The emerging field of genomics is poised to play an increasingly large role in the field of public health and should be integrated into the core curricula of public health schools, according to a genetics expert from the Centers for Disease Control and Prevention (CDC).
Muin Khoury
In 2006, HSPH offered the course ID509 Functional Genomics, Proteomics and Bioinformatics, taught by Marianne Wessling-Resnick, Dieter Wolf, and Simin Liu.
'Human genome epidemiology' refers to the assessment of the role of genetic variation and gene-environment interaction in population health and how this information can be used for disease prevention and health promotion, Khoury said during his talk, part of the Gene x Environment Interaction Seminar Series.
"Genomics is relevant to public health in so many ways because it will affect the way we think about the prevention of disease in populations, using the genetic information from individuals, whether they have single gene disorders or genetic risk factors,'' he said.
"Today, we are entering a new era where this genetic information is going to be explored across the board, whether you do environmental health, maternal-child health, or nutrition,'' he said. "We are at the cusp of major discoveries. But there are still major scientific gaps that exist in our ability to translate gene discoveries into population health benefits.''
Until science shows just how genetic information can be used to prevent disease, there is information already available for use - patients' family histories, he said. "Right now, family history is one of those low-hanging fruits in genetics,'' Khoury said.
"It captures much more than shared genes,'' he said. "It captures shared behaviors, culture, nutrition, and common exposures. While we are supposed to know and use family history in clinical practice, it is not being used. It is something we can do right now. In the future we are going to be able to meld and use genetic information and testing alongside family history. But today we are limited in our ability to do this.''
While there are more than 1,000 genetic tests now on the market, most of these test for rare single-gene disorders. The future of genetic testing will focus on using genetic information as risk factors or biological markers for diseases, particularly the more common diseases such as heart disease, cancer, and diabetes, he said. But the genetic information will have to be examined in the context of gene-environment interaction, he noted.
For example, about five percent of the population carries the gene for hemochromatosis, or iron overload, he noted. Yet less than one percent of those who carry the gene actually develop the disease. So the task will be to find out why some who carry disease genes are getting sick and others are not.
Whether to test for certain genes will depend on whether interventions can be developed for the diseases in question and on the cost-benefit ratio of doing such tests on a widespread scale, he said. Certainly, costs today are prohibitive, especially for testing around the world.
"In order to be used and used equitably, the prices will have to go down over time,'' he said. "I suspect that will be the case. We've seen this in research settings. We used to test for five or 10 genetic variants at a time. Now, for almost the same price, we can measure up to 100,000 variants.''
But there is no question that in time genetics will play a key role in public health, he said. That is why public health schools should be teaching genetics as part of their core curricula, he added, noting that the Institute of Medicine urged this in a 2004 report.
"Public health professionals must pay attention to genomics because it is one of those new crosscutting areas that will affect all public health programs,'' he said. "It would be nice to get public health schools to become leaders in this area and use genomics as part of their armament of tools. But we have heard that there are already so many demands on public health training. Maybe we need to become more savvy in trying to integrate genomics and other areas together in a way that could be seamless.''
—ML
Copyright, 2007, President and Fellows of Harvard College
