A Database of DNA
Scientists at Carolina and the National Institute of Environmental Health Sciences (NIEHS) will recruit about 20,000 patients at various Carolina medical facilities for a voluntary DNA registry. The "environmental polymorphism registry" (EPR) will help researchers investigate the relationships among environmental exposures, genetic susceptibility, and human disease. Genetic susceptibility and environmental exposures play roles in various diseases including Parkinson's disease, lung cancer, and even atopy — the genetic tendency to develop allergic diseases such as allergic rhinitis (hay fever), atopic dermatitis, and asthma.
The database will code all identifiers to maintain patient confidentiality, as have previous similar registries. But the EPR maintains the link between the code and the patient identifiers, making it possible for scientists to contact the participants later for permission to include their DNA in other studies. Such studies, including the process of identifying participants, will require approval of an oversight committee and Institutional Review Boards that protect the rights of research subjects. Participation in studies will be strictly voluntary, and anyone can drop out of the registry at any time.
The scientists conducted a pilot study involving an estimated 600 people at UNC-Chapel Hill's Ambulatory Care Clinic to determine the feasibility of putting the registry together. About 80 percent consented to allow a portion of a blood sample drawn for other medical purposes to be used for DNA isolation and for addition to the registry depository for twenty-five years.
Perry Blackshear, NIEHS director of clinical research, and Patricia Chulada, health science administrator at NIEHS, initiated the registry by approaching Carolina researchers Paul Watkins, professor of medicine and director of the Caviness General Clinical Research Center (GCRC), and Susan Pusek, GCRC director of training and career development. UNC-Chapel Hill's major role in the database is to provide access to its huge patient population. Once patients have been recruited, NIEHS will take direct charge of the follow-up studies on genetic variations of patients' DNA. But Watkins and Pusek will remain key players as members of the steering committee.
The data from the follow-up studies will help scientists identify groups of people with genetic polymorphisms — variations in DNA — in "environmentally sensitive" genes. These genes regulate the body's interactions with environmental factors, encoding proteins that control a wide variety of cellular functions. For instance, due to genetic variations, not all cigarette smokers will develop lung cancer. Another example — the Japanese are known to have a low incidence of cancer, but some Japanese, on switching to an American diet, have developed cancer. So, the environment affects different people in different ways, one of the major factors being the genetic makeup of individuals.
"The data collected from these studies may be used to define environmental
risk factors and develop preventive strategies to reduce the incidence
of disease," Blackshear says. Watkins says, "Creation of this registry
will keep UNC-Chapel Hill at the cutting edge of environmental health
research in the decades ahead."
