Can Genetic Testing Help Shed Light on the Autism Epidemic?
A little boy standing by a window in contemplation. (© altanaka/Fotolia)
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.
A historical perspective offers insights about how far we have come since the 1918 Spanish flu, and how far we have yet to go.
With a deadly pandemic sweeping the planet, many are questioning the comfort and security we have taken for granted in the modern world.
A century ago, when an influenza pandemic struck, we barely knew what viruses were.
More than a century after the germ theory, we are still at the mercy of a microbe we can neither treat, nor control, nor immunize against. Even more discouraging is that technology has in some ways exacerbated the problem: cars and air travel allow a new disease to quickly encompass the globe.
Some say we have grown complacent, that we falsely assume the triumphs of the past ensure a happy and prosperous future, that we are oblivious to the possibility of unpredictable "black swan" events that could cause our destruction. Some have begun to lose confidence in progress itself, and despair of the future.
But the new coronavirus should not defeat our spirit—if anything, it should spur us to redouble our efforts, both in the science and technology of medicine, and more broadly in the advance of industry. Because the best way to protect ourselves against future disasters is more progress, faster.
Science and technology have overall made us much better able to deal with disease. In the developed world, we have already tamed most categories of infectious disease. Most bacterial infections, such as tuberculosis or bacterial pneumonia, are cured with antibiotics. Waterborne diseases such as cholera are eliminated through sanitation; insect-borne ones such as malaria through pest control. Those that are not contagious until symptoms appear, such as SARS, can be handled through case isolation and contact tracing. For the rest, such as smallpox, polio, and measles, we develop vaccines, given enough time. COVID-19 could start a pandemic only because it fits a narrow category: a new, viral disease that is highly contagious via pre-symptomatic droplet/aerosol transmission, and that has a high mortality rate compared to seasonal influenza.
A century ago, when an influenza pandemic struck, we barely knew what viruses were; no one had ever seen one. Today we know what COVID-19 is down to its exact genome; in fact, we have sequenced thousands of COVID-19 genomes, and can track its history and its spread through their mutations. We can create vaccines faster today, too: where we once developed them in live animals, we now use cell cultures; where we once had to weaken or inactivate the virus itself, we can now produce vaccines based on the virus's proteins. And even though we don't yet have a treatment, the last century-plus of pharmaceutical research has given us a vast catalog of candidate drugs, already proven safe. Even now, over 50 candidate vaccines and almost 100 candidate treatments are in the research pipeline.
It's not just our knowledge that has advanced, but our methods. When smallpox raged in the 1700s, even the idea of calculating a case-fatality rate was an innovation. When the polio vaccine was trialled in the 1950s, the use of placebo-controlled trials was still controversial. The crucial measure of contagiousness, "R0", was not developed in epidemiology until the 1980s. And today, all of these methods are made orders of magnitude faster and more powerful by statistical and data visualization software.
If you're seeking to avoid COVID-19, the hand sanitizer gel you carry in a pocket or purse did not exist until the 1960s. If you start to show symptoms, the pulse oximeter that tests your blood oxygenation was not developed until the 1970s. If your case worsens, the mechanical ventilator that keeps you alive was invented in the 1950s—in fact, no form of artificial respiration was widely available until the "iron lung" used to treat polio patients in the 1930s. Even the modern emergency medical system did not exist until recently: if during the 1918 flu pandemic you became seriously ill, there was no 911 hotline to call, and any ambulance that showed up would likely have been a modified van or hearse, with no equipment or trained staff.
As many of us "shelter in place", we are far more able to communicate and collaborate, to maintain some semblance of normal life, than we ever would have been. To compare again to 1918: long-distance telephone service barely existed at that time, and only about a third of homes in the US even had electricity; now we can videoconference over Zoom and Skype. And the enormous selection and availability provided by online retail and food delivery have kept us stocked and fed, even when we don't want to venture out to the store.
Let the virus push us to redouble our efforts to make scientific, technological, and industrial progress on all fronts.
"Black swan" calamities can strike without warning at any time. Indeed, humanity has always been subject to them—drought and frost, fire and flood, war and plague. But we are better equipped now to deal with them than ever before. And the more progress we make, the better prepared we'll be for the next one. The accumulation of knowledge, technology, industrial infrastructure, and surplus wealth is the best buffer against any shock—whether a viral pandemic, a nuclear war, or an asteroid impact. In fact, the more worried we are about future crises, the more energetically we should accelerate science, technology and industry.
