Is Finding Out Your Baby’s Genetics A New Responsibility of Parenting?
Hours after a baby is born, its heel is pricked with a lancet. Drops of the infant's blood are collected on a porous card, which is then mailed to a state laboratory. The dried blood spots are screened for around thirty conditions, including phenylketonuria (PKU), the metabolic disorder that kick-started this kind of newborn screening over 60 years ago. In the U.S., parents are not asked for permission to screen their child. Newborn screening programs are public health programs, and the assumption is that no good parent would refuse a screening test that could identify a serious yet treatable condition in their baby.
Learning as much as you can about your child's health might seem like a natural obligation of parenting. But it's an assumption that I think needs to be much more closely examined.
Today, with the introduction of genome sequencing into clinical medicine, some are asking whether newborn screening goes far enough. As the cost of sequencing falls, should parents take a more expansive look at their children's health, learning not just whether they have a rare but treatable childhood condition, but also whether they are at risk for untreatable conditions or for diseases that, if they occur at all, will strike only in adulthood? Should genome sequencing be a part of every newborn's care?
It's an idea that appeals to Anne Wojcicki, the founder and CEO of the direct-to-consumer genetic testing company 23andMe, who in a 2016 interview with The Guardian newspaper predicted that having newborns tested would soon be considered standard practice—"as critical as testing your cholesterol"—and a new responsibility of parenting. Wojcicki isn't the only one excited to see everyone's genes examined at birth. Francis Collins, director of the National Institutes of Health and perhaps the most prominent advocate of genomics in the United States, has written that he is "almost certain … that whole-genome sequencing will become part of new-born screening in the next few years." Whether that would happen through state-mandated screening programs, or as part of routine pediatric care—or perhaps as a direct-to-consumer service that parents purchase at birth or receive as a baby-shower gift—is not clear.
Learning as much as you can about your child's health might seem like a natural obligation of parenting. But it's an assumption that I think needs to be much more closely examined, both because the results that genome sequencing can return are more complex and more uncertain than one might expect, and because parents are not actually responsible for their child's lifelong health and well-being.
What is a parent supposed to do about such a risk except worry?
Existing newborn screening tests look for the presence of rare conditions that, if identified early in life, before the child shows any symptoms, can be effectively treated. Sequencing could identify many of these same kinds of conditions (and it might be a good tool if it could be targeted to those conditions alone), but it would also identify gene variants that confer an increased risk rather than a certainty of disease. Occasionally that increased risk will be significant. About 12 percent of women in the general population will develop breast cancer during their lives, while those who have a harmful BRCA1 or BRCA2 gene variant have around a 70 percent chance of developing the disease. But for many—perhaps most—conditions, the increased risk associated with a particular gene variant will be very small. Researchers have identified over 600 genes that appear to be associated with schizophrenia, for example, but any one of those confers only a tiny increase in risk for the disorder. What is a parent supposed to do about such a risk except worry?
Sequencing results are uncertain in other important ways as well. While we now have the ability to map the genome—to create a read-out of the pairs of genetic letters that make up a person's DNA—we are still learning what most of it means for a person's health and well-being. Researchers even have a name for gene variants they think might be associated with a disease or disorder, but for which they don't have enough evidence to be sure. They are called "variants of unknown (or uncertain) significance (VUS), and they pop up in most people's sequencing results. In cancer genetics, where much research has been done, about 1 in 5 gene variants are reclassified over time. Most are downgraded, which means that a good number of VUS are eventually designated benign.
While one parent might reasonably decide to learn about their child's risk for a condition about which nothing can be done medically, a different, yet still thoroughly reasonable, parent might prefer to remain ignorant so that they can enjoy the time before their child is afflicted.
Then there's the puzzle of what to do about results that show increased risk or even certainty for a condition that we have no idea how to prevent. Some genomics advocates argue that even if a result is not "medically actionable," it might have "personal utility" because it allows parents to plan for their child's future needs, to enroll them in research, or to connect with other families whose children carry the same genetic marker.
Finding a certain gene variant in one child might inform parents' decisions about whether to have another—and if they do, about whether to use reproductive technologies or prenatal testing to select against that variant in a future child. I have no doubt that for some parents these personal utility arguments are persuasive, but notice how far we've now strayed from the serious yet treatable conditions that motivated governments to set up newborn screening programs, and to mandate such testing for all.
