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Genetic Literacy¹

Two reasons to promote genetic literacy, or understanding of genes and inherited biological variation, said Joseph McInerney, executive vice president of the American Society of Human Genetics, are to help understand the history and nature of life on earth and to understand the future of health care, including the ethical, legal, and social aspects of health care and the genetic contributions to health care. Understanding the history and nature of life on earth, which McInerney considers to be the fundamentals of basic biology, requires understanding five key concepts, each related in some way to genetics:

• Variation and continuity
• Evolution and the relatedness of all species
• Human evolution and the structure of human populations
• Biodiversity and biogeography
• Regulation of development and differentiation

Genetics is the study of inherited biological variation. Variation is the rule in the living world, not the exception, and this fact is a fundamental concept that McInerney believes all people should understand—if for no other reason than to foster a greater respect for and understanding of variation in their own community. Genetics, he continued, also explains biologi-

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¹ This section is based on the presentation by Joseph McInerney, executive vice president of the American Society of Human Genetics, and the statements have not been endorsed or verified by the National Academies of Sciences, Engineering, and Medicine.

cal continuity, not just variation, and the relatedness between cells, between generations, within species across time and space, and across species.

Noting that educators have been thinking about how to teach genetics for more than a half century, McInerney reviewed some of the efforts to understand what should constitute genetic literacy and to develop instructional materials to increase genetic literacy in the nation’s students. For example, the Next Generation Science Standards, developed jointly by the states, the National Research Council, the National Science Teachers Association, and the American Association for the Advancement of Science (AAAS), asks students to engage in what McInerney characterized as sophisticated intellectual tasks. One example of such a task would be to make and defend a claim based on evidence that inheritable variations may result from new genetic combinations through meiosis, viable errors during replication, or mutations caused by environmental factors. The Next Generation Standards, he explained, aim to establish some baseline of scientific literacy—in this case, genetic literacy—and do not focus on teaching isolated pieces of information or memorization.

In 2002, McInerney and other members of the education committee of the American Society of Human Genetics, proposed a set of six concept areas for genetic literacy for non-science majors at the undergraduate level (Hott et al., 2002) (see Box 2-1). He remarked that today the committee would have to elaborate on the content of each of these areas differently, given the advances that have occurred in understanding gene expression and epigenetics, for example. In 2009, a colleague of his proposed a completely different approach to content that would start with quantitative and complex traits rather than the single gene traits and Mendelian inheritance that are the usual starting points in genetic curricula (Dougherty, 2009). In that author’s view, focusing on Mendelian traits primes many students to think deterministically and with a confused understanding of risk.

With regard to the second reason to understand genetics—to understand the future of health care—McInerney’s view is that the United States is moving to a prevention-based health care system that will be informed increasingly by genetic perspectives. This is where genetic literacy and precision medicine intersect. In his opinion, he said, genetics education for the public and health professionals should be aligned—health professionals and the public should be getting the same messages about the genetic contributions to health and disease—and done in partnership. Such a partnership, he added, would shift the standard approach in genetic counseling from nondirective counseling toward more directive counseling with a focus on complex disease. As an example, McInerney said an informal genetic test—a family history—would reveal that he is at significant risk for heart disease, and based on taking a family history, his health care provider should direct

him to get more exercise, eat right, and take other preemptive actions designed to reduce his risk of developing heart disease.

As an example of the type of genetic competencies health care professionals should have, McInerney listed the categories of knowledge recommended for physician assistants. They should understand basic human genetics terminology and be able to identify patients with or at risk of a genetic condition. They should have interpersonal and communication skills, including the ability to consider various factors that may influence a patient’s response to genetic information and to seek coordination and collaboration with an interdisciplinary team of health professionals. With regard to patient care, physician assistants should be able to generate family

history information, construct an appropriate multigenerational pedigree, and identify and appropriately determine which patients would benefit from a referral for additional genetic services.

McInerney then proposed some central questions to address when developing ways to educate health professional about genetics and precision medicine:

• What content is appropriate, and for whom?
• Which clinical behaviors and attitudes need to be changed, and is that possible?
• How is success defined and measured?

