Genetic testing (PGD) is performed to determine if one or both parents have abnormal genes that may increase the chances of a specific genetic disease in their child. If the abnormal gene is passed on to the child, the child will usually not be affected with that genetic disease but will also be a carrier for it. If both parents are carriers of the abnormal gene for the same genetic disease, there is a 25% chance that their child will inherit one abnormal gene from each parent and be affected with that genetic disease.
Genetic screening is typically done on one parent first, and if the first parent tests positive, then the other parent is tested. During the course of your evaluation and treatment at CTTBC, our experts may recommend screening for specific genetic disease(s) based on your medical history and/or family history.
Genetic testing is a valuable tool but there are limitations:
- Negative result – The genetic testing laboratory usually tests for the most common mutations and may not identify the less common mutations. Hence, it is possible to have a negative test result but still have a genetic mutation that was not or could not be identified by the testing laboratory due to limitations of current technology.
- Positive result - A positive test result indicates that you are a carrier for a genetic mutation that can cause a specific genetic disease or can put you and/or your child at risk for developing a disease. If you are determined to be a carrier, your reproductive partner will then be advised to undergo genetic carrier testing.
- Inconclusive result – Sometimes it is not possible for the lab to determine genetic mutations. In this case, the genetic carrier test may need to be performed again at the same or different testing laboratory.