Genetic Epidemiology: What a Difference 20 Years Can Make!

September 12th, 2013 3:29 pm ET - Muin J Khoury, Director, Office of Public Health Genomics, Centers for Disease Control and Prevention

In my introduction to the textbook ”Genetic Epidemiology: Methods and Applications ” just published by Dr. Melissa Austin and colleagues, I commented on the remarkable evolution of the field in the 20 years since I wrote “Fundamentals of Genetic Epidemiology ” with Drs. Bernice Cohen and Terri Beaty from Johns Hopkins University School of Public Health.
Of course, the field is much older than that. In the 1970’s, Dr. Newton Morton

, a pioneer in human and population genetics coined the term genetic epidemiology to describe the study of genetic factors in families and populations. Fresh out of medical school in 1979, I was excited by the prospects of learning how to use genetic and epidemiologic methods to understand why some people get sick and others do not, even when exposed to the same environmental insults such as smoking and infectious agents. I also wanted to apply this knowledge to improve health and prevent disease. As a result, I joined the Department of Epidemiology at the Johns Hopkins School of Public Health and worked with Dr. Bernice Cohen

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to earn a doctoral degree in genetic epidemiology.

Bernice H. Cohen: a pioneer in genetic epidemiology

Bernice Cohen, who passed away in 2011, was a wonderful mentor, colleague, and friend. Her career spanned more than 50 years, and she was a pioneer in the field of genetic epidemiology. She helped integrate the fields of epidemiology and genetics and established the first formal academic training program in genetic epidemiology at Johns Hopkins University in 1979. She was truly a driving force in establishing genetic epidemiology and helped define its importance in public health and disease prevention.
Since 1993, genetic epidemiology has evolved from a relatively obscure specialty to a mainstream scientific discipline with impact on medicine and public health. Before the genome era, it was a niche for population and statistical geneticists, along with a few epidemiologists interested in the genetic basis of human disease. Today, genetic epidemiology is a thriving field that has its own International Society for Genetic Epidemiology

. The society was established in 1991, with Dr. James Neel

, a pioneer of human genetics, as founding president. Genetic epidemiology is also increasingly integrated into clinical and public health research. What has changed? In the decade since the Human Genome Project

was completed, new technologies and research initiatives have paved the way for increasingly sophisticated approaches for studying genetic factors in human health and disease. Genome-wide association studies (GWAS)

and next-generation sequencing

are among many new “omic” tools that put the “capital E

” into 21^st century genetic epidemiology. I like to refer to this emerging field as “human genome epidemiology”, or HuGE for short (pun intended!). The remarkable growth of the field can be tracked in the HuGE Navigator

, a continuously updated online knowledge base of epidemiologic articles on genetic associations. The database shows quadrupling of yearly publications and now includes thousands of genes, diseases, and environmental exposures.
Modern genetic epidemiology now includes a vast array of methods, technologies, tools, software and data resources that can be used in both population and family studies. Genetic epidemiologists continue to tackle the ever more complicated landscape of gene-environment interaction and to explore emerging genomic fields, such as epigenetics

, that could prove crucial in understanding health and disease throughout the lifespan. Furthermore, the field has established a translational framework for how to use emerging information to improve health outcomes both at the individual and population levels.
We truly live in exciting times and I would not even want to guess where the field will be in another 20 years! Nevertheless, while the knowledge accrued from genomics and related fields continues to evolve, the fundamental epidemiological principles for describing, evaluating, implementing and monitoring the impact of this knowledge will be with us for decades to come.