Be careful when ordering your own genetic tests

Direct-to-consumer genetic testing is increasingly available to the general public. Reduced cost and ease of testing make this service easy and seemingly harmless. For less than $100 and without even having your blood drawn (a saliva sample is sufficient), a private company promises to provide you with information about your ancestry and your health.

However, undergoing genetic testing of any kind is not a trivial decision. It is not like having routine blood work done at your doctor’s office. Participants in this commercial enterprise are opening the door to a vault that they can never close–and for the time being do very little about. Knowledge of ancestry, disease carrier status, and other disease risk factors will have far reaching effects on individuals and their entire family. Genetic testing should only be performed with expert counseling about the risks and benefits of choosing to undergo screening. Direct-to-consumer genetic testing services succeed in promoting benefits without identifying risks. This is not proper informed consent to testing.

There are serious risks to genetic testing that consumers should consider. One risk would be finding out something you didn’t want to know, such as non-paternity in your family or that your ancestry wasn’t what you thought it was. These incidental findings could be devastating and/or life changing. Among the most worrisome risks–despite every assurance about the privacy of your results from a private company–is the theoretical risk for this data to be sold to a 3rd party and impact your ability to obtain health or life insurance. Genes associated with certain diseases are the ultimate “pre-existing condition”. Another risk, which emphasizes the importance of counseling, is misinterpreting the results.

Take, for example, the BRCA gene test, which has been associated with breast cancer risk. The BRCA1 and BRCA2 gene mutations account for less than 5% of breast cancers, but if you have one of these mutations your individual risk of breast cancer might be up to 75%. Understanding the implications of a positive or negative test result and knowing what to do next should be part of a discussion with a trained professional–either a genetic counselor or a physician trained in this area. Patients should be informed of options that exist before they undergo genetic testing. Patients might not know that “gene therapy”, i.e., a treatment that targets disease associated genes, is not currently available despite how easily we can test for these genes.

Current risk-reduction strategies for women with a BRCA gene mutation include increased frequency of screening tests (e.g., mammogram), elective surgical removal of both breasts, or prophylactic chemotherapy. None of which are 100% effective. The latter two options are rather severe prospects for a healthy woman in her 30s to confront on her own. Genetic screening is clearly more nuanced than direct-to-consumer cholesterol screening, where the general public is probably aware that an abnormal result might lead to a doctor recommending a pill.

Furthermore, imagine receiving a negative BRCA test result and misinterpreting this to think that you could never get breast cancer when 95% of breast cancer is not associated with these genes. Imagine receiving the positive test result in the mail without the immediate counsel and/or reassurance of a medical provider you trust? The skill of “delivering bad news” is a didactic component of medical school curricula, and if you’ve ever been on the receiving end of bad news delivered well or poorly you surely know why. Where is the comfort of hand holding and the reassurance of an action plan when a patient spits into a container and receives a report in the mail shortly thereafter?

Screening, the testing of asymptomatic individuals, is a public health measure designed to detect diseases early in order to benefit patients by early intervention. Knowledge of the contribution that genes make to human disease offers to improve existing screening programs not limited to: newborn screening, prenatal screening, and cancer screening. These screening programs are undertaken by individuals with the help of their pediatrician, obstetrician, and primary care provider, respectively. Why leave out the trained professional when choosing genetic screening tests?

Benjamin T. Galen is an internal medicine physician.

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