February 2019: The Promise and Peril of DNA Testing

The explosive growth in genetic research and testing is creating a host of ethical and practical concerns, Bonnie LeRoy, professor and director of the Graduate Program of Study in Genetic Counseling at the University of Minnesota, told our February chapter meeting.

Things are moving so fast, much of it driven by commercial testing companies, that the medical community is having a hard time keeping up, she said. “There’s a lot of money in testing right now,” she said.

One example:  Prenatal cell-free DNA (cfDNA) screening, a new method to screen for certain chromosomal abnormalities in a fetus. It can be conducted early in the pregnancy with no risk to the fetus, unlike the more invasive amniocentesis. So there’s a danger it will be ordered for all pregnancies, she said,  and “you could find abnormalities in everyone.” The medical community doesn’t understand it well and most patients don’t know what to do with the results, she said.

Genetic research can help us learn more about how cancer and other diseases are transmitted — and has the potential to help us eliminate harmful conditions from the population. But LeRoy highlighted challenges including:

  • So far, the ability to translate genetic testing into information you can use is “not that great.” Many people are looking for a crystal ball that can predict how long they will live, she said. “We’re not there, we’re not even close to being there.”
  • People need to learn how to interpret risk when screening fetuses for abnormal chromosomes. For example, if you hear there is a one in 50 chance of abnormality, that sounds a lot scarier than expressing it this way: there’s a 98 percent chance there is no risk.
  • The use of technology to test for “benign” disorders, like the gender of children, raises ethical concerns.
  • There’s a risk of psycho-social harm to individuals and families who get unsettling genetic information about their health or family relationships. “Once you learn something, you can’t unknow that.” The growth of home DNA kits is making it easier for families to learn about previously undisclosed adoptions and misattributed paternity.
  • Safeguards must be put in place to protect the privacy of genetic information, which is different from other medical information because “it can change how you see yourself and how others see you.” As we all learn more about our DNA, she cautioned against returning to the days when people hid “defective” family members for fear no one would marry into their family.
  • In a much-criticized case, a Chinese scientist recently used CRISPR technology to edit the genes of twin human embroyos to resist HIV infection. CRISPR is “an amazing technology,” LeRoy said. But this scientist made a big jump from medical research to clinical application, she said, noting that we don’t know what will happen 30 years from now to the girls who were born using this procedure. “There was absolutely no reason to do that.”

— Suzanne Perry


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