e-mail Print Share

Scientists agree to disagree on genetic testing

October 14, 2014

By James Berry

An atmosphere of professionalism and cordiality prevailed Oct. 11 in Room 214B at San Antonio's Henry B. Gonzalez Convention Center — but there was a hint of restrained disagreement in the air as well.

Scientists from academia, research and industry had come together to explore current science and clinical applications for genetic testing in oral medicine. It's a controversial field of scientific exploration, the controversy resting heavily on questions about the clinical application of genetic tests already on the market.
Welcoming a panel of five experts and an audience of about 200, Dr. Daniel M. Meyer, senior vice president, ADA Division of Science, noted that the morning's forum was part of a tradition begun several years earlier at the ADA's annual meeting.

Its purpose, he said, was to bring scientists and clinicians together to "talk about issues where the answers aren't necessarily clear."

Dr. Meyer co-moderated the discussion with Dr. Michael Glick, editor of The Journal of the American Dental Association and dean of the State University of New York at Buffalo School of Dental Medicine. Sponsoring this event, titled Introducing Scientific Advances Into Your Clinical Practice, were the ADA Council on Scientific Affairs, JADA and the Task Force on Design and Analysis in Oral Health Research, a nonprofit think tank on clinical research in oral health.

Urging a "congenial and friendly" approach to the morning's deliberations, Dr. Glick reminded everyone that "science is a journey" — that they would hear a range of fact and opinion, some of it contradictory. "It's up to you to figure out how to use this information," he said.

Thomas Hart, Ph.D., director of Craniofacial Population Sciences Research and a professor in the Department of Periodontics, University of Illinois at Chicago and vice chair of the Council on Scientific Affairs, kicked off the series of brief presentations with an overview of the various types of genetic diseases.

He noted that humans were subject to about 5,000 inherited traits and disorders, of which about 30 to 40 percent were "important to the dental community."

Of greatest importance, he said, is the single nucleotide polymorphism, or SNP, a small percentage of which contribute to disease and can be associated with more than one disease. Later, he touched on the regulation — or lack of regulation — of genetic testing.

Dr. Peter Polverini, professor of oral and maxillofacial pathology in the Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, talked about the role of genomic technology and "personalized" cancer treatments.

The goal, he said, is "evidence-based personalized medicine, primarily getting the right care to the right cancer patient at the right time," delivering a "unique, customized therapy" for the individual patient.

Photo of crowd
Forum: A near capacity crowd listens Oct. 11 during a forum exploring current science and clinical applications for genetic testing in oral medicine.
Up next was Ken Kornman, D.D.S., Ph.D., founder of Interleukin Genetics, Inc., which markets a genetic test for periodontal disease, IL-1. Citing a number of studies, Dr. Kornman said patients who test positive for the IL-1 genotype are more susceptible to periodontitis — even beyond personal risk factors such as smoking and diabetes.

Such patients, he said, "have functional gene variation; they are functional at the molecular level; they have changed the regulation of the IL-1 gene."

He cited a study of 1,700 people in which he said "the IL-1 genotype had a significant association with severe periodontitis in Caucasians, African-Americans, Hispanics and Chinese." He said, too, that this study found periodontitis in 30 percent of cases that had not been identified by virtue of risk factors, smoking and diabetes.

Strongly countering Dr. Kornman's remarks was Scott Diehl, Ph.D., professor in oral biology and health informatics at Rutgers University, who noted that he had been studying periodontitis and working in the field of genetics for some 30 years.

"It is my pleasure to be here," he told the audience, "but not my pleasure to report to you that I am forced to disagree with [Dr. Kornman's] conclusions. I do not believe there is any scientific support for the IL-1 genetic test."

Valid genetic testing for periodontitis may emerge in the future, said Dr. Diehl, "but I don't think we have it yet."

He also questioned the value of focusing solely on the IL-1 gene. "We have the whole genome to cover, and that we've been covering," he said, adding that thousands of other genes are "biologically relevant" and have "stronger statistical association with disease."

Concluding the panel presentations, Dr. John Gunsolley, director, Clinical Research Unit, Virginia Commonwealth University School of Dentistry, talked about evaluating the clinical utility and plausibility of genetic testing. He also talked about common risk factors and the importance of plaque control.

There was general agreement among the panelists that genetic testing is a complex topic, especially as it applies to clinical dentistry and medicine. Panel members stressed the need for more education on genetics in dental schools.

Audience members asked a range of thoughtful questions, touching on such issues as the importance of home care, the future of salivary diagnostics and testing for the human papilloma virus.

In the end, differing points of view were fairly aired and professionally received. And the journey of science that Dr. Glick described continued on for another day.