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

Positive

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.

Negative

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).