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Pros and cons of clinical genetic testing

Genetic testing holds great potential for the future of medical care. It offers many benefits, including providing important information that can be used when making decisions about having a family and taking care of one’s own health. However, there are also limitations. For this reason, it is important to understand the nature of genetic testing and the information that it can and can’t provide. For example:

• Clinical genetic tests are not just descriptive as many laboratory tests are, but they are predictive as well. Predictive tests will not give a yes/no answer, but instead will tell what the chances are of developing a particular genetic condition. Such results are not definitive and may leave a person wondering what to do with those results, particularly if available treatments or therapies limit the course of action.

• A particular genetic test will only tell if there is specific genetic variant, or mutation; it cannot guarantee whether the disease will develop nor can the test provide information about other genetic diseases not being specifically looked for by that test.

• While the test may detect a particular problem gene, it cannot predict how severely the person carrying that gene will be affected. Again with cystic fibrosis, symptoms may be mild bronchial abnormalities or they may range to severe lung, pancreatic, and intestinal problems.

• Many genetic tests cannot detect all of the variations that can cause a particular disease. For instance, with genetic testing for cystic fibrosis, most genetic testing panels only look for the more common variants, not all of those that are associated with this disease.

• Many diseases are the result of an interaction between one’s genes and one’s environment. The way in which these interactions cause disease is not clearly understood. Examples of these diseases include coronary heart disease, type 2 diabetes, obesity, and Alzheimer disease.

• Legal issues, such as patient privacy, use of genetic testing to determine insurance coverage, and the use of archived patient samples are some of the broader social issues to be considered.

It is important to remember that genetic testing is different from other types of laboratory testing. Results of genetic tests may have implications not only for you the patient, but also for the your family members who may need to be tested as well. In addition, genetic education and counselling is often advised to help understand and cope with the results of genetic tests.