Interaction of genes, environment focus of national addiction study

A School of Medicine psychiatric geneticist is one of several principal investigators around the country who will participate in the Genes, Environment and Health Initiative (GEI), a unique collaboration between geneticists and environmental scientists. The $48 million initiative is sponsored by the National Institutes of Health (NIH).

Laura Bierut

Laura Jean Bierut, M.D., professor of psychiatry, will head the national study of addiction, looking both at genetic and environmental factors that contribute to the problem. The co-principal investigator is John Rice, Ph.D., professor of mathematics in psychiatry and of biostatistics.

Bierut received $561,000 in funding for the first year of her research, “Study of Addiction: Genetics and Environment.”

“Addiction is a classic condition requiring the interaction of genetic, environmental and behavioral factors,” Bierut said. “A person with a genetic tendency to become addicted to alcohol, nicotine or other drugs will never develop that addiction if that individual never drinks, smokes or uses. We want to get a better handle on how genes and environment interact to cause disease.”

Bierut and the other investigators involved in GEI projects will conduct whole genome association studies of problems from addiction and diabetes to heart disease and tooth decay. Whole genome association studies can identify specific points of variation in human DNA that underlie particular conditions. Identifying genetic factors that influence health, disease and response to treatment is believed to be central to discovering and developing next-generation medicines that target diseases with increased precision and reduced risk.

Virtually all diseases have a hereditary component, transmitted from parent to child through the 3 billion pairs of DNA letters that make up the human genome. When researchers completed the final analysis of the Human Genome Project in April 2003, they confirmed that the 3 billion base pairs of genetic letters in humans were 99.9 percent identical in every person.

But housed within that remaining 0.1 percent is the mystery of why some people are more or less susceptible to particular conditions than their neighbors or even other members of their own families.

That miniscule variation explains why some people inherit relatively rare disorders, such as cystic fibrosis and muscular dystrophy, or inherit an increased risk for more common problems such as cancer, heart disease, diabetes and addiction.

“This is groundbreaking research in understanding the complex factors that contribute to health and disease,” said U.S. Department of Health and Human Services Secretary Mike Leavitt. “Researchers have long known that our genes, our environmental exposures and our own behavioral choices all have an influence on our health. This new initiative will use innovative genomic tools as well as new instruments for measuring environmental factors — from diet and physical activity to stress and substance addiction — in order to begin sorting out how these different factors affect a person’s risk for a number of health conditions.”

To identify genetic risks, researchers will rely on the newfound ability to swiftly identify genetic differences throughout the genome between people with an illness and those who are healthy, leading to a better understanding of the underlying genetic contribution to the disease. The environmental component of the projects will begin by developing new technologies that accurately measure personal exposures with small, wearable sensors that can be used to assess environmental agents.

The final component of the research strategy is to determine whether the effect of genetic variants that increase disease risk is different in the presence of environmental exposures. In the first year of the initiative, the NIH will fund eight genome-wide association studies, two genotyping centers, a coordinating center and more than 30 environmental technology projects.

“Genome-wide association studies have proven themselves to be powerful tools for discovering the genetic contributions to common diseases,” said Elias A. Zerhouni, M.D., director of the NIH. “Early findings from such studies have identified new genetic variants contributing to a higher risk of common diseases such as prostate cancer, diabetes and heart disease, but researchers have only scratched the surface.”

The genome-wide association studies will be led by the National Human Genome Research Institute, part of the NIH. First-year funding for the studies was contributed by all NIH institutes and centers, including an extra investment of approximately $3.4 million by NIH’s National Institute of Dental and Craniofacial Research.