National Geographic : 2019 Jan
WHEN WE ASKED veteran journalist Fran Smith to write about new fron- tiers in medicine for this month’s issue, the first thing she did was volunteer to be, in her words, “a research guinea pig.” She got her genome sequenced. Smith didn’t hesitate. After all, she told me, she’s never understood some people’s skittishness about medical testing and learning what may—or may not—loom in their health future. “You’re not safer if you don’t know,” she says, sensibly enough. “And you can find out things that are very useful and that you can do something about.” Smith wanted her own experience of what’s come to be known as “precision medicine.” Unlike older medical mod- els that tend to lump patients together and treat them for a category of illness, this approach uses gene research and data analytics “to tailor prevention, diagnosis, and treatment to a person’s unique biochemical makeup,” Smith writes. And in decades to come, its advances will “upend the way medi- cine traditionally has been practiced.” At Stanford University, where she enrolled in a detailed biochemical profiling study for this assignment, Smith’s experience began not with needles or swabs but questions from a genetic counselor. “Did I understand that DNA se- quencing might produce ‘actionable’ results, such as BRCA mutations for breast and ovarian cancer, the problem that had famously spurred Angelina Jolie to undergo a preventive double mastectomy?” Smith writes. “Did I understand the test also might reveal problems I can’t do anything about, such as the APOE4 gene, which ele- vates the risk of Alzheimer’s? Did I want to learn all findings?” I won’t spoil the story, but as Smith notes, while she awaited the test results, “my stomach surprised me by knotting in protest.” Would she find out that she might follow her father’s fate—a slow decline into dementia? Or might she more resemble her mother, still living on her own at age 94, playing mah- jongg and dancing at the senior center? Another surprise: Smith told me later that she was fascinated to learn that the same genetic counselor who asked her all those questions has not had her own genome sequenced. She hasn’t decided if she wants to know. As researchers develop tools not imagined even a decade ago—to edit our genes, predict our risk of disease, even shape the biomedical future of our children—individuals and societies must think critically about the impli- cations. We believe that’s best done on the basis of sound facts and science, the foundation for the coverage you’ll find in this special issue. Thank you for reading National Geographic. PHOTO ILLUSTRATION: KTSDESIGN/SCIENCE PHOTO LIBRARY JANUARY | FROM THE EDITOR Into Medicine’s Future BY SUSAN GOLDBERG SPECIAL ISSUE To sequence a genome, long strands of DNA are cut into small pieces. Then each is analyzed to determine the arrangement of DNA’s four base chemicals— adenine, cytosine, guanine, and thymine— seen in this illustration as different colors.