Will a DNA test today yield unwanted information tomorrow?

My mother-in-laws arms look like shes been in a fight. The bruises dont hurt, but theyre embarrassing. Theyre likely due to the drug Plavix, a trade-off for preventing clots. But we dont know if the drug is actually helping, because she started it before the FDA urged physicians to use a pharmacogenetic (PGx) test to distinguish patients likely to respond to the drug from poor metabolizers, who wont. And no ones thought to test her since.

The original Plavix genetic test identified mutations in the CYP2C19 gene. More recent versions assess seven other genetic variants that affect metabolism of the drug. On June 29, the University of Florida Academic Health Center announced that it would use the wider genetic test to screen all cardiac catheterization patients for response to Plavix. And in the future, theyll check additional DNA variants in the samples. According to the press release from the university, researchers will collect results for the other 249 gene variations to continue investigating which ones might be clinically actionable and become the basis for additional PGx tests for other treatments such as warfarin and statins.

Is it OK to take DNA today for one purpose, and use it tomorrow for another? Should future use of DNA information be part of informed consent for participation in a clinical trial? And should patients, like someone giving blood for a PGx text, be told that his or her DNA might be used later, for reasons not currently known? And how can the Florida clinicians even obtain informed consent from patients in an emergency situation undergoing cardiac catheterization?

At least the Plavix case will use the DNA to address the same illness for which it was donated. But what if DNA collected today is eventually used to investigate a different condition, perhaps one that the original owner of that DNA didnt want to know about? A Native American tribe from Arizona offers a compelling (although not legal) precedent for future-use scenarios.

The Havasupai and Future-Use DNA

The Havasupai have lived at the bottom of the Grand Canyon for more than 10 centuries, but in 1882 the US government deemed the region a national park, restricting their home. When the tribe abandoned farming and turned to tourism to survive, they partook of junk food and a more leisurely lifestyle. Soon, diabetes became common.

In 1990, researchers from Arizona State University visited the Havasupai to take DNA samples to look for diabetes genes. Two years later, with no findings, they then analyzed the DNA for other traits, including schizophrenia (a stigma in the Havasupai culture), inbreeding (an insult), and worst of all, ancestry (Asian origins countered what the Havasupai told their children). The researchers also shared the DNA with others, without consent.

The Havasupai discovered the future-use of their DNA only after one of their own heard about it in a lecture at ASU. In 2004, they filed a lawsuit. The settlement in April 2010 brought $700,000 to 41 Havasupai members, return of blood samples, scholarships, and help to build a health clinic. But the researchers didnt own up to liability.

Bioethicists Arthur Caplan and Jonathan Moreno discussed implications of the Havasupai settlement in The Lancet, but, I think, too broadly. They compare the Havasupai DNA situation to that of organ donors, embryo donors, and people like Henrietta Lacks and John Moore, whose cervical cancer cells and spleen, respectively, were taken without consent and eventually yielded huge profits. But DNA is different.

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Is Future-Use DNA Sampling Ethical?