Beware of genetic testing

Opinion: May 20, 2010 at 12:00a.m.

By Arthur Caplan

Philadelphia Inquirer

Type “genetic testing” on an Internet search engine and then hang on. You will be in for quite a ride. There is an endless parade of companies touting genetic tests for everything, including determining whether your kid has the potential to be a star athlete, finding out whether your ancestors were kings or ne’er-do-wells, finding a date, optimizing your diet, or knowing what diet to use if your intake is not optimal. Apparently, there is more self-discovery to be had by spitting your saliva into a cup and sending it off to be genetically analyzed than in a whole month of Dr. Drew.

The push to get you to spend money on genetic testing has also reached your local drugstore.

Walgreens is entering into an agreement with Pathway Genomics to sell Pathway’s Insight genetic test kit. If you send your saliva to Pathway, it promises to tell you what risks you have for developing Alzheimer’s, breast cancer, diabetes, obesity, psoriasis and blindness. In addition, the company says you can find out how caffeine, cholesterol-lowering drugs, and blood-thinners might affect you.

Crude forms

Unfortunately, these crude forms of genetic testing cannot do any of these things.

The reality is that Internet offers and home-testing kits are not ready for prime time. Not enough Americans have had their genes analyzed so as to know what risks they face, particularly if you are in a minority ethnic group. Nor do genetic scientists know, except for a small number of rare diseases, enough to foretell how different genes will interact with different environments and lifestyles to produce health or illness. And not having a gene for a disease does not mean you won’t get that disease. If your house is full of radioactive radon gas leaking up from underlying rocks, your risk for lung cancer is high no matter what genes you do or don’t have.

Right now no government agency regulates the accuracy of genetic tests. There is no requirement that competent counseling be available to answer questions about the information you will get back. And for most risks there is nothing you can do except maintain a healthy lifestyle, which you can do without spending hundreds of dollars for genetic testing.

If you do have patterns of disease in your family, then seek out testing from a well-established, hospital-based, human genetics program. If you don’t, join a gym.

Arthur Caplan is director of the Center for Bioethics at the University of Pennsylvania. Distributed by McClatchy-Tribune Information Services.