Can Genetic Testing Help Shed Light on the Autism Epidemic?
Autism cases are still on the rise, and scientists don't know why. In April, the Centers for Disease Control (CDC) reported that rates of autism had increased once again, now at an estimated 1 in 59 children up from 1 in 68 just two years ago. Rates have been climbing steadily since 2007 when the CDC initially estimated that 1 in 150 children were on the autism spectrum.
Some clinicians are concerned that the creeping expansion of autism is causing the diagnosis to lose its meaning.
The standard explanation for this increase has been the expansion of the definition of autism to include milder forms like Asperger's, as well as a heightened awareness of the condition that has improved screening efforts. For example, the most recent jump is attributed to children in minority communities being diagnosed who might have previously gone under the radar. In addition, more federally funded resources are available to children with autism than other types of developmental disorders, which may prompt families or physicians to push harder for a diagnosis.
Some clinicians are concerned that the creeping expansion of autism is causing the diagnosis to lose its meaning. William Graf, a pediatric neurologist at Connecticut Children's Medical Center, says that when a nurse tells him that a new patient has a history of autism, the term is no longer a useful description. "Even though I know this topic extremely well, I cannot picture the child anymore," he says. "Use the words mild, moderate, or severe. Just give me a couple more clues, because when you say autism today, I have no idea what people are talking about anymore."
Genetic testing has emerged as one potential way to remedy the overly broad label by narrowing down a heterogeneous diagnosis to a specific genetic disorder. According to Suma Shankar, a medical geneticist at the University of California, Davis, up to 60 percent of autism cases could be attributed to underlying genetic causes. Common examples include Fragile X Syndrome or Rett Syndrome—neurodevelopmental disorders that are caused by mutations in individual genes and are behaviorally classified as autism.
With more than 500 different mutations associated with autism, very few additional diagnoses provide meaningful information.
Having a genetic diagnosis in addition to an autism diagnosis can help families in several ways, says Shankar. Knowing the genetic origin can alert families to other potential health problems that are linked to the mutation, such as heart defects or problems with the immune system. It may also help clinicians provide more targeted behavioral therapies and could one day lead to the development of drug treatments for underlying neurochemical abnormalities. "It will pave the way to begin to tease out treatments," Shankar says.
When a doctor diagnoses a child as having a specific genetic condition, the label of autism is still kept because it is more well-known and gives the child access to more state-funded resources. Children can thus be diagnosed with multiple conditions: autism spectrum disorder and their specific gene mutation. However, with more than 500 different mutations associated with autism, very few additional diagnoses provide meaningful information. What's more, the presence or absence of a mutation doesn't necessarily indicate whether the child is on the mild or severe end of the autism spectrum.
Because of this, Graf doubts that genetic classifications are really that useful. He tells the story of a boy with epilepsy and severe intellectual disabilities who was diagnosed with autism as a young child. Years later, Graf ordered genetic testing for the boy and discovered that he had a mutation in the gene SYNGAP1. However, this knowledge didn't change the boy's autism status. "That diagnosis [SYNGAP1] turns out to be very specific for him, but it will never be a household name. Biologically it's good to know, and now it's all over his chart. But on a societal level he still needs this catch-all label [of autism]," Graf says.
"It gives some information, but to what degree does that change treatment or prognosis?"
Jennifer Singh, a sociologist at Georgia Tech who wrote the book Multiple Autisms: Spectrums of Advocacy and Genomic Science, agrees. "I don't know that the knowledge gained from just having a gene that's linked to autism," is that beneficial, she says. "It gives some information, but to what degree does that change treatment or prognosis? Because at the end of the day you have to address the issues that are at hand, whatever they might be."
As more children are diagnosed with autism, knowledge of the underlying genetic mutation causing the condition could help families better understand the diagnosis and anticipate their child's developmental trajectory. However, for the vast majority, an additional label provides little clarity or consolation.
Instead of spending money on genetic screens, Singh thinks the resources would be better used on additional services for people who don't have access to behavioral, speech, or occupational therapy. "Things that are really going to matter for this child in their future," she says.
Today’s Focus on STEM Education Is Missing A Crucial Point
I once saw a fascinating TED talk on 3D printing. As I watched the presenter discuss the custom fabrication, not of plastic gears or figurines, but of living, implantable kidneys, I thought I was finally living in the world of Star Trek, and I experienced a flush of that eager, expectant enthusiasm I felt as a child looking toward the future. I looked at my current career and felt a rejuvenation of my commitment to teach young people the power of science.
