Genetic testing: Hope or hype?

“One hundred years ago no one imagined the impact that electrical energy would have on every aspect of daily life. Similarly, it is impossible to predict how the science of genetics will alter opportunities to advance individual, family, and community health.”1 Crystal-balling is a very precarious enterprise because, as Yogi Berra said, “It’s tough to make predictions, especially about the future. . . The future ain’t what it used to be.”2 Nevertheless, I believe that it is incumbent upon us as an organization and as a profession to look ahead, if not a hundred years, at least into the next ten or twenty, to get a sense of where genetics and, particularly, medical genetics are likely to be. There appears to be pervasive belief in both scientific and public circles that genetic testing is going to be the cornerstone of much, if not all, of what medicine holds for the future. And, what is generally meant is the wide scale testing for susceptibility to common diseases and for responsiveness to drugs—what has come to be described as genetic profiling. However, there are many who think that there is more hype than hope in what is being predicted, and I think that is important for us as geneticists to decide which it is. We need to do this to be able to define where we fit into the medical and health care system— what might be called our scope of practice—so that we can establish meaningful interactions with other medical specialists and professionals and with the public. And, we need to do this so that we can design our training programs to meet future needs. Therefore, I want to share with you my own personal and unofficial attempt to come to grips with the role that genetic testing will play in the future and with how we as medical geneticists should relate to it. However, before tackling these issues, I need to acknowledge that genetic testing and screening of many types are currently being done and will continue to be done in the future. Some are performed on an individual basis. These include preand postnatal diagnostic testing for monogenic and chromosomal disorders by cytogenetic, biochemical, and DNA mutation analysis, presymptomatic diagnosis of Huntington disease and other high penetrance late-onset neurodegenerative disorders, and diagnostic and presymptomatic testing for high penetrance familial cancer mutations. Others are performed on a population basis: maternal serum screening, newborn screening, and heterozygote detection for a variety of conditions. I present this list to make four points. First, the indications and targets for the current forms of testing will expand as technologies change (as, for example, in newborn screening with tandem mass spectrometry)3 and as new disease-causing mutations are discovered. Second, medical geneticists and genetic counselors are not the only parties involved with genetic testing, and there are many interactions between them and primary care providers, other medical specialists, and public health programs. Third, virtually all of the current forms of genetic testing have raised a large number of social, legal, and ethical issues. And, fourth, as the program of this meeting reveals, the American College of Medical Genetics is very much concerned with genetic testing in the present. Having acknowledged the present, I now turn to the perception that genetic testing and profiling are the wave of the future. Consider this quotation from Time magazine: “Even more genetic gee-wizardry lies just down the road. Using biochips. . . scientists should be able to identify genetic errors almost as quickly as a supermarket scanner prices a load of groceries. . . Genetic researchers are already talking about using ‘FISH. . . and chips’. . . to look for any number of genetic characteristics, including the more elusive web of genes that may lurk behind familial patterns of heart disease and stroke, cancer, diabetes, Alzheimer’s, various kinds of mental disorders and even gingivitis. . . ‘We’ll soon be governed by a new paradigm— genomic medicine—with tests and ultimately treatment for every disease linked to the human genome’. . . With the prestidigitation of gene amplification, only a single drop of blood or snippet of hair or a scraping of skin can reveal the full length of the human genome, including its myriad flaws.”4 The writing is a little florid, but the message is one that the scientific community has itself been promulgating. Here are but a few examples: “. . .[W]ithin the next 2 decades it will be technically feasible to sequence the genome of every new baby—providing them with a rundown of each and every one of their genes and their associated risk of developing certain diseases. This will enable them to seek preventable measures and adopt healthier lifestyles. . . There are benefits to having the ability to examine our genetic make up. Genetic technology could lead to an era of personalized medicine and better-tailored preventive treatment.”5 “The great potential of the genomic era is the development of interventions to prevent or better manage costly, chronic diseases. . . Medical interventions could include drugs and preventive measures that are tailored to a person’s genetic profile. . . Health professionals will increasingly use tests and family histories to assess risk for disease in individual patients, families, and populations. Once clinicians and public health professionals identify increased risk, they can recommend preventive measures. . .”1 “The poThe ACMG presidential address was presented March 4, 2004 at the 2004 Annual Clinical Meeting of the American College of Medical Genetics, Kissimmee (Orlando), Florida.