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Advancements in Prenatal Genetic Tests – Noninvasive

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New prenatal genetic tests hold promise, worries

By Carolyn Y. Johnson

SWANSEA — On a stormy Valentine’s Day in 2007, Courtney Kane felt herself detach from her body and float up to the ceiling. She watched as the figure below, 19 weeks pregnant, reclined on a bed in an exam room, talking to a doctor and a genetic counselor.

Her husband, Trafford, was holding her hand. Her mother had come along for support. She felt as if the rest of the world had dropped away and they were alone, like characters frozen in a spotlight on a stage.

A detailed ultrasound had given the medical team a strong indication that the Kanes’ baby had Down syndrome, and Courtney now found herself agreeing to have a long, thin needle inserted into her abdomen to retrieve amniotic fluid for genetic testing. The invasive test was uncomfortable and scary, and it carried a small risk of miscarriage.

The results wouldn’t be known for a few days, so the family traveled back to their 200-year-old home in Swansea, numb. The roof had started leaking and water was pooling on the dining room table, but they barely noticed.

When the Kanes were later asked to participate in a study that would help in the development of an alternative prenatal test that required ­only a tube of blood, they didn’t hesitate. Courtney wanted to help other women avoid the invasive procedure, called amniocentesis.

Fast-forward to 2013.

In the short span of a year and a half, four companies in the United States have launched prenatal tests that use maternal blood to detect syndromes such as Down, which are caused by abnormal numbers of chromosomes, as early as nine or 10 weeks into pregnancy. Not all the companies have disclosed their sales, but tens of thousands of tests have been sold, and the underlying technology has the potential to reveal more. Last year, researchers demonstrated that a mother’s blood could be used to reconstruct the entire genome of a fetus.

Meanwhile, rather than feel good about their contribution to this medical advance, the Kanes utterly regret the small role they played in helping push the technology forward. If the tests get more accurate and expand in use, as they seem poised to do, Courtney, 34, and Trafford, 32, expect that more families will opt for a seemingly harmless test very early in the pregnancy. Information, after all, is empowering. But information is also powerful in ways families don’t always anticipate; a positive result can push them toward a crossroads, a decision point. The Kanes worry that fewer families will know the joys of Julia.

The genome era — made possible by the ever-cheaper, ever-faster ability to read the DNA “book of life” — has brought ethical dilemmas along with biomedical insight. The medical community wrestles with questions about how genetic tests should be used and what information should be disclosed to patients.

But in perhaps no other area are the questions raised by the evolving technology as morally fraught as when they involve a 10-week-old fetus, when parents may use the test results to decide whether to terminate or continue a pregnancy.

Today, use of the new prenatal blood tests is limited. Medical groups recommend them only for high-risk pregnancies, including women 35 and older. They currently screen for a small number of chromosomal syndromes. A positive result must be followed up by more invasive tests for a definitive diagnosis. Many, however, anticipate the eventual expansion of the tests — both to a larger swath of pregnant women and to a wider catalog of genetic conditions and disorders.

Vastly increasing the number of women who learn about the genetic traits of their baby early on has the potential to reshape the medical and social experience of pregnancy, in the way it has already altered the lives of families that learn they are having a child with Down syndrome.

Advocates for the Down syndrome community worry that wider prenatal testing will mean more expectant parents receive an alarming test result without sufficient information to make an informed choice about whether to terminate or continue the pregnancy.

“I think Down syndrome is genetics’ canary in a coal mine,” said Dr. Brian Skotko, a physician at Massachusetts General Hospital who co-leads a clinic focused on caring for people with Down.

“There are today 250,000 Americans with Down syndrome, only [about] 50,000 away from being reclassified as a rare disease,” Skotko said. “We are, in the moment, potentially seeing through our society’s choices the elimination of a people.”

Skotko has a younger sister, Kristin, with Down, and he has performed surveys that have helped recalibrate perceptions of the lives of individuals with Down. In studies published in the American Journal of Medical Genetics, he found that 99 percent of people with Down report being happy with their lives, and 79 percent of parents credited having a child with Down with giving them a more positive outlook. Continued…

Our thoughts & responses:

Courtney Kane’s decision to participate in prenatal testing was an important decision for her family. This decision allowed her and her family to be prepared for their daughter born with Down syndrome.

The Kane’s decision did hold some risk, however, because of the Amnio procedure. Amniocentesis is an invasive procedure involving a long, thin needle into the abdomen. With such an invasive procedure, parents are faced with the risk of miscarriage. Prenatal testing continues to advance and noninvasive procedures from a blood test can now also provide sufficient prenatal information.

It is also important for parents who make this important decision to be fully prepared by their healthcare providers. While it’s important for a test to provide sufficient information, it is also important for a patient to be educated on how to interpret those results.

We agree with Dr. Skotko in believing that prenatal testing does not necessarily advocate pro-choice, but it is pro-information. Prenatal testing is meant for women looking to gather information regarding the health of their baby and their pregnancy. It’s important to understand that this does not mean patients are looking to terminate, since there are patients who have already decided to keep their pregnancy regardless of their prenatal test results.

By knowing your baby’s genetic conditions, a mother can seek guidance through the pregnancy and become prepared by educating themselves on what to expect. With testing done in as little as 8 weeks into a pregnancy, an early diagnosis could even be treated.

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