The well-rounded education of human beings needs to include lessons learned both from a study of the physical world, and from a study of humanity.
Whether we are teachers or not, those of us who admire technology and innovation, and who wish to support progress, usually embrace the importance of educating the next generation of scientists and inventors. Growing a healthy technological civilization takes a lot of work, skill, and wisdom, and its continued health depends on future generations of competent thinkers. Thus, we may find it encouraging that there is currently an abundance of interest in STEM– the common acronym for the study of science, technology, engineering, and math.
But education is as challenging an endeavor as science itself. Educating youth--if we want to do it right--requires as much thought, work, and expertise as discovering a cure or pioneering regenerative medicine. Before we give our money, time, or support to any particular school or policy, let's give some thought to the details of the educational process.
A Well-Balanced Diet
For one thing, STEM education cannot stand in isolation. The well-rounded education of human beings needs to include lessons learned both from a study of the physical world, and from a study of humanity. This is especially true for the basic education of children, but it is true even for college students. And even for those in science and engineering, there are important lessons to be learned from the study of history, literature, and art.
Scientists have their own emotions and values, and also need financial support. The fruits of their labor ultimately benefit other people. How are we all to function together in our division-of-labor society, without some knowledge of the way societies work? How are we to fully thrive and enjoy life, without some understanding of ourselves, our motives, our moral values, and our relationships to others? STEM education needs the humanities as a partner. That flourishing civilization we dream of requires both technical competence and informed life-choices.
Think for Yourself (Even in Science)
Perhaps even more important than what is taught, is the subject of how things are taught. We want our children to learn the skill of thinking independently, but even in the sciences, we often fail completely to demonstrate how. Instead of teaching science as a thinking process, we indoctrinate, using the grand discoveries of the great scientists as our sacred texts. But consider the words of Isaac Newton himself, regarding rote learning:
A Vulgar Mechanick can practice what he has been taught or seen done, but if he is in an error he knows not how to find it out and correct it, and if you put him out of his road he is at a stand. Whereas he that is able to reason nimbly and judiciously about figure, force, and motion, is never at rest till he gets over every rub.
What's the point of all this formal schooling in the first place? Is it, as many of the proponents of STEM education might argue, to train students for a "good" career?
If our goal is to help students "reason nimbly" about the world around them, as the great scientists themselves did, are we succeeding? When we "teach" middle school students about DNA or cellular respiration by presenting as our only supporting evidence cartoon pictures, are we showing students a process of discovery based on evidence and hard work? Or are we just training them to memorize and repeat what the authorities say?
A useful education needs to give students the skill of following a line of reasoning, of asking rational questions, and of chewing things through in their minds--even if we regard the material as beyond question. Besides feeding students a well-balanced diet of knowledge, healthy schooling needs to teach them to digest this information thoroughly.
Thinking Training
Now step back for a moment and think about the purpose of education. What's the point of all this formal schooling in the first place? Is it, as many of the proponents of STEM education might argue, to train students for a "good" career? That view may have some validity for young adults, who are beginning to choose electives in favored subjects, and have started to choose a direction for their career.
But for the basic education of children, this way of thinking is presumptuous and disastrous. I would argue that the central purpose of a basic education is not to teach children how to perform this or that particular skill, but simply to teach them to think clearly. We should not be aiming to provide job training, but thinking training. We should be helping children learn how to "reason nimbly" about the world around them, and breathing life into their thinking processes, by which they will grapple with the events and circumstances of their lives.
So as we admire innovation, dream of a wonderful future, and attempt to nurture the next generation of scientists and engineers, instead of obsessing over STEM education, let us focus on rational education. Let's worry about showing children how to think--about all the important things in life. Let's give them the basic facts of human existence -- physical and humanitarian -- and show them how to fluently and logically understand them.
Some students will become the next generation of creators, and some will follow other careers, but together -- if they are educated properly -- they will continue to grow their inheritance, and to keep our civilization healthy and flourishing, in body and in mind.
Do New Tools Need New Ethics?
Scarcely a week goes by without the announcement of another breakthrough owing to advancing biotechnology. Recent examples include the use of gene editing tools to successfully alter human embryos or clone monkeys; new immunotherapy-based treatments offering longer lives or even potential cures for previously deadly cancers; and the creation of genetically altered mosquitos using "gene drives" to quickly introduce changes into the population in an ecosystem and alter the capacity to carry disease.
