The Future Of Medical Genetics
By Marnelle J. Kinney

The future of medical genetics looks promising for patients anxious to predict and prevent medical predispositions for themselves and their future generations. With the advent of the Human Genome Project, physicians and genetic counselors can now offer a number of predisposition tests to patients who are interested in learning about their genetic makeup and the likelihood of developing an illness based on their family history. For a few medical conditions, gene therapy is becoming an effective treatment that replaces flawed genes. With the onset of such advanced capabilities, Penn State’s College of Medicine approaches one of the most exciting arenas of health care on very careful footing.

Since the early 1980s, the field of clinical genetics has rapidly progressed from simply anticipating the likelihood of a medical condition based on one’s family history to determining the actual existence of a genetic flaw. Today, patients are seeking answers about their genetic history to help determine their future health. Maria Mascari, Ph.D., a genetic counselor and medical geneticist at Hershey Medical Center, helps to predict the likelihood of a hereditary predisposition to cancer by guiding patients through a process called genetic counseling.

"Counseling is laborious and time intensive," Mascari explains. "We collect information from several generations of a family, document this information by obtaining medical records and identify patients’ concerns regarding this history," she says. By drawing a family pedigree and taking note of which relatives have been diagnosed with a particular cancer at what age, Mascari helps patients face the possible realities hidden in their genetic makeup. This journey involves providing an individualized risk assessment for cancer, as well as the option of genetic testing if appropriate.

Genetic counselors once functioned primarily in the field of prenatal and pediatric genetics. According to Mascari, "as more genes have been discovered, genetic counselors are increasingly becoming involved in ‘predispostion counseling’ regarding risks for cancer and cardiovascular disease, as well as other adult-onset disorders."

Michael Green, M.D., assistant professor of humanities and internal medicine, and Mascari are currently researching ways to educate patients using technology such as computers to enhance patients’ understanding of the potential information provided by genetic testing. Mascari explains that physicians need to be aware of how genetic information will affect the provision of medical care for their patients. She says that it is not sufficient to offer genetic testing for the sole purpose of identifying a genetic predisposition. Physicians must be prepared to offer management strategies such as diet modification, exercise and chemoprevention to help address a medical risk once identified.

According to Green, "In the next 10 to 15 years, we will have the ability to know a tremendous amount about people that we never could have known before." Green explained that the completion of the Human Genome Project, an initiative to identify every gene in the human DNA, will be pivotal in the future of genetic diagnosis and treatment. Upon completion of the genome project, "we will have the capacity to potentially know the entire genetic makeup of a person, including flaws and imperfections," Green says. To those seeking medical predictions, this seems monumental. But as Green cautions, access to such information needs to be tightly controlled, because the information can be troubling for not only the patient, but families who may not want to be confronted with their genetic flaws.

Green explains that as genetic testing becomes more widely available, "It is going to be extremely important to develop policies which define how the information will be used and who will or will not have access to it." Protecting privacy and confidentiality, Green adds, are extremely important ethical issues. Before genetic testing is widespread, "legislatively, limits on the access to the information will need to be defined," he says. Without such regulations, employers, insurance companies or even marketers could use genetic information to stigmatize or otherwise put patients at a disadvantage.

Michael Chorney, Ph.D., associate professor of microbiology and immunology, predicts that because of the extensive cost and potential health risk required for implementing and researching genetic therapies, genetics is an element of health care that will receive careful consideration. It is, however, one of many options to be weighed by the health system administration. "We’re at a crossroads," Chorney says. "Genetics is so broad and vast," he adds. The next decade will most likely be one of extensive research in the field, leading to gradual implementation but potentially great clinical reward.

Green explains that the future of genetics may rapidly transform the way medicine is practiced. A new field known as pharmacogenetics seeks to tailor drug therapy based on one’s genetic makeup. While revolutionizing healthcare options, the implications of genetic advances must be evaluated extensively before rushing to integrate genetic tests into standard practice.

****

This story appeared in the Winter 2000 edition of Penn State Medicine.