A genetic carrier screening is a blood test that looks at your genes to see if you carry any mutations that could potentially lead to your baby being born with a genetically inheritable condition. Cystic Fibrosis is one example of a genetically inheritable condition. In most cases, in order for your baby to be affected by one of these conditions, both you and your partner must be carriers of the genetic mutation(s) for the same condition. Even when both parents are carriers of a mutation for the same condition it does not guarantee that your baby will be affected by the condition.

For example, in the case of Cystic Fibrosis there would be a 1 in 4 chance that your baby would be affected by the condition if both you and your partner tested positive as carriers. There would be a 2 in 4 chance of your baby becoming a silent carrier, just as you are, and a 1 in 4 chance of your child neither having the condition nor becoming a carrier. Most people who are carriers do not ever experience any symptoms and the genetic mutation can be passed down from generation to generation without ever being detected or causing illness in a family (for instance if the carriers never pair with another carrier). Other genetically inheritable conditions may carry different statistical chances of affecting your baby if both parents are carriers. Cystic Fibrosis was used here as an example.

Genetically inheritable conditions that can be screened for include, but are not limited to:

  • Cystic Fibrosis
  • Spinal Muscular Atrophy
  • Tay-Sachs Disease
  • Canavan Disease
  • Familial Dysautonomia
  • Bloom Syndrome
  • Gaucher Disease
  • Fanconi Anemia
  • Mucolipidosis IV
  • Niemann Pick Disease
  • Sickle Cell Disease
  • Beta Thalassemia

Because a genetic carrier screening is looking at your genetics, if you choose to have the genetic carrier screening done, you would never need to have the screening done again in future pregnancies (because your genetics don’t change). People may choose to have the screening done for a variety of reasons. Learning your carrier status can help you prepare for the potential need for early screening and/or treatment for your baby. If you find that you and your partner are carriers for the same condition you may choose to seek genetic counseling to further assess your risks for this pregnancy and for future pregnancies. Likewise, you may find that you are not a carrier of any of the genetically inheritable conditions that were screened for, which may relieve some anxiety as you would know then that this baby and any future children would not be at risk of being born affected by one of these inheritable diseases.