Genetic Carrier Screening
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.
Please be aware preconception genetic screening is not the same as preimplantation genetic testing (PGT-A). The first is a blood test performed on the patient prior to beginning any treatment, during the diagnostic phase. Preimplantation genetic testing is performed on embryos generated through in vitro fertilization (IVF).