Prenatal search-and-destroy genetic testing is often wrong

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Eugenics is alive and well with prenatal tests deployed to detect conditions – such as Down syndrome and dwarfism – towards the frequent end (and often, goal) to ensure that delinquent babies are never born. Iceland therefore boasts that almost no Down child is ever born. What a tragedy for babies, parents and Icelandic society.

But here’s the thing. Prenatal testing companies make a lot of money selling early pregnancy prenatal blood tests that look for rare genetic conditions beyond Down syndrome. In addition, their test results are often wrong. From New York Times story:

In just over a decade, testing has grown from laboratory experiments to an industry that serves more than a third of pregnant women in America, attracting large companies like Labcorp and Quest Diagnostics to the company, alongside many start-ups.

The tests first looked for Down syndrome and worked very well. But as manufacturers tried to sell better, they began to offer additional screenings for increasingly rare conditions.

The dire predictions made by these new tests are generally wrong, according to a New York Times review. This includes screening that came back positive for Ms Geller, who tests for Prader-Willi syndrome, a condition that offers little chance of living independently into adulthood. Studies have shown that its positive results are incorrect more than 90 percent of the time.

Think about the consequences. The increase in abortions. Family stress.

In interviews, 14 patients who obtained false positives said the experience was distressing. They are named frantically searches for conditions they had never heard of, followed by sleepless nights and days hiding their bulging bellies from their friends. Eight said they never received any information about the possibility of a false positive, and five recalled that their doctor had considered the test results to be final.

When Meredith Bannon’s pregnancy tested positive for DiGeorge Syndrome, a nurse called her and told her that she and her husband would soon be faced with “tough decisions” related to “quality of life” of their child, which Ms. Bannon took to mean a choice to terminate the pregnancy.

The call came as Ms Bannon was driving to her parents’ house, with her son in the back seat wearing a ‘big brother’ t-shirt. “I would come home to tell them I was pregnant, but instead I had to tell them the news that I had recovered from this horrible result,” recalls Ms. Bannon.

Further testing revealed that the result was wrong. Her baby is due in April.

But the increase in testing for very rare conditions appears to be profit driven rather than limited to circumstances where it might be medically indicated.

Some have said that blood tests that look for the rarest conditions are only good for boosting the results of testing companies. “It’s a bit like doing mammograms on children,” said Mary Norton, an obstetrician and geneticist at the University of California, San Francisco. “The risk of breast cancer is so low, so why are you doing it? I think it’s purely a marketing matter.

According to history, the FDA does not regulate these tests. These tests, most of which are unnecessary and unjustified, also exemplify an “avoid all possible risks” approach to healthcare that makes costs unmanageable.

The modern will to exercise near absolute control – not just having a baby, but the baby we want – leads to deleterious consequences and tragic outcomes.

Businesses have known for years that follow-up testing doesn’t always happen. A 2014 study found that 6% of patients who tested positive obtained an abortion without having another test to confirm the result. That same year, the Boston Globe cited a doctor as describing three layoffs following unconfirmed positive results.

Three geneticists recounted more recent examples in interviews with The Times. One of them described a case in which follow-up tests found the fetus to be healthy. But by the time the results arrived, the patient had already terminated her pregnancy.

In the end, I blame us. Our culture no longer tolerates “imperfection”. If you doubt me, look at the seething hatred Sarah Palin was subjected to for choosing to give birth to Trig, knowing he has Down syndrome.

We are talking about a great game of tolerance and acceptance of differences. But we don’t really mean it.

Amanda J. Marsh