If the genetic test is done to diagnose a particular genetic disease, a positive result usually, though not always, means confirmation of diagnosis of a particular genetic disease, or prediction of its development in the future. However, in many circumstances the test result may not be able to predict disease severity and prognosis.
The interpretation of genetic susceptibility testing for common and complex diseases (e.g. cancer, high blood pressure and diabetes, etc.) has even greater uncertainty. The accuracy in predicting the development of such diseases, be it a positive or negative result, is usually even lower. Therefore, the clinical utility of such genetic susceptibility testing might also be limited.
When a test result is positive, the test subject should seek opinion from a medical specialist relevant to the particular disease as soon as they can.