DTC Genetics: Pros and Cons
* The ability to obtain personal genetic information quickly and privately without a “prescription”. The information can include disease predisposition and carrier status.
* This ability to make lifestyle changes, such as diet and exercise, based on the testing results.
* Access to interesting information about ancestry. Some DTC companies offer testing services that will determine the presence and percentage of ethnic, geographic and even Neanderthal DNA.
* The relative affordability of DTC testing compared to other forms of genetic testing. Many companies offer services for a few hundred dollars.
The majority of the drawbacks associated with DTC genetic testing stem from the absence of a medical professional that can help an individual understand the results. Many companies have genetic counselors on staff. However, email and phone exchanges are poor substitutes for a face-to-face discussion. Common misunderstandings regarding genetic testing results include:
* An overestimation of the role genetics plays in disease. The amount that genetics contributes to a trait varies, but very few traits and/or disease are controlled strictly be genes. Most traits are also affected by environmental factors and lifestyle choices.
* Difficulty in interpreting a disease risk. Participants must relay on emails and information on a website to understand their disease risk versus the average population risk. Also, the disease risk presented by DTC companies does not include a timeframe. For some diseases the risk remains low until later in life and then goes up incrementally with age.
* Confusion over the methodology. Not all genetic testing is “created equal”. Genetic tests for diseases that are caused by a known single gene defect can predict with more certainty (sometimes 100%) whether or not an individual will be affected by a disease or is a carrier. Often association studies (GWAS) are employed for diseases in which multiple genes contribute, or no specific gene has been identified. The results from GWAS do not have the same degree of certainty as traditional genetic tests.
* A lack of monitoring of the psychological and emotional status of the participant. Some DTC companies offer genetic tests for life-altering, and even terminal, conditions. Participants may feel a wide range of emotions including anger, depression and guilt after receiving difficult news.
* A lack of oversight of the companies. Because DTC genetics companies are relatively new, the government has not yet determined how to best regulate them. Many companies are reputable and offer quality services with reliable results. Other companies make false claims and use faulty practices. It is up to the consumer to distinguish the good from the bad.