In this sense, we have grown complacent. We take the modern world for granted, so much so that some question whether further progress is even still needed. The new virus proves how much we do need it, and how far we still have to go. Imagine how different things would be if we had broad-spectrum antiviral drugs, or a way to enhance the immune system to react faster to infection, or a way to detect infection even before symptoms appear. These technologies may seem to belong to a Star Trek future—but so, at one time, did cell phones.
The virus reminds us that nature is indifferent to us, leaving us to fend entirely for ourselves. As we go to war against it, let us not take the need for such a war as reason for despair. Instead, let it push us to redouble our efforts to make scientific, technological, and industrial progress on all fronts. No matter the odds, applied intelligence is our best weapon against disaster.
A participatory research project has evolved in the world's most powerful networked supercomputer to identify drug targets for COVID-19.
With millions of people left feeling helpless as COVID-19 sweeps across the U.S. and the rest of the planet, there is one way in which absolutely anyone can help fight the pandemic -- all you need is a computer and an Internet connection.
"The more donors that participate, the more science we're able to do."
The Folding@home project allows members of the public to contribute a portion of their computing power to a gigantic virtual network which has mushroomed over the past month to become the most powerful supercomputer on the planet.
As of April 6, more than one million people across the globe have donated some of their home computing resources to the project. Combined, this gives Folding@home processing powers that dwarf even NASA and IBM's most powerful devices. To join, all you have to do is go to this website and click 'Download Now' to load the Folding@home software on your computer. This runs in the background, and only adds your unused computing power to the project, so it will not drain resources from tasks you're trying to do.
"It's totally crazy," said Vincent Voelz, associate professor of chemistry at Temple University, Philadelphia, and one of the scientists leading the project. "A month ago, we had around 30,000 to 40,000 participants. And then last week, it rose up 400,000 and now we've hit a million. But the more donors that participate, the more science we're able to do."
Voelz and the other scientists behind Folding@home are using these vast resources to model the ever-changing shapes of the coronavirus's proteins, in the hopes of identifying vulnerabilities or 'pockets' in its structure that can be targeted with new drugs.
One of the reasons it's difficult to find treatments for viruses like COVID-19 and Ebola is because the proteins, the innate building blocks of the viral structure, have notoriously smooth surfaces, making it hard for drugs to bind to them.
But viral proteins don't stay still. They are constantly evolving and changing shape as the atoms within push and pull against each other. Having a supercomputer enables scientists to simulate all these different shapes, revealing potential weaknesses which were not immediately visible. And the more powerful the supercomputer, the faster these simulations can happen.
"Simulating these protein motions also enables us to answer basic questions such as what makes this new coronavirus strain different from previous strains," said Voelz. "Is there something about the dynamics of these proteins that makes it more virulent?"
Finding a genuinely novel drug for COVID-19 is particularly critical.
Once they have identified suitable pockets within the proteins of COVID-19, the Folding@home scientists can then take the many compounds being identified by chemists around the world as potential drugs, and try to predict which ones will stand the best chance of binding to those pockets and inhibiting the virus's ability to invade and take over human cells.
"We have so much bandwidth now with Folding@home that we really think we can make a dent with screening these, and prioritizing which compounds are then going to get experimentally tested," said Voeltz.
The team are particularly hopeful they can succeed, having already used the supercomputer to identify a new vulnerability in the Ebola virus, which could go on to yield a new treatment for the disease.
Finding a genuinely novel drug for COVID-19 is particularly critical. While researchers are also looking at repurposing existing medications, like the antimalarials Hydroxychloroquine and Chloroquine (which have just been approved by the FDA for emergency use in coronavirus patients), concerns remain about the safety of these treatments. Researchers at the Mayo Clinic recently warned that the use of these drugs could have the side effect of inducing heart problems and run the risk of sudden cardiac arrest.
But with the death toll increasing by the day, speed is of the essence. Voelz explains that the scientific community has been left playing catch-up, because a drug was never actually developed for the original SARS outbreak in the early 2000s. The enormous computational power of the Folding@home project has the potential to allow scientists to quickly answer some of the key questions needed to get a new treatment into the pipeline.
"We don't have a SARS drug for whatever reason," said Voelz. "So the missing ingredient really, is the basic science to reveal possible drug targets and then the pharma can take that information and do the engineering work and optimizing and clinically testing drugs. But we now have a lot of basic science going on in response to this pandemic."