Will new prenatal tests scare parents into bad decisions?

When William Hanley was a teenager, his body started changing in all the wrong ways. His hips widened, and his chest began to swell. He was growing breasts. Painfully self-conscious, he rounded his shoulders and hoped nobody would notice.

It wasn’t until he was 16 that an endocrinologist figured it out: Hanley’s sex chromosomes were XXY instead of the usual XY for males or XX for females. He had Klinefelter’s syndrome, the most common of a few dozen disorders caused by missing or extra sex chromosomes. He was put on hormone therapy to help his symptoms. And his family told him to keep it a secret. 

Today new high-tech prenatal tests make it possible to detect aneuploidies (abnornal numbers of chromosomes) that lead to conditions like Down syndrome (an extra copy of chromosome 21), including sex chromosome aneuploidies (SCAs) like Klinefelter’s, with just a blood sample as early as nine weeks into pregnancy. Such a test could have transformed Hanley’s adolescence. He could have started hormone therapy at puberty, avoiding dangerous surgeries to remove breast tissue, as well as a lot of humiliation and anxiety. “There was a lot of stigma that I wasn’t developing correctly, and psychologically that was really difficult,” he says. “The test would have been a good thing.”

But there’s also now a chance that people like him won’t be born at all. SCAs are nowhere near as debilitating as Down syndrome, for example. But because they have to do with gender, they inspire fear in prospective parents. According to several studies, 68 to 81 percent of the parents who get an SCA diagnosis decide to terminate the pregnancy — a rate comparable to that for Down syndrome. The new DNA-based prenatal screening tests, which are safer and more accurate than older tests, will doubtless identify more of these pregnancies in the first trimester, when abortions are medically simpler.

Four biotech companies — Sequenom, Ariosa, Natera and Verinata — offer these relatively noninvasive tests. The technology zeroes in on fragments of fetal DNA that float in a pregnant woman’s bloodstream, analyzing them for abnormal chromosome patterns. The most common SCAs in males are Klinefelter’s and XYY. Females can be XXX or sometimes single X, a rare but more serious condition called Turner syndrome. Collectively, these SCAs are more common than Down syndrome, occurring in roughly 1 in 400 births. They are not inherited; they are random mistakes in cell division.

An SCA diagnosis might sound terrifying, but these conditions usually result in relatively mild symptoms. In fact, experts estimate that 75 percent of people with one of these disorders are never even diagnosed.

Newborns with SCAs are anatomically normal, but as children they may struggle with muscle weakness, speech and learning delays, mood disorders or social difficulties. They often need speech therapy or special education. “The challenges are on the order of what you get with Asperger’s syndrome, not what you get with a true intellectual disability,” says social worker Virginia Cover, a board member of KS&A, a support and advocacy organization for people with atypical sex chromosomes.

About one-third of children with SCAs have no learning disabilities and need no special services. Some but not all are infertile as adults. Nonetheless, the diagnosis often carries a burden of shame, says Jeanne Nollman, a former president of AIS/DSD, a national support group for women and children with disorders of sex development. “Some people may have a learning disability, but it’s not anything so far out of the norm — except that it’s secret and shameful,” she says.

As the new tests catch on, many more women are likely to receive SCA diagnoses. The tests have been available for only two years, and already more than 200,000 pregnant women in the U.S. (500,000 worldwide) have had them. They have a stamp of approval from several major medical organizations and are covered by many insurers for any high-risk pregnancy (which includes all mothers over 35).

In fact, Sequenom, the company with the best-selling test so far, hopes eventually to offer the test to every pregnant woman in the U.S. — some 4 million a year.

“More and more people who are totally unprepared for this diagnosis are going to get this diagnosis and be confronted with a decision,” says Myra Byrd, chairwoman of KS&A’s board of directors.  The worst-case scenario, says bioethicist Bernard Dickens, a professor emeritus of health law and policy at the University of Toronto, would be if parents make decisions to terminate based on faulty or insufficient information.

The companies who market the tests point out that they are providing pregnant women with more and better information and encourage their customers to speak with a genetic counselor. Ariosa maternal fetal medicine specialist Dr. Adam Wolfberg says in an email that the company “works hard to make sure that doctors who order (its test) have resources that they can use to counsel their patients.”

The tests will likely save many pregnant women from getting riskier procedures like amniocentesis, in which a needle is inserted into the womb to withdraw fluid for testing. The new tests are still considered screening tests, meaning that a positive result is supposed to be confirmed with a more invasive procedure like amniocentesis. But because the new tests seem to be more accurate than older screening methods like ultrasounds, the overall number of false positives should decrease, thereby reducing more invasive testing. That “is a major advance toward making prenatal care safer for pregnant women,” writes Sequenom’s chief medical officer, Dr. Allan T. Bombard, in an email. (Verinata declined to comment, and Natera did not respond to requests for comment.)

Meanwhile, the technology is advancing. DNA sequencing experts have already demonstrated that it’s possible to decode the entire genome of an unborn baby, meaning that the ability to screen a fetus for any undesirable gene might be around the corner. In this vision of the future, any less-than-perfect pregnancy could be terminated.

But a more appealing future is also possible, suggests Dickens. Better information for parents and better-trained genetic counselors could help broaden social definitions of what’s normal. After all, everyone has minor deficits and imperfections. “It could widen the margins of tolerance for what’s an acceptable human condition,” he says.

Byrd says that one of the main goals of KS&A is to educate genetic counselors and physicians and provide more information for parents faced with a diagnosis. She believes that if properly informed, most parents will see that children with SCAs are a manageable challenge. Hanley agrees. “It’s a matter of information,” he says. “If we provide educational material and back it up with real-life cases — this is William Hanley, this is what he’s done with his life — people will say, ‘If this guy did all of this, why can’t our child?’”