What we’re really talking about when we talk about genetic testing | KUOW News and Information

What we’re really talking about when we talk about genetic testing

Feb 27, 2017

Science writer Bonnie Rochman says she likes as much information as she can get — she finds it empowering. But she knows not everyone feels the same way.

She especially knows that some soon-to-be parents don’t feel that way.

Rochman is the author of the book “The Gene Machine: How Genetic Technologies are Transforming Parenting and Reshaping Society." She writes about the seemingly endless number of tests and screenings available to expectant parents — and the difficult choices parents sometimes face.

“When my mother gave birth to me 44 years ago, she had to go to the doctor for a pregnancy test. They didn't even have over-the-counter pregnancy tests,” Rochman told KUOW’s Bill Radke. “Then you wait for nine months and see what you get. You didn't even know if it was a boy or a girl.”

Now tests can screen for Down syndrome, Tay Sachs disease, spinal muscular atrophy and a long list of other genetic conditions. And there are choices, some tougher than others.

“The more access to information we have, the more decisions that have to be made,” Rochman said. “As a result, some people actually decline all this prenatal testing. They just don't want to deal with it.”

In prenatal testing, abortion is the elephant in the room, Rochman said.

“Everyone dances around why you might want to do this testing,” she said. “No one says the A-word. That does a disservice to women.”

Not that abortion is the only option if tests return positive. Some moms want to be prepared if their child does have a disability. A mom with Down syndrome might choose to deliver at a hospital with a robust neonatal intensive care unit, instead of say, a birth clinic.

“Any time you go testing, you have to go in with your eyes wide open,” she said. “People go about it wrong — ‘I just want to rule things out.’ Any time you go looking for trouble, you may find it.”

She continued: “The way women approach it is screwed up, because their providers aren’t guiding them.”  

More advanced prenatal testing can turn up unknowns. Rochman interviewed a woman, a narcotics prosecutor in Brooklyn. The woman was inspired to get testing because a friend of hers had a child with severe special needs. 

“She and her husband were going to do every test imaginable, way more than usual,” Rochman said. The couple, who had gone through in vitro fertilization, had decided they would end the pregnancy if the child could not live independently as an adult.

The testing came back: Their fetus had a duplication and a deletion of genes, but they didn’t know how that would manifest in their child.

“They said, we’re going to have an abortion, but they weren’t very excited about the idea,” Rochman said. They asked their doctor for reassurance, and the doctor gave an 80 percent chance their child would turn out okay. They decided to have the baby.

“I met the baby at his one year birthday,” Rochman said. “He was adorable and seemed totally fine. Who could know?”

Rochman herself had prenatal testing done a decade ago, because her doctor was becoming certified. She said she would do it again.

“I wouldn’t go to the extent of deletions and duplications,” she said. “So much is unknown about those small genetic errors.”

In the U.S., termination rates are around 67 percent for fetuses with Down syndrome, although rates vary by region. In California, 88 percent of moms studied terminated. In South Carolina, three of nine moms studied had abortions. 

But genetic testing isn't just about the babies — parents, too, can undergo testing to find out if they're carriers. 

Since certain genetic conditions have historically been more prominent among specific ethnicities, physicians don’t always recommend carrier screenings (blood tests that determine if either parent could pass on a genetic mutation).

“For a long time, carrier screening has been done based on ethnicity, and even when it's done based on ethnicity, not all the same tests are offered to all the same people,” Rochman said.

Some researchers now believe that approach is outdated, since our ethnic backgrounds are becoming increasingly complex and difficult to track.

“There's a move to embrace something called expanded carrier screening, which is testing for a large number of diseases,” Rochman said. “Genetic technology now allows us to do that from the same blood sample and to test for a large number of diseases — and to test all people for the same sorts of diseases.”

Expanded carrier screening is a blood test that looks for dozens of genetic conditions parents might pass on to their children, not just the conditions they’re historically at risk of carrying due to ethnicity. But this testing can be costly — thousands of dollars in some complicated cases — and insurance companies won’t always pay.

If a parent is found to be a carrier prior to the conception of a child, they could attempt pregnancy through in vitro fertilization, which would allow an embryo to be screened for the genetic condition prior to implantation. IVF is also expensive, with treatments starting around $12,000 and running much higher.

Parents could also opt for early prenatal testing during the pregnancy; many conditions can be detected by a blood draw around 10 weeks into a pregnancy, Rochman said. But if a test is positive, it would need to be confirmed by more invasive measures such as an amniocentesis, which involves inserting a needle into the uterus.

If a debilitating genetic condition is detected during the pregnancy, Rochman said parents sometimes decide not to continue the pregnancy, particularly when “it's a disease where the child won't have any kind of meaningful quality of life.”

While researching her book, Rochman met with parents whose children were affected by devastating genetic conditions. One particularly painful interview centered around a one-year-old with Canavan disease, a neurological disease that causes nerve damage in the brain, eventually leading to physical and mental disabilities and early death.

The boy died before his second birthday. His mother hadn’t been screened for genetic disorders, even though she has Eastern European Jewish ancestry — an ethnic group that has an unusually high rate of Canavan cases.

But Rochman also spoke with people whose children have Down syndrome, and they said they wouldn’t do anything differently.

“Most every parent I have spoken to who has a child with Down syndrome doesn't consider Down syndrome to be a terrible problem,” Rochman said. “They love their child just the way he or she is.”

Critics of genetic testing say the technology is a slippery slope that could contribute to widespread gene editing and the prevalence of so-called “designer babies.” 

“I think that it's important to keep having these conversations about the human condition and how tests can help us gain insight into who we are and how our bodies function,” Rochman said.

She said ultimately, the technology is all about giving parents information.

“It's not about whether it's good or bad,” she said. “It really depends on what you do with it.” 

Written for the web by Amy Rolph and Isolde Raftery.