Joshua Sharfstein, the associate dean for public health practice and training at Johns Hopkins, is the former secretary of the Maryland Department of Health and Mental Hygiene.

Last January, President Obama announced a $215 million research initiative that would, in part, sequence the DNA of up to a million volunteers to help develop more tailored medical treatments. The promise of the initiative, he said, is "delivering the right treatments, at the right time, every time, to the right person."

But whether mass genome sequencing will improve health depends, in large part, on how well the application of treatments based on genetic information is regulated.

Many so-called laboratory-developed tests do not work as advertised, and that could only get worse with the greater attention to genome-sequencing.

Researchers are just beginning to sift through more than 80 million genetic variations, attempting to link which genes, out of thousands, contribute to disease progression, drug metabolism and other outcomes. There will be many correlations and statistical associations between genes and illnesses discovered, but it will not be clear right away which of these are due to coincidence. Correlation, after all, does not necessarily indicate causation.

A key purpose of regulation, then, is to set standards that help differentiate coincidence from meaningful discovery.

Yet while the Food and Drug Administration encourages companies to rely on the best available data and is developing a common electronic platform for information sharing, the agency does not regulate many independent laboratories that develop and market genetic tests.

The agency has long exempted private labs from regulations applied to medical device companies. In the past, these labs were mainly based in hospitals and provided services only to a few patients, but today, many laboratories are independent and market their tests broadly. Because there is no accountability for whether these tests provide meaningful information, many so-called laboratory-developed tests do not work as advertised.

This will only get worse with greater attention to genome sequencing, as we already see with the burgeoning field of genetic testing for psychiatric patients: The labs that are popping up with proprietary formulas to interpret genetic information for mental health care are not usually independently assessed by the F.D.A. Most of their claims are based on scant research, and financial arrangements between the laboratories and clinics that use the tests have raised ethical concerns.

Problems with unregulated tests undermine care for many disorders. The F.D.A. has linked laboratory-developed tests to “patients being over- or undertreated for heart disease; cancer patients being exposed to inappropriate therapies or not getting effective therapies; incorrect diagnoses of autism; unnecessary antibiotic treatments; and exposure to unnecessary, harmful treatments for certain diseases such as Lyme disease.”

Should private labs continue to go unregulated, it may become impossible for the F.D.A. to stop marketers from cluttering clinical medicine with misleading and unproved claims — including claims about what we can learn from our DNA.



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