Genomics heralded as new tool for improving public health: emerging science.
The study of genomics has broad applications to public health, especially as the science grows from its traditional focus on rare diseases to include more common chronic diseases, such as heart disease, cancer, stroke and diabetes. According to the Centers for Disease Control and Prevention, genomics plays a part in nine of the 10 leading causes of U.S. deaths, and can likely help health care professionals understand why certain infections, behaviors and environmental factors will make some people sick but not others. Such information could lead to new and better ways to improve health and prevent disease.
"All branches of public health will be touched by genomics, if not today, in the next five to 10 years," said Muin J. Khoury, MD, MPH, director of CDC's National Office of Public Health Genomics.
CDC defines genetics as the study of inheritance, or the way traits are passed down from one generation to another. Genomics is a newer term that describes the study of all the genes in a person, as well as interactions of those genes with each other and with that person's environment.
Genomic advances are occurring rapidly. On March 30, for example, scientists from the National Human Genome Research Institute announced that they had identified six additional genetic variants that are involved in type 2 diabetes, raising to 16 the total number of genetic risk factors associated with increased risk of the disease. And new research published in Nature in April found that people who carry a certain gene may be particularly likely to get addicted to cigarettes and may consequently be at greater danger of lung cancer and other diseases.
Despite its promise to public health, genomics technology is so new that most U.S. health care professionals, including public health professionals and physicians, are largely unprepared to integrate it into clinical and public health practice.
Education, training and competency-based learning are needed to prepare the public health work force to embrace genomics, "not to become genomicists, but to be able to use the new tool to improve the health of the population," said Khoury, an APHA member.
The development of public health genomics training is a major initiative within the CDC genomics office, which has also funded public health genomics training and capacity-building programs in several states.
"At the end of the day, public health professionals are very pragmatic and down to earth," Khoury said. "They want to improve the population's health and they want to use whatever tools are at their disposal. Our job is to close the gap between those new scientific genomics discoveries and our ability to actually use them to improve population health."
Translating genomic discoveries into real-life applications for preventing disease has been slow, in part because of a lack of funding.
"When the Human Genome Project was completed, we were all revved up," said Deborah Klein Walker, EdD, a past president of APHA. "We thought there was going to be a lot you could implement fast, but it's been a lot slower. There has not been enough research money for the translation of the findings of what we know about genomics into clinical and public health practice."
Translational research must be done in the public sector, Walker said. However, much of the work in genomics right now is taking place in the private sector, which might have different incentives than the public sector, and "might not be looking out for the full benefit of everyone in the population," she said.
Within the public health genomics community, concerns are rising that products produced by the private sector could mislead the general public. For example, with a click of the mouse and a credit card, Americans can go online and purchase direct-to-consumer genetic tests that promise to do everything from predicting buyers' risk for colon cancer to figuring out what kinds of foods they should or should not be eating. Most of the tests sell for between $300 and $1,000, but for close to $500,000, consumers with very deep pockets can buy tests that promise to give them the entire "alphabet soup" of their genes, Khoury said.
Adding to the concern, the products are largely unregulated by the federal government. A 2006 U.S. Government Accountability Office report found several of the tests made misleading or unsubstantiated predictions.
"They are a premature integration of this technology, and there is no clinical validity of this information," Khoury said. "If you have $1,000 to spend, you'd be better off buying a subscription to the gym and knowing your family history."
As more becomes known about gene-environment interactions and relationships, public health professionals will likely look to genomics for insights into health disparities and health differences. But an effort must be made to ensure genetic information "decreases rather than increases" health disparities, said Jody Platt Garcia, MPH, assistant director of the Life Sciences and Society Program at the University of Michigan.
To address health disparities, the public health community will need to form partnerships with genomics communities, said Garcia, who chairs APHA's new Genomics Forum. Created in November, the Genomics Forum aims to address the critical need for a competent public health work force trained in genomics and a society informed on the issues of genomics and public health.
"If genomics findings and applications are not influenced by the public health community, genomics can be misapplied and lead to the widening of health disparities," Garcia said. "It is our goal to prevent this from happening."
The National Institutes of Health recently launched a new center devoted to the study of genomics and health disparities. The NIH Intramural Center for Genomics and Health Disparities "will employ a genomics approach to collect and analyze genetic, clinical, lifestyle and socioeconomic data to study a range of clinical conditions that have puzzled and troubled public health experts for decades," center officials announced in March.
But genetics has long been surrounded by ethical, legal and social implications. Today, as genetics makes room for the much broader field of genomics, issues of stigmatization and discrimination will grow increasingly more concerning, and with good reason: Genetics research has not always been kind to all populations.
"In the 1970s, there were sickle cell screening policies that led to marriage laws," Garcia said, noting that such laws were "very much unintended consequences" of genetic practice in public health.
"Certainly, as genetics and genomics become increasingly important, we want to avoid that kind of application," Garcia said.
Several states have enacted laws prohibiting health insurers and employers from using genetic information to deny employment or insurance coverage, and federal legislation that would prohibit such discrimination has been proposed.
Maren Scheuner, MD, MPH, lead author of a study examining barriers to applying genomics information, said discrimination is not happening on a widespread basis. The study reviewed 68 relevant studies published between 2000 and 2008 and concluded that there were no well-documented cases of employers or health insurance companies asking for or using genetic test results to define eligibility for coverage. However, there were several instances in which people were denied the opportunity to purchase long-term care insurance and life insurance because of genetic information, Scheuner told The Nation's Health.
In her clinical practice, Scheuner sees first hand the public's concern about the adverse consequences of genetic testing--the loss of privacy in particular.
"Back in the early '90s, when some of the hereditary tests for cancer susceptibility became available, most of the patients I saw would pay cash and use a pseudonym," Scheuner said. "They were very concerned about confidentiality and privacy to the extent that I didn't even know their real names. Today, I never see that level of concern among our patients. I think there has been a level of improvement along these lines, and I hope it continues."
For more information about genomics and public health, visit www.cdc.gov/ genomics or www.genome. gov.
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|Author:||Johnson, Teddi Dineley|
|Publication:||The Nation's Health|
|Date:||May 1, 2008|
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