Which brings me to the other problem with the call for sequencing newborn babies: the idea that even if it's not what the law requires, it's what good parents should do. That idea is very compelling when we're talking about sequencing results that show a serious threat to the child's health, especially when interventions are available to prevent or treat that condition. But as I have shown, many sequencing results are not of this type.
While one parent might reasonably decide to learn about their child's risk for a condition about which nothing can be done medically, a different, yet still thoroughly reasonable, parent might prefer to remain ignorant so that they can enjoy the time before their child is afflicted. This parent might decide that the worry—and the hypervigilence it could inspire in them—is not in their child's best interest, or indeed in their own. This parent might also think that it should be up to the child, when he or she is older, to decide whether to learn about his or her risk for adult-onset conditions, especially given that many adults at high familial risk for conditions like Alzheimer's or Huntington's disease choose never to be tested. This parent will value the child's future autonomy and right not to know more than they value the chance to prepare for a health risk that won't strike the child until 40 or 50 years in the future.
Parents are not obligated to learn about their children's risk for a condition that cannot be prevented, has a small risk of occurring, or that would appear only in adulthood.
Contemporary understandings of parenting are famously demanding. We are asked to do everything within our power to advance our children's health and well-being—to act always in our children's best interests. Against that backdrop, the need to sequence every newborn baby's genome might seem obvious. But we should be skeptical. Many sequencing results are complex and uncertain. Parents are not obligated to learn about their children's risk for a condition that cannot be prevented, has a small risk of occurring, or that would appear only in adulthood. To suggest otherwise is to stretch parental responsibilities beyond the realm of childhood and beyond factors that parents can control.
Pregnant and Breastfeeding Women Might Have a New Reason to Ditch Artificial Sweeteners
Women considering pregnancy might have another reason to drop artificial sweeteners from their diet, if a new study of mice proves to apply to humans as well. It highlights "yet another potential health impact of zero-calorie sweeteners," according to lead author Stephanie Olivier-Van Stichelen.
The discovery was serendipitous, not part of the original study.
It found that commonly used artificial sweeteners consumed by female mice transfer to pups in the womb and later through milk, harming their development. The sweeteners affected the composition of bacteria in the gut of the pups, making them more vulnerable to developing diabetes, and greatly reduced the liver's capacity to neutralize toxins.
The discovery was serendipitous, not part of the original study, says John Hanover, the senior author and a cell biologist at the NIH National Institute of Diabetes and Digestive and Kidney Diseases. The main study looked at how a high sugar diet in the mother turns genes on and off in the developing offspring.
It compared them with mothers fed a low sugar diet, replacing sugar with a mix of sucralose and acesulfame-K (AK), two non-nutrient artificial sugars that are already used extensively in our food products and thought to be safe.
While the artificial sweeteners had little effect on the mothers, the trace amounts that were transferred through the placenta and milk had a profound effect on the pups. Hanover believes the molecules are changing gene expression during a crucial, short period of development.
"Somewhat to our surprise, we saw in the pups a really dramatic change in the microbiome" of those whose mothers were fed the artificial sweeteners, Hanover told leapsmag. "It looked like the neonates were much, much more sensitive than their mothers to the sucralose and AK." The unexpected discovery led them to publish a separate paper.
"The protective microbe Akkermansia was largely missing, and we saw a pretty dramatic shift in the ratio of two bacteria that are normally associated with metabolic disease," a precursor to diabetes, he explains. Akkermansia is a bacteria that feeds on mucus in the gut and helps remodel the tissue to an adult state over the first several months of life in a mouse. A similar process takes several years in humans, as the infant is weaned off of breast milk as the primary food source.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week.
Another problem the researchers saw in the animals was "a particularly striking change in the metabolism of the detoxification systems" in the liver, says Hanover. A healthy liver is dark red, but a high dose of the artificial sweeteners turned it white, "which is a sign of massive problems."
The study was conducted in mice and Hanover cautions the findings may not apply to humans. "But in general, the microbiome changes that one sees in the rodent model mimics what we see in humans...[and] the genes that are turned on in the mouse and the human are very similar."
Hanover acknowledges the quantity of artificial sweeteners used in the study is on the high end of human consumption, roughly the equivalent of 20 cans of diet soda a day. But the sweeteners are so ubiquitous in consumer products, from foods to lipstick, and often not even mentioned on the label, that it is difficult to measure just how much a person consumes every day.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week. Until further studies provide a clearer picture, women who want to err on the side of caution can choose to reduce if not eliminate their exposure to artificial sweeteners during pregnancy and breastfeeding.