The environment for conducting science is dramatically different today than it was in the 1970s, 80s, or even the early 2000s.
Each of these examples puts pressure on current policy guidelines and approaches, some existing since the late 1970s, which were created to help guide the introduction of controversial new life sciences technologies. But do the policies that made sense decades ago continue to make sense today, or do the tools created during different eras in science demand new ethics guidelines and policies?
Advances in biotechnology aren't new of course, and in fact have been the hallmark of science since the creation of the modern U.S. National Institutes of Health in the 1940s and similar government agencies elsewhere. Funding agencies focused on health sciences research with the hope of creating breakthroughs in human health, and along the way, basic science discoveries led to the creation of new scientific tools that offered the ability to approach life, death, and disease in fundamentally new ways.
For example, take the discovery in the 1970s of the "chemical scissors" in living cells called restriction enzymes, which could be controlled and used to introduce cuts at predictable locations in a strand of DNA. This led to the creation of tools that for the first time allowed for genetic modification of any organism with DNA, which meant bacteria, plants, animals, and even humans could in theory have harmful mutations repaired, but also that changes could be made to alter or even add genetic traits, with potentially ominous implications.
The scientists involved in that early research convened a small conference to discuss not only the science, but how to responsibly control its potential uses and their implications. The meeting became known as the Asilomar Conference for the meeting center where it was held, and is often noted as the prime example of the scientific community policing itself. While the Asilomar recommendations were not sufficient from a policy standpoint, they offered a blueprint on which policies could be based and presented a model of the scientific community setting responsible controls for itself.
But the environment for conducting science changed over the succeeding decades and it is dramatically different today than it was in the 1970s, 80s, or even the early 2000s. The regime for oversight and regulation that has provided controls for the introduction of so-called "gene therapy" in humans starting in the mid-1970s is beginning to show signs of fraying. The vast majority of such research was performed in the U.S., U.K., and Europe, where policies were largely harmonized. But as the tools for manipulating humans at the molecular level advanced, they also became more reliable and more precise, as well as cheaper and easier to use—think CRISPR—and therefore more accessible to more people in many more countries, many without clear oversight or policies laying out responsible controls.
There is no precedent for global-scale science policy, though that is exactly what this moment seems to demand.
As if to make the point through news headlines, scientists in China announced in 2017 that they had attempted to perform gene editing on in vitro human embryos to repair an inherited mutation for beta thalassemia--research that would not be permitted in the U.S. and most European countries and at the time was also banned in the U.K. Similarly, specialists from a reproductive medicine clinic in the U.S. announced in 2016 that they had performed a highly controversial reproductive technology by which DNA from two women is combined (so-called "three parent babies"), in a satellite clinic they had opened in Mexico to avoid existing prohibitions on the technique passed by the U.S. Congress in 2015.
In both cases, genetic changes were introduced into human embryos that if successful would lead to the birth of a child with genetically modified germline cells—the sperm in boys or eggs in girls—with those genetic changes passed on to all future generations of related offspring. Those are just two very recent examples, and it doesn't require much imagination to predict the list of controversial possible applications of advancing biotechnologies: attempts at genetic augmentation or even cloning in humans, and alterations of the natural environment with genetically engineered mosquitoes or other insects in areas with endemic disease. In fact, as soon as this month, scientists in Africa may release genetically modified mosquitoes for the first time.
The technical barriers are falling at a dramatic pace, but policy hasn't kept up, both in terms of what controls make sense and how to address what is an increasingly global challenge. There is no precedent for global-scale science policy, though that is exactly what this moment seems to demand. Mechanisms for policy at global scale are limited–-think UN declarations, signatory countries, and sometimes international treaties, but all are slow, cumbersome and have limited track records of success.
But not all the news is bad. There are ongoing efforts at international discussion, such as an international summit on human genome editing convened in 2015 by the National Academies of Sciences and Medicine (U.S.), Royal Academy (U.K.), and Chinese Academy of Sciences (China), a follow-on international consensus committee whose report was issued in 2017, and an upcoming 2nd international summit in Hong Kong in November this year.
These efforts need to continue to focus less on common regulatory policies, which will be elusive if not impossible to create and implement, but on common ground for the principles that ought to guide country-level rules. Such principles might include those from the list proposed by the international consensus committee, including transparency, due care, responsible science adhering to professional norms, promoting wellbeing of those affected, and transnational cooperation. Work to create a set of shared norms is ongoing and worth continued effort as the relevant stakeholders attempt to navigate what can only be called a brave new world.