Expanded (Multiplex) Carrier Screening

Is Testing Right for Me?

Expanded (Multiplex) Carrier Screening

What Is Expanded Carrier Screening?

Expanded carrier tests, also called multiplex carrier tests, are screening tests designed to find out if you are a carrier of 76 or more genetic conditions. Carrier screening looks to see if you "carry" certain mutations in your DNA that may not affect you, but can cause your children to inherit a disease. Carriers are healthy and don’t get the disease.

Medical organizations such as the American College of Obstetrics and Gynecology (ACOG) recommend that people who are pregnant or planning a pregnancy be offered carrier screening for certain diseases. The screening tests they recommend are for genetic diseases that are severe or life-threatening, and that are present from birth or develop in early childhood. Which screening tests a person should consider depends on that person’s ethnicity and family history.

Expanded carrier tests cover most of the diseases that are recommended for screening in each major ethnic group. They also include many conditions that aren't recommended for regular carrier screening. Some tests focus on severe conditions that affect people from birth or childhood. Other tests also include conditions that are mild, may never lead to symptoms, and develop in adulthood. Some of the diseases covered by universal carrier testing are common, especially in certain ethnic groups, while others are very rare. The tests that are available today don't cover a few of the most common inherited genetic diseases, such as fragile X.

If you choose to have expanded carrier screening, it is very important to ask your healthcare provider or lab how well the test identifies carriers for each disorder. In some cases, the ability of the expanded carrier test to find a carrier may be lower than the standard test. This may or may not be relevant based on your ethnicity and family history.

Common Diseases Covered by Expanded Carrier Screening

Next: Genetics