As all the world knows now, Hollywood star Angelina Jolie chose to have a preventive double mastectomy to reduce her risk of hereditary breast cancer from around 90 percent to five percent. Jolie made her decision based on the results of a specific genetic test that found she carried a high-risk version of the BRCA gene. Once a significant advance in diagnostics, such single-disease genetic tests are already being superseded by whole genome testing, in which all of a person's genes can be checked for variants that are associated with higher or lower risks of various diseases. In response to the rapid progress in whole genome testing, a panel of experts convened by the American College of Medical Genetics and Genomics (ACMG) issued a new policy statement in March on the medical and ethical implications of incidental genetic findings for patients and physicians. Some prominent bioethicists claim that the claim that the college's recommendations violate your right to remain ignorant of your genetic risks.
In its report, the ACMG panel recommended that laboratories performing clinical genome sequencing on both adults and children look at 57 specific genes for disease-causing mutations. These mutations are associated with 24 different disorders, chiefly related to cancer and heart disease risks. The laboratories, the panel continued, should report all their findings about those genes to patients and physicians so that they can take early action to prevent or reduce the chances of illness or early death. Do those recommendations violate the hallowed bioethical principle of patient autonomy?
Whole genome testing is becoming ever cheaper and more widespread, enabling testing clinics to detect not only mutations relevant to the specific illness being investigated but also genetic variants that may be associated with other disease risks. The ACMG likened the situation to the case of a competent doctor who, while investigating a patient's complaint about gastro-intestinal symptoms, also examines her cardiac and respiratory systems. For example, a physician using ultrasound to check a patient for gallstones might also discover an aortic aneurysm; the aneurysm is incidental to the gall bladder problem, but it is obviously relevant to the patient's future health. Surely most of us would agree that it would be wrong for the doctor not to tell her patient about the aneurysm.
Consider a physician who finds a number of polyps while performing a colonoscopy on a female patient. As part of her treatment plan, the physician orders a genetic test to look for possible gene variants associated with increased risk of colon and other cancers. (Labcorp, for example, offers a test that looks for particular mutations associated with higher colon cancer risk.) In this case, the patient's tissue is sent to a lab, such as Ambry Genetics or XomeDx, whose standard comprehensive genomic tests look not just for gene variants related to colon cancer but mutations in other genes that correlate with other risks as well. The results reveal that the patient, like Jolie, carries mutations in the BRCA gene that dramatically boost her lifetime risk of breast cancer. The patient has not consented to being checked for breast cancer risk. Should the lab report those findings to her physician, and should her physician tell her those results?
Three prominent bioethicists say they shouldn't. In a May 17 article for Science, Susan Wolf of the University of Minnesota, George Annas of Boston University, and Sherman Elias of Northwestern University wrote that patients "have a right to refuse testing and findings, even if potentially lifesaving. Just because many patients might want this information does not mean that it can or should be imposed on all." They dismiss the gallstone/aneurysm analogy, arguing that "patients would have no reason to expect a hunt for incidental findings in the 57 disparate genes on the ACMG list." They further point out that the ACMG list "includes genes whose analysis and reporting have long required patient consent."
The bioethicists additionally objected to giving parents incidental genomic test results obtained by testing their kids. Previous bioethical statements have called for limiting the genetic testing of children to those assays that provide information that is medically necessary for treatments during childhood, and so many bioethicists are opposed to testing kids for adult-onset risks. The idea is that when a child reaches adulthood she can decide then whether or not she would like to take such tests or know the results of earlier tests. Bioethicists also worry that knowing a kid's future genetic risks will adversely affect how parents rear the child.
The ACMG accepts that children in principle should not be tested for adult-onset genetic risks such as BRCA gene breast cancer mutations. The panel notes, however, that an incidental finding that a child carries a pathogenic mutation also suggests that there is a high probability that one parent does as well; reporting such an incidental finding could benefit the affected child by preventing a bad health outcome for her parent. In addition, in the absence of any known family history of risk, a child might benefit from being alerted to an incidental finding because, unaware of her risk, she might not otherwise get herself tested before the onset of the disease in her adulthood.
In my view, the bioethicists writing in Science are indulging in moral hyperventilation. Genomic testing companies like Ambry Genetics and XomeDx have indeed adopted the AMCG incidental findings recommendations, and they report the results to physicians and patients as a default. But they also offer test subjects and patients consent forms that allow them to opt out of learning about any incidental findings. In the real world, patients are not being forced to hear genetic information to which they have not consented. Their right to remain ignorant is being honored.
Will that practice stand? I predict that, as genomic testing becomes more precise and prognostic, failing to tell a patient about her genetic disease risks will be seen as being just as moral as neglecting to tell her about an aortic aneurysm discovered during an ultrasound examination for gallstones. Keeping people ignorant is rarely the right thing to do.