Don’t Fall for Genetic Screening

Genetic Screening Is Ripe for Abuse

Genetic screening is often touted as the high-tech alternative to old-fashioned family histories. It’s theoretically possible, after all, to precisely identify which genetic predispositions to disease are actually present in your body rather than may be present based on family history.

The operative word here is “theoretically”.

Someday this kind of everyday genetic screening may be practical and useful – and someday our doctors and hospitals may better coordinate our medical care to reduce medical errors and wasteful spending. But don’t hold your breath expecting either to occur anytime soon.

A Promising Future

Medical genomics – using your unique DNA profile to predict disease and target therapies – is well-established today at select academic medical centers. Early applications are found in pediatrics (cystic fibrosis and lymphatic leukemia, for example) and certain cancers. The BRCA1 and BRCA2 mutations in breast cancer, the KRAS gene test for metastatic colon cancer, and genetic testing of tumor samples to decide which drug(s) to use with certain lung cancers are several examples.

The future of genomic and proteomic medicine – there are even more proteins in the human body than genes and they also hold powerful predictive information – is not just promising, it’s disruptive.

It will eventually enable the kind of personalized medicine that will help you and your doctor identify your personal disease risks with far greater precision that’s customized to your unique DNA.

However, we’re a long time away from this potential being realized, largely because this will require far greater adoption of electronic medical records. The data demands for genomics and proteomics are huge. It also requires greater physician acceptance of decision support tools based on clinical best practices that many in mainstream medical practice continue to resist.

More Danger Than Promise For Now

The use of personal genetic information that’s now available via direct-to-consumer (DTC) commercial labs and even over-the-counter genetic screening products to screen for disease vulnerabilities is highly premature and may even be dangerous.

As with direct-to-consumer advertising of medications, direct-to-consumer genetic screening is ripe with potential for abuse.

An article by Harvard researchers in The New England Journal of Medicine [1] noted that the FDA has issued 20 warning letters to DNA testing companies that their genetic screening products may require FDA approval they currently don’t have.

The article mentions a Government Accountability Office investigative report that cited the following infractions and concerns about genetic screening company practices:

“Deceptive marketing practices, erroneous medical management advice from (Direct-to-Consumer) genetic testing companies, and a lack of standardization of results among companies. Discordant results from four DTC (genetic screening) companies analyzing identical DNA samples highlight the need for standards.”

Interpreting DNA results is obviously not a simple matter when four different DTC genetic screening services come up with four different results using the same DNA.

The article also warned that population-based genetic screening of people without disease symptoms may prove harmful without proven treatments or interventions for many pre-disease conditions that may never develop into actual disease.

Not only does this generate unnecessary expense, but the risk of treatment-caused disease also increases with the follow-up tests and procedures these genetic screening tests produce (see “Angelina Jolie’s Brave Example – and the Other Side of the Story” for more on this).

Preying on an Unsuspecting Public

Another article in the same journal issue stated:

“Consumers must be protected from unrealistic claims and misinterpretations of complex, dynamic genomic information…In many cases, there is little or no evidence of the clinical validity of genetic tests.”[2]

It also notes the potential privacy violations when such highly personal data is placed in the hands of commercial interests who may sell or otherwise make this confidential information available to third-parties without your consent.

The bottom line: DTC genetic screening is currently unregulated and without standards to assure consistent methods for data analysis and interpretation.

The premature marketing of these genetic screening products and services to those anxious about their disease risks represents preying on an unsuspecting public.

Anyone willing to fork over hundreds and thousands of dollars – generally not reimbursable by insurers – for DTC genetic screening tests that stand a high risk of being bogus is overly obsessed with their health.

There are far more prudent ways to get a more precise handle on your disease risks, although they entail a bit more work to assemble and integrate the various measures needed to fine-tune your disease risk profile.

Doing so, however, will not only save you money, but will avoid the unnecessary testing and procedures these commercial DNA tests generate – a prime goal of intelligent risk assessment.

Parental History Trumps Genes

When it comes to your risk for heart attacks, there’s solid evidence that your parental history is a better predictor of your own risk than even your genes.

A study in the prestigious Journal of American Cardiology found you have a 50% increased risk for heart attack if one of your parents suffered a heart attack.

It’s even worse if both parents had heart attacks – an almost six-fold increased risk.[3]

The importance of parental history was found less significant for stroke, where high blood pressure is the dominant risk factor, not parental history.

Those with a parental history of heart attacks should ask their physician about having a CT Calcium scan performed as “traditional risk calculations underestimate the risk in this group”, according to the HeartWire report.

Excess calcium buildup in your arteries can be a precursor to heart attack, stroke, and sudden cardiac death. For this high-risk population, learning how much calcium you’ve accumulated in your arteries outweighs the radiation risk from the CT scan itself.

This is one crucial area where there’s no need to wait for high-tech genetic analyses when the answer may be right before your eyes.

[1] Risks of Presymptomatic Direct-to-Consumer Genetic Testing. N Engl J Med. 9/16/10.

[2] Preparing for a Consumer-Driven Genomic Age.  N Engl J Med. 10.1056/NEJMp1006202, 9/16/10.

[3] MI more heritable than stroke, clusters more in families. HeartWire. theheart.org. 7/27/11.

John Lynch: John Lynch was founder and CEO of Medical Diagnostics, Inc. - twice named to Business Week's "Best Small Companies" in America. He's since founded MedSmart Members to publish consumer health education publications.
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