With regard to the first question, McInerney said he struggles to determine how much health professionals need to know to be effective. “Educational content can be accurate, but not necessarily complete in the way that a genetics professional would want to see it or understand it,” he said, “and while it is not necessary to turn health care professionals into geneticists, they do need enough information to work effectively in a genetics context in their own clinics.”

Concerning the last of these three questions, McInerney noted it is often asked too late in the development of most educational programs. “You should ask this question first, and the evaluator should be at the table with you so they know what your objectives are and they can help you design appropriate evaluations,” he said. He added that over many years of working as an educator, he has learned to ask what students need to know, what they should value, and what they should be able to do with knowledge they have gained.

McInerney then made a modest proposal to help integrate genetics into education and mainstream health care. “I think we should be careful about the use of the terms ‘genetic disorder’ and ‘genetic disease,’” he said. “We in the genetics community like to say we believe that genetics is the fundamental science of all health and all disease, but then we talk about genetic disease and genetic disorders. I think we send mixed messages as if there is a category of disease for which there are genetic contributions and a category for which they are not.” The definition of genetic counseling that he likes is one from the National Society of Genetic Counseling (Resta et al., 2006, p. 79), which states: “Genetic counseling is the process of helping people understand and adapt to the medical, psychological, and familial implications of genetic contributions to disease.”

There are a number of terms that some use interchangeably but that McInerney said have distinctly different meanings. For example, “precision medicine” refers to a medical model that proposes the customization of health care, with medical decisions, practices, and products being tailored

to the individual patient. “Predictive medicine” entails predicting the probability of disease and instituting preventive measures in order to either prevent the disease altogether or significantly decrease its impact upon the patient, such as by preventing premature mortality or limiting morbidity. “Individualized medicine” represents a way of thinking that incorporates the concepts of genetic variation and notions of the evolutionary nature of disease and adaptive and maladaptive phenotypes in the context of the environment, while “personalized medicine” refers to a way of practicing medicine that is rooted in tests, technologies, and procedures not limited to genetic medicine. McInerney said that physicians get testy at the mention of personalized medicine because they believe they personalize all of their interactions with patients. “We have to be careful about how we couch these concepts for providers and for the public,” he said, “for while it might be great to tell the public that the goal is to personalize their health care, clinicians think they are already doing this.” He added that he believes it is unimportant for either health care professionals or the public to understand the distinction between genetics and genomics.

McInerney also distinguished between science, which proposes explanations for observations of natural phenomena, and technology, which proposes solutions to problems of human adaption to the environment (Biological Sciences Curriculum Study and Social Science Education Consortium, 1992). The principles of technology, as spelled out by the AAAS (1989), include

• Technology extends our senses, and often relies heavily on inference for interpretation.
• All technologies have unintended consequences.
• All technologies are fallible, and the consequences can be circumscribed or expansive.
• All technologies serve the interests of particular individuals, groups, or agencies.

McInerney said he believes that it is important to include these principles when constructing any program focused on scientific literacy because most people will never encounter the underlying science—in this case genetics—but they will encounter the technological manifestations of that science. In the same way, most people do not encounter the underlying scientific constructs behind the health care regimes they experience, but they do encounter the technology and should understand what the technology is about in a broad sense, he said.

Neuroscientist Sam Harris wrote, “There is an epidemic of scientific ignorance in the United States. This is not surprising, as very few scientific truths are self-evident and many are deeply counterintuitive. It is by no

means obvious that empty space has structure or that we share a common ancestor with the house-fly and the banana” (Harris, 2010). McInerney’s concern is that the counterintuitive nature of scientific knowledge does leave the public susceptible to explanations that are more intuitive, but wrong. He cited creationism and invoking an intelligent designer as an explanation for the way life is organized on the planet as examples.

The most important aspect of science literacy for the public, McInerney said, is the idea that science is a way of understanding and explaining the natural world and how that is different from other types of explanations. Science, he said, relies on evidence and on setting criteria for what counts as good evidence. Science relies on intellectual honesty and strives to be authoritative but not authoritarian. “These are extremely important concepts for understanding what science is and making decisions about what information you will act on,” he said.