Expanded Carrier Screening 101:
Who Should Test & Why

What Is Expanded Carrier Screening (ECS)?

Expanded Carrier Screening (ECS) is the type of genetic testing we do and is used to determine your risk of passing on 150-300 or more genetic diseases. Carrier screening looks for mutations, or changes, in both you and your partner’s genes that together can increase your risk of having a child with a genetic disease.

Genes provide instructions for the body to grow, function, and repair itself. The genes babies inherit from their parents pass along such characteristics as eye and hair color but sometimes mutations in these genes, if inherited by their children, can cause genetic disease and can significantly impact the child’s health and well-being. Some inheritable diseases such as Phenylketonuria or Wilson disease can be treated early. Other diseases such as Cystic Fibrosis or Bloom syndrome require lifelong management. Still others such as Canavan disease have no treatment.

What Does Carrier Screening Test For?

ECS is recommended for people who are planning a family or early in pregnancy, even those without any family history of genetic disease. In fact, 80% of children born with a genetic condition have no family history of that disease. ECS is an easy way to find out if changes in your DNA make you more likely to have an affected child.

Expanded Carrier Screening Is Appropriate For People Who Are:
  • Thinking of having a child
  • Trying to conceive (TTC)
  • Undergoing fertility treatments or IVF
  • Considering egg freezing
  • Currently pregnant

Learning about your genes can help you make decisions about your family’s health. For each condition on the ECS panel, you will be identified as either a carrier, indicating an increased risk, or a non-carrier, indicating a significantly decreased risk. Carriers usually do not have any symptoms and may not have any family history of the condition they carry, making screening important for everyone.

What To Expect After Expanded Carrier Screening?

As part of your ECS your results will be shared with your IRMS physician and you will have the opportunity to review them over the phone with a specially trained genetic counselor.

If you are found to have an increased risk of passing on a high-impact genetic disease, you have a number of reproductive options available to you that you can discuss with your IRMS physician:

  1. Prevent transmission of genetic disease via genetic testing of your embryos and transferring an embryo without disease,
  2. Intervening once you are pregnant – consider testing of the pregnancy and possible termination, or
  3. Preparing for the birth of a child with special needs due to the disease – lining up appropriate obstetric and pediatric care prior to birth
  4. Consider conceiving using donor egg or donor sperm to prevent transmission of a genetic disease in one or both parents.