Companies that sell DNA testing to pinpoint individual risks for common diseases provide little real information, says one of four commentaries featured in the New England Journal of Medicine

MondayMorning, April 20, 2009

Companies that sell DNA testing to pinpoint individual risks for common diseases provide little real information, says one of four commentaries featured in the New England Journal of Medicine. David Goldstein, a Duke University researcher, wrote that most common disorders, including cancer and diabetes, involve hundreds of genes, and many mutations may have the capacity to raise a person's risk. That suggests the testing offered by companies now, which focuses on the few variants that have already been identified, isn't likely to spot people at highest risk, he said. "In pointing at everything, genetics would point at nothing," Goldstein wrote in the journal. DeCode Genetics Inc., based in Reykjavik, Navigenics Inc. (Foster City CA), and 23andme Inc. (Mountain View CA) are among companies that test the DNA of individuals to pinpoint variants that may identify disease risk. The journal commentaries are the first public forum featuring leading genetic researchers discussing the usefulness of so-called genome-wide association studies, research that scans the DNA of thousands of people to identify mutations that may be common to certain ailments.

The headline on the lead commentary asks, "Are we there yet?" The answer suggested by the authors is not quite. Goldstein refers to commercially available genetic tests as "recreational." Linda Avey, co-founder of 23andme said: "We agree for the most part that we're still really early in the process of learning the genetic programming for risk factors. We are always reaching out to the research community to communicate with them and this type of commentary is very frustrating for us." Researchers hoped the studies, made possible by completion of the Human Genome Project in 2003, would open new windows on why ailments such as cancer and diabetes occur, and allow doctors to offer highly personalized treatment regimes that would focus on the underlying cause.