.
It is puzzling that in claiming their own reproductive freedom, couples would need to ignore their children's and possibly grandchildren's future freedom – including the constraints resulting from being monitored over the course of their lives and the indirect constraints of the children's own right to reproductive freedom. From a medical standpoint, it would be highly recommended for them, too, to have children through assisted reproduction. This distinguishes germline gene editing from any other procedure of assisted reproduction: we need the data from the second and third generations to see whether the method is safe and efficacious. Whose reproductive freedom should count, the parents' or the future children's?
But for now, the question of parental rights may well divert the discussion from the question of responsible gene editing research; its conditions and structures require urgent evaluation and adjustment to guide international research groups. I am concerned that we are in the process of developing a new technology that has tremendous potential and ramifications – but without having considered the ethical framework for a responsible path forward.
Editor's Note: Check out the viewpoints expressing enthusiastic support and mild curiosity.
Gene Editing of Embryos Is Both Ethical and Prudent
Human cells under a microscope
BIG QUESTION OF THE MONTH: Should we use CRISPR, the new technique that enables precise DNA editing, to change the genes of human embryos to eradicate disease--or even to enhance desirable traits? LeapsMag invited three leading experts to weigh in.
Now that researchers around the world have begun to edit the genes of human embryos with CRISPR, the ethical debate has become more timely than ever: Should this kind of research be on the table or categorically ruled out?
All of us need gene editing to be pursued, and if possible, made safe enough to use in humans. Not only to pave the way for effective procedures on adults, but more importantly, to keep open the possibility of using gene editing to protect embryos from susceptibility to major diseases and to prevent other debilitating genetic conditions from being passed on through them to future generations.
Objections to gene editing in embryos rest on three fallacious arguments:
- Gene editing is wrong because it affects future generations, the argument being that the human germline is sacred and inviolable.
- It constitutes an unknown and therefore unacceptable risk to future generations.
- The inability to obtain the consent of those future generations means we must not use gene editing.
We should be clear that there is no precautionary approach; just as justice delayed is justice denied, so therapy delayed is therapy denied.
Regarding the first point, many objections to germline interventions emphasize that such interventions are objectionable in that they affect "generations down the line". But this is true, not only of all assisted reproductive technologies, but of all reproduction of any kind.
Sexual reproduction would never have been licensed by regulators
As for the second point, every year an estimated 7.9 million children - 6% of total births worldwide - are born with a serious birth defect of genetic or partially genetic origin. Had sexual reproduction been invented by scientists rather than resulting from our evolved biology, it would never have been licensed by regulators - far too inefficient and dangerous!
If the appropriate benchmark for permissible risk of harm to future generations is sexual reproduction, other germline-changing techniques would need to demonstrate severe foreseeable dangers to fail.
Raising the third point in his statement on gene-editing in human embryos, Francis S. Collins, director of the National Institutes of Health, stated: "The strong arguments against engaging in this activity remain … These include the serious and unquantifiable safety issues, ethical issues presented by altering the germline in a way that affects the next generation without their consent."
"Serious and unquantifiable" safety issues feature in all new technologies but consent is simply irrelevant for the simple and sufficient reason that there are no relevant people in existence capable of either giving or withholding consent to these sorts of changes in their own germline.
We all have to make decisions for future people without considering their inevitably absent consent. All would-be/might-be parents make numerous decisions about issues that might affect their future children. They do this all the time without thinking about consent of the children.
George Bernard Shaw and Isadora Duncan were possibly apocryphal exceptions. She, apparently, said to him something like: "Why don't we have a child? With my looks and your brains it cannot fail," and received Shaw's more rational assessment: "Yes, but what if it has my looks and your brains?"
If there is a discernible duty here, it is surely to try to create the best possible child, a child who will be the healthiest, most intelligent and most resilient to disease reasonably possible given the parents' other priorities. This is why we educate and vaccinate our children and give them a good diet if we can. That is what it is to act for the best, all things considered. This we have moral reasons to do; but they are not necessarily overriding reasons.
"There is no morally significant line between therapy and enhancement."
There is no morally significant line that can be drawn between therapy and enhancement. As I write these words in my London apartment, I am bathed in synthetic sunshine, one of the oldest and most amazing enhancement technologies. Before its invention, our ancestors had to rest or hide in the dark. With the advent of synthetic sunshine--firelight, candlelight, lamplight and electric light--we could work and play as long as we wished.Steven Hawking initially predicted that we might have about 7.6 billion years to go before the Earth gives up on us; he recently revised his position in relation to the Earth's continuing habitability as opposed to its physical survival: "We must also continue to go into space for the future of humanity," he said recently. "I don't think we will survive another thousand years without escaping beyond our fragile planet."
We will at some point have to escape both beyond our fragile planet and our fragile nature. One way to enhance our capacity to do both these things is by improving on human nature where we can do so in ways that are "safe enough." What we all have an inescapable moral duty to do is to continue with scientific investigation of gene editing techniques to the point at which we can make a rational choice. We must certainly not stop now.
At the end of a 2015 summit where I spoke about this issue, the renowned Harvard geneticist George Church noted that gene editing "opens up the possibility of not just transplantation from pigs to humans but the whole idea that a pig organ is perfectible…Gene editing could ensure the organs are very clean, available on demand and healthy, so they could be superior to human donor organs."
"We know for sure that in the future there will be no more human beings and no more planet Earth."
We know for sure that in the future there will be no more human beings and no more planet Earth. Either we will have been wiped out by our own foolishness or by brute forces of nature, or we will have further evolved by a process more rational and much quicker than Darwinian evolution--a process I described in my book Enhancing Evolution. Even more certain is that there will be no more planet Earth. Our sun will die, and with it, all possibility of life on this planet.As I say in my recent book How to Be Good:
By the time this happens, we may hope that our better evolved successors will have developed the science and the technology needed to survive and to enable us (them) to find and colonize another planet or perhaps even to build another planet; and in the meanwhile, to cope better with the problems presented by living on this planet.
Editor's Note: Check out the viewpoints expressing condemnation and mild curiosity.