The Unintended Consequences of Genetic Tests - The Atlantic

I was pregnant with my first baby when my grandmother died. The last time I saw her,  she had moved into an assisted-living facility where all of her worldly possessions were condensed down to two small rooms. She had been condensed down, too, from the tall southern woman of my childhood memories into a pale and thin ghost of herself curled in an armchair. She was 80 years old and had been battling metastatic breast cancer for 15 years.<br>She must have known when she was diagnosed that the cancer would be what killed her, just as it had killed the other women in her family—her mother at age 58, her sister at 65. What she did not know when she touched my belly, just weeks before she died, was that my mother, standing nearby, had breast cancer too.<br>My mother told me that the only thing that got her through the grueling radiation treatments to eliminate her own cancer over the next several months was the thought of holding my baby. She pulled through and arrived at the hospital just in time for the delivery. I remember the way she peered over my shoulder at my bedside, gazing down at the face of the baby girl resting on my breast.<br>Three years later, I gave birth to a second daughter. Both of them have my husband’s wavy hair and my dark eyes. As my girls grew older, I began to wonder about what else they may have inherited from me.<br>Breast cancer is the most common cancer among women in the United States, and is the second most common cause of cancer-related death among American women, after lung cancer. Roughly one in eight women—or 13 percent—will be diagnosed with the disease in their lifetime, with risk rising as they age.<br>Sensing that breast cancer ran in certain families, the geneticist Mary-Claire King and a team of researchers at UC Berkeley spent 17 years hunting for a genetic marker for the disease. After analyzing interviews with thousands of women—half of them breast-cancer patients—her team developed a statistical model that supported her theory that risk was hereditary. In 1990, they identified a mutated gene linked to breast cancer, which they labeled BRCA-1. Scientists discovered a second breast-cancer gene five years later, which they called BRCA-2. More than 60 percent of women who carry these mutations will develop breast cancer in their lifetime.<br>Read: The genes that could cancel out a fatal diagnosis<br>Before this breakthrough, genetic testing had been the preserve of couples who hoped to identify any risk they bore for having a baby with a genetic disorder, such as Down syndrome, cystic fibrosis, congenital deafness, and Huntington’s disease. King’s discovery radically transformed the field of genetic counseling by introducing the prospect of predicting ailments in living adults.<br>The advent of genetic testing helped make breast cancer seem like something that could be predicted and therefore controlled: a known quantity rather than a spectral danger striking at random. In a 2013 New York Times essay, Angelina Jolie announced her decision to get a prophylactic double mastectomy after losing her mother to breast cancer and discovering that she carries the BRCA-1 gene. Demand for genetic screenings for breast cancer duly spiked.<br>I was thinking of Jolie’s essay earlier this year when my new primary-care doctor offered me a genetic screening. I said yes. Surely I owed it to myself and my daughters to take a proactive approach to a disease that had killed so many women in my family. Weeks later, I went to a women’s clinic at my local hospital for a simple blood draw. The genetic counselor told me that the results could take a few weeks, and that I would get a call if they found reasons for concern.<br>I was in the car about a month later when the clinic’s caller ID flashed on my phone. I picked up and immediately recognized the voice of the genetic counselor, who was kind, calm, and ready to have a conversation that I had not prepared for.<br>Her news was initially and unexpectedly encouraging: Despite my family’s history of breast cancer, I carry no mutations known to elevate my risk for the disease. Whatever predisposition is responsible for my family’s medical history, our genes would neither determine my own destiny, nor that of my daughters.<br>But there was something else. The analysis had also located a “variant of uncertain significance,” or VUS. The counselor gently explained that this meant the laboratory simply had not seen enough instances of this mutation to know whether it was a normal variation with no harmful consequences or something more concerning. The mutation, she said, was on a gene called WT-1, which is associated with a rare childhood kidney cancer. What, I asked, did this mean for my children? Should I take them to see a specialist? Set up regular screenings? Was there anything I could do with this information? The counselor patiently told me that the lab didn’t have enough information to dictate any particular course of...