The last children of Down syndrome / Humans + Tech - #55

+ Social fragmentation resembles the melting of ice, we may be near tipping point + How the mRNA vaccines from Pfizer and Moderna work

Hi,

When it comes to humans and technology, the articles that I particularly find interesting are those with ethical dilemmas. “The last children of Down syndrome” is one such article. Let’s dive into it.

The last children of Down syndrome

In 2004, Denmark made prenatal Down syndrome screening available to every pregnant woman. Nearly all choose to take the test. 95 percent choose to abort if the results are positive.

As a result, the number of babies born with Down syndrome has declined sharply [Sarah Zhang, The Atlantic]. Only 18 were born in Denmark in 2019, compared to over 6,000 in the US. 11 of those were born to parents who either declined the test or got a false negative.

The screening in Denmark consists of blood tests, an ultrasound, and maternal age to calculate the odds of Down syndrome. A DNA test is only offered to high-probability patients. DNA tests are of two types, invasive and non-invasive. The invasive ones have a slight risk of miscarriage but can detect other genetic disorders in addition to Down syndrome. Thus, the invasive option is more popular in Denmark as the more disorders that get ruled out, the more peace of mind parents have.

It’s a very thought-provoking article. Here are a few excerpts from the article, although I highly recommend reading the full article.

Stina Lou, an anthropologist studies how parents make decisions after a prenatal diagnosis of a fetal anomaly, wanted to find out what happened when parents did not get good news after the test results came out.

In a study of 21 women who chose abortion after a prenatal diagnosis of Down syndrome, she found that they had tended to base their decisions on worst-case scenarios. An extra copy of chromosome 21 can cause a variety of symptoms, the severity of which is not known until birth or even later. Most people with Down syndrome learn to read and write. Others are nonverbal. Some do not have heart defects. Others spend months or even years in and out of the hospital to fix a heart valve. Most have healthy digestive systems. Others lack the nerve endings needed to anticipate bowel movements, necessitating more surgeries, possibly even a stoma bag or diapers. The women who chose abortion feared the worst possible outcomes. Some even grieved the possibility of aborting a child who might have had a mild form of Down syndrome. But in the end, Lou told me, “the uncertainty just becomes too much.”

David Wasserman, a bioethicist at the U.S. National Institutes of Health, said that he didn’t think that most parents who make these decisions are seeking perfection, but that, “there’s profound risk aversion.”

This decrease in people with Down syndrome affects those born with it in significant ways.

And when fewer people with disabilities are born, it becomes harder for the ones who are born to live a good life, argues Rosemarie Garland-Thomson, a bioethicist and professor emerita at Emory University. Fewer people with disabilities means fewer services, fewer therapies, fewer resources. But she also recognizes how this logic pins the entire weight of an inclusive society on individual women.

Then there is a wealth disparity too. A study in the US found higher rates of termination in the wealthy areas and among highly educated mothers. Laura Hercher mentioned below is a genetic counsellor.

If only the wealthy can afford to routinely screen out certain genetic conditions, then those conditions can become proxies of class. They can become, in other words, other people’s problems. Hercher worries about an empathy gap in a world where the well-off feel insulated from sickness and disability.

For those with the money, the possibilities of genetic selection are expanding. The leading edge is preimplantation genetic testing (PGT) of embryos created through in vitro fertilization, which altogether can cost tens of thousands of dollars. Labs now offer testing for a menu of genetic conditions—most of them rare and severe conditions such as Tay-Sachs disease, cystic fibrosis, and phenylketonuria—allowing parents to select healthy embryos for implantation in the womb. Scientists have also started trying to understand more common conditions that are influenced by hundreds or even thousands of genes: diabetes, heart disease, high cholesterol, cancer, and—much more controversially—mental illness and autism. In late 2018, Genomic Prediction, a company in New Jersey, began offering to screen embryos for risk of hundreds of conditions, including schizophrenia and intellectual disability, though it has since quietly backtracked on the latter. The one test customers keep asking for, the company’s chief scientific officer told me, is for autism. The science isn’t there yet, but the demand is.