NASA Has the Technology to Save Us From an Asteroid Strike, But Congress Won’t Fund It
At the biannual Planetary Defense Conference earlier this year, NASA ran a simulation of an asteroid slamming into the center of Manhattan.
For several millennia now, we've been lucky, but our luck won't hold out forever.
The gathering of astronomers, planetary scientists, and FEMA disaster-response experts attempted a number of interventions that might be possible within a time window of eight years, the given warning period before impact.
Catastrophic asteroid crashes are not without precedent, and scientists say it's only a matter of time before another one occurs—that is, if we do nothing to prevent it. It's believed that a huge asteroid crash off the coast of Mexico's Yucatan Peninsula created a worldwide disaster that helped to speed the extinction of the dinosaurs 65 million years ago.
In 1908, a meteoroid less than 300 feet in diameter exploded in the air over the Tunguska region of Siberia, creating a shockwave that leveled trees for hundreds of square miles. It's a matter of sheer luck it didn't hit a major population center, where human casualties could have been enormous.
For several millennia now, we've been lucky, but our luck won't hold out forever. There are millions of asteroids circulating about in our solar system, some of them hundreds of miles across, and although the odds of a massive one crashing to Earth in the near future is statistically low, the devastation could be apocalyptic.
Back at the conference, the experts tried sending several spacecrafts to knock the asteroid off-course by slamming into it. They considered blasting it with nuclear weapons. They even considered painting it white so it absorbed less of the sun's energy, hoping that would shift the asteroid's trajectory. In the simulations, all of the interventions failed and the giant space rock crashed into Manhattan, killing 1.3 million people in a massive explosion that was 1,000 times more powerful than the Hiroshima bomb.
NEOCam is designed, tested, and ready to build, but the project is currently frozen because of a $40 million gap in NASA funding.
Given more time, the scientists said, they might have succeeded in preventing the disaster. However, with today's asteroid-hunting telescopes, it's not likely we would have more warning. Our current telescopes are not powerful enough to detect all the near-earth asteroids, nor are they positioned well enough for sufficient detection. As recently as last week, for example, an asteroid traveling 15 miles a second narrowly missed crashing into the Earth, and it was only noticed several days in advance.
Now for the good news: There is a new technology that could buy us the time we need, says MIT planetary sciences professor Richard P. Binzel and colleagues who attended the conference. The Near-Earth Object Camera, or NEOCam, designed by NASA's Jet Propulsion Laboratory, would detect more than 90 percent of nearby objects that are 420 feet across or larger, according to Binzel.
The powerful infrared telescope is designed to sit within the L1 Lagrange point, a stable location in space where the gravitational pulls of the Earth and the sun cancel each other out. From there, large space bodies could be detected early enough to give scientists decades of warning when an asteroid is heading for Earth. NEOCam is designed, tested, and ready to build, but the project is currently frozen because of a $40 million gap in NASA funding.
The status of NEOCam, according to Binzel, is a case-study in short-sightedness and a lack of leadership. Congress needs to raise NASA's Planetary Defense budget from its current $160 million to $200 million to get the telescope built and launched into space, a goal that would seem eminently doable within the strictures of 2020's $4.75 trillion government budget. But Binzel describes a current deadlock between NASA, Congress, and the Office of Management and Budget as a "cosmic game of chicken."
If we don't use our technology to defend the planet, "it would be the most epic failure in the history of science."
In an excruciatingly budget-conscious atmosphere, "No one wants to stick their neck out and take adult responsibility" for getting the funding allocated that would unfreeze the project, says Binzel. But, he adds, "We have a moral obligation to act."
NEOCam would not only spot the overwhelming majority of asteroids in Earth's vicinity, it would determine their size and pinpoint exactly where they are likely to strike the Earth. And it would allow us decades to act, according to Binzel. Repeated ramming by an international armada of specialized spacecraft could slightly change the trajectory of an asteroid, he says. Changing the trajectory only a tiny bit, given the scale of millions of miles and several decades for the course change to take effect, could cause an asteroid to miss the Earth altogether.
"So far we've been relying on luck," says Binzel, "but luck is not a plan." Now that we have the technology to discover what's careening through our space neighborhood, it's our ethical duty to deploy it. If we don't use our technology to gain the knowledge we need to defend the planet, Binzel concludes, "it would be the most epic failure in the history of science."
Should Congress green light the $40 million budget for the new asteroid-hunting telescope? @NASA #NASA #astroid— leapsmag (@leapsmag) 1564681293.0