Modern medicine is more often than not formulaic. Everyone with a certain health problem—for example, heart disease or depression—gets basically the same standard treatment. Typically, this involves one or more medications within a related class of drugs.

New thinking: There’s a fresh approach to diagnosis and treatment, variously called personalized medicine, individualized medicine or precision medicine. Rather than treating a disease based on a therapeutic formula, it takes into account a person’s unique genetic makeup—his/her DNA, or genome—and customizes treatment to fit the individual.

Personalized medicine is still in its infancy, but some types of individualized diagnoses and treatments are now available…


DNA testing can help determine whether or not your genes will impact the way a medication affects you. This field of drug-gene interactions is called pharmacogenomics—and it can benefit just about everybody who takes a prescription drug.

Breakthrough research: The Mayo Clinic recently conducted the RIGHT study (the right drug, at the right dose, used at the right time). In this investigation of more than 1,000 patients, 990 of them were discovered to have at least one genetic variant that could impact the way the body processes common medications.

Pharmacogenomics can help your physician determine the likely effectiveness of various drugs and pick the best one for you…choose the right dose for you…and spot possible side effects in advance, including life-threatening reactions that make the drug too risky to take.

At present, pharmacogenomic testing—a simple cheek swab, blood test or saliva test—can help evaluate the individual impact of more than 300 drugs. Drugs commonly tested include: Fluorouracil (Efudex), for colon, skin and other cancers…clopidogrel (Plavix) and warfarin (Coumadin), blood thinners used to reduce heart attack and stroke risk…and antidepressants such as fluoxetine (Prozac) and citalopram (Celexa).

My advice: Before your doctor writes you a new prescription—or if you are having side effects from your current medication—ask about getting genetic testing. The cost of a pharmacogenomic test is becoming more affordable. Some labs are now able to offer the testing for as low as $250. Results are typically available in one to two weeks. Getting such testing done preemptively allows you to have the results at the moment they are needed. Helpful: You can find a list of the drugs approved by the FDA for genetic testing at


There are many ways that personalized medicine can assist in the treatment of cancer. Tailoring the treatment to the cancer’s specific molecular variation is one such approach. Example: Mayo Clinic research has shown that 65% of patients with various advanced cancers had a genetic target that could potentially be addressed by a matched drug specific to that patient and that cancer.

A cancer gene panel costs $300 to $5,000, depending on whether you are being tested for a specific gene or multiple genes. Insurance may cover all or at least part of this testing. Check with your insurer first.

If you have cancer: Ask your doctor whether having your DNA sequenced would provide information to improve your treatment—especially if your tumor(s) is not responding to treatment.


Personalized medicine is also about discovering health issues you may not know you have—so you and your doctor can do something about them to protect yourself.

For example, 25 managers at the Mayo Clinic Center for Individualized Medicine, who were all seemingly healthy, had their genomes sequenced. Five of them—20%—had medically relevant results.

One participant had a genetic predisposition to blood clots, putting that person at almost five times a greater risk for a heart attack or stroke. In another situation, the individual was found to be a carrier of a gene for cystic fibrosis—information that was passed on to the person’s adult children so that they could decide whether or not to be tested for the same genetic variant (to determine their own risk and possibly that of any future offspring).

Another person had a genetic condition called malignant hyperthermia, which causes a fast rise in body temperature and severe muscle contractions when anesthesia is administered. Complications can include kidney failure, fluid buildup in the lungs, bleeding and even death. Using certain medications during surgery can prevent these problems.

Helpful: Consider having your genome sequenced to spot any potential, preventable health problems or inheritable conditions you would want your children or grandchildren to know about. Couples who are planning a family and want to understand their genetic risk for inherited diseases also should consider DNA testing. And families with a high risk for cancer may want to be assessed for a predisposition to certain cancers.


In about 30% of cases, precision medicine can detect the cause of an otherwise mysterious disease.

For example, a young man recently treated at the Mayo Clinic had a problem with tremors and had gone from doctor to doctor for years, without getting effective treatment. With genetic testing, a mutation in the gene that controls the movement of potassium into and out of the body’s cells was discovered. A potassium-lowering diuretic was prescribed, which significantly reduced the man’s tremors.

If you have a mysterious illness or rare disorder—and have visited many doctors without getting a diagnosis and/or successful treatment—ask your doctor whether DNA testing might identify a genetic disorder.

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