Genetic tests on shelves - Usefulness of consumer screenings questioned
By Keith Darcé, UNION-TRIBUNE STAFF WRITER
Tuesday, May 11, 2010 at 12:02 a.m.
Consumer interest in genetic testing could receive a major boost this week when kits from Pathway Genomics of San Diego hit the shelves of Walgreens drugstores nationwide, even as some scientists question the usefulness of the screenings.
Pathway and the three other big companies that make genetic-testing products, sold mainly on the Internet or through doctors’ offices, have attracted relatively few customers since debuting the items less than three years ago.
Estimates put total sales at 50,000 to 100,000 tests.
Prices have been part of the problem. The cost ranges from about $400 to $2,000 for a comprehensive genetic-marker test that seeks to identify risks for adverse drug reactions, passing on mutations to children or developing certain diseases and health conditions.
Pathway’s kit will sell for about $20 in Walgreens stores. The buyer spits into a specialized container and then ships the saliva to the company for an analysis that costs $79 to $249, depending on the tests requested.
On Pathway’s website, the company offers a single testing package for $399.
“We are really doing this to increase consumer awareness, not just for us but for the entire genetic-testing industry,” said Jim Woodman, vice president of corporate strategy for Pathway.
The move represents a big step for the privately owned company, which launched its service in September. About 50 people work at Pathway’s laboratory and headquarters in the Sorrento Valley area of San Diego.
Interest in genomics has soared as the pace of research in the field has accelerated. Scientists are regularly uncovering new mutations in human DNA sequences that are tied to cancers, chronic health conditions, Alzheimer’s disease and illnesses that run in families.
More than 60 prescription drugs, including the anti-blood-clotting medications Plavix and Warfarin, have been associated with genetic markers indicating that a patient might have trouble taking them.
Not everyone welcomes the services of Pathway and its counterparts.
Officials for the American Medical Association said genetic tests shouldn’t be done without direct supervision of a doctor who can help interpret the results and recommend care based on the findings.
Consumers can easily misunderstand the test results if left on their own, said Dr. Eric Topol, a cardiologist and geneticist who serves as chief academic officer for San Diego-based Scripps Health.
Several states have banned direct sales of genetic tests to consumers.
In California, companies that offer such services must obtain a laboratory license from the Department of Public Health. The state has issued licenses to all of the major genetic-testing businesses — Pathway, 23andMe of Mountain View, Navigenics of Forest City and DECODE Genetics of Reykjavik, Iceland.
For the past year, Palomar Pomerado Health has sold 23andMe test kits at its “expresscare” retail clinics inside Albertsons grocery stores in Escondido and Rancho Peñasquitos.
The Federal Trade Commission, which oversees labeling for the tests, is the only federal agency that regulates the industry.
One concern about the retail genetic testing involves what isn’t covered.
Some scientists believe accurate measurements of each person’s disease risk aren’t possible without looking at all 3 billion DNA base pairs that make up that individual’s genome. That process costs more than $10,000 and requires the work of supercomputers.
Instead, the companies offering consumer genetic testing isolate only several hundred thousand genetic variations for review.
The results can be misleading, Topol said.
For example, a test could indicate that a person has a 30 percent risk of developing a particular type of cancer while the average risk is half that amount. The difference might seem alarming, but it may not matter if the likelihood of getting the cancer is more strongly driven by rare genetic variances occurring in particular family lines, Topol said.
In another case, a person might take false comfort in test results showing genetic markers for lower-than-average risk of a heart attack. The patient might push aside the more important fact that numerous relatives going back several generations have suffered congestive heart failure.
“Our ability to look at an individual’s DNA sequence and tell them their risk for these types of health conditions is low,” said Kelly Frazer, chief of genome information sciences for the department of pediatrics at the University of California San Diego’s School of Medicine.
The main businesses offering retail genetic testing said they’ve been careful to market their products as educational information rather than medical advice or a diagnosis.
“We make it very clear that this doesn’t mean (customers) are going to get a condition, but it’s something they should be aware of, and here are things they can do to mitigate that risk,” Woodman said.
But even among these companies, there often is wide variation in how genetic results are explained.
Francis Collins, director of the National Institutes of Health, reported in an October article in The New England Journal of Medicine that he sent his personal DNA sample to the three leading genetic-testing companies.
“They were not consistent in how they interpreted the results,” said Collins, a geneticist who helped guide the Human Genome Project. “I think all the companies probably overrepresented the degree to which we already can predict people’s future risk of illness and underrepresented how much of heritability has yet to be discovered.”
Keith Darcé: (619) 293-1020; firstname.lastname@example.org