Introduction to Carrier Screening

You might have heard about genetic carrier screening. But what is it, and how does it help you plan for a pregnancy? Let’s dive in!

Carrier screening is a genetic test done on both reproductive partners before or during pregnancy. It helps find genetic changes that hide in your DNA and can put your future children at risk of severe genetic disorders.

You might have learned about recessive conditions in school using punnett squares. With recessive conditions parents are “carriers” and they pass on the genetic changes that are hiding in their DNA to their children.

People don’t know that they are carriers for recessive genetic conditions unless they do genetic testing. This is because we have two copies of these genes. If one isn’t working properly, we have a backup copy. As long as one copy works properly, we’re healthy with no signs of a non-working gene. Having one copy that works and one copy that doesn’t is called being a “carrier”.

When we have a child, half of our DNA gets passed on. This means if we are a carrier for a recessive condition, you will either pass on the copy of the gene that works properly, or the one with the genetic variant. But each person is only responsible for half of the DNA a child inherits.

Being a carrier for a recessive condition becomes a high risk when both reproductive partners are carriers for the same condition.

If both partners are carriers for the same autosomal recessive condition, there is a 1 in 4 chance that they will both pass on the genetic variant. If a child inherits both genetic variants, this means they have no copies of the gene that work. This is what causes the genetic disease.

The point of carrier screening is to test recessive genes to see if you are a carrier for any of the conditions they’re associated with. Your partner or donor can get tested too. Most people learn they’re a carrier for a recessive condition because they have a child with a severe disease.

Carrier screening can lower the chance that a recessive condition takes you by surprise. If it sounds right for you, learn more via one of DNAide’s Information Programs