Prenatal genetic testing is only going to increase going forward. That is inevitable. Its impact on humanity is what is in question.

The medical field has also been grappling with its ability to offer this power. “If no one with Down syndrome had ever existed or ever would exist—is that a terrible thing? I don’t know,” says Laura Hercher, a genetic counselor and the director of student research at Sarah Lawrence College. If you take the health complications linked to Down syndrome, such as increased likelihood of early-onset Alzheimer’s, leukemia, and heart defects, she told me, “I don’t think anyone would argue that those are good things.”

But she went on. “If our world didn’t have people with special needs and these vulnerabilities,” she asked, “would we be missing a part of our humanity?”

And, whether prenatal genetic testing is ethical or unethical will largely depend on your personal beliefs and those of the societies and communities that you live in.


Social fragmentation resembles the melting of ice - and we may be near the tipping point

Social media has created more divisions and bubbles of like-minded people rather than the initial promise of bringing us all together. Tuan Minh Pham, Imre Kondor, Rudolf Hanel, and Stefan Thurner have published research that indicates that social fragmentation is similar to the melting of ice and we may be close to the tipping point [Mike McRae, Science Alert].

It's a metaphor that extends beyond the poetic. A model of social cohesion created by researchers from the Complexity Science Hub Vienna draws a comparison between phase transitions in materials and our own 'bubbles' of communal interaction.

Their model shows that society is at risk of approaching a tipping point of social bonds, potentially thanks to the rise of smart phones and social media.

[…]

Find the right combinations of stress in a block of ice, and it'll shatter. Raise the temperature, and it'll melt.

Similarly, stretch the bonds of friendships within a community of humans too far by adding too many connections, and sooner or later it'll hit a tipping point where the whole network can no longer maintain its shape.

One problem they say is that our brains did not evolve to deal with so many relationships. Thurner points out that people staying within their bubbles weakens democracy as society is less willing to compromise.

There is other research linked in the article that indicates that the level of fragmentation from social media is not as bad as expected, so there may be some hope yet.


How the breakthrough mRNA vaccines from Pfizer and Moderna work

The vaccines from Pfizer and Moderna have provided much-needed optimism in an otherwise difficult year for the world. Traditional vaccine development is slow, and it would have been impossible to develop one so quick to respond to the pandemic [Sanjay Mishra, The Conversation].

Both Pfizer and Moderna used mRNA technology which eliminates much of the manufacturing process since they are manufactured by chemical rather than biological synthesis.

For example, for seasonal flu, it takes roughly six months from identification of the circulating influenza virus strain to produce a vaccine. The candidate flu vaccine virus is grown for about three weeks to produce a hybrid virus, which is less dangerous and better able to grow in hens’ eggs. The hybrid virus is then injected into a lot of fertilized eggs and incubated for several days to make more copies. Then the fluid containing virus is harvested from eggs, the vaccine viruses are killed, and the viral proteins are purified over several days.

The mRNA vaccines can leapfrog the hurdles of developing traditional vaccines such as producing noninfectious viruses, or producing viral proteins at medically demanding levels of purity.

MRNA vaccines eliminate much of the manufacturing process because rather than having viral proteins injected, the human body uses the instructions to manufacture viral proteins itself.

Incredibly, the mRNA code for a candidate vaccine was ready within a few days of the genetic code of the SARD-CoV-2 virus being available.

Although mRNA technology has been available for many years, it’s very unstable and difficult to deliver to the target in the human body.

But beginning in 2005, researchers figured out how to stabilize mRNA and package it into small particles to deliver it as a vaccine. The mRNA COVID-19 vaccines are expected to be the first using this technology to be approved by the FDA.

After a decade of work, the mRNA vaccines are now ready for evaluation. Physicians will be watching for unintended immune reactions, which can be both helpful and detrimental.


Quote of the week

If our world didn’t have people with special needs and these vulnerabilities, would we be missing a part of our humanity?

—Laura Hercher, genetic counselor and the director of student research at Sarah Lawrence College, in the article, “The Last Children of Down Syndrome” [The Atlantic]

I wish you a brilliant day ahead :)

Neeraj