What is Genetic Carrier Screening?
At IHR, we are strong advocates of pre-conception genetic screening (also called carrier screening) to our patients as part of our routine pre-conception counseling. Its benefit to patients and their future children is immeasurable!
At a minimum, every female patient is requested to complete genetic screening, through a blood test. To reduce costs, if not covered by insurance, we only ask for the male partner to be tested if the female’s test returns positive as a carrier for any genetic diseases. We test the male to ensure he is not a carrier of the same genetic diseases.
If a genetic disease is found, the couple has the option to use in vitro fertilization (IVF) with preimplantation genetic testing for monogenic disorders (PTG-M) to avoid passing that disease onto their offspring. Couples who choose not to undergo pre-conception genetic screening are asked to sign a form declining testing.
Genetic screening tests gene mutations that fall into each of these three categories:
- Those mutations that are common in a certain ethnic group
- Recessive mutations (dominant genes often show symptoms and are typically known already)
- Those mutations that have some likelihood of causing serious disease in affected offspring. Even if you’re healthy and have never had a family member affected by these diseases, you could be a carrier of a genetic mutation(s), which can put your future children at risk. This makes screening all the more important.
The Potential Results
A positive result means that a disease-causing variant was found, and you are a carrier of one or more of the disorders tested. Being a carrier typically does not affect your own health; however, it does mean that there is an increased risk of having a child with that disorder. The next step is usually to test your partner. Genetic counselors are also available to discuss your specific risks and concerns.
A negative result means that no disease-causing variants were identified for any of the disorders tested. A negative test provides reassurance because the chance of you having a child with any of the tested disorders is reduced. However, no test can detect all carriers, so there is still a small chance, called a residual risk, of being a carrier. Genetic counselors are available to discuss your specific risks and concerns.