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Carrier Testing






Reasons for testing


You may have many reasons for testing, including if you have:

  • concerns regarding inherited diseases

  • an increased risk of being a carrier of an inherited disease due to ethnic background

  • a family history of a specific inherited disease


Genetic disorders are caused by a change in a gene; this change is called a mutation. Every person has two copies of each gene, one inherited from each parent. A carrier is a person who has one normal copy of a gene and one abnormal copy. Having one normal gene is enough to prevent the disease. However, if both parents are carriers of the same abnormal gene, there is a chance that each parent will pass his or her abnormal gene on to their baby. If the baby inherits two copies of the abnormal gene, the baby will have the disease. Diseases that are inherited this way are called autosomal recessive diseases.


Couples may decide to have carrier testing to find out if they are carriers, and therefore are at risk of having a baby with one of these genetic diseases. If both parents are carriers of the same disease gene, prenatal diagnosis can be performed to determine whether or not the fetus is affected.


Carrier testing determines if a couple is at increased risk of having a baby with a specific inherited disease, such as Tay-Sachs disease or cystic fibrosis.


How does the test work?

Carrier testing is performed by testing a blood sample to see if a person has one abnormal copy of a specific gene.


For a couple planning a pregnancy, one partner is usually tested first. If that person is found to be a carrier, the other partner should be tested. If a woman is already pregnant, both partners may be tested at the same time.


What's not detected?

Carrier testing usually tests for the most common mutations that can result in an abnormal gene. Carrier testing often does not detect less common mutations.



Click on the buttons above to find out about carrier testing for Cystic Fibrosis, Fragile X, and SMA.  




To learn more abbout SMA or to donate to the Miller McNeil Woodruff Foundation to fund research for treatment and a cure for SMA, visit this link:






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