Would You Use a Home DNA Kit?

Direct-to-consumer advertising (DTC) has elevated some everyday conditions to diseases needing prescriptions but other prescription products have gone over-the-counter.

Claritin, one of the first drugs sold DTC along and its allergy drug cousins, Zyrtic and Benadryl, is now sold over-the-counter -- though Sudafed is now behind the counter thanks to its use in meth labs. And so are pregnancy tests and home tests for blood sugar, cholesterol and urinary tract infections.

And then there's Insight, the at-home DNA tests almost sold at Walgreen's last month.

San Diego-based Pathway Genomics Corporation planned to place the Insight Saliva Collection Kits in 6,000 Walgreen stores until the FDA said, "you're selling WHAT?" and it put its plans on hold. The $20 to $30 genetic testing kits -- essentially containers for saliva which customers mail in for analysis in Pathway's labs -- would predict someone's risk of diseases, chance of transmitting health problems to offspring and reaction to prescription drugs. The company which was incorporated in 2008 also markets ancestral DNA tests.

Insight was supposed to reveal risk for heart attack, venous thromboembolism, high blood pressure, leukemia, colon, lung, prostate and breast cancer and celiac, Crohn's, Huntington's, Parkinson's and Alzheimer's disease. It also could pinpoint risk for diabetes, obesity, polycystic kidney disease, multiple sclerosis, macular degeneration, psoriasis and more said the manufacturers, though their claims have since been disputed.

Of course DNA self-tests were already available online from companies like 23andMe and Navigenics. And DNA paternity tests have been sold at major drug stores by Sorenson Genomics and Identigene for over two years. But selling Insight over-the-counter would widen the window of DNA products sold with no pretence of a need for clinical geneticists, genetic counselors or other health professionals to interpret results for consumers.

Nor did the scientific establishment supported at-home DNA tests. The National Cancer Institute, Federal Trade Commission and NIH director, Francis Collins, MD, all question their predictive value. Dr. Collins, who presided over the Human Genome Project from 1993 until its completion in 2003, says he sent his own DNA to three major testing companies with a disappointing outcome, the San Diego Union-Tribune reports.

"They were not consistent in how they interpreted the results," says Dr. Collins. "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."

Others like Robert Superko, MD, a metabolic and genetic specialist at Atlanta-based St. Joseph's Hospital, don't doubt the predictive value of knowing if you have a "heart attack gene" but want consumers to use doctors or genetic counselors to interpret test results.

But even if the tests are right and you use a counselor, do you really want to know bad news? Stephanie, a 49-year-old woman in the Chicago suburbs, was just recovering from radiation and lumpectomies from ductal carcinoma in situ (DCIS) -- a common breast cancer that has not spread -- when a test for BRCA, known as the breast cancer gene, was suggested for her 47-year-old husband. The doctor felt Ricky might carry the gene because his mother, sister and grandmother all had breast cancer.

"He has not told me the results of the test so I think they weren't good," says Stephanie. "He is either trying to protect me from the implications for his health since this could put him at risk for colon and prostate cancer, or our daughter's health. Both of her parents would be then be living under a medical cloud."

Others fear, unlike a home urinary tract infection test, genetic home tests open the public up to biotech/industrial adventurism. "This kind of direct-to-consumer advertising is troubling because it begins a concerted campaign to desensitize the public to the very real dangers of genetic engineering," says Robert Davidson, MD, PhD, who practices internal medicine in Gladewater, TX. "The recent contaminants found in rotavirus vaccines highlight the risk of horizontal transfer of genetic material between species and there are literally hundreds of such 'innovative' new inoculations in the pipeline."

And there are other questions. Will a lab sell your DNA for testing or research? Will employers and insurance companies learn your results and discriminate?

And then there's pharma. One of Insight's actions was confirming, on the basis of DNA, how well people will respond to prescriptions like the anti-clotting drug Plavix, breast cancer drug, Tamoxifen, blood thinner, Coumadin and statins. How soon before "statin responders" get scare emails and marketing campaigns targeting them for AstraZeneca's Crestor or Pfizer's Lipitor? Already pharma is partnering with DNA testing firms.

In fact when you think of the profit potential your DNA represents to bio-enterprising companies, the real danger of at-home DNA kits is probably not the lack of a genetic counselor but the lack of legal one.